manufacture of disposal canisters - etusivu - posiva · 2010-01-05 · the manufacturing process...

P O S I V A O Y

O l k i l u o t o

F I N - 2 7 1 6 0 E U R A J O K I , F I N L A N D

P h o n e ( 0 2 ) 8 3 7 2 3 1 ( n a t . ) , ( + 3 5 8 - 2 - ) 8 3 7 2 3 1 ( i n t . )

F a x ( 0 2 ) 8 3 7 2 3 7 0 9 ( n a t . ) , ( + 3 5 8 - 2 - ) 8 3 7 2 3 7 0 9 ( i n t . )

POSIVA 2009 -03

Manufacture of Disposal Canisters

December 2009

Leena No lv i

POSIVA 2009 -03

December 2009

P O S I V A O Y

O l k i l u o t o

F I - 2 7 1 6 0 E U R A J O K I , F I N L A N D

P h o n e ( 0 2 ) 8 3 7 2 3 1 ( n a t . ) , ( + 3 5 8 - 2 - ) 8 3 7 2 3 1 ( i n t . )

F a x ( 0 2 ) 8 3 7 2 3 7 0 9 ( n a t . ) , ( + 3 5 8 - 2 - ) 8 3 7 2 3 7 0 9 ( i n t . )

Leena No lv i

Pos i va Oy

Manufacture of Disposal Canisters

ISBN 978 -951 -652 -171 -1ISSN 1239 -3096

Posiva-raportti - Posiva Report Raportin tunnus - Report code

POSIVA 2009-03 Posiva Oy Olkiluoto FI-27160 EURAJOKI, FINLAND Puh. 02-8372 (31) - Int. Tel. +358 2 8372 (31)

Julkaisuaika - Date

December 2009

Tekijä(t) – Author(s) Toimeksiantaja(t) – Commissioned by

Leena Nolvi, Posiva Oy Posiva Oy

Nimeke – Title

MANUFACTURE OF DISPOSAL CANISTERS

Tiivistelmä – Abstract

The report summarizes the development work carried out in the manufacturing of disposal canister components, and present status, in readiness for manufacturing, of the components for use in assembly of spent nuclear fuel disposal canister. The disposal canister consist of two major components: the nodular graphite cast iron insert and overpack of oxygen-free copper. The manufacturing process for copper components begins with a cylindrical cast copper billet. Three different manufacturing processes i.e. pierce and draw, extrusion and forging are being developed, which produce a seamless copper tube or a tube with an integrated bottom. The pierce and draw process, Posiva's reference method, makes an integrated bottom possible and only the lid requires welding. Inserts for BWR-element are cast with 12 square channels and inserts for VVER 440-element with 12 round channels. Inserts for EPR-elements have four square channels. Casting of BWR insert type has been studied so far. Experience of casting inserts for PWR, which is similar to the EPR-type, has been got in co-operation with SKB. The report describes the processes being developed for manufacture of disposal canister components and some results of the manufacturing experiments are presented. Quality assurance and quality control in manufacture of canister component is described. Avainsanat - Keywords

spent fuel disposal canister, pierce and draw, extrusion, forging, copper components, insert

ISBN ISSN

ISBN 978-951-652-171-1 Sivumäärä – Number of pages Kieli – Language

76

English

Posiva-raportti - Posiva Report Raportin tunnus - Report code

POSIVA 2009-03 Posiva Oy Olkiluoto FI-27160 EURAJOKI, FINLAND Puh. 02-8372 (31) - Int. Tel. +358 2 8372 (31)

Julkaisuaika - Date

December 2009

Tekijä(t) – Author(s) Toimeksiantaja(t) – Commissioned by

Leena Nolvi, Posiva Oy Posiva Oy

Nimeke – Title

LOPPUSIJOITUSKAPSELIEN VALMISTUS

Tiivistelmä – Abstract

Raportissa esitetään yhteenveto kehitystyöstä loppusijoituskapselikomponenttien valmistamiseksi sekä nykytilanne valmiudesta komponenttien valmistamiseksi käytettäväksi käytetyn ydinpoltto-aineen loppusijoituskapselikokoonpanossa. Loppusijoituskapseli koostuu kahdesta pääkomponentista: pallografiittivalurautaisesta sisäosasta ja hapettomasta kuparista valmistetusta ulkovaipasta. Kuparikomponenttien valmistus alkaa sylinterimäisestä kuparivaluaihiosta. Kolmea eri valmistus-menetelmää, jotka ovat pisto-veto, pursotus ja takominen, kehitetään saumattoman putken tai pohjallisen putken valmistamiseksi. Pisto-veto -prosessilla, Posivan referenssimetelmä, on mah-dollista valmistaa putkeen yhtenäinen pohja, jolloin hitsausta vaaditaan vain kannen liittämisen osalta. BWR-elementin sisäosiin valetaan 12 neliömäista kanavaa ja VVER 440 -elementin sisäosiin valetaan 12 pyöreää kanavaa. EPR-elementin sisäosissa on neljä neliömäistä kanavaa. Tähän mennessä on tutkittu BWR sisäosan valamista. Kokemusta PWR sisäosan, mikä on vastaavan-lainen kuin EPR, valusta on saatu yhteistyössä SKB:n kanssa. Raportissa on kuvattu prosessit, joita kehitetään loppusijoituskapselikomponenttien valmista-miseksi ja on esitetty valmistuskokeiden tuloksia. Kapselikomponenttien valmistuksen laadun-varmistusta ja laadunvalvontaa on kuvattu.

Avainsanat - Keywords

käytetyn ydinpolttoaineen loppusijoituskapseli, pisto-veto, pursotus, takominen, kuparikomponentit, sisäosa

ISBN ISSN

ISBN 978-951-652-171-1Sivumäärä – Number of pages Kieli – Language

76

Englanti

1

TABLE OF CONTENTS

ABSTRACT TIIVISTELMÄ

1 INTRODUCTION................................................................................................... 3

2 DESCRIPTION OF THE CANISTER ..................................................................... 5

3 MANUFACTURING REQUIREMENTS ................................................................. 7

3.1 Requirements for the manufacture of copper components ........................... 7

3.2 Requirements for the manufacture of inserts ............................................... 8

4 MANUFACTURING TECHNIQUES - OVERVIEW ................................................ 9

5 MANUFACTURING PROCESSES FOR COPPER COMPONENTS ................... 11

5.1 Casting copper billets ................................................................................ 11

5.2 Hot forming of copper tubes ...................................................................... 15

5.2.1 Pierce and draw process of copper tubes with integrated bottom ........................................................................................... 15

5.2.2 Extrusion of copper tubes .............................................................. 27

5.2.3 Forging copper tubes ..................................................................... 30

5.3 Manufacturing copper lids and bottoms ..................................................... 33

6 MANUFACTURE OF INSERTS .......................................................................... 35

6.1 Manufacture of the steel cassette .............................................................. 35

6.2 Casting the iron insert ................................................................................ 37

6.3 Steel lid ..................................................................................................... 39

7 MACHINING AND ASSEMBLY OF CANISTER COMPONENTS ........................ 41

8 STATUS AND COMPARISON OF MANUFACTURING METHODS .................... 43

9 QUALITY ASSURANCE ...................................................................................... 45

9.1 Quality control of copper canister components .......................................... 45

9.2 Quality control of inserts ............................................................................ 46

REFERENCES ........................................................................................................... 47

APPENDICES............................................................................................................. 49

1. KTS001 rev. 7, Copper ingots and billets for canister components 2. KTS002 rev. 5, Copper components for canisters 3. KTS011 rev. 9, Nodular cast iron EN1563 insert 4. KTS022 rev. 5, Hollow square sections for steel section cassette

3

1 INTRODUCTION

This report summarises the development work carried out in the manufacture of disposal canister components, and the present status, in terms of readiness for manufacture, of the components for use in the assembly of the spent nuclear fuel disposal canister. The disposal canister consists of two major components: the nodular graphite cast iron insert and the oxygen-free copper overpack. The requirements specified for component manufacture are presented and the main points of the manufacturing processes for the major components are described. Three different manufacturing processes – pierce and draw, extrusion and forging – for manufacturing a copper overpack are shown. Pierce and draw, as Posiva's reference method for manufacture of the copper overpack with an integrated bottom, is described in more detail. Some experiences and results of the test manufacturing of canister components are presented. The present state of quality assurance for disposal canister component manufacture is also shown.

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2 DESCRIPTION OF THE CANISTER

The canister consists of two main components: the integral insert structure of nodular cast graphite iron and the copper overpack. The insert has an integral bottom, the nominal thickness of which includes a steel plate at the ends of the steel cassettes and the rest of it is cast iron. The insert is the load carrying part of the structure and the copper overpack makes the vessel tight and acts as corrosion resistant cladding. An overall view of the canisters is shown in Figure 2-1, and components of the BWR-canister are shown separately in Figure 2-2. (Raiko 2005a) The overpack has an integral flat bottom and an EB-welded lid on the top in the reference case. Optionally, the flat bottom can be a separate lid jointed with a weld. The top lids contain a shoulder by which the canister can be gripped using a gripping device during lifting operations. (Raiko 2005a) The canisters contain 12 positions for BWR and VVER 440 fuel assemblies and four positions for EPR fuel assemblies. The total weight of the canisters including fuel assemblies, is: for 18.6 tons VVER 440, 24.3 tons for BWR and 29.1 tons for EPR. The outer diameter of the canister for all types is 1.05 m and the total length is about 3.6 m, 4.8 m and 5.25 m, respectively (Raiko 2005a). The total length may vary slightly depending on the bottom lid construction variation of the copper overpack.

Figure 2-1. Disposal canister for the spent fuel from the Loviisa 1–2 (VVER-440),

Olkiluoto 1–2 (BWR) and Olkiluoto 3 (EPR) reactors (from left to right). All versions of

the canister have the same outer diameter of 1.050 m. The heights are 3.6 m, 4.8 m, and

5.25 m (from left to right). (Raiko 2005a)

6

Figure 2-2. BWR- canister components, from the left: copper cylinder, iron insert, steel

lid and copper lid. (Raiko 2005a)

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3 MANUFACTURING REQUIREMENTS

The disposal canister consists of two main components. The outer shell is made of phosphorus-doped oxygen-free copper, and the insert is made of nodular graphite cast iron. The outer shell consists of a copper tube with or without integrated bottom and copper lid. Some components for insert assembly are made from a steel – like lid, lid fixing screw and the cassette used in insert casting to get the channels in which the fuel assemblies will be placed. The requirements, which have been used in the most recent manufacturing experiments for disposal canister components, are presented in the following sections. The manufacturing specifications/requirements are preliminary and those may be completed when more knowledge is available from the design analysis and along with the development of non-destructive testing.

3.1 Requirements for the manufacture of copper components

The most recent manufacturing experiments for copper canister components described in this report the specifications KTS001, rev. 7 (Appendix 1) and KTS002 rev. 5 (Appendix 2) were applied, where requirements for chemical composition, mechanical properties and for grain size are shown. The specifications are preliminary. The material used for manufacturing copper components is high conductivity oxygen-free copper alloyed with 30–70 ppm phosphorus. The material fulfills the specification in EN1976:1988 for the grades Cu-OFE or Cu-OF1 with the following additional requirements: O < 5 ppm, P 30–70 ppm, H < 0.6 ppm and S < 8 ppm. Micro-alloying with phosphorus is done to improve the creep strain properties of Cu-OF copper. The addition of phosphorus (P) has been later on modified and is in the most recent specification 30–100 ppm. The specified minimum elongation of hot-worked copper material in components is set to 40 % in uni-axial tension test. From the non-destructive quality control point of view the grain size of the copper components is currently limited to < 360 µm. A grain size of 360 µm or less gives a reasonable resolution in ultrasonic testing. (Raiko 2005a) The required wall thickness for copper is stated to be at least 35 mm (TKS-2009). The designed nominal wall thickness of the copper overpack is about 50 mm. The outer diameter of the copper canister used in assemblies is 1050±1 mm and the inner diameter is 952 +1.0/-0.0 mm. The surface roughness requirement for the weld preparation of an electro-beam weld between the copper lid and the cylinder is Ra 3.2 µm. All other machined surfaces have the requirement Ra 12.5 µm (Raiko 2005a). The surfaces to be welded must be free from all kinds of grease and dirt and generally, the components to be EB-welded must be reasonably clean to avoid disadvantageous boiling of the foreign medium during vacuuming in the welding chamber.

