ADVANCES IN STUDSVIK’S SYSTEM FOR SPENT FUEL ANALYSES

Teodosi Simeonov,Charles Wemple,M Margulis,P Blaise

doi:10.1051/epjconf/202124702021

Abstract

Studsvik’s approach to spent nuclear fuel analyses combines isotopic concentrations, fluxes, and cross-sections, calculated by the CASMO5 neutron transport and depletion code, with irradiation history data from the SIMULATE5 reactor core simulator and tabulated isotopic decay data. These data sources are used and processed by the SNF code to compute the spent nuclear fuel characteristics. Recent advances in the system, including cross-sections and decay data from ENDF/B-VIII.R0, are presented in this paper, together with validation results against decay heat power and isotopic compositions measurements. Measurements conducted at the Swedish interim storage facility, CLAB, are used for validation of the decay heat power, while comparisons to the results of the international program ARIANE are used to demonstrate the capability of CMS5/SNF to accurately predict isotopic compositions. The paper shows the results calculated with ENDF/B-VIII.R0, and the effect on the spent fuel characteristics is evaluated by comparisons to the earlier ENDF/B-VII.R1 results.

Highlights

Studsvik’s approach to spent nuclear fuel analyses combines isotopic concentrations, fluxes, and crosssections, calculated by the neutron transport and depletion code CASMO5 [1], with irradiation history data from the reactor core simulator SIMULATE5 [2] and tabulated isotopic decay data
In addition to the basic spent fuel characteristics, the SNF code is supplied with various optional modules intended to support and facilitate data preparation for analyses related to handling, transportation and storage of spent fuel, including accident analyses, burnup credit in criticality safety evaluations, and dry cask loading scenarios
The results presented in this work are obtained by applying the irradiation histories from SIMULATE5 [23], two sets of crosssection data from CASMO5, and two sets of decay data based on E7R1 and E8R0, respectively

Summary

INTRODUCTION

Studsvik’s approach to spent nuclear fuel analyses combines isotopic concentrations, fluxes, and crosssections, calculated by the neutron transport and depletion code CASMO5 [1], with irradiation history data from the reactor core simulator SIMULATE5 [2] and tabulated isotopic decay data. These data sources are used and processed by the SNF code [3,4] to compute the basic spent nuclear fuel characteristics: isotopic concentrations; radioactivity; decay heat power; photon sources and spectra; neutron source and spectra from spontaneous fission; neutron source and spectra from ( ,n) reactions. Its application to two validation benchmarks is presented in this work, along with a brief description of the methodology

METHODOLOGY

DECAY DATA

CLAB decay heat power measurements

CONCLUSIONS