INNOVATIONS IN EQUIPMENT

ERECTION OF PROTOTYPE FAST

BREEDER REACTOR (PFBR)

S.Sreekanth, Prabhat Kumar

Bharatiya Nabhikiya Vidyut Nigam Limited (BHAVINI),

Department of Atomic Energy, INDIA

Email: skanth@bhavini.co.in

INTRODUCTION ON PFBR

• Type : Fast Breeder Reactor

• Fuel : PuO2 + UO2

• Reactor thermal Power: 1250 MWth

• Electrical output : 500 MWe

• Coolant : Sodium

• Gross thermal Efficiency: 40%

Sectional View of PFBR Reactor

Assembly

PFBR Plant Layout

SAS NICB PI

Reactor Vault (RV)

• The reactor assembly is housed in a concrete

vault lined with carbon steel called reactor vault.

• Tertiary containment for radioactive primary

sodium in Main Vessel in the highly unlikely

eventuality of leak in the both Main Vessel and

Safety Vessel.

• Reactor vault consists of Bottom Shield, Lower

lateral and Upper Lateral

Reactor Vault (RV)

RV

• PFBR Equipment erection was a challenging task where

thin walled vessels had transported and handled with utmost

precautions to avoid redial forces on the vessels, which

could buckle the vessels.

• There was a real challenge in lifting the vessels without

swing, placement of large size and heavy vessel at a

distance of 57 meters where the crane operator has no line

of sight to equipment's being erected.

• Lot of care had been taken during lifting, handling and

erection of thin walled ODC with innovative methods used

for lifting fixtures, guiding arrangements, alignment fixtures

and achieved the stringent erection tolerances.

EQUIPMENT ERECTION OF PFBR

Details of Safety Vessel(SV)

• SV dimensions (OD) - Ø 13540 mm x

12800mm (height)

• SV with thermal insulation(OD) - Ø 13840 mm

• SV shell thickness - 15 mm to 20 mm

• Material of Construction - SS 304LN

• Weight - 155 MT

• SV support flange (OD) - Ø 14960 mm

• RV opening (ID) - Ø 14200 mm approx.

• On outer surface of SV, metallic insulation (0.1 mm thick sheet) of 150 mm thickness is provided.

• Handling of SV during the erection was a very challenging task , because SS insulation was a fragile sheet and impossible to repair any defects occur on the same.

SV

Requirement of Load test before SV erection

• To handle such a huge ODC, there was a

requirement of conducting a load test to qualify

the lifting gear for handling of SV and validate

the SV erection procedure.

• Load test for base frame, rails and trolleys.

- Fabrication of test base frame of 16 m x 16 m

Load Testing of base frame, rails, trolleys

Test Base frame

Innovations in safety vessel erection

• PFBR project is being constructed very proximity to sea

shore and to handle such huge vessel (SV), the following

mock up tests were conducted to validate the SV

erection procedure.

• Mock up test for estimating wind load acting on SV

during shifting towards RV.

• Mock up test for smooth passage of SV inside RV

Mock up test for estimating wind load acting on SV

SV cruciform structure

Mock up test for smooth passage of SV into RV

SV diametrical mock-up structure

Schematic view for shifting of SV to RCB

SV lifting gear connection for lifting

SV

Lifting Spider

Safety Vessel is being lifted

SV

Safety Vessel is being lowered into Reactor Vault

SV

Safety Vessel Alignment & Welding Completed

SV

Challenges faced during SV erection

• Lifting & handling of such a huge cylindrical shell and

maintaining the same horizontally at top.

• Safely lowered into RV without any damage on SV

thermal insulation and achieved erection tolerances as

per design requirements

Details of Main Vessel (MV)

• MV dimensions (OD) - Ø 12900 mm x

12940mm (height)

• MV shell thickness - 25 mm to 30 mm

• Material of Construction - SS 316LN

• MV Weight with CC, CSS, MVCP - 202 MT

• The primary sodium circuit is housed in a single

vessel called main vessel and it is very important

reactor component which supports the Core

Catcher, Core Support Structure, Thermal baffle ,

Grid Plate, Inner Vessel and active Core.

MV

Integration of CC, CSS with Main Vessel

15/09/2008

CC

CSS

Load testing of MV handling gear

Connecting Rods

Ring Spider

Main Vessel Shifting

MV

Main Vessel lifting gear connection

MV

MV Lifting gear

Main Vessel is being lifted out from the supporting frame

structure MV

Main Vessel is being shifted towards RCB to lower into Safety vessel

MV

Crane

Main Vessel is being lowered into Safety vessel through Slab opening

MV

Ring Spider

MV Ring spider arms were seated on stools

Main Vessel is being lowered and aligned through guiding mechanisms

Radial Guiding System

Angular Guiding System

Ring spider Arm

MV

Grid plate Erection inside Main Vessel

Innovations in erecting Main Vessel

• 4 nos. of connecting rods were designed for MV load and

fabricated to achieve an uniform length, to avoid tilting of MV

during handling/erection.

• MV was lifted from below the centre of gravity point (CG) (i.e.

lifting points of MV are below CG point). To avoid toppling of

MV, 4 nos. of connecting rods were used for MV handling.

• The connection between lifting spider and component is a rigid

connection through the connecting rods. Since connecting rods

can take tensile and compressive loads.

• 4 nos. of lifting lugs have been welded on CSS such way that, it is

radially towards the centre of vessel to avoid dangling of MV

during handling of the same.

• Precise alignment of MV horizontality achieved by ring spider

arms and connecting rods.

Challenges faced during MV erection

• Lifting of main vessel was from below the CG point.

• Lifting of main vessel without swing and dangling.

• Lifting & handling of such a huge cylindrical shell and

maintaining the same horizontally at top.

• MV lowered safely into SV without any mechanical hindrance

within the small radial clearance between MV and RV.

• Precise alignment of MV with its internals to achieve

concentricity, axis orientation and horizontality.

Alignment requirements Target Achieved

GP Horizontality in MV mm) ±0.5 ± 0.45

GP vertical axis shift w.r.t. LRP support

flange (mm) Concentricity)

Within 3 1.32

Height between GP and LRP support

flange (mm)

11559 ± 1.5 mm 11557.5 to 11558

LRP flange horizontality (mm) ±1.0 ± 0.5

Details of Steam Generator (SG)

• Steam generator (SG) is a vertical, shell and tube type heat

exchanger and PFBR consists of 8 nos. of SGs.

• SG Material - 9Cr-1 Mo

• SG Overall dimensions - 26 m length xØ1500mm

• Weight of SG - 35MT

• Total nos. of tubes - 547

• Dimensions of each tube-17.2 mm x 2.3 mm wall thickness

• The main function of SG is to transfer the heat from

secondary sodium system to feed water there by generating

superheated steam.

INNOVATIONS IN SG ERECTION

• 26 meters length, 45 MT weight dummy Steam

generator structure was made exclusively for

conducting load test for transportation cum

vertical making structure.

• Mock up test was conducted with simulating the

actual SG handling conditions and validated SG

erection procedure.

Mock up test for SG

Dummy SG Structure

Vertical making of Dummy SG

Dummy SG fixing with SG support structure

SG vertical support structure

Transportation structure with dummy SG

Horizontal and vertical lifting of SG

SG handling gear

Steam generator

SG is being lifted and lowered

SG

SG is being aligned

SG

SG

SG support flange

Challenges faced during SG erection

• Making of Steam generator horizontal to vertical

position without dangling.

• Lifting of Steam generator alone in horizontal

condition due to non-uniform mass

Thank You