TIME-DEPENDENT STUDIES OF THE NUCLEAR CHARACTERISTICS OF HRE-3

Technical Report · Tue Dec 31 04:00:00 EST 1957

OSTI ID:4311388

Tobias, M; Rosenthal, M W; Fowler, T B

A method has been devised for examining the build-up of higher isotopes and fission-product poisons in tworegion thorium breeder reactors assuming operation at constant power (rather than constant flux). This procedure has been employed to study seven reactors of the HRE-3 type, four of which are assumed charged with U/sup 233/ fuel originally, and three of which are fueled with U/sup 235/ at the start. The principal conclusions drawn from this study were the following: (1) Reactors fueled with U/sup 233/ display a steady drop in breeding ratio which is interrupted sharply by initiation of core processing; (2) Reactors fueled with U/sup 235/ show a much more constant, but lower, breeding ratio over comparable time intervals; (3) All the cases show a remarkable constant critical fuel concentration in the core; (4) The build-up of higher uranium isotopes in the core is quite slow and periods of the order of 10 years or longer are required for the total core uranium concentration to approach equilibrium levels; (5) Build-up of blanket isotopes is also slow and Pa/sup 233/ builds up to equilibrium levels rapidly, usually well before initiation of chemical processing. Calculation of critical concentrations and breeding ratios was performed using a two-group, tworegion spherical reactor code. The accuracy of the results is subject to the well-known limitations of this procedure. It is noted that no account has been taken of the poisoning effect of corrosion products, which may be considerable. (auth)

• Research Organization: Oak Ridge National Lab., Tenn.
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-12-004994
• OSTI ID: 4311388
• Report Number(s): CF-57-12-1
• Country of Publication: United States
• Language: English

Related Subjects

BLANKETS
BREEDING
CORROSION
EFFICIENCY
FISSION PRODUCTS
GROUP THEORY
HOMOGENEOUS REACTORS
HRE-3
ISOTOPES
PHYSICS
POISONING
PROTACTINIUM 233
REACTORS
SPHERES
THORIUM
URANIUM 233
URANIUM 235