Conversion reactor

The conversion reactor, e.g. a heavy-water cooled reactor with 238U as the fertile material with the conversion factor r and the value R(t) for the ratio between fissile and fertile material at the moment t, is defined by the fissile material content E(t). Its lifetime, which depends on the neutron situation in the reactor field, is increased by choosing the initial charges of fissile and fertile material E(0) and R(0) and the conversion factor r in consideration of the neutron losses so that the mathematically derived relation r >= 1-E(0) = 1/[1 + R(0)] is fulfilled. It is further stated that E(0) = R(0)/[1 + R(0)]. The initial value of the conversion factor r is about 0.8 and that of the initial content of fissile material E(0) about 0.3. (TK/AK)