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3.2 Requirements for the manufacture of inserts

The insert is made of nodular graphite cast iron. The material cast iron inserts must meet the grade EN-GJS-400-15U requirements regarding mechanical properties. The content of the copper must not exceed 0.05 % to minimise the risk of radiation embrittlement. The latest manufacturing experiments for insert casting the specification KTS011, rev. 9 (Appendix 3) was applied, where requirements for chemical composition, mechanical properties and for microstructure are shown. The samples for mechanical testing when taken from inserts must meet the following requirements: yield strength Rp0,2 min. 240 N/mm2, Rm min. 370 N/mm2 and elongation min. 7 %. At all position of the casting, the microstructure must correspond to a minimum of 80 % graphite structure to forms V and VI in EN ISO 945. The machining tolerance of ±0.5 mm in diameter in cylindrical products of diameter 1 m and length of 4–5 m is achieved typically with "good manufacturing practice" (Raiko 2005a). The diameter for insert is 949+0.5/-0 mm. Eccentricity, which here means the inaccuracy in the polar symmetry of the openings for the fuel elements in the inserts, is set to a maximum limit of 5 mm after machining. Due to stress concentration, the outer corner radius of the square steel tubes in the BWR insert is specified to be 15–25 mm. (Raiko 2005a) The general surface roughness requirement on machined surfaces is Ra 12.5 µm. The steel and iron surfaces for the lid gasket shall be finer, Ra 3.2 µm.

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4 MANUFACTURING TECHNIQUES - OVERVIEW

Inserts

The insert for the disposal canister will be manufactured by casting nodular graphite cast iron. So far, there have been casting experiments for two types of inserts. Inserts for BWR- elements are cast with 12 square channels and inserts for PWR-elements are cast with four square channels. Inserts for VVER-440 elements have 12 round channels. There is no manufacturing experience with regard to VVER-type inserts yet, but the plan is to complete the first casting experiment for the VVER-type insert in 2010. The assumption is that the casting process does not differ much from the process used for casting a BWR-type insert. There are several foundries where manufacturing tests have been conducted. The most recent development work on insert casting has been conducted at Metso Foundries Jyväskylä Oy, Heavycast AB in Sweden and Coswig Walzengiesserei GmbH in Germany. Copper components

Copper components, i.e. copper cylinders or copper tubes and lids/bottom are manufactured from copper billet by hot forming techniques. The hot forming processes, which are now being studied for the manufacture of the copper overpack are pierce and draw, extrusion and forging. Previously, the manufacture of the copper overpack was also studied by forming hot rolled copper plates into tube halves which were joined together by welding. The development work for manufacture of the copper overpack is continuing by studying only those processes which produce a seamless copper tube or cylinder.

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5 MANUFACTURING PROCESSES FOR COPPER COMPONENTS

The manufacturing process for the copper components begins with a cylindrical copper billet, which is a starting material for the manufacture of copper tubes and copper lids/bottoms. For the manufacture of copper tubes there are three methods being developed: pierce and draw, extrusion and forging. Forged copper lids for welding tests have been bought from two suppliers. Currently, Posiva has one supplier, Luvata Pori Oy (formerly Outokumpu Poricopper Oy) in Finland, for producing copper billets for tube manufacturing. Tube manufacturing is carried out in Germany at Vallourec & Mannesmann Tubes (pierce and draw), in Sweden at Scana Steel Björneborg (forging) and in Scotland at Wyman-Gordon Ltd (extrusion).

5.1 Casting copper billets

The casting process for copper billets with a diameter of 850 mm is carried out on a semi-continuous casting line at the Luvata Pori foundry for oxygen-free copper. Originally the Ø850 mm billet casting process was introduced in the early 1990s for disposal canister production. The first casts for the Ø850 mm billet were produced in 1995 in Pori and after preliminary trials some modifications have been made in the casting process. There were four casting campaigns during 2001-2004, totalling altogether 18 billets. After 2004 several copper billets have been cast, which have been used in the development of tube manufacturing. Posiva has ordered ten billets to be used in copper tube manufacturing using the pierce and draw method. Copper billets for copper tube manufacturing by extrusion and forging processes are ordered by SKB. The billet orders have been coordinated between Posiva and SKB but the experience is received from the orders of the both companies. The development work on copper tube manufacturing is carried out in co-operation between Posiva and SKB. Posiva has been responsible for the pierce and draw tests and SKB for the extrusion and forging tests. The casting of oxygen-free copper billets starts by melting preheated cathodes in a melting furnace. As the target temperature is reached, the melt is poured via a launder into a holding furnace. Then the melt is in reducing atmosphere poured into a mould via a casting tube. Phosphorus is fed into the melt in the launder. The mould is a water-cooled matrix (Ø850 mm) where the solidification starts. Casting occurs in a semi-continuous process through an accurate, pre-prepared casting assembly. The whole billet is cast downwards into a casting pit, where it is inclined and lifted later by a crane. A visual check and analyses are carried out on the cast product before approval for further processing. Quality control includes examinations during and after the casting process. During the casting process, casting parameters (casting speed, amount of cooling water etc.) are kept constant and the billets' surface quality is followed on-line.

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After the casting process, the quality control for the billet consists of analyses/inspections for dimension, weight, surface quality and chemical composition. Analyses for chemical composition are taken from triangular samples from the top and bottom of the billet. Dye penetration inspection is carried out after every 50 mm machining. After rough machining visual and dimensional inspection is done and a full chemical analysis and dye penetration inspection are done at both ends. The top end of each copper billet will be marked with a cast number and identification number given by Posiva to ensure traceability. The weight requirement for billets used for tube manufacturing in the pierce and draw process is about 13.4 tons, and a billet weight of about 12.4 tons is needed for tube manufacturing using extrusion or forging. The cast mould diameter is 850 mm and the final diameter after machining is about 830 mm. The casting capacity is currently about 16 tons and full capacity is used when cast to have some excess material at the both billet ends. Excessive material in the billet length is needed as central cracks occur at the starting end before the steady state is achieved. To minimise the amount of central cracks excessive material is machined from the bottom of the billet. After machining there may have still appeared some tiny central cracks. The cast weight is limited by available casting equipment. A simulation has been done how the discontinuities move in the billet during piercing of a billet when processing with the pierce and draw method. The results of the simulation was that most of the centre line discontinuities will end up to the bottom of which material is machined away at the last machining phase leaving no defects to the final bottom with thickness of 50 mm. (Koivula & Pihlainen 2003) The chemical composition of the cast billets to be used in manufacturing experiments for copper tubes is shown in Table 5-1. It can be seen that the specified requirements set for chemical composition are met. The Figures 5-1 and 5-2 show billet ends after some machining and dye penetration testing. A machined billet, which is ready for transportation for further processing by hot forming, is shown in Figure 5-3. Similar results in casting of about 15-16 tons copper billets have been received since 2004.

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Table 5-1. Chemical analyses of the two most recent billets at both billet ends, which

were cast for tube manufacturing.

Cast

number

B09-29-1-1 T09-29-1-1 B09-29-2-1 T09-29-2-1

Copper

tube

Specification

T70

Bottom

T70

Top

T71

Bottom

T71

Top

Cu % min 99.99 99.993 99.993 99.992 99.992 O ppm max < 5 1.1 1.3 1.5 1.2 P " 30–70 48.6 51.0 50.0 50.2 S " <8 5.7 5.7 5.7 5.5 H " <0,6 0.37 0.28 0.30 0.29 Ag " <25 10.4 10.1 10.9 12.2 As " <5 0.50 0.46 0.46 0.48 Bi " <1 0.25 0.22 0.24 0.30 Cd " <1 <0.003 <0.003 <0.003 <0.003 Fe " <10 0.43 0.45 0.48 0.42 Hg " <1 <0.5 <0.5 <0.5 <0.5 Mn " <0.5 <0.11 <0.11 <0.11 <0.11 Ni " <10 0.67 0.57 0.92 0.66 Pb " <5 0.27 0.27 0.29 0.30 Sb " <4 0.15 0.16 0.16 0.17 Se " <3 0.19 <0.94 <0.094 <0.094 Sn " <2 0.14 0.14 0.008 0.022 Te " <2 0.14 0.14 0.15 0.18 Zn " <1 <0.14 <0.14 <0.14 <0.14

Figure 5-1. Top of billet T70 after the 85 mm machining.

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Figure 5-2. The bottom of billet for tube T70 after 250 mm and 330 mm machining,

when the final length of the machined billet is 2840 mm. Small indications can be seen

in the centre.

Figure 5-3. The copper with billet a diameter of 850 mm and weight of about 13.5 tons

after machining and grinding and ready for delivery to the hot forming mill.

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5.2 Hot forming of copper tubes

Currently there are three different methods being studied by Posiva to produce seamless copper tubes for disposal canisters. These are pierce and draw, extrusion and forging. The pierce and draw process makes an integrated bottom possible and only the lid requires welding. Both the bottom and lid must be welded if extrusion or forging is used for copper tube manufacturing. The number of tubes that have been manufactured so far (by the end of 2009) with the methods being developed currently is: 17 tubes by pierce and draw, 30 tubes by extrusion, and 10 tubes by forging. Machined copper billets (manufacturing process described in section 5.1) are used as the starting material for the hot forming processes of tube manufacturing (see Figure 5-4.) Posiva has chosen the pierce and draw process as the reference method for copper tube manufacturing. As the integrated bottom is achieved in the hot forming process, only the lid requires welding. The process is also robust and acceptable material properties are achieved. The results of tube manufacturing using the pierce and draw process, Posiva's reference method, are described in the subsection 5.2, and more thoroughly than the results for the two alternative tube manufacturing methods.

Figure 5-4. Copper billets for hot forming of copper tubes.

5.2.1 Pierce and draw process of copper tubes with integrated bottom

The pierce and draw process is one of the three methods that are currently being developed for manufacturing seamless copper tubes for use in disposal canister assemblies. The method enables to manufacture a copper tube with an integrated bottom. The development of the pierce and draw process of copper tubes has been carried out at Vallourec & Mannesmann Tubes in Reisholz, Germany, in co-operation with Posiva and SKB. In 2001 Posiva conducted the first manufacturing experiment for a large copper tube using the pierce and draw method. The results from the first experiment were promising and it was decided to develop the process further. One of the areas, where

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development was needed was the grain size of the integrated bottom where, at that time, the grain size was several millimeters. Also, due to the limited size of the copper billet, the length of the first tube produced using the pierce and draw method was not enough. Casting of such a large copper billet was also developed further. The second manufacturing experiment was conducted in 2003 when it was possible to manufacture a full length tube with an integrated bottom. The grain size was also evenly good through the overpack except for the middle area of the bottom, which did not practically deform at all during the last pierce and draw steps (Raiko 2008). Since then the process parameters (tools, temperatures, bottom forming, etc.) have been optimized to find a process which produces the required deformation rate and gives the target properties and uniform grain size. The manufacturing experiments have continued and by 2009 a total of 17 tubes have been manufactured. A process has been achieved where the required properties are met through the tube and bottom. A total of six tubes with integrated bottoms, which have been manufactured by pierce and draw method, have had the required properties. The manufacturing experiment for the tubes with the required properties using the pierce and draw method is described in detail in the Posiva Working Report 2008-73, Manufacturing of the Canister Shells T54&T55 (Raiko 2008).

5.2.1.1 Pierce and draw process

The pierce and draw process consists of two separate phases: (1) upsetting and piercing of the block, and (2) expanding and drawing steps. The material used to start the pierce and draw process is a copper billet with a diameter of approximately 850 mm and the billet weight is about 13.4 tons. Upsetting and piercing

The steps for upsetting and piercing are shown schematically in Figure 5-2. The heated billet is upset with one stroke to a die and then the billet is pierced using a mandrel (see Figures 5-3 and 5-4). The mandrel is not punched through the billet but a bottom with a thickness of 200–300 mm is left. Upsetting, piercing and the first drawing step (see Figure 5-5) are performed continuously in one phase without reheating.

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Figure 5-2. Phases of upsetting and piercing. (Vallourec & Mannesmann Tubes)

Figure 5-3. Transferring the billet from the furnace to the upsetting die.

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Figure 5-4. Positioning of the upsetting plate (left) and billet after upsetting and

piercing (right).

Figure 5-5. The first drawing pass with a horizontal mandrel through a drawing ring

after the piercing of the billet (on the left). The billet after the first drawing is shown on

the right.

After the first drawing pass the billet is cooled down and the dimensions including straightness, ovality and eccentricity are controlled and, when needed, machining is performed before further drawing. Expanding and drawing steps

The billet, having been drawn once and inspected, will be heated and the expanding and drawings steps are continued. Intermediate heating is carried out before every drawing step, except for the first drawing, which is done directly after piercing. The drawing steps are continued until the desired tube wall thickness is achieved and the bottom is formed using special tools. The inner diameter will be expanded by using a mandrel with a diameter larger than the tube's inner diameter and by pressing the tube and the mandrel against a steel plate after which the tube is then pushed through the drawing ring (see Figures 5-6 and 5-7).

