06.02.2009 Lauri Myllyvirta
The company responsible for managing the waste from world’s first Areva EPR reactor, under construction in Olkiluoto, Finland, writes in their environmental impact assessment report (Posiva 2008):
“The amount of rapidly released radionuclides is important for long-term safety [of the high-level waste depository]. The instant release fraction of I-129 dominates the radiation dose caused by deposition of a damaged waste capsule. This fraction tends to grow when fuel burn-up increases. Models depicting the instantly released fraction of nuclear fuel with a burn-up within the range of 37-75 MWd/kg have been developed in the EU project “Spent Fuel Stability Project”. Results indicate that, for example, the instant release fraction of iodine-129 could triple when burn-up increases 41 MWd/kgU to 48 MWd/kgU and grow seven-fold when burn-up increases 41 MWd/kgU to 75 MWd/kgU.”
The source referenced in the EIA report, Nagra (2005), refers further to Nagra (2004). The latter report shows that the fraction of iodine-129 instantly released from spent fuel increases from 3 percent to 26 percent when burn-up increases 41 MWd/kgU to 75 MWd/kgU. From data presented by Dixon and Wigeland (2008), it can be calculated that the amount of iodine contained in the spent fuel increases simultaneously by over 60 percent.
Areva webpage (Areva 2009) confirms that the EPR is designed to operate at a burn-up above 70 GWd/t. The Finnish waste dump company Posiva (2004) expects the Olkiluoto EPR to use a burn up of up to 70 GWd/t.
Richards (2008) from the UK based Nuclear Consultation Working Group that fuel produced by the EPR reactor “is more demanding at every stage of the nuclear cycle from the reactor itself, subsequent cooling in ponds, through drying and storage in dry casks to eventual burial. It will increase potential worker and public exposure to radiation.” Furthermore, the uncertainties about management and long-term storage of high burn-up spent fuel are so large, that allowing its generation “would expose the future taxpayer to the risk of huge uncovered liabilities.”
Areva (2009): A cost effective reactor. Visited Jan 15, 2009.
Dixon and Wigeland (2008): The Impact of Burnup on the Performance of Alternative Fuel Cycles.
Dr. Ian Fairlie (2008): Estimated Radionuclide Releases and Collective Doses from the Rokkasho Reprocessing Facility.
Nagra (2004): Estimates of the Instant Release Fraction for UO2 and MOX Fuel at t=0.
Nagra (2005): Spent Fuel Evolution Under Disposal Conditions.
Posiva (2004): Localisation of the SR 97 Process Report.
Posiva (2008): Expansion of the Repository for Spent Nuclear Fuel. Environmental Impact Assessment Report.
Hugh Richards (2008): Too Hot to Handle. The truth about high burnup spent fuel.