Evaluation and application of delayed-neutron precursor data

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6547508

Brady, M C

Up to 1300 nuclides are yielded in fission. Of these, 271 have been identified as precursors for delayed neutron emission. An extensive reference library of delayed neutron data has been complied which contains fission yields and branchings, delayed neutron emission probabilities and spectra for each of these 271 precursor nuclides. The data complied in the precursor library have been used to calculate the aggregate behavior of delayed neutrons for the 43 fissioning system having evaluated fission yields. Delayed neutron activities predicted using the explicit precursor data have also been approximated by three, six, nine, and twelve time-groups using least squares techniques. The fitted six group data, being the more conventional representation, were also used to predict a consistent set of six-group spectra. Comparisons with the University of Lowell's recently published measurements of {sup 235}U delay interval spectra were also made. Beta-effective calculations for a simple Godiva system were performed and were compared to the experimental value. The point reactor kinetics equations were modified to accommodate the data in the precursor library. Both the explicit data and the group data were used to calculate the kinetic response of a reactor to step changes in reactivity. The precursor data and the six-group data are intended for inclusion in the next version of the Evaluated Nuclear Data Files, ENDF/B-VI.

• Research Organization: Texas A and M Univ., College Station, TX (USA)
• OSTI ID: 6547508
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
99 GENERAL AND MISCELLANEOUS
990300 -- Information Handling
BARYONS
COMPARATIVE EVALUATIONS
COMPILED DATA
DATA
DELAYED NEUTRONS
ELEMENTARY PARTICLES
EQUATIONS
EVALUATION
FERMIONS
FISSION NEUTRONS
FISSION YIELD
HADRONS
INFORMATION
KINETICS
MODIFICATIONS
NEUTRONS
NUCLEAR DATA COLLECTIONS
NUCLEAR REACTION YIELD
NUCLEONS
NUMERICAL DATA
REACTIVITY
REACTOR KINETICS
REACTOR KINETICS EQUATIONS
USES
YIELDS