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Figure 5-6. Expanding the tube by pressing the tube with the mandrel against a steel

plate.

Figure 5-7. Drawing pass.

From the second draw to the fifth draw the outside of the cylinder was drawn through two rings. After the fifth draw the bottom was deformed into a spherical form (see the tools in Figure 5-8 and a formed bottom in Figure 5-9), and after the sixth draw the bottom was reshaped with a specially formed blind ring back to a planar (see the tools in Figure 5-10 and a formed bottom in Figure 5-11).

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Figure 5-8. A deformation device used for bottom forming (left) and a spherical

mandrel used for bottom forming (right).

Figure 5-9. A bottom formed with the spherical mandrel after the penultimate draw.

Figure 5-10. The tools used for the final deformation of the bottom.

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Figure 5-11. Bottom after final deformation.

5.2.1.2 Results from the pierce and draw manufacturing experiments

Some of the results achieved from the manufacturing experiments are presented in this section. After the hot deformation process, tubes with integrated bottom T54 and T55 were cut into pieces (see Figure 5-12) and samples from the bottom, middle and top of the cylinder were taken for further destructive inspections. The remaining tube parts were machined and the dimensional control (length and diameter) was carried out (see the results of the dimensional control in Figure 5-13).

Figure 5-12. The cutting of the sample rings from cylinder T55. (Raiko 2008)

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Figure 5-13. The dimensional control results of the parts of the T55 cylinder after

machining. (Raiko 2008)

Ultrasonic inspection was carried out on the machined tubes. The C-scan pictures of the inspections done on tube T55 are shown in Figure 5-14. Black or blue color illustrates the highest attenuation and red illustrates the lowest attenuation of ultrasound. A higher damping area normally means that the area has a larger grain size. Variation of grain size is, however, well within the required maximum value of 360 µm in all examined locations of the samples. Microstructure studies were not focused to the area of higher attenuation, but the cutting of the sample rings from cylinder T55 is shown in Figure 5-12 and the sectors for the examination of the rings were cut out from rings at three circumferential locations 0⁰, 120⁰ and 240⁰. (The results of the grain size measurements are shown in Table 5-4.) Attenuation of ultrasound in inspection of copper components is handled in report (Pitkänen 2009).

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Figure 5-14. The C-scan presentations of ultrasonic testing of the cylinders of the T55

tube after machining. (Raiko 2008)

As the base was not machined to the final dimensions after hot forming the outer diameter of the bottom (see Figure 5-15) was about 1085 mm and inner diameter about 925 mm and the thickness of the bottom 163–185 mm.

Figure 5-15. A slice of etched bottom from tube T55. (Raiko 2008)

The grain size of the bottom of tube T55 was measured along the inside radius every 80 mm towards to centre as shown in Figure 5-16. The precise examination points are 140 mm (A), 210 mm (B), 290 mm (C), 370 mm (D) and 450 mm (E) from the outer diameter (see Figure 5-16). The measurements were taken for both the top and bottom of the slide. The results of the grains size examination are shown in Table 5-2. All the values are below the limit of 360 µm. Some grains were not completely re-crystallized in the bottom.

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Figure 5-16. Sample locations for hardness and grain size measurements. (Raiko 2008)

Table 5-2. The hardness and grain sizes of the T55 bottom along the radius every 80

mm towards to the centre. (Raiko 2008)

Hardness [HV5] Grain size [mm]

Top Bottom Top Bottom

A 37 36 0.210 0.210 B 36 37 0.220 0.200 C 36 36 0.280-0.300 0.170 D 39 36 0.150 0.220 E 38 37 0.170 0.150

The sectors for the examination of rings (see Figure 5-12) were cut out from rings at three circumferential locations 0⁰, 120⁰ and 240⁰. The length of the sectors is about 250 mm and the rings were specified as top ring (TR), center ring (CR) and base ring (BR). The samples for tensile tests were taken from the inner circle of the ring and the samples for hardness and grain size measurements were taken from the outer circle of the ring (see Figure 5-17). The measured mechanical properties of T55, yield strength (44–47 MPa), tensile strength (207–210 MPa) and elongation values (55–58 %), are typical for soft copper. The elongation values fulfil the specified limit >40 %. The results of the mechanical testing carried out of the rings cut out from the eight pierce and draw tubes, with acceptable material properties in the tube wall, are shown in Tables 5-3, 5-4, 5-5 and 5-6. The results of grain size measurements of the same tubes are shown in Table 5-7. The presented values vary between: yield strength 35–67 MPa, tensile strength 196–212 MPa, elongation 48–59 %, hardness 36–50 HV and grain size 90–300 µm.

25

Figure 5-17. Locations of the samples for tension bar and hardness and grain size

measurements.

Table 5-3. Yield strength (Rp0.2) values [MPa].

Tube/

ring

T43 T54 T55 T61 T62 T63 T64 T71

TR 0⁰ 62 54 46 37 39 38 44 51 TR 120⁰ 41 53 47 35 43 54 53 67 TR 240⁰ 45 69 44 35 50 38 42 55 CR 0⁰ 41 54 45 42 47 44 43 50 CR 120⁰ 40 55 44 42 45 44 45 48 CR 240⁰ 36 51 44 43 45 42 44 50 BR 0⁰ 40 50 46 51 47 47 48 60 BR 120⁰ 42 52 45 43 46 53 49 56 BR 240⁰ 49 54 47 44 47 52 48 56

Table 5-4. Tensile strength (Rm) values [MPa].

Tube/

ring

T43 T54 T55 T61 T62 T63 T64 T71


26

Table 5-5. Elongation values [%]. Requirement for elongation is >40 %.

Tube/

ring

T43 T54 T55 T61 T62 T63 T64 T71


Table 5-6. Hardness values [HV5].

Tube/

ring

T43 T54 T55 T61 T62 T63 T64 T71


Table 5-7. Results of the grain size measurements [mm]. Requirement for grain size is

<0.360 mm.

Tube/

ring

T43 T54 T55 T61 T62 T63 T64 T71

TR 0⁰ 0.160 0.100 0.120 0.120 0.150 0.120 0.090 0.170 TR 120⁰ 0.300 0.120 0.120 0.200 0.120 0.120 0.150 0.140 TR 240⁰ 0.160 0.190 0.120 0.150 0.150 0.190 0.150 0.120 CR 0⁰ 0.210 0.120 0.140 0.200 0.150 0.200 0.200 0.160 CR 120⁰ 0.250 0.170 0.150 0.180 0.170 0.200 0.120-0.300 0.150 CR 240⁰ 0.250 0.150 0.120 0.180 0.180 0.180 0.150 0.140 BR 0⁰ 0.140 0.120 0.150 0.170 0.230 0.250 0.120-0.150 0.180 BR 120⁰ 0.210 0.120 0.120 0.230 0.300 0.130 0.120-0.200 0.140 BR 240⁰ 0.160 0.120 0.120 0.200 0.130 0.150 0.150 0.140

27

5.2.2 Extrusion of copper tubes

Hot extrusion is one of the three methods that are currently being developed for the manufacture of copper tubes to be used in disposal canister assemblies. The process development of copper tube extrusion is being done with SKB at Wyman Gordon Ltd in Scotland. The extrusion process for copper tube manufacturing consists of two separate steps: (1) upsetting and piercing of the block, and (2) extrusion of the tube. The process starts with a copper billet with a diameter of approximately 850 mm and a weight of 12.4 tons. The first step is to heat the billet in a furnace. The billet is then upset to increase its diameter as shown on the left side of the Figure 5-19. Then the billet in a container is pierced by a mandrel, which is centrally and vertically pressed through the billet to get the right form for the extrusion. The pierced billet is machined and the centralisation is checked. Machining is performed to get a totally symmetric tube form for the extrusion. The extrusion is started with heating the blocker. Then the blocker is placed into an extrusion container which is pressed down over the blocker, as shown on the right side of Figure 5-19. As the container has contact with the blocker, the copper starts to extrude through the die. The extrusion continues until the full length of the tube has been extruded.

Figure 5-19. Upsetting (1), blocking (2), piercing (3) and trimming (4) of a billet shown

on the left and on the right the principle for the extrusion of the block is shown.

During years 1999-2008 it has been extruded and studied the properties of 20 tubes (tube T58 is the last, which is included), where material properties (elongation and grain size) have been acceptable. In previous manufacturing experiments before the extruded series for tubes T56-T58, a frequent problem was that the tubes were curved, which

28

resulted in the problem of not getting all the surfaces fully machined. In order to improve the straightness of the tubes, an extended guide for steering the copper tube was in used in the manufacturing series for tubes T57–T58. Some of the results from a previous series of extruded tubes are presented below. It has been shown that the properties required for the copper tube can be achieved using the extrusion process. After extrusion the tubes T56-T58 were measured of straightness, roundness and inner diameter. The measurements are shown in table 5-4. All the three tubes could be fully machined on all surfaces to get the final dimensions.

Table 5-4. Maximum measured deviations of roundness and straightness.

Roundness/

Straightness

Tube T56 Tube T57 Tube T58

Roundness 3.99 mm 2 mm 3.12 mm Straightness 7.99 mm 1.56 mm 4.14 mm

The results of the mechanical testing of tubes T56–T58 are shown in Table 5-5. The results of the mechanical testing show that the elongation after fracture was well above 40 %, which was the set requirement. More mechanical testing was done of tube T58 and the samples were cut out from three rings (rings from the both ends and the center) at three circumferential locations 0⁰, 120⁰ and 240⁰. The measured mechanical properties, yield strength (41–43 MPa), tensile strength (206–216 MPa) and elongation values (50–53 %), are typical for soft copper. As the yield strength (Rp0.2) values in the further testing of tube T58 were much lower (results 40-43 MPa) than shown in Table 5-5, the test bars probably were cold worked resulting in some higher yield strength values.

Table 5-5. Mechanical results for the extruded tubes T56–T58.

Tube Tube end* Rp0.2

[N/mm2]

Rm

[N/mm2]

Elongation

[%]

T56 A B

65 68

221 225

60.5 57.5

T57 A B

83 83

219 219

56.5 60.0

T58 A B

81 80

215 221

57.0 58.0

* “A” refers to the leading end during extrusion (i.e. the end that first comes out of the press during extrusion) and “B” refers to the trailing end. The grain size measurements were taken at both tube ends for all of the tubes at three points along the wall thickness: inside the tube diameter (ID), the middle of the wall thickness (MW) and outside of tube diameter (OD).The results of the grain size measurements are shown in Table 5-6. As can be seen, all of the results from all of the samples are well below the maximum limit set for the grain size, which is 360 µm.

29

Table 5-6. Grain size measurements for extruded tubes T56–T58. “A” refers to the

leading end during extrusion (i.e. the end that first comes out of the press during

extrusion) and “B” refers to the trailing end.

Position T56 A

[µm]

T56 B

[µm]

T57 A

[µm]

T57 B

[µm]

T58 A

[µm]

T58 B

[µm]

ID

MW

OD

76

65

76

32

32

27

106

89

89

76

76

-

106

89

106

76

76

76

The C-scan pictures of ultrasonic testing are shown in Figure 5-20. Ultrasonic testing of

two of the tubes, T56 and T57, showed low attenuation, while T58 revealed an area in

the middle of the tube with higher attenuation (blue-black area). The average grain size

is coarser in the area with high attenuation compared to the surrounding material. The

reason for this phenomenon is still not known and an obvious reason was not found

when comparing the process routes for the three tubes. Studies done of T58 showed that

the manufacturing requirement of a maximum grain size of less than 360 µm is met in

the areas of higher attenuation. The grain size of the coarser area, which was found in

microstructure studies of the tube T58, was 200–220 µm. More studies are ongoing to

eliminate such areas with higher attenuation of ultrasound. For example, the effect of

friction and the extruding temperature will be studied. Other factors than the

microstructure of the inspected material may also cause higher attenuation of

ultrasound. Ultrasonic testing is handled in more detail in the report "Inspection of

canister components" (Pitkänen 2009).

30

Figure 5-20. C-scan pictures from the ultrasonic testing of tubes T56–T58, the A-end is

to the right and the B-end is to the left. (“A” refers to the leading end during extrusion,

i.e. the end that first comes out of the press during extrusion, and “B” refers to the

trailing end.)

