Gas-cooled fast breeder reactor fuel rod design considerations

The GCFR fuel rod is presently designed within the same conservative limitations adopted for the LMFBR project. Since fuel rod irradiation experience is accumulating and fuel rod mathematical modeling is becoming more reliable, it is interesting to consider what improvement in power plant economics can be obtained by designing with less conservatism. Economic studies described here show that savings of over 20% in fuel cycle cost and 10% in doubling time might be achieved in this way. Increasing the rod linear heating rate reduces the fuel cycle cost. The use of thinner cladding and increased fuel density lead to reduced inventory and doubling times.