Nuclear Thumbrule Questions

[Mr. Lee]

I was wondering if you guys had some info in these areas that was shareable.

What is a good thumbrule for kwhr per kg fuel ?  Let's say 4% enriched.  Is 4% enriched relatively standard?

I've heard that reprocessing costs are about 10 times what burn it and bury it costs.  I've heard bury it costs are 1 mil/kWhr and reprocessing costs are 10 mil/kWhr.  Am I remembering these costs correctly?  Am I using the right units? 

Would reprocessing shut the deep greens up or do you immediately run into the proliferation Catch 22?  Is proliferation still the concern it was in Carter's day? Will this topic be revisited any time soon?  I've heard that Argonne has some pyroprocessing techniques they're working on that could reduce the life of waste to 300-400 years.  This news inspired me but much of the work is only on paper.    Any guesses on whether we will pursue reprocessing and when?

[SloGlo]

dey ill perobillie laze da fule 'n nock da hafflifes outa it befour dey ill rheeperossest it.

[Mr. Lee]

well sure... which brings up another question...  Any thumbrules on how long you'd want to wait until reprocessing

[Roll Tide]

4.5% enrichment is about the limit of what you see in commercial nukes.
http://www.nrc.gov/reactors/operating/licensing/techspecs/techspecs-pdf/wog-specs.pdf pages 350-352 have some discussion of max enrichment for "standard tech specs for Westinghouse PWR's".
Based on my experience with Westinghouse PWR's, getting 4.25% - 4.40% enrichment allows extended life cycles for the core (18-24 months). I know of no commercial applications for >5% enrichment.

Rather than pontificating on those matters where I have no expertise, I dug up some info on Britain's reprocessing. Link and excerpt follow:

http://www-pub.iaea.org/MTCD/publications/PDF/cnpp2003/CNPP_Webpage/countryprofiles/UnitedKingdom/UnitedKingdom2003.htm
2.5 Fuel Cycle and Waste Management 1

Apart from raw uranium mining, the UK has an independent nuclear fuel cycle capability. The full range of the nuclear fuel cycle services - from fuel enrichment and manufacture through to spent fuel reprocessing, transport, waste management and decommissioning - are provided to the UK and international markets by British Nuclear Fuels plc (BNFL), which is wholly owned by the Government.

The Government announced in July 1999 that they are looking to introduce a Private Public Partnership into BNFL, subject to progress towards achieving a range of safety, health, environmental and business performance targets, and further work by DTI and its advisers.

Part of the Government's 1995 review into the future prospects of nuclear power in the United Kingdom confirmed that BNFL would continue to offer customers the full range of nuclear fuel cycle services and restated the Government's continuing support for the company in developing its overseas markets.

Fuel enrichment in the UK is carried out at Capenhurst near Chester by Urenco Capenhurst Limited, a wholly owned subsidiary of Urenco Ltd., the holding company for the Urenco Group. The Urenco Group is the joint Anglo-Dutch-German organization which operates uranium enrichment plants in all three countries using centrifuge technology.

Uranium refining and conversion are carried out at BNFL's Springfields site which processes several tonnes of uranium each year for UK and overseas customers. Springfields has the expertise to manufacture fuel for all major reactor designs world-wide and a new, integrated fuels complex was officially opened in July 1996.

Spent fuel from the UK's Magnox and AGRs and overseas light water reactors is reprocessed at BNFL's Sellafield site. The company's Thermal Oxide Reprocessing Plant (THORP) began operations in March 1994 and has so far sheared and dissolved more than 2000 tonnes of spent fuel. It is expected that some 7,000 tonnes of spent nuclear fuel will be reprocessed in its first ten years of operation.

[HydroDave63]

well sure... which brings up another question...  Any thumbrules on how long you'd want to wait until reprocessing

5 half-lives would probably be a bit TOO long to wait... but using the old old AEC nuclear fallout rule of 7s, 5 or 6 months would let most of the short-lived fission products cook off. If THORP is going to process ~700 tons of spent fuel a year, it looks like the pipeline for processing will be kept fairly short.