eas sales brochure

8/12/2019 EAS Sales Brochure

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Registered in EnglandCompany Registration Number 2266443

.. structural integrity specialists

Engineering Analysis Services Limited is an advanced engineering consultancy specialisingin providing cost-effective solutions to structural integrity problems. Our services include thedesign, analysis and assessment of engineering components, systems and structures.

The company has a proven track record of providing consultancy services to a number ofsatisfied clients in the nuclear, defence, power generation, oil and gas industries.


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Engineering AnalysisServices Limited

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8-10 Ashley RoadAltrincham

CheshireWA14 2DW

Telephone 0161 923 0070Facsimile 0161 923 0077

Date: 24 May 2005

Stress Analysis & Assessment Capabilities

Engineering Analysis Services Limited is an engineering consultancy specialising instress analysis and structural integrity assessment.

Please find enclosed literature describing our analysis and assessment capabilities.It includes sections describing our collective experience, company history and staff.

EASL has quality assurance standards and procedures developed the company wasformed in 1988. The company is currently working towards ISO9001 approval.

Supplementary information describing our Health and Safety Policy, EnvironmentalPolicy and Computer System are available.

EASL maintains insurance cover in respect of professional indemnity, employer'sliability and public liability for 1M, 10M & 2M respectively.

All of the information provided herein is commercially-sensitive and should not becopied or transmitted to any third party without the written consent of EASL.

Yours faithfullyfor and on behalf ofEngineering Analysis Services Limited,

Antony HurstManaging Director .


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Contact Details

Address:

Engineering Analysis Services Limited (EASL)8-10 Ashley Road,Altrincham,Cheshire,WA14 2DW.

Phone Numbers:

General 0161 923 0070

Antony Hurst 0161 923 0072

Fax 0161 923 0077

E-mail:

Antony Hurst [email protected]


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Capability Statement

EASL has capabilities and extensive experience in the following technical areas:

Structural Analysis Static analysis of vessels, plant, piping, components, buildings and structures

made from steel, zirconium alloys, nickel alloys, graphite and concrete. Dynamic and seismic analysis of steel and/or concrete structures together

with soil-structure interaction. Geometric non-linear analysis comprising large deflection, non-linear joints,

contact problems with and without friction and collapse/buckling analyses. Material non-linear analysis including post yield characteristics, elevated

temperature creep and irradiation-induced creep. Steady state and transient thermal analyses including the effects of

convection, conduction and radiation to assess temperature distributions.

Structural Integrity Assessment Assessments using British, American and European design codes with

particular expertise in ASME III, PD5500, ASME B31.3, BS806, BS5400. Assessment of defective components using BS7910, British Energy specialist

codes R5 and R6. Life extension, re-validation and fitness for purpose assessments.

Safety Case Production Providing structural analysis support and key references to safety cases. Particular expertise in respect of beyond design basis faults, events and

accidents studies.

Methods Development Assisting British Gas/Transco/Advantica to develop methods, based on their

in-house codes, to be used in the maintenance, assessment, life extensionand uprating of plant and piping.

Peer Review Independent peer review or technical assessment of design and analysis

work by others. Assessing documents produced by NNC in support of the 2005 and Astute

class safety cases for the Faslane shiplift. High-level support and advice to British Gas and their principal sub-contractors for the design of a 110km long sub-sea pipeline running across anumber of faults in respect of its seismic response and behaviour.


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Company History

Engineering Analysis Services Limited (EASL) has been operating successfullysince 1988. The company is an engineering consultancy specialising in design,analysis and integrity assessment of engineering components, systems andstructures.

The company has a proven track record of providing consultancy services to anumber of satisfied clients in the nuclear, power generation, oil and gas industries,with an approach focussed on solving our clients problems.

Our clients include: British Energy NNC British Nuclear Fuels

Central Electricity Generating Board, Wythenshawe (via W S Atkins) National Power Rolls Royce and Associates EON Powertech Framatome Mowlem Engineering OSC Process Engineering British Gas Transco J Murphy & Sons Advantica Technologies

The company has generated a sound financial base, with substantial cash assetsand no external financing from banks or other corporate bodies. The annual feeearnings (turnover) for the last financial year was been in excess of 500,000.

