Aggregate delayed neutron intensities and spectra using augmented ENDF/B-V precursor data

Journal Article · Sat Oct 01 00:00:00 EDT 1983 · Nucl. Sci. Eng.; (United States)

OSTI ID:6172872

England, T R; Mann, F M; Schenter, R E; Wilson, W B

The evaluated nuclear data files (ENDF/B-V) have been used for 105 precursors, augmented with experimental spectral data for 29 emitters and recent model calculations for the remaining 76 emitters, in aggregate summation calculations. The equilibrium-delayed neutron intensities and spectra in the conventional six time groups for 11 fissionable nuclides were calculated. Normalized experimental neutron spectra for 29 emitters were supplied by Rudstam. Augmentation of the spectra uses data calculated with a recently developed code, BETA. Fission yields of the precursors and their delayed neutron branching fractions, P /SUB n/ , are from ENDF/B-V. Results are compared where possible with corresponding group and total evaluations of aggregate measurements. The intent of these calculations is to examine the adequacy of precursor data for inclusion in ENDF/B-VI. Most of the results, particularly with the added model parameters, are sufficiently accurate to be of direct interest to the reactor community. The total delayed neutron yield per neutron absorption, v /SUB d/ , for /sup 238/U and /sup 232/Th suggests that either an improvement in ENDF/B fission yields is needed or the evaluated experimental v /SUB d/ values are in significant error.

• Research Organization: Los Alamos National Laboratory, Theoretical Division, Los Alamos, New Mexico
• OSTI ID: 6172872
• Journal Information: Nucl. Sci. Eng.; (United States), Vol. 85:2
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DELAYED NEUTRON PRECURSORS
NEUTRON SPECTRA
ACCURACY
BRANCHING RATIO
DATA COVARIANCES
DELAYED NEUTRON ANALYSIS
FISSION RATIO
FISSION YIELD
FISSIONABLE MATERIALS
NUCLEAR DATA COLLECTIONS
THORIUM 232
URANIUM 238
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
CHEMICAL ANALYSIS
EVEN-EVEN NUCLEI
HEAVY NUCLEI
ISOTOPES
MATERIALS
NONDESTRUCTIVE ANALYSIS
NUCLEAR REACTION ANALYSIS
NUCLEAR REACTION YIELD
NUCLEI
RADIOISOTOPES
SPECTRA
THORIUM ISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
YIELDS
651722* - Nuclear Properties & Reactions
A=90-149
Experimental- Radioactive Decay- (-1987)
652026 - Nuclear Properties & Reactions
A=220 & above
Experimental- Spontaneous & Induced Fission- (-1987)