Abstract
The program PUFF-IV is used to process resonance parameter covariance information given in ENDF/B File 32 and point wise covariance matrices given in ENDF/B File 33 into group-averaged covariances matrices on a user-supplied group structure. For large resonance covariance matrices, found for example in 235U, the execution time of PUFF-IV can be quite long. Recently the code was modified to take advantage of Basic Linear Algebra Subprograms (BLAS) routines for the most time-consuming matrix multiplications. This led to a substantial decrease in execution time. This faster processing capability allowed us to investigate the conversion of File 32 data into File 33 data using a larger number of user-defined groups. While conversion substantially reduces the ENDF/B file size requirements for evaluations with a large number of resonances, a trade-off is made between the number of groups used to represent the resonance parameter covariance as a point wise covariance matrix and the file size. We are also investigating a hybrid version of the conversion, in which the low-energy part of the File 32 resonance parameter covariances matrix is retained and the correlations with higher energies as well as the high energy part are given in File 33.
| Original language | English |
|---|---|
| Pages (from-to) | 2791-2795 |
| Number of pages | 5 |
| Journal | Nuclear Data Sheets |
| Volume | 109 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2008 |
Funding
∗Electronic address: [email protected] †Managed by UT-Battelle, LLC, under contract 00OR22725 with the U.S. Department of Energy. This work has been performed with support from the U.S. Nuclear Criticality Safety Program.