THE FINAL JEZEBEL EVALUATION?

摘要

A reevaluation of the ~(239)Pu Jezebel experiment of 1954-1955 was published in the 2013 edition of the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook. Four high-fidelity benchmark models were included, but assumptions had to be made about the distribution of the mass among the Pu-ally parts. Since then, historic documents have been found that give the as-built Pu-alloy part masses, mass densities, and some dimensions. These quantities are not consistent, and to reconcile them we have retained the masses and densities but varied the dimensions. The final average calculated-to-experiment k_(eff) of the four detailed models is only 0.00001 greater than in the 2013 reevaluation, and the experimental uncertainty is 0.00017 less. This reevaluation has not yet received an independent external review or approval by the ICSBEP Working Group.