Technical Meeting on Nuclear Data Processing

Agenda

The agenda is available here.

Summary Report

The summary report is available as INDC(NDS)-0834.

Background

The Meeting is a follow-up of meeting of this subject in September 2019 TM NDP 2019 and previous meetings on this subject. A number of codes that can process evaluated nuclear data files became available.

Objectives

The overall objective of the IAEA Project is to validate nuclear data processing codes that can prepare data libraries in ACE format for continuous-energy Monte Carlo calculations. Specific objective is to compare the results from different codes and provide recommendations and best practices in data processing.

At the previous Meeting the results of the first phase of the data processing exercise were discussed, in which the codes were found to adequately process the cross sections and differential data. The test problem was processing of given evaluations for U-235 and U-238. The generated ACE files were tested on a selected group of benchmark experiments from the ICSBEP Handbook. Without self-shielding the calculated multiplication factors agreed to within the statistical uncertainty. When data processing included the preparation of probability tables (or multi-band parameters) in the unresolved resonance range to account for seld-shielding, the results differed by up to 100 pcm due to different methods applied in different codes; the total worth of self-shielding in some benchmarks amounted to more than 1000 pcm. The uncertainties in the benchmarks did not permit an assessment of the accuracy of the different methods.

The next phase of the exercise involved the processing of thermal scattering data into ACE-TSL format. The results are to be presented at the coming meeting.

Validation of the self-shielding methods is important for all nuclear applications and especially for deep penetration problems. An experiment was performed recently at RPI measuring the transmission through a thick Ta target. The usefulness of this experiment for validating the self-shielding methods is to be discussed.

Presentations