5.2.3 Forging copper tubes

Forging is one of the three processes that are being developed for tube manufacturing by Posiva. The process development of copper tube forging is done in with SKB at Scana Steel Björneborg AB. The first copper tube (T32) for canister manufacturing purposes was forged in 2002 and most recent tubes (T59 and T60) were forged in 2007. So far (by the end of 2009), ten tubes have been forged. The process for the manufacture of copper tubes by forging starts with a copper billet with a diameter of 850 mm and a weight of about 12 tons. The forging process consists of several steps. First, the heated copper billet is upset to increase its diameter. Then a mandrel is vertically pressed down in the centre of the billet to get a hole of 550 mm in diameter. Then hammer forging begins to increase the diameter of hole until the

31

diameter is large enough to set a mandrel with a diameter of 930 mm. Hammer forging is carried out by turning and moving the mandrel axially until a long tube with a uniform wall thickness is formed. The process for manufacturing large copper tubes by forging is schematically shown in Figures 5-21 and 5-22 and in pictures in Figure 5-23.

The heated billet is placed upright in the press.

The billet is upset to increase its diameter. A mandrel is pressed down in the centre of the billet.

The mandrel is pressed down as far as the press will go.

The billet is turned over and the mandrel is pressed down from the other side.

The remaining plate is pressed away and the through hole stays.

Figure 5-21. Process steps for upsetting and piercing a copper billet.

Figure 5-22. Steps in copper tube forging: hammer forging and forging with a mandrel.

32

Upsetting of billet Piercing of the billet with a Ø550 mm mandrel

Hammer forging Hammer forging with a V-formed tool

Final step in hammer forging Finalized tube

Figure 5-23. Photographs of the manufacture of a large copper tube (Scana Steel

Björneborg AB).

33

The manufacturing experiments have shown that by forging it is possible to manufacture large copper tubes within the geometry and the stated material property requirements. However it has been difficult to control the process to achieve the correct geometry. Also, the yield strength of forged tubes is somewhat higher than the yield strength achieved for tubes which have been manufactured using the pierce and draw and extrusion methods. On the basis of previous experiments carried out by forging, it is believed that the reason for the higher yield strength is that some deformation occurs in a lower temperature, which causes some cold working. Forging is a slow process and during the process the billet has time to cool down. The forging method is advantageous as there are many forgeries which could be used if the forging process could be adapted to the manufacture of large copper tubes so that the requirements for manufacturing are met and the process is robust.

5.3 Manufacturing copper lids and bottoms

Copper lids are machined from hot formed blanks. Hot forming gives the desired homogeneous and fine-grained structure. The manufacturing process for the hot pressing of the lids at Luvata Oy starts with a cast cylindrical copper billet with a diameter of 350 mm and a length of 1200 mm. The quality of the billet has been controlled at both ends before hot pressing. The test pieces for quality control are taken after the hot pressing and the tests, which are mechanical and analysis of gases, chemical composition, microstructure and hydrogen cracking, are carried out. After the acceptance of hot formed blankets the blankets are raw machined to a thickness of 140 mm and a diameter of 958 mm. The final machining of the surfaces is performed without any cutting fluids to ensure that the lid surface is clean for the welding process. Posiva has also ordered copper lids from SKB, which have been forged at Scana Steel Björneborg AB. The copper billets for the forged lids are continuous cast at Aurubis AG (former Norddeutsche Affinierie AG in Hamburg). The bottom of the canister is flat. The copper bottoms are needed if a tube with an integrated bottom is not produced in the copper tube manufacturing process (i.e. extrusion and forging). The process for manufacturing copper bottoms is similar to the manufacturing process for lids except for the shoulder. The final machined copper lids and bottoms can probably be bought directly from suppliers without need for further development.

35

6 MANUFACTURE OF INSERTS

The types of inserts have been described in section 2, in the Figure 2-1. The inserts are cast with 12 square channels for BWR (see Figure 6-1) and with 12 round channels for VVER-440 fuel assemblies. Inserts for EPR fuel assemblies have four square channels. Casting of the BWR insert type has been studied. Casting of the VVER type has not yet been carried out, but the plan is to start experiment in 2010. The manufacture of inserts for EPR fuel assemblies has not yet been studied and experiments are not planned in the near future as the estimated demand for EPR type inserts is after 60 years. SKB is conducting experiments for the manufacture of inserts for PWR fuel assemblies, which is similar to the EPR- type and Posiva is co-operating with SKB in the manufacture of PWR- type inserts. Also the development for manufacture of BWR insert type is done in co-operation with SKB. So far (by end of 2009), about 70 inserts have been cast at different foundries. The most recent experiments have been carried out at Metso Foundries Jyväskylä Oy, Heavycast AB (former Metso Foundries Karlstad AB) and Coswig Walzengiesserei GmbH. The inserts are made of nodular graphite cast iron.

Figure 6-1. Machined BWR insert. (Raiko 2003)

The inserts are cast with 12 channels for BWR and VVER-440 -inserts and four channels for PWR inserts (similar to EPR). The channels are made when the inserts are cast by using a steel cassette assembly. The insert is cast with an integrated bottom.

6.1 Manufacture of the steel cassette

The channels in the inserts originate when casting the inserts. The round or square steel pipes (EN10210-1 S355J2H or similar) are welded together to form a cassette (see Figures 6-2 and 6-3), which is placed into the casting mould before the insert is cast.

36

The material for the steel plates and flat bar used in the cassette construction is EN10025 S235JRG2 or similar. The SKB specification KTS022 (Appendix 4) is followed in the manufacture of steel cassettes. As the straightness of the channels is important, the straightness of the pipes is controlled by gauging, before and after assembling the cassette (see Figure 6-4).

Figure 6-2. A welded cassette with 12 square channels for casting of inserts for BWR

fuel assemblies.

Figure 6-3. Top of the welded cassette (left) and bottom of a cassette (right).

37

Figure 6-4. Controlling the straightness of the square tube cassette assembly using a

gauge. (Raiko 2005b)

6.2 Casting the iron insert

The casting process can vary depending on the foundries where the development work for insert manufacture is carried out. The filling of the mould with iron melt can be done either from the top or bottom of the mould. To avoid deformation of the cassette due to melt pressure, the open channels are filled with packed sand before casting. After casting, the insert is allowed to cool down in the mould for a few days. The cast is then cleaned and the insides of the cassette channels are emptied and sand blasted. After cleaning and cutting the excess material from the top and sample slices for mechanical testing and microstructure analysis, the channel tubes are gauged (see Figure 6-5). Machining is carried out according the applicable drawing. Typically, the slice for mechanical testing has been taken from the top of the cast, but additional slices may be cut from the bottom and middle of the cast insert. The sampling is shown in Figure 6-6.

Figure 6-5. Gauging of an insert for BWR fuel.

38

Figure 6-6. Test piece positions, BWR (left) and PWR (right). [Appendix 3]

It has been shown that the manufacturing technique of insert casting is capable of serial manufacturing. Five BWR inserts were cast and the mechanical properties, microstructure and gauging of the channels fulfilled the requirements in KTS011 (Appendix 3). The requirement of a maximum of 5 mm eccentricity was not met in all the inserts as the channels were bent during casting. The casting process was modified for casting BWR insert I63 at the same foundry and all the specified requirements were met, including the eccentricity. Three slices were cut from the insert (top, middle and bottom) for testing. Results from the tensile testing are shown in Table 5-7. Table 5-7. Mean values of the mechanical properties in insert I63 (five of the six highest

values are counted.)

Insert I63 Rp0,2 [MPa] Rm [MPa] Elongation [%]

Manufacturing

requirements

240 370 7

Top 274 395 15.9 Middle 284 398 15.2 Bottom 287 404 16.8

The microstructure was analysed from two samples from each cut slice (top, middle and bottom). The nodularity, which is given as %-share of form V and VI nodules, was 90 % in all test pieces. All the tube channels passed the gauging, which was carried out after casting. Machining of insert I63 was carried out according to the SKB drawing and dimensions after pre-machining fulfilled the dimensions stated in the applicable drawing (see Table 5-8.).

39

Table 5-8. Dimensions of I63 after pre-machining according to the applicable SKB

drawing.

Location of measurement Measured dimension [mm] Required dimension [mm] 1st insert end 961.0 960±1 Middle of insert length 961.0 960±1 2nd insert end 961.0 960±1 Insert lenght 4595.0 4595±2

Preliminary results of the ultrasonic test did not reveal unacceptable defects. The casting process for the manufacture of BWR inserts, which fulfil the requirements, is being developed. Further manufacturing experiment are needed to verify that the process is robust. Also, the aim is to find more foundries that can cast inserts with the required properties.

6.3 Steel lid

All insert types have separate flat lids made of 50 mm steel plate on the top end. The top lids are fixed centrally with one pin screw (size M30) and there is a gasket between the lid edge and the insert body. (Raiko 2005a) It is planned to manufacture steel lids for canister inserts ready at a machine shop from steel plates machined to the final dimension and with the holes for a screw and a valve according to the Posiva's steel lid drawing. The steel is S355J2 or similar grade at least the same tensile strength and ductility, in hot rolled or normalised condition. The steel must be ordered with a material certificate which shows that the chemical composition and the mechanical properties of the material grade are met.

41

7 MACHINING AND ASSEMBLY OF CANISTER COMPONENTS

When final disposal facility is operated it is planned to acquire the canister components as either final machined or hot formed copper components, and inserts as cast and machined. Machining will be performed to size and shape as stated in the applicable Posiva drawings. If the components are acquired as machined, the insert can be assembled inside the copper canister by the supplier. There is also the option to machine and assemble the canister components in a canister factory "Kapselfabrik" (SKB 2006), which is an alternative for canister assembly when co-operating in canister manufacture with SKB. The manner of acquisition has not yet been decided (TKS-2009).

43

8 STATUS AND COMPARISON OF MANUFACTURING METHODS

Inserts

Posiva has the readiness to manufacture inserts for BWR fuel assemblies, but manufacturing experiments will continue to ensure routine readiness to manufacture inserts with the required properties and, if possible, more foundries will be qualified for insert casting. Casting experiments for the VVER-440 type insert are not taking place yet, but the plan is to start these experiments in 2010. Inserts for EPR-type fuel have not been cast, but co-operation is ongoing with SKB to study the manufacture of PWR-type insert, which is similar to the EPR-type. Copper tubes

The copper cylinders with the required properties can be achieved using the pierce and draw method. The advantage of the method is that the bottom is integrated with the tube already after the hot forming process and only lid requires welding. The set requirements are also achieved using the extrusion process, which produces a tube without a bottom. Ultrasonic testing of extruded tubes has revealed some areas have a higher attenuation of ultrasound. The grain size requirement is met, even in the areas with higher attenuation, but studies are ongoing to find the reason for the higher attenuation. The required properties can be achieved by forging; however, the forging process is difficult to control in order to achieve the right geometry. Also, the yield strength of forged tubes is somewhat higher than the yield strength achieved with alternative methods. Development for optimisation of the forging process is ongoing.

45

9 QUALITY ASSURANCE

The quality system for order procedures for canister components is a part of Posiva's quality system, which is certified according to ISO 9001. The quality handbook for manufacture of canister components is under development. Actual specifications are sent for suppliers with orders of canister components. Quality controls at different phases of the manufacture of disposal canister components are presented in the following subsections. Suppliers prepare quality plans for canister component manufacturing, which are sent to the development project leader (Posiva or SKB) for approval. The development of the main components in canister manufacturing is carried out in co-operation with SKB. Component manufacturing operations are controlled to fulfil the requirements set in the manufacturing specifications. Before the components are delivered from the suppliers, permit for delivery is needed from Posiva. Any non-conformities appearing during manufacturing are handled and registered according to Posiva's quality system. Each copper component and cast insert is uniquely marked and its identity is maintained throughout the manufacturing process, including the machining stages, and traceability to the casting is maintained.

9.1 Quality control of copper canister components

Copper billet

A preliminary specification (KTS001) for production of copper billets is in Appendix 1. The composition of the melt is verified by chemical analysis. After casting, inspections for dimension, weight, surface quality and chemical composition are performed. The analysis of chemical composition is taken from the top and bottom of the billet. When the cast billet is being rough machined, dye penetration inspection is carried out after every 50 mm machining at the billet ends to make sure if further machining is needed to ensure the billet ends are acceptable. When the rough machining is complete visual and dimensional inspection is performed and full chemical analysis and dye penetration inspection are carried out at both ends of the billet. The top end of each copper billet is marked with a cast number and identification number given by Posiva to ensure the traceability. Copper canister

Mechanical testing is performed on the hot formed copper canister to verify that the set requirements are met. Microstructure analysis is performed to determine if the grain size is acceptable.

46

The surface of the copper canister is inspected visually. Eddy current testing is used to find defects near the canister surface and ultrasonic testing is used to find defects through the canister wall thickness. Non-destructive testing of the copper canister is handled in more detail in the report "Inspection of disposal canister components" (Pitkänen 2009). Copper lid/bottom

The properties of the hot formed copper lids/bottoms are analysed before machining to ensure that the required mechanical properties, chemical composition and grain size are met. Ready machined copper lids (and/or bottoms) will be inspected non-destructively using three methods: visual, eddy current and ultrasonic inspection (TKS-2009). The non-destructive testing is reported in "Inspection of disposal canister components" (Pitkänen 2009).

