Part 2 of 3 Parts (Please read Part 1 first)
In 1976, the U.K. began operating a new type of reactor called the Advanced Gas-cooled Reactor (AGR). They still have fifteen AGRs in operation. The U.K. constructed the Thermal Oxide Reprocessing Plant in 1995 to reprocess spent nuclear fuel from these reactors as well as spent nuclear fuel from reactors overseas. It has had a very difficult history. It never operated at full capacity, it suffered a serious leakage of radioactive materials in 2005, and the cost far exceeded the initial estimates. It was finally shut down before it reached the end of its planned and licenses service life. By the time it was permanently shuttered, it had only reprocessed twenty-three metric tons of plutonium
Was the fleet of fast breeder reactors that were designed to burn reprocessed fuel ever constructed? Unfortunately, there are only two such fast reactors in current commercial operation in the world today. These two reactors are the BN-600 and the BN-800, both designed by Russia. In spite of rosy projections of a nuclear reactor boom, the 1960s and 1950s did not see a steep rise in reactor construction so uranium demand was lower than anticipated. In addition, during that time new deposits of uranium were discovered which relieved concerns about a uranium shortage.
It was found that the use of multi-cycle spent nuclear fuel turned out to be far more difficult that was expected. There are also some difficulties and risks that are only associated with fast reactors. There is a serious latent proliferation risk in the use of the technology to separate plutonium and uranium from spent nuclear fuel.
Today, the U.K.’s civilian stockpile contains one hundred and thirty-nine metric tons of plutonium. This includes twenty-three metric tons of which are owned by other countries. The U.K. Nuclear Decommissioning Authority (NDA) has considered two options for the disposal of their plutonium. The first possibility is to burn the recovered plutonium in reactors. It is claimed that such reuse would be proliferation resistant because the spent nuclear fuel being reprocessed as well as the recovered plutonium would be highly radioactive and very dangerous to handle.
A second possible option for the disposal of the plutonium stockpile would be what is called immobilization. This process involves mixing the plutonium with other materials that would reduce the risk of leaching and also complicate any attempt at extraction. It is thought that the radioactive waste in the mix would be a toxic obstacle to any attempt at proliferation. Both of these two options would ultimately require the burial of the plutonium in a deep geological repository.
The NDA would prefer to reuse the recovered plutonium in a mixed-oxide (MOX) fuel also including uranium as a fuel in light water reactors. The use of such an option depends on the availability of reactor owners to construct such reactors and their willingness to burn the MOX fuel. Not all operators of commercial power reactors are excited by this possibility. EDF is a French owned utility that is constructing the first new commercial power reactors in Britain at Hinkley Point C. They considered and then rejected the use of MOX at Hinkley Point C in 2013.
Please read Part 3 next