Meltdown narrowly avoided at nuclear plant

News has gradually been leaking out that a nuclear plant near Toledo, Ohio in the US narrowly avoided a serious accident in February when workers repairing a cracked control-rod drive mechanism at the Davis Besse reactor discovered a six-inch deep, seven-inch wide hole in the reactor's outer casing. The hole, caused by coolant containing boric acid leaking from a cracked nozzle and eating away at the outside casing, was within 3/8 inch of breaking through the casing, which would have permitted coolant at a pressure of 2,200lb/sq.inch to gush out, potentially permitting the reactor core to overheat and precipitating a meltdown.

But why wasn't the hole, which is estimated to have been developing over a period of several years, detected sooner? Apparently it was obscured by crystallised boric acid accumulating on the surface of the casing. Fair enough, except that boric acid shouldn't have been present on the non-corrosion proofed outer casing in the first place…

Critics of the nuclear industry in the US have been using the case to demonstrate how lax and industry-determined nuclear safety procedures increase the risk of a major nuclear accident - there is suspicion that the plant's management (FirstEnergy) may have suspected there was a potential problem when they successfully begged the Nuclear Regulatory Commission to 'let them off' the 2001 year-end inspection. Read the briefing by the Union of Concerned Scientists - 'Davis-Besse - the reactor with a hole in its head' at http://www.ucsusa.org/energy/bf_davisbesse.html

Press coverage of this potential disaster abetted by cost-cutting has been slight. In the UK, only the Telegraph caught the story, mentioning that the reactor at Sizewell B, which is of the same design as Dvis-Besse , will undergo more checks at its next safety shutdown.
http://www.telegraph.co.uk/news/main.jhtml?xml=%2Fnews%2F2002%2F03%2F27%2Fnuke27.xml