Improving Fission-product Decay Data for Reactor Applications: Part I -- Decay Heat

TL;DR

This paper reviews and assesses methods for improving decay heat data of fission products using gamma-ray spectroscopy techniques, recommending new evaluations and measurements for about 120 fission products to enhance reactor safety and modeling.

Contribution

It provides a comprehensive assessment of decay data measurement techniques and offers specific recommendations for new evaluations and targeted spectroscopy studies for key fission products.

Findings

Assessment of TAGS and DGS methods for decay data improvement

Recommendations for new decay-data evaluations for 120 fission products

Identification of measurement requirements for high-resolution gamma-ray spectroscopy

Abstract

Effort has been expended to assess the relative merits of undertaking further decay-data measurements of the main fission-product contributors to the decay heat of neutron-irradiated fissile fuel and related actinides by means of Total Absorption Gamma-ray Spectroscopy (TAGS/TAS) and Discrete Gamma-ray Spectroscopy (DGS). This review has been carried out following similar work performed under the auspices of OECD/WPEC-Subgroup 25 (2005-2007) and the International Atomic Energy Agency (2010, 2014), and various highly relevant TAGS measurements completed as a consequence of such assessments. We present our recommendations for new decay-data evaluations, along with possible requirements for total absorption and discrete high-resolution gamma-ray spectroscopy studies that cover approximately 120 fission products and various isomeric states.