Jeremy Dillon
NS&D Monitor
1/24/2014

The United Kingdom’s Nuclear Decommissioning Authority has concluded that reusing its separated plutonium stock as fuel for potential new reactor technology remains the preferred disposition option, according to a position paper released by the NDA this week. The position paper stressed that MOX fuel remains the preferred option for reuse by the NDA, but new technologies including CANDU EC6 reactors and PRISM fast reactors have emerged as other potential solutions. “In summary, this work has resulted in NDA concluding that reuse remains the preferred option and, based on the information provided and against our definitions, there are three credible reuse options: reuse as MOX in light water reactors, reuse in CANDU EC6 reactors and reuse in PRISM fast reactors,” the paper said. “We note all the technologies being considered have pros and cons and that no ‘perfect’ solution exists. It may be that a multi-track approach offers best value for money.”

The NDA has contacted the developers of these new technologies for help in furthering the studies of what the best course of action for the separated plutonium would be, and technical studies on the feasibility of the technologies will take one to two years, according to the paper. “Currently, we believe there is insufficient understanding of the options to confidently move into implementation and consider that significant further work must be undertaken, focusing on technical and commercial risks and uncertainties, to enable DECC and UK Government to ultimately select and subsequently implement its preferred reuse option,” the paper said.

The developers have indicated that they are willing to engage with the government to address any issues. “We are motivated and willing to work with our technology partners and the NDA to refine our approach to best meet their, and the UK’s, needs over the next 12-24 months,” said Ala Alizadeh, Candu Energy senior vice president of marketing & business development. “Our focus is on defining an implementation path which will give confidence to the NDA that our CANDU technology and integrated commercial CANMOX solution can be delivered in a safe, timely and cost effective manner.”

MOX as Preferred Option

The UK government has been studying the use of MOX as a solution to the stored plutonium stockpile for some time. In 2011, it released a policy report stating its preference for MOX, albeit with caveat for further research. The NDA has conducted research with help from industry that showed the MOX program was do-able. “On the basis of this work, NDA consider that reuse as MOX remains a credible and technically mature option for the majority of plutonium and, given the current planned new build reactor types, remains implementable,” the paper said. “Based on the current nuclear new build program, NDA consider the next 1-2 years are critical to establishing the options for implementation of MOX and for understanding the willingness and potential involvement of technology vendors, utilities and investors to realize the solution.”

Doubts still persist though, mainly because of a lack of confidence in concrete results on MOX. “Due to the relative immaturity of the UK new build program, at this stage, the appetite of developers to ultimately include MOX in their considerations remains uncertain,” the paper said. This uncertainty has opened up room for other technologies to emerge.

A Vote of Confidence

While the government said in the position paper that all three options were under consideration, the developers of the new technology see the position as an endorsement for their technology. “The NDA Position Paper confirms Candu Energy’s view that our CANMOX option is credible and could potentially be implemented earlier than other reuse options,” Alizadeh said. The NDA indicated that the CANDU E6 reactors offer a simpler, more cost-efficient reactor than the other options, but it worried that the reactor still needs further development. The CANDU reactor runs on CANMOX fuel, which has a simpler fuel manufacturing process compared to LWR MOX due to the smaller amount of plutonium used. Candu Energy estimates that it could have its reactor up and running in 10-12 years, although the NDA sees that timetable as “ambitious.”

Meanwhile, GE Hitachi, the manufacturers of the PRISM technology, emphasized its technology as the best solution to the UK’s stored plutonium stockpile. “The UK has the largest storage of civil plutonium anywhere in the world and its Government is committed to re-using that material as an asset rather than a liability, maximizing taxpayer benefits,” said Mark Elborne, president and CEO of GE UK & Ireland. “We believe PRISM offers the most effective solution for accomplishing this goal and look forward to the next stage of this process.” The NDA highlighted in the paper that the PRISM technology would offer “a reduced time for disposition of the UK stockpile due to greater incorporation of plutonium in the fuel, and a simplified fuel manufacturing and reactor construction process—all of which reduce the costs of implementation.” Like the Candu technology, though, the paper concluded that the greatest uncertainty with the PRISM technology resided in the need for further development.

GE-Hitachi’s PRISM technology is a sodium-based reactor technology that uses a high amount of stored plutonium as fuel. “PRISM can not only re-use the UK plutonium stockpile safely and responsibly whilst generating a step-change in industrial opportunity, but can also provide significant revenue for UK taxpayers,” Elborne said. “This is a socially and financially responsible solution.”