RERTR Publications:
Analysis Methods for Thermal Research and Test Reactors
ANL/RERTR/TM-30
PERTURBATION-INDEPENDENT METHODS FOR
CALCULATING RESEARCH REACTOR KINETIC PARAMETERS
M. Bretscher
RERTR Program
Argonne National Laboratory
Argonne, IL 60439-4841 USA
ABSTRACT
The analysis of research reactor transients depends on the effective delayed neutron fraction (beff), its family-dependent components (beff,i), the prompt neutron lifetime (lp), and the decay constants (li) for each delayed neutron family. Based on ENDF/B-V data, methods are presented for accurately calculating these kinetic parameters within the framework of diffusion theory but without the need for a perturbation code. For heavy water systems these methods can be extended to include the delayed photoneutron component of beff which results from fission product gamma rays energetic enough to dissociate the deuteron. However, a separate calculation is needed to estimate the fractional loss of fission product gamma rays from leakage, energy degradation, and absorption in fuel and structural materials. These methods are illustrated for a light-water Oak Ridge Research Reactor (ORR) LEU core and for a heavy-water Georgia Tech Research Reactor (GTRR) HEU core where measured and calculated values of the prompt neutron decay constant (beff/lp) are found to be in good agreement. In addition, the calculated beff,i values compare favorably with results obtained from a 3D perturbation code.
PDF version available
This document, "PERTURBATION-INDEPENDENT METHODS FOR
CALCULATING RESEARCH REACTOR KINETIC PARAMETERS", ANL/RERTR/TM-30,
December 1997, is available in PDF format.
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Contact:
Manuel M. Bretscher
Physicist
Argonne National Laboratory – 362
9700 South Cass Avenue
Argonne, IL 60439 USA
Phone: (630) 252-8616
Fax: (630) 252-5161
DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.