9.2 Quality control of inserts

Chemical analysis is carried out on melt iron before the insert is cast to ensure the right composition of the material. The cast insert composition is also analysed. Each cast insert is uniquely marked and its identity is maintained throughout the manufacturing process. Mechanical properties and material microstructure are analysed from samples taken from the cast insert. The channels are gauged after casting to ensure that the channels are not bent or otherwise deformed during the casting and to verify that the channels are clean so that the spent fuel assemblies will fit into the channels. Non-destructive testing (visual and ultrasonic) is used to inspect manufacturing related defects, such as pores, inclusions and flaws, in the insert. The geometrical requirements can also be verified ultrasonically. Non-destructive testing of inserts is handled more detail in the report "Inspection of disposal canister components" (Pitkänen 2009).

47

REFERENCES

Koivula, J. & Pihlainen, H. 2003.Further development of the Structure and Fabrication of the Final Disposal Canister. Working Report 2003-49, Posiva Oy. Pitkänen, J. 2009. Inspection of disposal canister components. POSIVA report 2009-XX, to be published. Raiko, H. 2008, Manufacturing of the Canister Shells T54&T55, Working 2008-73, Posiva Oy. Raiko, H. 2005a. Disposal Canister for Spent Nuclear Fuel - Design Report. Report POSIVA 2005-02, Posiva Oy. Raiko, H. 2005b. Test Manufacture of the Canister Insert I35. Working Report 2005-53, Posiva Oy. Raiko, H. 2003. Test Manufacture of the Canister Insert. Working Report 2003-59, Posiva Oy. SKB 2006. Kapsel för använt kärnbränsle, SKB Rapport R-06-03, Svensk Kärn-bränslehantering AB. TKS-2009, Olkiluodon ja Loviisan voimalaitosten ydinjätehuolto: Selvitys suunnitel-luista toimenpiteistä ja niiden valmisteluista vuosina 2010-2012, Posiva Oy.

Internal information DOCUMENT ID 1064458

VERSION 7.0

STATUS Approved

REG.NO KTS001

PAGE 1(5)

Instruction AUTHOR

Greger Hägg DATE OF CREATION 2006-11-29

REVIEDWED BY Magnus Johansson

REVIEWED DATE 2007-08-21

APPROVED BY Nina Leskinen

APPROVED DATE 2007-08-23

KTS001-Copper ingots and billets for canister components

1064458 - KTS001-Copper ingots and billets for canister components.doc

Svensk Kärnbränslehantering AB Swedish Nuclear Fuel and Waste Management Co

PO Box 925, S-572 29 Oskarshamn Visiting address Gröndalsgatan 15 Phone +46-491-76 79 00 Fax +46-491-76 79 30 www.skb.se 556175-2014 Seat Stockholm

Contents 1. Purpose .....................................................................................................................1 2. Requirements ...........................................................................................................2

2.1 Quality plan ....................................................................................................2 2.2 Material specification .....................................................................................2 2.3 Chemical composition ....................................................................................2 2.4 Weight, size and surface condition .................................................................3 2.5 Macroscopic discontinuities ...........................................................................3 2.6 Identification marking ....................................................................................3 2.7 Sampling .........................................................................................................3 2.8 Ingots ..............................................................................................................3 2.9 Continuously cast billets.................................................................................3

3. Inspection and testing .............................................................................................3 3.1 Chemical analysis ...........................................................................................3 3.2 Visual inspection ............................................................................................3

4. Nonconformities.......................................................................................................4 5. Request for concession ............................................................................................4 6. Supplier’s documentation.......................................................................................4

6.1 Quality plan ....................................................................................................4 6.2 Certification of copper ingots and cast billets.................................................4 6.3 Submission of documents and information ....................................................4 6.4 Retention of documentation............................................................................4

7. Retention of test samples.........................................................................................5 8. Document control ....................................................................................................5 Revision record .......................................................................................................................5 Footnotes..................................................................................................................................5

1. Purpose Copper ingots and billets are used for production of copper components to canisters 1. This technical specification, KTS001, defines technical requirements and documentation procedures for copper ingots, including continuously cast billets, for this purpose.

Note: The term ingot may be replaced by billet, depending on the producer’s method and terminology.

49

1064458 - KTS001-Copper ingots and billets for canister components

Internal information 7.0 Approved 2(5)



2. Requirements 2.1 Quality plan A quality plan 2 shall be established by the producer and accepted by SKB prior to production of copper ingots and billets.

2.2 Material specification The material for copper canisters shall fulfil the specification in EN 1976:1988 3 for the grades Cu-OFE (Table 2) or Cu-OF1 (Table 3) with the following additional require-ments: O < 5 ppm, P 30–70 ppm, H < 0,6 ppm, S < 8 ppm.

2.3 Chemical composition Table 1. Requirements and comments concerning various properties

Note: The P content in Table 1 is required for the canister application. It is substantially higher than in the standard referred to in Table 2 on the next page.

Table 2. EN 1976 Cu-OFE composition (UNS C10100 4) Element Cu Ag As Fe S Sb Se Te Pb % ppm b) ∧ 99,99 a) 25 5 10 15 4 3 2 5 P Bi Cd Mn Hg Ni O Sn Zn ppm b) ∧ 3 1 1 0,5 1 10 5 2 1 Table 3. EN 1976 Cu-OF1 composition Element Cu Ag As Fe S Sb Se Te Pb (rem.) ppm ∧

25 b) 5 c) 10 d) 15 b) 4 b) 2 e) 2 f) 5 b) a) Including Ag b) Maximum content c) Σ As + Cd + Cr + Mn + Sb ≤ 15 ppm

Property Specification Comments Weldability O < 5 ppm Higher levels give a reduced weldability. Ductility H < 0,6 ppm Higher levels give reduced mechanical

properties. (Hydrogen embrittlement).

Tensile strength, ductility

S < 8 ppm Higher levels give reduced mechanical properties caused by non-dissolved sulphur which will be concentrated to grain boundaries.

Creep ductility P 30–70 ppm A phosphorus content of this order reduces the influence of sulphur impurities, increases creep ductility, increases recrystallisation temperature and has a minor influence on the weldability.

50





d) Σ Co + Fe + Ni + Si + Sn + Zn ≤ 20 ppm e) Σ Bi + Se + Te ≤ 3 ppm f) Σ Se + Te ≤ 3,0 ppm

2.4 Weight, size and surface condition Delivery net weight per piece, size and surface condition of ingots and continuously cast billets shall be as stated in the SKB order.

2.5 Macroscopic discontinuities Experience is being collected to determine permissible types and extent of discontinuities. Possible acceptance is yet to be agreed with SKB case by case when discontinuities appear.

2.6 Identification marking Each copper ingot or continuously cast billet shall be marked with the producer’s cast number and any additional requirements in the SKB order. The top end of each ingot intended for tubes shall be marked TOP. No marking is needed on the bottom end.

2.7 Sampling Sampling for chemical analysis and any other testing shall be described by the manufacturer and be made available to SKB.

2.8 Ingots Samples shall be taken from representative material of cut-off ends.

2.9 Continuously cast billets The manufacturer’s normal sampling method shall be applied. Additional samples for P test shall be taken at least from the start and final ends of a casting intended for forged blanks, unless other sampling is agreed with SKB.

3. Inspection and testing 3.1 Chemical analysis The analysis shall be performed in accordance with industry practice by an accredited laboratory or by a laboratory meeting ISO 9001:2000 5 requirements. Laboratory reference material shall be traceable to accredited sources and its identity and use for the analysis shall be recorded.

3.2 Visual inspection The manufacturer shall inspect the ingots and billets visually for surface defects, for example cracks or flaws, particularly at the centre of the ingot end surfaces. The result shall be recorded and sent to SKB for possible acceptance prior to delivery. Any further inspection as specified in the SKB order.

51





4. Nonconformities Any deviation, e.g. from specified weight, size, surface condition or any other significant deviation from requirements shall immediately be reported in accordance with the manufacturer’s quality management system. This party shall consult with SKB for decision about suitable action.

5. Request for concession Any request for concession 6 shall be documented on SKB form 7 or similar and sent to SKB.

6. Supplier’s documentation 6.1 Quality plan The quality plan 2 according to 2.1 shall be completed and submitted to SKB.

6.2 Certification of copper ingots and cast billets The copper ingot/billet manufacturer shall issue a certificate according to EN 10204 3.1.B 8 or declaration of conformity according to EN 1655 Type C or Type D 9, stating as a minimum:

• the manufacturer’s name and address, • date of issue, • SKB order and specification numbers, • heat or cast number, • copper ingot or billet dimensions and net weight per piece, • applicable standard, • chemical composition, • result of visual inspection, • illustrated description or sketch of sampling of solid material, • a declaration that the material has been produced in accordance with the manufacturer’s

own current quality system and quality plan, both to be accepted by SKB, • any other requirement specified in the SKB order.

6.3 Submission of documents and information Any request for concession, the certificate according to 6.2 and request for delivery permit 10 shall be sent to SKB by mail or telefax for authorization prior to dispatching the copper ingot or billet for hot working. SKB shall be informed when the shipping takes place. The manufacturer shall, without delay, give complete information to SKB on all observations and other circumstances in connection with the production, which may influence the design and properties of the copper canister. SKB shall have the right to use this information without any restriction.

6.4 Retention of documentation PE, Projekt Engineer, is responsible for the retention of documentation according to sections 2, 3, 4, 5, 6.1 and 6.2, described in a separate procedure 11. QA Co-ordinator Canister Manufacturing Technique, QASK, is to be informed by PE if nonconformities according to section 4 occurs. The manufacturer shall retain the documentation according to sections 2.7 and 3.1 for (presently) at least 10 years under suitable security. If any records are stored on electronic/magnetic media the readability shall be ensured for this time period.

52





7. Retention of test samples SKB shall retain samples for determination of the chemical composition for (presently) minimum 10 years under suitable conditions. Identifiable samples from ingots and billets is to be sent by the supplier to SKB.

8. Document control QASK is responsible for document control, including distribution, of this technical specification 12.

Revision record Revision Date Revision includes Author Reviewed Approved

5.0 2005-06-01 MWn LW/PEr NLe 6.0 2007-08-13 Responsibility for retention of documents changed to

PE, test samples to be retained by SKB GH See SKBdoc

Footnotes 1. SKB Technical Specification KTS002, Copper components for canisters 2. SKB Procedure KT0704, Requirements on 1) Quality plan, 2) Manufacturing and

inspection plan 3. EN 1976:1998, Copper and copper alloys – Cast unwrought copper products 4. UNS C10100 according to Application Datasheet, Standard Designation for Wrought

Alloys, www.copper.org 5. ISO 9001:2000, Quality management systems – Requirements 6. SKB Procedure KT1102, Supplier’s request for concession 7. SKB Form KTF11-1 (Eng) or KTF11-2 (Sv) 8. EN 10204:1995, Metallic products – Types of inspection documents 9. EN 1655:1997, Copper and copper alloys – Declaration of conformity 10. SKB Form KTF07-07 (Eng) or KFT07-08 (Sv) or similar 11. SKB Procedure KT1002, Retention of quality documents and records 12. SKB Procedure KT1001, Establishing and control of SKB technical specifications,

procedures and forms

53


VERSION 5.0

STATUS Approved

REG.NO KTS002

PAGE 1(6)

Instruction AUTHOR

Greger Hägg DATE OF CREATION 2006-11-29

REVIEDWED BY Magnus Johansson

REVIEWED DATE 2007-11-23

APPROVED BY Nina Leskinen

APPROVED DATE 2007-11-23

KTS002-Copper Components for Canisters

1064459 - KTS002-Copper Components for Canisters.doc Svensk Kärnbränslehantering AB Swedish Nuclear Fuel and Waste Management Co

PO Box 925, S-572 29 Oskarshamn Visiting address Gröndalsgatan 15 Phone +46-491-76 79 00 Fax +46-491-76 79 30 www.skb.se 556175-2014 Seat Stockholm

Contents 1. Purpose .....................................................................................................................2 2. Requirements ...........................................................................................................2

2.1 Quality plan ....................................................................................................2 2.2 Material specification .....................................................................................2 2.3 Grain size and mechanical properties .............................................................2 2.4 Macroscopic discontinuities ...........................................................................2 2.5 Size, shape and tolerances ..............................................................................3 2.6 Identification marking ....................................................................................3

3. Hot forming process ................................................................................................3 4. Machining.................................................................................................................3

4.1 Copper lid .......................................................................................................3 4.2 Copper base ....................................................................................................3 4.3 Copper tube.....................................................................................................3

5. Inspection and testing .............................................................................................3 5.1 Visual inspection and non-destructive testing ................................................3 5.2 Sampling for determination of mechanical properties and structure ..............4 5.3 Mechanical properties.....................................................................................4 5.4 Structure..........................................................................................................4 5.5 Photographic documentation ..........................................................................4

6. Nonconformities.......................................................................................................4 7. Request for concession ............................................................................................4 8. Manufacturer’s documentation .............................................................................4

8.1 Quality plan ....................................................................................................4 8.2 Material certificate..........................................................................................5 8.3 Submission of documents and information ....................................................5 8.4 Retention of documentation............................................................................5

9. Retention of test samples.........................................................................................5 10. Document control ....................................................................................................5 Revision record .......................................................................................................................6 Footnotes..................................................................................................................................6

55

1064459 - KTS002-Copper Components for Canisters



1. Purpose Copper blanks for lids or bases are manufactured by forging, and seamless copper tubes are produced by the pierce and draw process, extrusion or forging. This technical specification, KTS002, defines technical requirements and documentation routines for those components. Note: An alternative tube manufacturing process includes roll forming and longitudinal welding of copper plate. When applicable, details of the process will be specified separately.

