Babcock has successfully completed a programme, ahead of schedule, to overhaul the reactor gas circulators as part of a major outage at EDF Energy’s Dungeness B power station, which was brought back on line in early June.
In undertaking this programme, which is planned every three years at each of the reactors at Dungeness B, Babcock worked closely with EDF Energy personnel and alongside contractors such as Doosan who undertook similar programmes to overhaul the boilers, all helping to bring the station back online on time, keeping within the target planned by EDF Energy.
Over 100 Babcock personnel were on site to undertake the project, which involved the maintenance of rotating plant including gearboxes, clutch assemblies, motors and cartridge units on the gas circulators, for which Babcock is the original equipment manufacturer. Having produced method statements for the work involved, the Babcock site team fully stripped two of the circulators down to their component parts (using dedicated lifting equipment), and inspected the equipment for wear. The main motors and pony motors driving the circulators were removed and sent off-site for specialist maintenance. Additionally all affected gaskets and sealing arrangements were replaced in a leak mitigation project to minimise oil leaks. Two other gas circulators were visually inspected and tested to confirm that they were working satisfactorily.
A further partial stripdown of another gas circulator involving a full penetration tube strip down to replace the running seal was also undertaken before the start of the main outage by a Babcock team mobilised in advance. This allowed the other reactor to be brought up to full power at the end of March 2012.
Babcock is also the fuel route contractor for Dungeness B power station, based on the company’s extensive knowledge of fuel route design. In this role, Babcock maintains a full time team of some 40 people year round on site, working alongside EDF Energy personnel to optimise the fuel handling within the station to maximise power generation, by maintaining and modifying key items of equipment, such as the Fuel Handling Machine.
Babcock applied its experience in managing outage projects to optimise safe delivery of this project, including the procurement of new equipment such as a cantilever lifting beam and the development of a trolley to remove the shield block, rather than bringing a mobile crane to site. This saved several days on the critical path of the outage, as well as reducing direct costs.
“The close working relationship between Babcock and EDF Energy has been key to successfully completing all planned works on this outage to quality and ahead of schedule,” Babcock business manager Sue Shaw commented.
Babcock applies its expertise and experience to create efficiencies which can shorten outage duration without compromising safety. With a strong safety record, Babcock has been providing a successful nuclear outage management service for 40 years, and provides full turnkey capability, from requirements capture and design support through to site operations. The company has the in-house capability to supply all the specialist equipment, and the full capability to design and manufacture.
Babcock provides year-round outage support for EDF Energy, and works alongside other contract partners such as Alstom, Weirs, Doosan Power, Cape and Balfour Beatty to enable EDF Energy to minimise outage durations while ensuring safe and efficient work to the highest quality.