An Overview of the Status of Lead Evaluations in ENDF/B-Ⅷ.0 and JEFF 3.3

摘要

A new effort is under way to reevaluate neutron interaction data for incident neutron energies corresponding to resolved resonances in the isotopes of lead. Table I gives a summary of the abundances and nuclear spins of the stable isotopes of lead. ORNL and IRSN work in close collaboration on this study.Lead is a ubiquitous material in the nuclear industry. Lead possesses not only high photon attenuation properties, which make it almost a universal choice as a gamma-ray shielding material, but also desirable neutronic qualities, as discussed below, that find applications in advanced reactor design.,. Stemming from the work of Subgroup 26 of the Working Party on Nuclear Data Evaluation Cooperation (WPEC) of the OECD/NEA, lead has been identified as a significant contributor to the uncertainty of nuclear systems calculations . Subgroup 26 issued a report. Uncertainty and Target Accuracy Assessment for Innovative Systems Using Recent Covariance Data Evaluations and completed its operations in 2008. At that time, new evaluations of ~(206)Pb and ~(207)Pb were recommended.