2. Requirements 2.1 Quality plan A quality plan 1 shall be established by the manufacturer and accepted by SKB prior to production of copper blanks for lids or bases and seamless copper tubes.

2.2 Material specification The starting copper billet and ingot material for hot working to components for canisters shall fulfil requirements in a separate specification 2.

2.3 Grain size and mechanical properties Forged copper blanks and seamless copper tubes shall have a grain size less than the limit specified in Table 1. The grain size is to be determined according to EN ISO 2624 3, using the comparison, intercept or planimetric procedure. Note: The standard grain size chart for the comparison method showing the structure for 0,120 mm (120 µm) average grain diameter at 75x magnification can be used for 360 µm grain size at 25x magnification.

2.4 Macroscopic discontinuities Experience is being collected to determine acceptance criteria for internal and surface defects of copper blanks and tubes. See also 5.1. Table 1. Requirements and comments concerning grain size and mechanical properties in hot formed material.

Property Specification Comments Microstructure in forged copper blanks

Grain size < 360 µm This grain size gives a resolution at ultrasonic testing comparable to X-ray testing of 50 mm thick copper.

Microstructure in seamless copper tubes

Grain size < 360 µm Same comment as above.

Ductility Elongation > 40% RT–100°C

The canister will be deformed 4% in final repository.

Creep ductility Elongation at creeprupture > 10% RT–100°C

Same comment as above.

56




2.5 Size, shape and tolerances Forged copper blank for base or lid Size, shape, surface condition and tolerances according to the SKB order and applicable drawing. Seamless copper tube Length, diameter, wall thickness, surface condition and tolerances according to the SKB order and applicable drawing.

2.6 Identification marking Each forged copper blank or copper tube shall be marked in accordance with requirements in the SKB order and applicable procedure 4.

3. Hot forming process The hot forming process shall be performed in such a manner that the specified properties of the delivered product are met. The process shall be controlled and documented by the manufacturer of copper blanks or tubes to the extent necessary for ensuring reproducibility. It shall be ensured that appropriate, identified tools or equipment are selected and used. This shall be suitably documented. Note: If an accepted ingot shows minor line cracks, pores or other inhomogeneities in one end surface, that end shall be the base end when upset forging and piercing is applied.

4. Machining 4.1 Copper lid Machining of each blank for copper lids shall be performed in accordance with applicable SKB drawings, normally in two steps, pre-machining to a rough shape and final machining to the end shape.

4.2 Copper base Machining of each blank for copper bases shall be performed in accordance with applicable SKB drawings normally in two steps, pre-machining to a rough shape and machining to the shape necessary for welding. Final machining shall be carried out after welding of the base to the copper tube in accordance with applicable SKB drawings.

4.3 Copper tube Machining of all surfaces of each copper tube shall be performed after hot forming to size and shape as stated in applicable SKB drawings. When welding of base to the tube is applied (such as for extruded or forged tube), the final machining of the top end shall be performed after the base-to-tube welding, since the tube length may be affected by the welding.

5. Inspection and testing 5.1 Visual inspection and non-destructive testing The copper blank or tube shall be inspected visually and by 100% non-destructive testing. Experience is being collected to determine methods to be applied, sizes and shapes of reference defects, which will be stated in separate procedures. Result of the examination shall be recorded.

57




5.2 Sampling for determination of mechanical properties and structure All sampling is to be described or referenced in the quality plan in agreement with SKB 5.

5.3 Mechanical properties Test pieces for tensile testing (R p 0,2; Rm; A5 ) preferably according to EN 10002-1 6, shall be taken from tubes and from blanks for lids and bases as specified by SKB. Tensile testing shall be performed in accordance with EN 10002-1 by an accredited laboratory or by a laboratory meeting at least ISO 9001 7 requirements with exclusion of clause 7.3, if this clause is not applicable. Test records shall be retained.

5.4 Structure Specimens shall be taken from both ends of each tube for grain size/structure inspection. For similar purpose, samples of specimens from blanks shall be taken as specified in the SKB order. The structure shall be documented by photos at approximately 25x magnification. Blank for lid or base Grain size/structure shall be determined close to the surface or rim and also, when specified in the SKB order, in the centre of the material. The centre part refers to the surface of the blank centre. Tube Grain size/structure shall be determined at both tube ends close to the envelope surface and also in the centre (in thickness direction) of the material, unless otherwise specified in the SKB order. Experience is being collected regarding the possibility to determine the copper grain size from ultrasonic parameters (damping).

5.5 Photographic documentation The production sequence shall be photographically documented when required by SKB. The extent is to be agreed with SKB from case to case.

6. Nonconformities Any deviation, e.g. from specified shape or size or any other significant deviation from requirements shall immediately be reported in accordance with the manufacturer’s quality management system. This party shall consult with SKB for decision about suitable action.

7. Request for concession Any request for concession 8 shall be documented on SKB form 9 or similar and sent to SKB.

8. Manufacturer’s documentation 8.1 Quality plan The quality plan 1 according to 2.1 shall be completed and submitted to SKB.

58




8.2 Material certificate The copper blank or copper tube manufacturer shall issue a certificate according to EN 10204 3.1.B 10, or declaration of conformity according to EN 1655 Type C or D 11, stating or including as a minimum: • the manufacturer’s name and address, • date of issue, • SKB order number, • applicable SKB drawing and specification numbers, including revisions, • original heat or cast number, • lot number and/or number of the blank or tube, • dimensions of the blank or tube, • results of non-destructive testing, • results of tensile testing when applicable, and determination of grain size and structure, • illustrated description of sampling 5, • a declaration that the component has been produced in accordance with the company’s own current quality system and quality plan, both to be accepted by SKB, • any other requirement specified in the SKB order.

8.3 Submission of documents and information Any request for concession, the certification according to 8.2 and request for delivery permit 12 shall be sent to SKB for authorization prior to delivery of the blank or tube. SKB shall be informed when ingots or billets arrive and when shipping of blanks or tubes takes place. The supplier shall, without delay, give complete information to SKB on all observations and other circumstances in connection with the production, which may influence the design and properties of the components and/or the copper canister. SKB shall have the right to use this information without any restriction.

8.4 Retention of documentation PE, Projekt Engineer, is responsible for the retention of documentation according to sections 2, 3, 4, 5, 6,7 and 8 described in a separate procedure 13. QA Co-ordinator Canister Manufacturing Technique, QASK, is to be informed by PE if nonconformities according to section 6 occurs. The manufacturer shall retain the documentation according to sections 5.1, 5.2, 8.1 and 8.2 for (presently) at least 10 years under suitable security. If any records are stored on electronic/magnetic media the readability shall be ensured for this time period.

9. Retention of test samples SKB is to retain samples for determination of microstructure and, when applicable, tensile properties for (presently) minimum 10 years under suitable conditions. The identification of samples shall be maintained

10. Document control QA Co-ordinator Canister Manufacturing Technique is responsible for document control, including distribution, of this technical specification 14.

59




Revision record Revision Date Revision includes Author Reviewed Approved

2.0 2005-06-01 MWn LW/PEr NLe 3.0 2007-08-13 Responsibility for retention of documents shifted to

PE. SKB retains the test samples GH See SKB doc

4.0 2007-11-22 A50 changed to A5 GH See SKB doc

Footnotes 1. SKB Procedure KT0704, Requirements on 1) Quality plan, 2) Manufacturing and

inspection plan 2. SKB Technical Specification KTS001, Copper ingots and billets for canister components 3. EN ISO 2624:1995, Copper and copper alloys – Estimation of average grain size 4. SKB Procedure KT0705, Identification of canister components and assembled canisters 5. Requirements on sampling, including sample positions, may be added in a later revision of

this document. 6. EN 10002-1:2001 – Metallic materials – Tensile testing 7. ISO 9001:2000, Quality management systems – Requirements 8. SKB Procedure KT1102, Supplier’s request for concession 9. SKB Form KTF11-1 or KTF11-2 10. EN 10204:1995, Metallic products – Types of inspection documents 11. EN 1655:1997, Copper and copper alloys – Declaration of conformity 12. SKB Form KTF07-7 or KTF07-8 or similar 13. SKB Procedure KT1002, Retention of quality documents and records 14. SKB Procedure KT1001, Establishing and control of SKB technical specifications,


60


VERSION 9.0

STATUS Approved

REG.NO KTS011

PAGE 1(10)

Instruction AUTHOR Torbjörn Engquist

DATE OF CREATION 2006-11-29

REVIEDWED BYJohan Hassan

REVIEWED DATE2009-02-18

APPROVED BYNina Leskinen

APPROVED DATE2009-02-18

KTS011-Nodular Cast Iron EN 1563 Insert

1064461 - KTS011-Nodular Cast Iron EN 1563 Insert.docSvensk Kärnbränslehantering ABSwedish Nuclear Fuel and Waste Management CoPO Box 925, S-572 29 OskarshamnVisiting address Gröndalsgatan 15Phone +46-491-76 79 00 Fax +46-491-76 79 30www.skb.se556175-2014 Seat Stockholm

ContentsContents ............................................................................................................................1

1 Purpose.....................................................................................................................2

2 Requirements ...........................................................................................................22.1 Quality plan ...............................................................................................................22.2 Chemical composition ...............................................................................................22.3 Mechanical properties................................................................................................22.4 Microstructure ...........................................................................................................32.5 Macroscopic discontinuities.......................................................................................32.6 Size and shape ...........................................................................................................32.7 Identification marking................................................................................................3

3 Steel section cassette 6 ..............................................................................................3

4 Casting .....................................................................................................................3

5 Machining ................................................................................................................45.1 Cutting of ends and test disk ......................................................................................45.2 Rough machining and cleaning from filler medium, e.g. sand ....................................4

6 Inspection and testing..............................................................................................46.1 Chemical analysis ......................................................................................................46.2 Mechanical testing and microstructure evaluation ......................................................46.3 Size and shape inspection ..........................................................................................56.4 Non-destructive testing ..............................................................................................5

7 Final machining .......................................................................................................6

8 Nonconformities.......................................................................................................6

9 Request for concession.............................................................................................6

10 Transport and storage protection ...........................................................................6

11 Manufacturer’s documentation ..............................................................................611.1 Quality plan ...............................................................................................................611.2 Photographic documentation......................................................................................611.3 Process documentation...............................................................................................6

61

1064461 - KTS011-Nodular Cast Iron EN 1563 Insert


1064461 - KTS011-Nodular Cast Iron EN 1563 Insert.docSvensk Kärnbränslehantering ABSwedish Nuclear Fuel and Waste Management Co

11.4 Certification...............................................................................................................611.5 Submission of documents and information.................................................................711.6 Retention of documentation .......................................................................................7

12 Retention of test samples .........................................................................................7

13 Document control ....................................................................................................7

Revision record................................................................................................................7

Footnotes..........................................................................................................................8Annex A – Test piece positions, BWR...............................................................................9Annex B – Test piece positions, PWR .............................................................................10

1 PurposeCast iron inserts are essential canisters components. This technical specification, KTS011, defines the technical requirements and documentation for nodular cast iron inserts.

2 Requirements2.1 Quality planA quality plan 1 shall be established by the producer and accepted by SKB prior to production of nodular cast iron inserts.

2.2 Chemical compositionThe chemical composition given as information in SS 14 07 17 2 (expired 1997) may be adjusted.

Additional requirementAn additional requirement is that the copper content should not exceed 0,05 %.

Experience is being collected to determine if any change of the specification is required.

2.3 Mechanical propertiesThe material for nodular cast iron inserts shall in principle fulfil the requirements in EN 1563 3

grade EN-GJS-400-15U (Number EN-JS1072, SS 07 17-00) regarding mechanical properties.

