| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To non-destructively evaluate burnup after the irradiation in a reactor of an atomic fuel containing plutonium before loading into the reactor. <P>SOLUTION: Burnup BU<SB POS="POST">G</SB>is determined from a gamma-ray intensity C7 of cesium 137 (S12), an initial pultonium enrichment degreeε<SB POS="POST">M</SB>is determined from a ratio (C4/C7) of gamma-ray intensities C4 and C7 of cesium 134 and Bu<SB POS="POST">G</SB>(S13), and a composition ratio f<SB POS="POST">M</SB>of fissile pultonium and a composition ratio P<SB POS="POST">2M</SB>of Pu 242 are determined from a ratio (Φ/C4) of neutron fluxΦand C4, BU<SB POS="POST">G</SB>andε<SB POS="POST">M</SB>(S14). Then, a neutron effective multiplication factor (k) is determined (S16), and a neutron emission rate S is determined from an expressionΦ=S×P/(1-k) (S17). By using a coefficientαand a coefficientβas functions of the initial pultonium enrichment degreeε<SB POS="POST">M</SB>, the composition ratio f<SB POS="POST">M</SB>of the initial fissile pultonium and the composition ratio P<SB POS="POST">2M</SB>of the initial Pu 242, burnup BU<SB POS="POST">N</SB>is determined from an expression S=α×BU<SP POS="POST">β</SP>(S18). <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
