As part of the Draft Nuclear National Policy Statement (NPS) an appraisal of sustainability was carried out. The Main Appraisal of Sustainability Report1 (Chapter 6) and Annex K2 present the findings for the arrangements for managing radioactive and hazardous wastes arising from the Nuclear NPS.
The main hazardous material that is expected to be stored at new nuclear power stations will be spent fuel. It is the operator's responsibility to provide storage facilities for the waste produced. Storage facilities will have to satisfy the requirements of the independent safety, security and environmental regulators. The quantity of spent fuel produced by a single new nuclear power station depends on a number of factors, including the capacity of the plant, its operational lifetime and various other operational considerations.
The Nuclear Decommissioning Authority (NDA) has estimated that an AP-1000 reactor operating for 60 years would give rise to an estimated 2,560 spent fuel assemblies, equivalent to 640 disposal canisters. And that a UK EPR reactor operating for 60 years would give rise to an estimated 3,600 spent fuel assemblies, equivalent to 900 disposal canisters.
It is possible that interim storage facilities for spent fuel could be required for around 160 years (estimated 60 years station operating life, 100 years cooling period prior to disposal). However, the estimate of up to 100 years cooling is based on a set of conservative assumptions and there are a number of factors that may shorten the actual storage period that is likely to be required.
The actual cooling time required will depend in practice upon the level of burn-up achieved, designs of the disposal package, the disposal concept and design and its geological setting, which will all offer scope for optimisation and consequent shortening of the required storage time.
The activity and dose rate of spent fuel from new reactors are presented in the NDA's Disposability Assessment Reports for the AP-10004 and UK EPR5 reactors. The NDA concluded in its assessments that the radionuclide characteristics of spent fuel from the AP-1000 and UK EPR reactors are consistent with those from Sizewell B Pressurised Water Reactor.
There will also be other hazardous materials produced. These will include intermediate level wastes (ILW), low level wastes (LLW) and non-radioactive hazardous wastes.
The volume of packaged ILW (both operational and decommissioning) produced by a UK EPR operating for 60 years is estimated to be in the range 2,097-3,65lm3 dependent upon the packaging system used. For an AP-1000 operating for 60 years, the volume of packaged ILW produced is estimated to be around 3,450m3.
The Government expects that ILW will be safely and securely stored on site as it is for current UK nuclear power stations. The ILW will be disposed of when a geological disposal facility is available to accept this waste.
The NDA has assessed the activity and dose rate from ILW and reported that the principal radionuclides present in the wastes are similar to those present in the wastes arising from Sizewell B Pressurised Water Reactor.
Long-term storage on site of LLW and non-radioactive hazardous wastes is not expected to take place. Regulators discourage accumulation of waste at sites of origin if a disposal route is available. These wastes are expected to be disposed of promptly, after it has been generated, through a suitable disposal route.
1 DECC. “Appraisal of Sustainability of the draft Nuclear National Policy Statement: Main Report.” November 2009:
2 DECC. “Appraisal of Sustainability: Radioactive and Hazardous Waste. November 2009.”
3 Burn-up is a measure of the amount of energy extracted for a given mass of uranium. Units are GWd/tU (gigawatt days per tonne uranium).
4 NDA. “Geological Disposal Generic Design Assessment: Summary of Disposability Assessment for Wastes and Spent Fuel arising from Operation of the Westinghouse AP1000.” October 2009.
5 NDA. “Geological Disposal Generic Design Assessment: Summary of Disposability Assessment for Wastes and Spent Fuel arising from Operation of the UK EPR.” October 2009.