The company has developed methods and standards designed to ensure clientsatisfaction and endeavours to maintain close working relationships with clients toguarantee repeat business. The company traditionally operated with minimumpermanent staffing levels, bringing in other specialist expertise as and when requiredvia a wide network of resources.

In 2001 the company won a substantial order to provide partnering services to

British Energy. In response to the increased demand, a director, three seniorengineers, one engineer and a clerical/technical assistant were appointed. Thecompany moved to office premises in the centre of Altrincham providing suitableaccommodation and infrastructure. These offices are more than adequate tocomfortably accommodate the current staff, equipment and records and aresufficient to allow room for future expansion.

Further information, copies of the certificate of incorporation, VAT registrationcertificate, bank account details and Memorandum and Articles of Association of thecompany are available on request.


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Staff

The management structure of EASL is presented graphically in an organisationchart. Overall responsibility for the company lies with the Managing Director, AntonyHurst, who is the main point of contact on all technical, contractual and financialmatters.

All staff members have a proven record of competence and reliability. If required,we will use our extensive network of contacts to bring in other appropriate expertisewhere necessary. A clerical/technical assistant provides support to the operation ofthe company.


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SQEP Register

British Energy (BE) Structural Analysis Group maintains a register of suitablyqualified and experienced personnel (SQEP) in a form approved and agreed with theNuclear Regulator. It details the accredited skill areas relevant to the activities of theStructural Analysis. The following is an extract from that register Group in respect ofstaff provided by EASL to BE under a partnering arrangement. Additional entries inrespect of EASLs other staff are based on our interpretation of the SQEP register.

Engineer 0 1 2 3 4 5 6 7 8 9 10 11 12 15

BE-EASL Partner Team

A M Hurst A A A A A A A A

D A Faulke A A A A A A

P A Shard A A A A A A A A

A D Oldershaw A A A A A A

G J Rigg A A A A A A A

E G Sinclair A A A A A A A

Other EASL Staff

D Baguley A A A A A A A A

S Robinson A A A A A A A A

K Wright A A A A

A Adeyefa A A A A A A A A

Skill Areas:

-1 Numeracy; spreadsheets, databases & data manipulation, figure preparation etc.

0 Classical strength of materials, statics/mechanics, limit load analysis, fatigue etc.1 Design code assessments2 Stress FEA (simple)3 Stress/fracture FEA (complex)4 Pipework analysis & assessment5 Low temperature fracture assessment, R66 High temperature fracture assessment, R5 volumes 4 & 77 Creep-fatigue initiation assessment, R5 volumes 2, 3 & 68 Impacts and pipewhip, R39 Seismic design & walk-down10 Seismic analysis11 Dynamic analysis12 Stress analysis of graphite


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Company Structure


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Thermally Induced Tube Bore Cracking

In recent years widespread cracking of steam tube bores has been found at fossil-fuelledpower stations. To date the cracking has been found in CrMoV pipework with

2Cr1Mo welds and is generally associated with thicker pipework operating in the creepregime.

These cracks are usually occur in butt or branch welds or inthe stress concentrating feature associated with the end ofthe counter-bore close to pipe butt welds. They are usuallyfully circumferential, radial and very straight and are oftendeep. Where cracking is found it is often extensive.

It has been shown that this cracking can be explained byfatigue or creep mechanisms or by a combination of bothcombined with thermal ageing of the parent material. Theprincipal source of the stresses leading to creep or fatigue

crack initiation is thermal shock arising from rapid changesof steam temperature and/or conditions which may takeplace during routine operation of the plant or during warmthrough operations taking place after extended shutdowns.

Predictions of the potential for tube bore cracking have been carried out by EASL for anumber of UK power stations. These investigations include:

gathering data on the operation of the power stationsin question including steam temperature andconditions during plant transients;

transient thermal analysis and stress analysis ofboth plain pipe and branch geometries andestablishing bounding load cycles;

assessment of the bounding loading cycles for creepfatigue crack initiation using a range of material dataassumptions.

