M.Sc.Thesis: Spent nuclear fuel reprocessing technology assessment

Background
The worldwide use of nuclear energy and the challenges it faces raise many important issues, for example concerning waste management, uranium availability and regarding economic and environmental aspects.
Most reactors in the world today operate in a once-through fuel cycle meaning that uranium is mined and used once as fuel before prepared for long-term storage. Ever since the start of operation of nuclear power plants, considerable interest has been devoted to the management of the back-end of the fuel cycle. By extracting long-lived radionuclides from the spent fuel and re-using them in reactors, a partly or fully closed fuel cycle could be achieved with the potential to for example enhance resource utilisation.

The adopted strategy in Scandinavian countries is direct disposal of spent fuel in underground geological repositories. However, it is still important to have an understanding of the potential and difficulties of closed fuel cycles. The evaluation of such fuel cycles brings up even more complex technological and policy challenges, for example concerning the introduction of new reactor types (for instance fast spectrum reactors), new fuel forms, new separations technologies, new international institutional arrangements, and new system integration and operational issues.

Objective of the M.Sc. thesis
This M.Sc. thesis will focus on nuclear reprocessing which is the method used to extract re-usable materials, for example plutonium and uranium, from spent nuclear fuel. The aim of the study is the assessment of the options for spent fuel reprocessing technologies and in-depth technology evaluation of the PUREX (Plutonium and Uranium Recovery by EXtraction) process. The technologies should be analysed from technical, economical and environmental viewpoints.

Detailed objectives:
Current state of the art assessment should consider:
(i) Origin and quality of spent fuel.
(ii) Options for spent fuel reprocessing technologies (pyrochemical, precipitation, solvent extraction etc.).
(iii) Recovered, recycled forms of spent fuel (MOX fuel for example).
(iv) Current status: technology maturity level or/and the level of development.
(v) Future development trends of advanced reprocessing technologies in regard to economic and environmental concerns, process flexibility and advanced recycling possibilities.
In-depth analysis of PUREX:
- Complexity, main achievements in efficiency.
- Quality of produced fuel (UO2 or MOX).
- Technical concerns, improvements and further challenges.
- Waste issues.

Conditions
The length of the thesis is 30 hp (Swedish) and it will be carried out at the Råcksta office of Vattenfall Research and Development AB during 2011. Suggested time period is late Mars – August. Supervision will be provided by Anna-Maria Wiberg and Anna Velin at Vattenfall Research and Development AB.

Application
The application should be sent no later than 2011-03-06 and should contain: CV, Certificate, Personal letter and suggestion of examiner or supervisor from the own university.

Contact
Anna-Maria Wiberg
Vattenfall Research and Development AB
SE-162 87 Stockholm
Visit: Jämtlandsgatan 99
Phone: +46 (0)8 699 89 15
Mobile: +46 (0)72 733 58 22
[email protected]