Cast–on samplesThe specified mechanical properties for dimension 60< t 200 mm (Rm min 370 N/mm2, Rp0,2 min240 N/mm2, A min 11%) shall apply for cast-on samples (a sample may be used for one or more test pieces).

At least two cast-on samples are to be taken, one from the lower part and one from the upper part of the casting. The sample size shall be representative for the casting. At least one tensile test pieces shall be taken from each sample. Retest, see 6.2.

62




Samples from insertFrom the insert normally 6 test pieces shall be taken according to the Annexes A and B. The following requirements shall be fulfilled:

At least five values of Rp0,2 shall reach min 240N/mm2(reported in units. At least five values of Rm shall reach min 370 N/mm2 (reported in units) If these

requirements for Rpo,2 and Rm are not fulfilled It is allowed to take out one new piece for retest according to marked positions in Annex A and B. The values of this retest shall be used.

The average elongation value among the five highest values (rounded to the nearest 0,5 %) shall exceed 7 %. If one or two elongation values are below 4 % one new piece for retest must be taken out according to marked positions in Annex A or B. This new value shall be used. If a retest due to low Rpo,2 and Rm values is made the elongation value from that test shall be used. If two or more test pieces then fail to exceed 4 % the insert is not accepted.

About retest for other reasons, see §10.1 EN 15633. Pieces for such retests must also be taken out from the marked positions in Annex A and B.

2.4 MicrostructureAt all positions of the casting, the microstructure shall correspond, to a minimum of 80 %, to forms V and Vl in EN ISO 945 4. The magnification used shall be minimum 50x and recorded.

The microstructure shall nowhere be as illustrated by forms I and II.

2.5 Macroscopic discontinuitiesExperience is being collected to determine permissible types, positions and extent of discontinuities such as non-metallic and other types of inclusions, cold flows, gas porosities, shrinkage cavities and shrinkage cracks.

2.6 Size and shapeSize and shape of inserts shall be as stated in drawings according to applicable SKB order. Sufficient machining allowance should be added to the cast insert diameter. See 6.3 for corresponding inspection requirements.

2.7 Identification markingEach cast insert shall be uniquely marked and the identification shall be maintained throughout the manufacture, including the machining stages. At delivery the insert shall be marked in accordance with requirements in the SKB order and applicable procedure 5. The traceability to the casting shall be maintained.

3 Steel section cassette 6

The cassette shall be stored under dry conditions to prevent rusting and the hollow sections shall, if necessary, be shot blasted inside and outside to remove oxide. Any shot blasting shall be done as closely in time as possible prior to casting. The steel section cassette shall be filled with a suitable filler to prevent distortion during casting.

4 CastingThe casting process shall be controlled to ensure an acceptable microstructure. This shall include specifying and recording of melting parameters such as tapping temperature, temperature for Mg

63




addition and inoculation, time elapsed between Mg addition and pouring, pouring temperature and time. This shall be described in an internal work instruction, available at the melt shop.

Samples for chemical analysis shall be taken after Mg treatment in accordance with normal melt shop practice.

5 Machining5.1 Cutting of ends and test diskCutting of insert ends, including any test disk, shall be performed by suitable means, e.g. bandsaw cutting. It is recognised that cooling liquids have to be used, efforts shall be taken, however, tominimise exposure of insert surfaces, in particular the top end of cassette sections to water or any other liquid. Warning: Machining in nodular cast iron together with water will expose phosfine, which is a toxic gas.

5.2 Rough machining and cleaning from filler medium, e.g. sandCleaning the channel surfaces from remainder of the filler medium, e.g. sintered sand particles canbe performed by adding tumbling media in the channels during the rough turning operation. Afterwards the channels shall be properly cleaned from dust etc. Rough machining of the insert circumference, top end and the recess for steel lid shall be done without any cooling liquid.

6 Inspection and testing6.1 Chemical analysisThe analysis shall be performed in accordance with industry practice by an accredited laboratory or by a laboratory meeting ISO 9001 7 requirements with exclusion of clause 7.3 of the standard, if this clause is not applicable. Laboratory reference material shall be traceable to accredited sources and its identity and use for the analysis shall be recorded.

6.2 Mechanical testing and microstructure evaluationSamplingTest pieces for tensile and hardness testing and for microstructure examination shall be taken as specified in 2.3 or in the SKB order. A sketch of the actual sample size and position(s) shall be provided.

Tensile testingTensile testing shall be performed in accordance with EN 10002-1 8 and EN 15633, by an accreditedlaboratory or by a laboratory meeting ISO 9001 requirements with exclusion of clause 7.3, if this clause is not applicable.

Results from each test piece shall be recorded and provided in the certificate, see 11.4. Requirements for mechanical properties and possible retests shall be as specified in 2.3.

In case a test result from a cast-on sample is not accepted, one retest (one test piece) representing the insert may be performed. The result of the retest shall be used.

Hardness testingHardness testing – HB according to EN ISO 6506-1 9, preferably using 10 mm ball –shall beperformed on the test pieces from cast-on samples and the result shall be recorded.

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MicrostructureMicrostructure evaluation shall be performed on the test pieces from cast-on samples and on the two specimens with the highest and lowest elongation values from the insert. The structure shall be documented in micrographs at minimum 50x magnification.

6.3 Size and shape inspectionThe insert shall be measured to check its conformity with the specified size after machining.

Channel shape1. BWRFor BWR fuel canister inserts with cassettes made from square sections (VKR or KKR) 180 x 180 x 10 mm (outer size x thickness) the straightness of the channels shall be sufficient to permit a 152 x 152 mm square profile test-gauge in accordance with applicable SKB drawing to freely move down the entire channel. The length of the test-gauge shall not be shorter than the channel.

In case the 152 x 152 mm test-gauge does not pass down the entire channel, i.e. the result is not acceptable, the following shall be done in order to collect experience:

a) the distance that the test-gauge can be freely moved down is to be measured for various diminishing sizes from 152 x 152 mm,

b) the largest size that will pass the entire channel is to be determined.

2. PWRFor PWR fuel canister inserts with cassette sections 260 x 260 x 12,5 (outer size x thickness) the straightness of the channels shall be sufficient to permit a 224 x 224 mm square profile test-gauge in accordance with applicable SKB drawing to freely move down the entire channel. The length of the test-gauge shall not be shorter than the channel.

Channel length1. BWRThe shortest acceptable channel length from any channel bottom to the cut and machined surface at the insert top end is 4518 mm (before the 50 mm top end recess for the steel lid is machined, as shown in premachined NTD drawing ), if not otherwise prescribed in the applicable SKB drawing. After top end machining, the length of each channel shall be measured from the top end of the insert and recorded. The difference in length among the channels should not exceed 5 mm

2. PWRThe corresponding shortest channel length is 4498 mm, (as shown in premachined NTD drawing ),before machining of the 50 mm steel lid recess, and the maximum permissible variation in channel length is 5 mm. Each channel length shall be recorded.

RecordsThe result of the shape and size measurement shall be documented on a separate form 10.

EccentricityMaximum permissible eccentricity of the machined insert is 5 mm. The eccentricity will be defined as the distance between centre of the cassette and the centre of the casting at the same height, measured as well at the bottom end as at the top end of the insert. The methods of measurement and the results are to be recorded.

6.4 Non-destructive testingThe casting shall be ultrasonically tested according to EN 12680-3 11 from the outside with regardto inner discontinuities such as non-metallic inclusions and other inhomogeneities. Provisionally,

65




the 30 mm rim zone of total surface area shall be tested. The reference defect shall be a 5 mm flat bottom hole. Experience is being collected to determine suitable acceptance criteria.

The structure is to be checked using measurement of ultrasonic damping and speed of sound to collect experience of the possibility to determine the homogeneity.

7 Final machiningFinal machining shall be done in accordance with applicable SKB drawing. The machining shall be done in the dry condition, i.e. without any cooling liquid.

8 NonconformitiesAny deviation, e.g. from specified shape or size or any other significant deviation from requirements shall immediately be reported in accordance with the manufacturer’s quality management system. This party shall consult with SKB for decision about suitable action.

9 Request for concessionAny request for concession 12 shall be documented on SKB form 13 or similar and sent to SKB.

10 Transport and storage protectionTo prevent exposure to snow, water, dust, dirt etc. during any outdoor transport and storage the insert and in particular the channel ends shall be suitably protected, e.g. by plastic wrapping or cover. A special rust preventive liquid are permitted after acceptance by SKB. Long range transports shall be performed on covered trucks, lorries, railway trucks etc. See also a separate procedure 14.

11 Manufacturer’s documentation11.1 Quality planThe quality plan 1 according to 2.1 shall be completed and sent to SKB.

11.2 Photographic documentationThe production sequence shall be photographically documented when required by SKB. The extent is to be agreed with SKB from case to case.

11.3 Process documentationInformation regarding the casting process in accordance with clause 4 shall be documented by the manufacturer.

11.4 CertificationA certificate according to EN 10204 3.1 15 shall be issued by the manufacturer stating as aminimum:• the manufacturer’s name and address,• SKB order number,• SKB drawing number,• insert number,• casting date,• cast or heat number,• chemical composition,

66




• results of tensile testing, hardness testing and micro structure evaluation,• result of size and shape inspection,• result of non-destructive testing,• a declaration that the material has been produced in accordance with the company’s

current quality system and quality plan, both to be accepted by SKB.

11.5 Submission of documents and informationThe documentation according to 6, 9, 11.4 and request for delivery permit 16 shall be sent to SKB for authorisation prior to delivery.

SKB shall be informed when the shipping takes place.

The supplier shall, without delay, give complete information to SKB on all observations and other circumstances in connection with the production which may influence the design and properties of the insert. SKB shall have the right to use this information without any restriction.

11.6 Retention of documentationProject engineer, PE, is responsible for the retention of documentation according to sections 6, 9 and 11 described in a separate procedure 17.

The manufacturer shall retain the documentation according to sections 4, 6, 9 and 11 for (at present) at least 10 years under suitable security. If any records are stored on electronic/magnetic media the readability shall be ensured for this time period.

12 Retention of test samplesSKB shall retain samples for determination of chemical composition, microstructure and tensile properties for (at present) minimum 10 years, under suitable conditions. The identification of samples shall be maintained.

13 Document controlQASK is responsible for document control, including distribution, of this technical specification 18.

Revision recordRevision Date Revision includes Author Reviewed Approved

4.0 2006-03-05 CGA JH NLe7.0 2007-08-21 PE-ansvar för redovisande dokumentation. SKB-

ansvar för arkivering av teststycken.GH Se SKBdoc

8.0 2007-09-27 Tilläggskrav. Cu-innehåll får ej gå över 0,05 %.Se protokoll Teknikmöte 2, 2007. SKBdoc: 1082825

GH Se SKBdoc

9.0 2009-02-18 Chemical composition completed with chart from SS 14 07 17, machining of cassette completed with warning for phosfine, size and shape inspection completed with length of the test-gauge, dimensions of PWR cassette sections are changed, BWR and PWR Shortest channel length are changed, the difference in length among the channels is changed to maximum 5 mm, special rust preventive liquid permitted for transport and storage., 3.1B certificate changed to 3.1, editions of standards are moved from this specification to chapter 15 in the Quality Manual

TEng Se SKBdoc

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FootnotesEditions of standards are specified in chapter 15 in the Quality Manual

1. SKB Procedure KT0704, Requirements on 1) Quality plan, 2) Manufacturing and inspection plan

2. SS 14 07 17, Segjärn – SS-gjutjärn 0717 (Spheroidal graphite iron) 3. EN 1563, Founding – Spheroidal graphite cast iron 4. EN ISO 945, Cast iron – Designation of microstructure 5. SKB Procedure KT0705, Identification of canister components and assembled canisters6. SKB Technical Specification KTS021, Steel section cassette7. ISO 9001, Quality management systems – Requirements 8. EN 10002-1, Metallic materials – Tensile testing 9. EN ISO 6506-1, Metallic materials – Brinell hardness test – Part 1:Test method10. SKB Forms KTS001F-1, KTS001F-2, KTS001F-3 or similar11. EN 12680-3 Founding – Ultrasonic examination Part 3: Spheroidal graphite cast iron

castings 12. SKB Procedure KT1102, Request for concession13. SKB Form KTF11-1, Supplier’s request for concession14. SKB Procedure KT0702, Handling, storage, packing and transport of canister components

and assembled canisters15. EN 10204, Metallic products - Types of inspection documents 16. SKB Form KTF07-07 (Eng) or KTF07-08 (Sv) or similar17. SKB Procedure KT1002, Retention of quality documents and records18. SKB Procedure KT1001, Establishing and control of SKB technical specifications,


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Annex A – Test piece positions, BWRThe sketch shows the positions of the regular series of six test pieces, when tensile testing is to be carried out on a nodular cast iron BWR insert itself (and not on cast-on samples). It also shows retest positions.

