The neutron and gamma sources of the spent nuclear fuel
were assessed by calculating the nuclide inventory of the
spent fuel using
SAS2H/ORIGEN-S code. The calculations were performed by
VTT Energy under Task JNT A 1071 FIN Partial Defect Test
on
Spent Fuel LWRs. According to the calculation results the
neutron emission of the spent LWR fuel is dominantly from
spontaneous
fission of Cm-244 at cooling times longer than two years.
The parameters that affect the Cm-244 concentration at
discharge are fuel
bundle type, burnup, and in BWR also void fraction. The
power history has only a slight influence on buildup of
Cm-244. Also the
axial distribution of the neutron source can be
determined. Spent LWR fuel contains a variety of gamma
emitting nuclides. However,
only Cs-137 and Cs-134 gamma peaks stand out from the
gamma spectrum. Cs-137 is a better indicator of the
burnup than Cs-134,
but the ratio between the amount of Cs-134 and Cs-137 can
be used to estimate the cooling time.

Original language | English |
---|

Place of Publication | Helsinki |
---|

Publisher | Säteilyturvakeskus |
---|

Number of pages | 31 |
---|

Publication status | Published - 2000 |
---|

MoE publication type | D4 Published development or research report or study |
---|

Series | STUK-YTO-TR |
---|

Volume | 170 |
---|

ISSN | 0785-9325 |
---|