Materials data scatter and uncertainties concerning theeffects of ageing make the prediction of the onset oftube bore cracking imprecise. However, assessment isuseful in giving an overall view of the threat presentedby thermally induced tube bore cracking to identify:

the plant areas most at risk

the plant events which are most likely to give rise to tube bore cracking.

Furthermore EASL is working on the concept that the uncertainties involved in predictingthermal tube bore cracking can be reduced by compiling a database of assessments ofobserved tube bore cracking.


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Seismic Design and Assessment of a Sub-Sea Gas Pipeline

A consortium of oil companies,including British Gas Trinidad &

Tobago Limited, have constructed a107 km long, 24" diameter steel gaspipeline, between the Hibiscusplatform in the North Coast MarineArea and the Atlantic LNG plant inTrinidad. Studies of the regionaltectonic, geology and seismicityindicate that Trinidad and Tobago isa region of high seismic potential.

EASL assisted Advantica Technologies to provide expert design and assessment advice tothe piping contractors to assure the integrity of the pipeline for seismic loading and itsconsequences. A seismic hazard study was carried out for the proposed pipeline route and

the 500-year return earthquake chosen as the design event. Various seismic studies werecarried out to determine the potential for seismically-induced soil liquefaction, slopeinstability and reduction in fatigue life of the pipeline from span vibration or fault movement.

Two approaches were adopted to reduce the risk to pipeline integrity posed by seismiceffects. Conventional design checks were made to ensure that the pipeline meets therequirements of modern codes; and the potential impact of other failure modes, e.g. slopefailure, was reduced by the judicious route selection.

EASL provided an independent peerreview of all seismic aspects of thedesign calculations and in additioncarried out a detailed assessment ofslope instability and a soil columnanalysis.

It was recognised that despite the designmeasures, there remained a small riskthat a severe seismic event couldsignificantly reduce the structuralreliability of the pipeline during theeconomic life of the structure. EASLassisted in the preparation of the Seismic

Risk Management System for the pipeline. This system enables the operator to evaluatewhat, if any, actions need to be taken after any significant seismic event to minimise risk tothe structural integrity of the pipeline.

Various initiating events, arising from an earthquake, each with the potential to fail thepipeline, have been considered. For each initiating event, the limiting seismic strength, ortrigger level, has been calculated for each of associated potential failure mode. This equatesto a level above which post-event investigation is prudent because of the high likelihood ofpipe distress. The following initiating events were examined: fault movement where an unburied length of pipe crosses the fault liquefaction slope failure reduction in fatigue life of the pipeline due to span vibration fault movement where a buried length of pipe crosses the fault.


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Structural Integrity Assessment of a Fabricated Pipe Tee

The steam pipework at British Energy's power stations is routinely inspected during outagesto check for any indications of degradation. If any indications are found then a structural

integrity assessment of the component in question is required in order to investigate itscontinued fitness-for-purpose. EASL provides support to British Energy's Structural IntegrityBranch in carrying out such assessments.

This example describes the assessment of an equaltee forming part of a hot reheat system.The tee is subject to a complex loading regime. Inaddition to internal steam pressure, the pipeworksystem imposes moments on the branches of thetee. Thermal stresses are also present, along withweld residual stresses. The high temperatures atwhich the pipework system operates also means thecomponent operates within the creep regime.

Detailed stress data within the tee were determinedfrom a series of 3D finite element studies, employingboth solid modelling and shell modelling. Theimages show pressure stresses and system loadingstresses within the tee.

The detailed stress data were used to carry outfracture assessments and creep assessmentsusing British Energy's in-house assessmentprocedures, known as R6 and R5 respectively.

From the structural integrity assessments carriedout it was possible to demonstrate continuedfitness-for-purpose of the tee, thereby making acase for a return to service, avoiding the high costsof replacing the component.


