  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.
