Major upgrade for MOX plant

02 July 2010

A new manufacturing line is to be installed at the Sellafield MOX Plant that will carry out work for Japanese utilities and might secure the plant's future. 


MOX pellet
A pellet of MOX nuclear fuel
As well as improving overall performance the new rod manufacturing line will ultimately replace the existing one, and this is "critical to achieving the planned throughput in SMP to secure long term operation," Sellafield Ltd said. It is hoped that modifying the manufacturing area will improve reliability and allow faster production of fuel.


The plant mixes uranium and plutonium oxides and forms them into ceramic fuel pellets that fill the rods of nuclear fuel assemblies. This mixed-oxide (MOX) nuclear fuel allows uranium and plutonium to be recycled as part of what is called a closed fuel cycle strategy that reduces waste and prolongs fuel supplies.


The new rod line as well as associated inspection equipment will be designed by Areva, which has been instrumental in improving the performance of the current line. The French national nuclear firm is a partner in the consortium managing Sellafield, the UK's fuel cycle centre and one of the largest nuclear sites in the world.


Areva said it would draw on its own technology and operating experience producing MOX at the Melox plant in the south of France. Sellafield Ltd said Areva "has committed to sharing its technology." A contract has been signed and work has already begun but no details were revealed.


The move is linked to a May agreement with ten Japanese utilities that want to use all their plutonium in MOX fuel. The reprocessing that separates re-usable uranium and plutonium from wastes takes place at Sellafield's Thermal Oxide Reprocessing Plant (Thorp).


Recent UK governments have maintained no firm policy on reprocessing and recycling for the future, but a change in fortunes of SMP would certainly go some way to encouraging new commitments.


A discussion document released in March highlighted the uncertainty over the future of Thorp, whose design life ends next year. The facility would require refurbishment to handle the complete inventory of used nuclear fuel it was built to process - all that coming from the fleet of Advanced Gas-cooled Reactors as well as export jobs. Some 6600 tonnes of AGR fuel remains outstanding, with options storing it unclear until a permanent repository is available in about 2075.


'Credible options' for managing the situation are to be published later this year.


Meanwhile, there are no plans to reprocess used nuclear fuel from Sizewell B, the country's only current pressurized water reactor, although Thorp would be suitable for the job and Sizewell B could use MOX. Current plans by a range of utilities could see over ten new large reactors start within 15 years with more to follow. As yet there is no policy on using MOX in these or reprocessing their used fuel, although a plant for that would not be required to operate before about 2040.


Another interesting factor is the 100 tonne stockpile of civil plutonium at Sellafield, built up by the national nuclear development program stretching back into the 1950s. With no policy on its future use or disposal, this is accounted as having no value.
Researched and written
by World Nuclear News

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