BE finds another damaged wire at an AGR

As investigations continue into thecondition of wire windings in the boiler closure units (BCUs) of someof British Energy's (BE's) Advanced Gas Reactors (AGRs), the companyannounced that a damaged wire had been found at Heysham 1 Reactor 2. Ina statement, BE said, "Inspections of Heysham 1 Reactor 2 have so farnot shown any evidence of broken wires in the BCU. However, there isevidence from the radiographic inspections that are in progress thatone wire is showing signs of thinning." The company reported on 22October that "an issue relating to a wire winding" was discovered atits Hartlepool Reactor 1 during a planned inspection of boiler closureunits. BE subsequently shut down its Hartlepool 2 and both Heysham 1reactors, which share the same design of BCU. The company previouslyannounced that initial results of inspections at Heysham 1 Reactor 1had identified a similar issue with the wire windings, saying that "onewire has failed as a result of corrosion." An inspection of Hartlepool2 will start soon. BE said that the discovery of a thinning wire atHeysham 1 Reactor 2 "will likely place the reactor in the same categoryas Hartlepool Reactor 1 and Heysham 1 Reactor 1 for a return to servicesafety case and/or remedial repairs." In an AGR, eight boilers arewithin the concrete pressure vessel that safely contains the reactorcore and potentially dangerous materials. The steel and concrete boilerclosure units form part of the reactor pressure boundary and arepre-stressed with nine layers of wire windings. It is the condition ofthis wire that BE is investigating.