Tuesday, May 09, 2006

Ponds, Leaks and "Lethal Beams".

According to Nirex, which is responsible for matters related to the storage of Britain's nuclear waste and decommissioning the plants that produced it, a lot more information (and time?) will be necessary before any determined effort can be made to clean-out the "cooling-ponds" at Sellafield, and to decontaminate radioactively polluted land both at Sellafield and other nuclear sites, and to sort-out the leaky waste-shaft at Dounreay, the fast-breeder installation located on the coast of Scotland. Dounreay is the name of a now ruinous castle on the north coast of Caithness, in the Highlands of Scotland, and is 9 miles from Thurso, a town that grew rapidly once the nuclear facility was established.
50 years back, the Sellafield ponds were an integral part of the programme which developed the U.K. into a nuclear power, both in terms of weapons technology and in the 1960's to provide electricity from that first generation of "Magnox" reactors. Now, the NDA (Nuclear Decommissioning Agency) intends to spend a third of its £1 billion budget on emptying them, and remediating any land that has been contaminated by leakage of radioactive material over the long time of their use, a strategy for which will be determined once the extent of this is known.
The "ponds" are radioactive junkyards, which contain machine parts and reactor components such as cladding from the magnox reactors, among others. (I have been told by an "old hand" that there are even old bicycles dumped in them). Two of the ponds are open, and are not a pretty sight. In fairness, the ponds and much of the older construction of the Sellafield facilities belong to a far more cavalier age.
British Nuclear group Sellafield faces a rather more immediate problem, namely a criminal prosecution by The Health and Safety Executive in connection with a serious leak of "radioactive liquor" inside a heavily shielded facility at THORP (the infamous Thermal Oxide Reprocessing Plant). Apparently the material had leaked out for nine months without arousing suspicion, to the extent that there is now enough to fill an olympic-sized smimming pool so radioactive that no-one can go anywhere near it. Since it not feasible to deal with the matter using robots either, I can only guess that it will just have to sit there, hoping that there is no leakage of that plutonium and uranium contaminated "liquor", otherwise the problem will become more urgent.
There is one other - more bizarre - incident too. Apparently an old cancer therapy unit (probably containing cobalt-60, which is an intense gamma-ray emitter) was being carried on the back of a lorry from Leeds to Sellafield for decommissioning. Apparently a safety-cap had inadvertently been left off the cargo before it made its 130 mile journey, sanguinely irradiating the picturesque route as it crossed the Pennines. Luckily, the highly focussed "needle" beam was pointing downwards (as it would for its purpose of irradiating tumours, when you think about the configuration of the procedure) so no harm was done. However, the haulage firm responsible for its transportation was fined £250,000 in February, I guess to make an example of them.
The independent Sellafield watchdog "the West Cumbria Sites Stakeholder Group" is undertaking an enquiry into the incident and its chairman David Moore has reassured the public that nothing of the kind can ever happen again.

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