CRITICAL MASSES IN OPERABLE, AIR-COOLED BERYLLIUM CARBIDE MODERATED REACTORS

Technical Report · Tue Jan 10 04:00:00 EST 1950

OSTI ID:4812478

Mitchell, T R

The criticality requirements of nuclear reactors at operating conditions are presented. The effects of high temperature, coolant, coating and fission product poisons were incorporated in the calculations for the determination of critical reactor sizes and uranium requirements after l00 hours of continuous operation at 600,000 kw. The assumptions for the reactors dealt with in this report are given. Calculations were based on neutron diffusion theory. The Fermi Age'' method was used to obtain bare reactor results, and both one and two group methods were used for reflected reactors. Computations were performed for reactors with 0 , 3' , and 6 reflectors, having free flow ratios of 0.2, 0.3, and 0.4, and over a wide range of uranium concentrations. The results are presented graphically to show the interrelations among reactor size, uranium requirement, reflector thickness, uranium concentration, free flow ratio and free flow area. A comparison is shown of the bare operating effects'' reactors with the no effects'' reactors. Two graphs are also included to give an indication of the energies of the neutrons that are causing fission in the various reactors considered. (auth)

• Research Organization: Fairchild Engine and Airplane Corp. NEPA Div., Oak Ridge, Tenn.
• NSA Number: NSA-16-006902
• OSTI ID: 4812478
• Report Number(s): NEPA-1263
• Country of Publication: United States
• Language: English

Related Subjects

AIR
BERYLLIUM CARBIDES
COMPUTERS
COOLANTS
CRITICALITY
DIFFUSION
ENERGY RANGE
FERMI AGE
FISSION
GROUP THEORY
HIGH TEMPERATURE
MASS
MODERATORS
OPERATION
PHYSICS
PLANNING
POISONING
REACTORS
REFLECTORS
USES