21 March 2011

Safety of Light Water Reactors (LWRs)

Alvin Weinberg invented and held the patents on Light Water Reactors (LWRs). The UK's new-build nuclear programme is selecting from Areva's EPR or Westinghouse's AP1000, both of which are a version of an LWR known as Pressurised Water Reactors (PWRs); these are also the most prevalent civil nuclear reactor currently in use. The Fukushima plants are Boiling Water Reactors (BWRs), which are another version of LWRs.

The reactor vessels of LWRs contain pressurised water (wanting to turn to steam, if depressurised) or steam, at about 160 times atmospheric pressure. This is a high energy 'driver' capable of expelling radioactive substances into the atmosphere. Accidental and planned depressurisation played parts in both Three Mile Island and Fukushima accidents. The degree of atrophying of the nuclear industry, resulting from TMI, may well be amplified, in coming years, because of Fukushima.

The Enrico Fermi Award, presented to scientists of international standing for their contribution to energy - 1980, Alvin Weinberg.

This is a man who should be listened to; his opinions are important.

Weinberg railed against the use of LWRs for civil use, because of his awareness of their safety-fallibility. As Director of Research at Oak Ridge National Laboratory (ORNL), conducting experiments and operations of Molten Salt Reactors (MSRs),he argued vehemently for the use of one such MSR, the Liquid Fluoride Thorium Reactor (LFTR). LFTRs operate at atmospheric pressure and have no pressure 'driver', or any other form of driver (such as highly reactive chemicals), to expel radioactive substances into the environment. Weinberg went head-to-head with the political and military paymasters of the nuclear programme, in the criticism of LWRs and the promotion of the safety superiority of LFTRs, and for this, he was asked to leave the nuclear industry. His loss to ORNL, meant that his work had a short-lived legacy, withering on the vine until funds were withdrawn in the early 70s.

Until his dying day, Weinberg thought that the Earth's inexhaustible thorium resources would be the future of energy supply for all of humankind.

In his autobiogra­phy Weinberg confessed:
“I became obsessed with the idea that humankind’­s whole future depended on the breeder. For Society generally to achieve and maintain a standard of living of today’s developed countries depends on the availabili­ty of relatively cheap, inexhausti­ble sources of energy.”

In saying ‘breeder’, he was talking about the transmutat­ion of thorium232 to fissile Uranium233 in a LFTR.

Sunday 30 March 2011, reported in The Telegraph,  Chris Huhne said: "Globally, this undoubtedly casts a shadow over the renaissance of the nuclear industry. That is blindingly obvious."

I intend to vociferously lobby Chris Huhne and all members the Select Committee on Energy and Climate Change to consider, over and above the views of the Committee's expert witnesses, the views of the inventor of LWRs in respect of their safety and his desire to invest civil society with the ultimate in electricity and heat generation - the LFTR.

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