Actinide-Only Burnup Credit for Pressurized Water Reactor Spent Nuclear Fuel—I: Methodology Overview

Autor: Emilio Fuentes, Meraj Rahimi, D.B. Lancaster, Chi H. Kang
Rok vydání: 1999
Předmět:
Zdroj: Nuclear Technology. 125:255-270
ISSN: 1943-7471
0029-5450
Popis: A conservative methodology is presented that would allow taking credit for burnup in the criticality safety analysis of spent nuclear fuel (SNF) packages. The method is based on the assumption that the isotopic concentration in the SNF and cross sections of each isotope for which credit is taken must be supported by validation experiments. The method allows credit for the changes in the 234 U, 235 U, 236 U, 238 U, 238 Pu, 239 Pu, 240 Pu, 241 Pu, 242 Pu, and 241 Am concentration with burnup. No credit for fission product neutron absorbers is taken. The methodology consists of five major steps: 1. Validate a computer code system to calculate isotopic concentrations of SNF created during burnup in the reactor core and subsequent decay. Chemical assay benchmarks are used for this purpose, in conjunction with a method for assessing the calculational bias and uncertainty for each isotope. 2. Validate a computer code system to predict the subcritical multiplication factor k eff of an SNF package by use of UO 2 and UO 2 /PuO 2 critical experiments. The method uses an upper safety limit on k eff (which can be a function of trending parameters) to ensure that the calculated k eff when increased for the bias and uncertainty is
Databáze: OpenAIRE