GHA Livigunn’s PE design capabilities help revolutionise Reactor Sea Water (RSW) pipeline management

 Specialist process, mechanical & electrical engineering design consultancy, GHA Livigunn, of Frodsham, UK – working in association with main contractors, Boultings Nuclear – has developed a metal-free Polyethylene (PE) Reactor Sea Water (RSW) cooling piping solution that is all set to offer wide ranging safety, cost, reliability and longevity benefits across the nuclear generating industry. Already in place at British Energy’s Heysham 2 Nuclear Power Station, the PE solution is attracting considerable interest from other nuclear power sites across the British Isles.

 The solution developed by GHA Livigunn. came about after Heysham 2’s System Health Engineer, Mike Craddock, embarked on an investigation into establishing a more effective means of RSW cooling water transportation than traditional vylastic coated carbon steel; a material requiring frequent replacement because of corrosion, lining failure and bore reduction through infestation by molluscs and other sea life.

Contracts awarded

Following a small-scale test, and after attending a symposium hosted by the Sizewell team, Mike Craddock, along with Dave McKenzie of British Energy Barnwood Engineering Division, had collected sufficient data to begin the task of RSW pipeline replacement.

A contract for the design, manufacture and installation of replacement pipework in the Cooling Water (CW) Pump House and Reactor Basement of Heysham 2’s Reactor 7 RSW cooled turbine system was then awarded to Boultings Nuclear with GHA Livigunn - a company with specific expertise regarding the mechanical and electrical design aspects of numerous projects across the nuclear, pharmaceuticals, fine chemicals and utility sectors - being subcontracted to take full responsibility for all aspects of design of the PE pipeline, with Plasflow Ltd. being selected as the pipework fabricator.

 Tight shutdown window

As an additional complication to an already complex task, British Energy also stipulated that if the replacement PE material was to be used, the project would have to be successfully designed within five weeks in order to allow installation to take place during a 25-day outage window already scheduled for autumn 2005. Working to a comprehensive design brief, GHA Livigunn was also tasked with ensuring that all wetted parts used should only be manufactured from polyethylene, with neoprene to be used as an effective gasket material.

 Detailed survey

Embarking on a thorough survey of the RSW system, a task involving a study of the existing carbon steel pipework within the CW Pump House and Reactor Basement, as well as existing pipe tie-ins and constraints,  GHA Livigunn began a programme of research to investigate the various PE materials and fittings available complete with the associated manufacturing constraints.

 Pipeline mimicking

Taking into account various geometrical considerations, the thermal characteristics of PE and all necessary seismic likelihoods, GHA Livigunn then commenced the 3-D modelling stage; a process requiring mimicking the existing pipework, analysing the mechanical properties of the PE material to be used and compensating for the difference in characteristics between the existing metal piping and the proposed PE.

 

 

Meeting all design criteria

Working closely with British Energy’s engineers throughout the project, GHA Livigunn. were able to fulfil all necessary design and material requirements, limit mollusc infestation and enable British Energy to enjoy significantly extended RSW pipeline life, with a product offering a design expectation of 50 years.

 

‘World first’ design

“We were delighted to be invited to design this highly significant polyethylene installation at Heysham 2 - especially as the project has provided the necessary technology for other nuclear sites to consider the benefits of upgrading their pipework systems,” commented GHA Livigunn  Director, Craig Stockton.  “The installed system has proved itself to be wholly reliable and robust. It is a ‘seismically design safety rated’ installation – one which British Energy believes is the first of its kind in the world. Polyethylene offers strength, flexibility and erosion resistance. It won’t corrode and, as even the sea life which previously attached itself to the old pipeline doesn’t like it, there’s also the added advantage of consistently better sea water flow.”

 

Ends…

 

For more information, please contact:

 

Craig W Stockton

C/o  GHA Livigunn.

Tel: 01928 734777

Fax: 01928 734888

Email: craig.stockton@livigunn.com

 

 

Photo Captions :

Pic 1:  the fouling experienced by existing coated carbon steel pipework having a detrimental effect on the system's performance.

 

Pic 2:  the first of its kind at Heysham, the new RSW7AB cooling water pumps polyethylene pipework system.