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Post by eclipse on Jan 6, 2016 11:23:03 GMT 9.5
I'm just having trouble picturing why we don't have enough waste? What is the bottleneck? If the average breeder doubling time is 10 years, surely that means that in 50 years we would have 32 reactors for every one reactor in the first year of our breeding program? So I assume that the bottleneck is at the start, and that if we carefully processed all the world's nuclear waste into IFR's then that initial number must not be impressive enough to make much difference in the first few decades?
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Post by Greg Simpson on Jan 8, 2016 6:08:56 GMT 9.5
Ok, I was puzzled by this when reading some of Charles Barton's posts recently. What I think is happening is you're burning 1000 kg of fissile material, and breeding 1100 kg of new fuel. What's missing is that it takes 10000 kg of fissile material to run a reactor.
Maybe. Anyhow, that's my best guess.
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Post by Roger Clifton on Jan 8, 2016 8:45:59 GMT 9.5
Ok, I was puzzled by this when reading some of Charles Barton's posts recently... What's missing is that it takes ... ... it takes 5 tonnes of fissiles to start up a 1 GW fast reactor, according to Plentiful Energy, a lot more than for a PWR.
Avoiding shortages, China appears to be planning the acquisition of sufficient plutonium for the start-up fuel for a fleet of fast neutron reactors. Sufficient initial startup fissiles for each new reactor would become available as the currently-deploying fleet of (slow neutron) PWRs (link) refuel after each three years or so of burn. The rate of installing fast reactors would overtake the PWRs about 2050 and scale up to 1400 GW by 2100. That would supply ~1 kW per person in all China, implying no significant reliance on wind.
Ed Leaver started a discussion on that plan in (link). For their planned rate of expansion, the minimum breeding ratio averaged across China's fleet of fast reactors would need to be 1.04 pa (link), with most of the later startups fuelled from reprocessing used fast fuel.
(Eclipse: Let's avoid using the worrier's word, "waste". It is loaded, drags in a lot of emotive baggage that we should not validate by repeating it.)
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