SPECTRAL SHIFT CONTROL REACTOR BASIC PHYSICS PROGRAM. Quarterly Technical Report No. 4, April-June 1961

Technical Report · Wed Oct 31 04:00:00 EST 1962

OSTI ID:4822312

Critical experiments were performed with 4%-enriched UO/sub 2/ fuel rods in moderators containing 70-mole% D/sub 2/0, 70-mole % D/sub 2/0 with dissolved boric acid, and 50-mole% D/sub 2/O with boric acid. The experiments measured the critical mass, the critical buckling, the thermal disadvantage factor, and the cadmium ratio of U/sup 235/. Also reported are the results of measurements of epithermal absorptions in U/sup 238/, by several techniques, and the neutron spectra at 76.7- and 70-mole% D/sub 2/O. Preliminary results are discussed of a zone-loaded critical assembly containing an inner region of highly enriched uraniurn -thorium oxide fuel rods and an outer region of 4%-enriched UO/sub 2/ fuel rods at a D/sub 2/0 concentration of about 82 mole%. The room- temperature exponential experiments with highly enriched uranium --thorium oxide fuel were completed. The material buckling, cadmium ratio of U/sub 235/, and cadmium ratio of thorium at 80-, 71-, and 53-mole% D/sub 2/0 are reported. Preparations for exponential experirnents at elevated temperatures and pressures continued: the hazards review was completed, and design modifications were made for the D/sub 2/ 0 handling system. Neutron age measurements in a lattice of ThO/sub 2/ rods at / sub 2/0 concentrations of 80, 70, and 50 mole% are reported, and earlier measurements at 0 and 90% D/sub 2/O are re-analyzed. Additional refinements were made to the BPG code, which is used to analyze the experiments, and the cross section library was improved. This code was used to compute the nuclear properties of the poisoned and unpoisoned critical experiments; good agreement was found in most measurements. Discrepancies in the calculations of the neutron age and the disadvantage factor still exist. Several calculations in support of the design and the interpretation of experiments are reported. (auth)

• Research Organization: Babcock and Wilcox Co. Atomic Energy Div., Lynchburg, Va.
• NSA Number: NSA-16-001232
• OSTI ID: 4822312
• Report Number(s): BAW-1221
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
BORON OXIDES
BUCKLING
CADMIUM
CADMIUM RATIO
COMPUTERS
CONFIGURATION
CONTROL
CRITICAL ASSEMBLIES
CRITICALITY
CROSS SECTIONS
ENRICHMENT
EPITHERMAL NEUTRONS
EQUATIONS
ERRORS
EXPONENTIAL PILES
FERMI AGE
FUEL ELEMENTS
HEAVY WATER
HEAVY WATER MODERATOR
HIGH TEMPERATURE
IMPURITIES
LOW TEMPERATURE
MASS
MEASURED VALUES
MODERATORS
NEUTRON FLUX
NEUTRONS
NUMERICALS
PLANNING
POISONING
POWER PLANTS
PRESSURE
PROGRAMMING
REACTIVITY
REACTOR CORE
REACTOR SAFETY
REACTOR TECHNOLOGY
REMOTE HANDLING
REPROCESSING
RESONANCE ESCAPE PROBABILITY
RODS
SPECTRA
SPECTRAL SHIFT
STANDARDS
STORAGE
THERMAL NEUTRONS
THORIUM
THORIUM OXIDES