6 1

2 5

3 4

Results can be recorded on SKB form KTF07-15.

1

2

3

6

Cutting

5

Cutting

4

Retest positionsRetest positions

69




Annex B – Test piece positions, PWRThe sketch shows the positions of the regular series of six test pieces, when tensile testing is to be carried out on a nodular cast iron PWR insert itself (and not on cast-on samples). It also shows retest positions.

1 4 6

2 5 3

Results can be recorded on SKB form KTF07-16.

1

23

6

Cutting

5

Cutting

4

Retest positionsRetest positions

70

Företagsintern DOKUMENTID 1064464

VERSION 5.0

STATUS Godkänt

REG.NOKTS022

SIDA 1(6)

Instruktion AUTHORTorbjörn Engquist

DATE OF CREATION2006-11-29

REVIEDWED BYJohan Hassan

REVIEWED DATE2009-02-18

APPROVED BYNina Leskinen

APPROVED DATE2009-02-18

KTS022-Hollow Square Sections for Steel Section Cassette

1064464 - KTS022-Hollow Square Sections for Steel Section Cassette.doc

Svensk Kärnbränslehantering ABSwedish Nuclear Fuel and Waste Management CoPO Box 925, S-572 29 OskarshamnVisiting address Gröndalsgatan 15Phone +46-491-76 79 00 Fax +46-491-76 79 30www.skb.se556175-2014 Seat Stockholm

ContentsContents ............................................................................................................................1

1 Purpose.....................................................................................................................1

2 Technical requirements ...........................................................................................22.1 Material specification for VKR (RHS 3) square hollow sections .................................22.2 Material specification for KKR1 square hollow sections.............................................32.3 Material specification for plates and flat bars .............................................................32.4 Macroscopic discontinuities.......................................................................................3

3 Inspection and testing of square hollow sections ....................................................33.1 Size and shape inspection, surface finish....................................................................33.2 Inspection of welds ....................................................................................................43.3 Identification .............................................................................................................43.4 Mechanical properties................................................................................................4

4 Inspection and testing of other steel parts ..............................................................4

5 Nonconformities.......................................................................................................4

6 Manufacturer’s documentation ..............................................................................46.1 Material certificate.....................................................................................................46.2 Submission of documents and information.................................................................46.3 Retention of documentation .......................................................................................5

7 Document control ....................................................................................................5

Revision record................................................................................................................5

Footnotes..........................................................................................................................5

1 PurposeProfiles according to this technical specification are intended for use in steel section cassettes. This technical specification, KTS022, defines technical requirements and documentation routines applicable to profiles and other steel parts for that propose.

71

1064464 - KTS022-Hollow Square Sections for Steel Section Cassette

Företagsintern 5.0 Godkänt 2(6)


Svensk Kärnbränslehantering ABSwedish Nuclear Fuel and Waste Management Co

2 Technical requirementsProfiles for steel section cassettes are either hot or cold formed square hollow sections, designations VKR 1 (see 2.1) and KKR 2 (see 2.2) respectively. Seamless sections as well as weldedsections can be used. In the latter case the weld bead shall be flush against the section inner wall, if necessary machined.

2.1 Material specification for VKR (RHS 3) square hollow sectionsChemical composition and mechanical propertiesThe material for VKR (RHS) square hollow sections shall fulfil the requirements in EN 10210-14 S355J2H or SS 14 21 74-03 or -04 5, concerning chemical composition and mechanical properties (ReL, Rm, A5

5).

Size, shape and tolerancesFor BWR fuel canisters 180 x 180 x 10 mm (outer size [H x B] x thickness [t]) VKR square hollow section size applies, and for PWR fuel canisters the corresponding size is 260 x 260 x 12,5 mm.

Size and shape tolerances, based on EN 10210-2 5: (except end squareness, outer corner radius and internal weld beam height)

H, B: 180 ±1,8 mm for BWR260 ±2,6 mm for PWR

t: -10% + a) mm squareness: 90 ±1 (cross section)flatness deviation: 1,8 mm for BWR

2,6 mm for PWR(across section, concavity/ convexity)

twist: max 2 mm +0,5 mm/m section lengthouter corner radius: 20+/-5mm b) (additional SKB requirement)length: +10 -0 mmstraightness: 0,20% of total lengthMass: ±6% c)

end squareness: 90 ±0,5 (at least one end) (additional SKB requirement)Maximum internal weld beam height:

The weld bead shall be flush against the section inner wall, if necessary machined

(additional SKB requirement)

a) The positive deviation is limited by the tolerance on mass.b) Minimum radius added. (provisional; no lower limit in EN 10210-2)c) -6 +8% for seamless hollow sections.

72





2.2 Material specification for KKR1 square hollow sectionsChemical composition and mechanical propertiesThe material for KKR square hollow sections shall fulfil the requirements in EN 10219-1 6

S355J2H, concerning chemical composition and mechanical properties (ReL, Rm, A56).

Size, shape and tolerancesFor BWR fuel canisters 180 x 180 x 10 mm (outer size [H x B] x thickness [t]) KKR square hollow section size applies, and for PWR fuel canisters the corresponding size is 260 x 260 x 12,5 mm.

Size and shape tolerances, based on EN 10219-2 7: (except end squareness, outer corner radius and internal weld beam height)

H, B: 180 ±1,4 mm for BWR260 ±1,6 mm for PWR

t: 10 ±0,5 mm for BWR12,5 ±0,5 mm for PWR

squareness: 90 ±1 (cross section)flatness deviation: 1,4 mm for BWR

2,0 mm for PWR(across section, concavity/convexity)(across section, concavity/convexity)

twist: max 2 mm +0,5 mm/m section lengthouter corner radius: 20+/-5mmlength: +5 -0 mmstraightness: 0,15% of total lengthend squareness: 90 ±0,5 (at least one end) (additional SKB requirement)Maximum internal weld beam height:

The weld bead shall be flush against the section inner wall, if necessary machined

(additional SKB requirement)

2.3 Material specification for plates and flat barsThe material for steel plates and flat bars shall fulfil the requirements in EN 10025 8 S235JRG2, or similar. The surface shall be free from contaminants such as rust and dirt.

Plate and bar sizes are specified on applicable SKB drawings.

2.4 Macroscopic discontinuitiesNo defects, such as cracks or incomplete welds in welded hollow sections, leading to risk for penetration of nodular cast iron in the subsequent use, are permitted. Repair welds are allowed.

3 Inspection and testing of square hollow sections3.1 Size and shape inspection, surface finishOuter size, thickness, straightness and twist are to be checked for compliance with applicable standard. For square hollow sections (VKR or KKR) 180 x 180 x 10 mm (outer size x thickness) the shape and straightness of the sections shall be sufficient to permit a 156 x 156 mm square profile test-gauge, manufactured according to applicable SKB drawing, to freely move down the entire channel length. The result shall be recorded 9. The surface finish shall be visually inspected.

At least one end of each ca 6 m long hollow section (for example, after sawing from a longer section length) shall fulfil the requirement regarding end squareness to the length axis.

For 260 x 260 x12,5 mm (outer size x thickness) sections the corresponding square profile test-gauge shall be 230 x 230 mm (provisional requirement).

73





3.2 Inspection of weldsWelded hollow sections intended for cassettes shall be visually inspected for welding defects. Requirements, see 2.4. Non destructive testing of the weld seam is described in EN 10219-1.The weld bead shall be flush against the section inner wall, if necessary machined, see 2.2.

3.3 IdentificationThe steel grade identity shall be ensured. However, no individual marking of the steel hollow sections is required by SKB.

3.4 Mechanical propertiesNo specific mechanical testing (i.e. testing specimens from the current sections or from the lot of which the sections are a part) is required. The manufacturer shall, however, be able to show evidence that sections of the size in question, manufactured under similar conditions, will meet the requirements specified in 2.1 and the applicable standard 10.

4 Inspection and testing of other steel partsThe steel grade identity of other steel parts intended for cassettes shall be ensured in accordance with industry practice. No additional SKB inspection and testing requirements presently apply.

5 NonconformitiesAny deviation from specified shape or size or any other significant deviation from requirements shall immediately be reported to the party having issued the purchase order for steel hollow sections. This party shall consult with SKB for decision about suitable action.

6 Manufacturer’s documentation 6.1 Material certificateThe manufacturer of the sections shall issue a certificate according to EN 10204 2.2 or 3.1 11, stating as a minimum:• the manufacturer’s name and address,• date of issue,• reference to applicable material/product standard,• steel grade and execution,• result of size and shape inspection,• for EN 10204 2.2 certificate in addition:

- typical chemical composition; or• for EN 10204 3.1 certificate in addition:

- original heat or cast number,- actual chemical composition,- mechanical properties.

6.2 Submission of documents and informationThe material certificate according to 6.1 shall be sent to the cassette manufacturer for check of compliance with standard and purchase order.

The cassette manufacturer shall, without delay, give complete information to the applicable foundry or directly to SKB on all observations and other circumstances in connection with the production, which may influence the design or properties of the canister components. SKB shall have the right to use this information without any restriction.

74





6.3 Retention of documentationThe cassette manufacturer shall retain the documentation according to section 6.1 for (at present) at least 10 years under suitable security. If any records are stored on electronic/magnetic media the readability shall be ensured for this time period.

Projekt Engineer, PE, is responsible for the retention of documentation according to section 6.1, described in a separate procedure 12.

7 Document controlQASK is responsible for document control, including distribution, of this technical specification 13.

Revision recordRevision Date Revision includes Author Reviewed Approved

3.0 2005-06-01 outer corner radius specified MWn JH/Evert Lidén

NLe

4.0 2007-08-20 PE-responsibility for retention of recording documents

GH See SKBdoc

5.0 2009-02-18 Square hollow sections (VKR or KKR) for PWR fuel canisters the corresponding size is changed to 260 x 260 x 12,5 mm, corresponding square profile test-gauge for PWR fuel canisters shall be 230 x 230 mm, Size and shape tolerances are changed, certificate according to EN 10204 are changed from 3.1B to 3.1Editions of standards are specified in chapter 15 in the Quality Manual and are removed from this specification

TEng See SKBdoc

FootnotesEditions of standards are specified in chapter 15 in the Quality Manual

1. Hot finished square structural hollow sections (Varmbearbetade konstruktionsrör)2. Cold formed welded structural hollow sections (Kallformade svetsade konstruktionsrör)3. Rectangular hollow sections 4. EN 10210-1, Hot finished structural hollow sections of non-alloy and fine grain structural

steels – Part 1: Technical delivery conditions5. EN 10210-2, Hot finished structural hollow sections of non-alloy and fine grain structural

steels – Part 2: Tolerances, dimensions and sectional properties6. EN 10219-1, Cold formed welded structural hollow sections of non-alloy and fine grain

steels – Part 1: Technical delivery requirements7. EN 10219-2, Cold formed welded structural hollow sections of non-alloy and fine grain

steels – Part 2: Tolerances, dimensions and sectional properties 8. EN 10025, Hot rolled products of non-alloy structural steels – Technical delivery

conditions9. SKB KTS001F-1

75





10. Requirements on specific testing, including sampling, may be added in a later revision of this document.

11. EN 10204, Metallic materials – Types of inspection documents12. SKB Procedure KT1002, Retention of quality documents and records13. SKB Procedure KT1001, Establishing and control of SKB procedures and technical

specifications

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LIST OF REPORTS

POSIVA-REPORTS 2009

_______________________________________________________________________________________

POSIVA 2009-01 Olkiluoto Site Description 2008 Posiva Oy

ISBN 978-951-652-169-8 POSIVA 2009-02 Olkiluoto Biosphere Description 2009 Reija Haapanen, Haapanen Forest Consulting Lasse Aro, Finnish Forest Research Institute, Parkano Research Unit Jani Helin. Posiva Oy Thomas Hjerpe, Saanio & Riekkola Oy Ari T. K. Ikonen, Posiva Oy Teija Kirkkala, Pyhäjärvi Institute Sari Koivunen, Lounais-Suomen vesi- ja ympäristötutkimus Oy Anne-Maj Lahdenperä, Pöyry Environment Oy Liisa Puhakka, Haapanen Forest Consulting Marketta Rinne, Agrifood Research Finland Tapio Salo, Agrifood Research Finland ISBN 978-951-652-170-4 POSIVA 2009-03 Manufacture of Disposal Canisters Leena Nolvi, Posiva Oy ISBN 978-951-652-171-1

manufacture of disposal canisters - etusivu - posiva · 2010-01-05 · the manufacturing process...

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