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Consequences of Postulated Pipe Hanger Failure

EASL evaluated the effects of a postulated failure in an individual pipe hanger on the creeplives of welds and other components in a complex high-temperature piping system. The

results of this assessment enabled the client to target inter-outage inspections on thosehangers whose failure was shown to cause potentially unacceptable increases in predictedcreep damage.

In the unlikely event of such a failure, increased forces and moments may adversely affectpipework and there is a requirement to show that the consequences are acceptable if failureshould occur and remain undetected between reactor outages.

The key stages in the assessment were:

Flexibility analysis of the system in normal operation with all hangers intact. The selection of hangers whose failure was assessed to lead to the most adverse

consequences for adjacent regions.


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Creep-Fatigue Assessment of Boiler Casing

This work involved the analysis of a boiler casing at a UK power station. The work enabledthe client to identify areas at risk from potential creep-fatigue damage initiation and to

examine the consequences of initiation in those areas.

At the station there are 4 boilers, each of which consists of two physically separate half unitslocated side by side. Hot gas at 625C passes into the top of the boilers and transfers heatto the various tube banks as it is drawn down the boiler by the gas circulators.

The boiler casing surroundsthe boiler tubes in each halfunit and contains the hot gasflow within the casing. Verticalstiffeners protrude externallyfrom the casing at 90. Aroundthe outside of the boiler casing,baffles are fitted to prevent thepenetration of hot gas into theboiler annulus interspaces.

A small amount of cooler gasflows in these boiler annulusinterspaces and passes up theoutside of the casinggenerating temperaturegradients in the stiffenerswhich extend from the hotboiler casing into the cool gasflow. This temperature gradientis the major source of loadingin the casing. The boiler casingis held in place by variousbrackets.

It is important to the client that areas of potential damage in the boilers are identified beforeproblems occur. The effects of potential defects in these regions can then be examined. Toenable these regions to be identified an assessment of the boiler casing and brackets wasperformed by EASL. A three dimensional finite element (FE) model of the casing and anumber of smaller sub-models of the brackets were constructed in the FEMAP pre-processor using a mixture of plane stress, solid, beam and spring elements.

The stress and loads in the casing and brackets were then analysed using the FE programABAQUS and examined using the FEMAP post-processor. Using these stresses and thetemperature variation up the boiler casing, the creep-fatigue damage around the casing wascalculated using a specialist assessment procedure. This uses a damage fraction to indicatethe level of creep fatigue in a structure and determine the potential for initiation.

The regions of the casing and the brackets most susceptible to damage were identified fromthe results of this assessment. This enabled the client to examine the consequences offailure in these regions, consequently the client was able to ensure boiler integrity andensure continued operation of the plant.


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AGR Nuclear Power Station: Superheater header analysis following reprofiling

Superheater headers at one of the country's AGR stations are undergoing a plannedreplacement programme. A study was undertaken to test the feasibility of modifying the

header geometry as an interim measure before replacement.

To demonstrate structural integrity the modifiedheader was assessed to the ASME III design code.Thermal stresses during normal cyclic operatingsequences, such as reactor start-up and shutdown,were analysed using a quasi-static procedure in theABAQUS finite element program.

The stress analysis used a half-symmetry solidmodel comprising the header and nozzle as shownto the left. It is common that analyses of this sortdispense with explicitly modelling of the nozzle

thereby allowing axisymmetry for simplicity. Thequality of our pre-processing tools and experienceactually allowed the nozzle/header intersection tobe modelled fairly easily. The model geometry wascreated within a few hours.

The header itself is subjected to internalpressure loading and thermal loading. Thenozzle is mechanically loaded by theattached piping. This was simulated byloading a reference point at the centre ofthe cut face of the nozzle and definingappropriate constraints at the slave nodeson the cut edges. Examples of the stresscontours superimposed on the displacedshape of the structure under pressure andsystem loading are shown to the right.

At locations where the stresses wereobserved to peak, through thickness datawere collected and exported from the post-processor for use in the code assessmentprocedure. Care was taken to ensure thatthe transient effects were capturedsufficiently to determine the most onerousthrough thickness variations of stressduring the transients.

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