Critical Experiments for Reactor Physics Studies

Technical Report · Fri Sep 16 00:00:00 EDT 1960

DOI:https://doi.org/10.2172/4130748· OSTI ID:4130748

Gwin, R. ^[1]; Magnuson, D. W. ^[1]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

The thermal value of $$\overline{η}$$ for U²³³ and for U²³⁵ has been determined in a series of experiments involving direct comparison of the critical parameters of unreflected homogeneous aqueous solutions of the two isotopes. Auxiliary experiments establishing limits of error, testing certain aspects of the theoretical model employed, and experimentally determining the parameters in the critical equation, have been performed. Experiments performed with 27-in.-dia and 48-in.-dia spheres, and 5-ft-dia and 9-ft-dia cylinders have yielded consistent values of η. Measurements of the nonleakage probability in cylindrical geometry have given values consistent with those predicted by a two-group model in which the theoretical value of the age was used. Within the experimental error no differences were found in the ages of fission neutrons for U²³³ and U²³⁵. The average thermal values of eta determined are: $$\overline{η}$$ for U²³³, 2.284 ± 0.015 and η for U²³⁵, 2.074 ± 0.015. The 2200 m/sec values are the same since the g-factors for eta are unity.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); US Atomic Energy Commission (AEC)
• NSA Number: NSA-14-026168
• OSTI ID: 4130748
• Report Number(s): CF-60-4-12
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CRITICAL ASSEMBLIES
CRITICALITY
CYLINDERS
Criticality
DIFFERENTIAL EQUATIONS
Differential Equations
ERRORS
Eta
Experimental
Experiments
FERMI AGE
FUEL SOLUTIONS
GROUP THEORY
Group Theory
HOMOGENEOUS REACTORS
Homogeneous Aqueous Solutions
Isotopes
LEAKAGE
LOSSES
MEASURED VALUES
MULTIPLICATION FACTORS
Nuclear Criticality Safety Program (NCSP)
Physics
REACTOR CORE
SPHERES
Studies
THERMAL NEUTRONS
Theoretical
Theory
URANIUM 233
URANIUM 235
WATER