Fast reactor design for economic power production

• Published in: Journal of nuclear energy. Parts A/B, Reactor science and technology Reactor science and technology, 1962-01, Vol.16 (11), p.509-532
• Main Author: Blake, L.R.
• Format: Article
• Language: English
• ISSN: 0368-3230
• DOI: 10.1016/0368-3230(62)90167-2

The main physics, engineering and safety design principles are described of a conservatively-rated 750 MW t , 250 MW e , power fast reactor. The estimate of capital cost is £50–£60 per kW installed. With a coolant outlet temperature of 450°C and with the equivalent of plutoniumuranium metal fuel operating at 6 per cent average burn-up, 700°C maximum fuel temperature, the power cost in the U.K. should be 0·28 to 0·32 d/kWh, which is substantially less than with any other reactor or with conventional coal-fired plant. The cost of electrical power has three main components: (1) fuel cost; (2) interest and depreciation on capital; and (3) operating cost. The fast reactor compares with the best reactors with respect to (2) and (3) and is potentially superior with regard to fuel cost, (1). This also has three components: (1.1) interest charge on the initial fuel loading; (1.2) cost of fertile-fuel feed and of reprocessing and refabricating spent fuel; and (1.3) credit for excess plutonium produced. The fast reactor is at a disadvantage with respect to (1.1), as it requires a large quantity of highly enriched fuel for its first core, but this is offset since it needs a fertile-fuel feed only thereafter, usually depleted or natural uranium. Its main advantage is that poisoning effects of fission products are virtually absent, so burn-up is limited only by fuel element distortion. At high burn-up, about 10 per cent in metal fuel, cost (1.2) tends to zero and, as (1.3) can be greater that (1.1), it is possible for the fuel cost to be negative. A power cost of 0·2 d/kWh at 0·7 load factor should be within the bounds of possibility, given a 10 percent burn-up metal fuel capable of operating at 750°C centre temperature, or the equivalent conditions in other fuel. Even now it should be possible to achieve 6 per cent burn-up at 700°C centre temperature. This is confirmed by tests, previously reported by the author, of fuel pins to 5 per cent burn-up with no measurable distortion under more onerous conditions of power density, temperature gradient and centre temperature than in the design above. Thus it is argued that economic power is possible with the fast breeder reactor with no significant extrapolation of present knowledge; moreover, there is scope for considerable further development, particularly to higher burn-up and to higher coolant temperature, giving a station efficiency of over 40 per cent rather than 33 per cent as assumed.