The Measurement of Eta and Other Nuclear Properties of U²³³ and U²³⁵ in Critical Aqueous Solutions

Journal Article · Wed Feb 28 23:00:00 EST 1962 · Nuclear Science and Engineering

OSTI ID:4805366

Gwin, R. ^[1]; Magnuson, D. W. ^[1]

---

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

The thermal value of eta for U²³³ and U²³⁵ is determined in experiments on unreflected homogeneous aqueous solutions of the two isotopes. These experiments also yield a value for the neutron age and the limiting concentrations of the fissile isotope in the aqueous solutions for infinite volumes. Auxiliary experiments, establishing limits of error, testing certain aspects of the theoretical model employed, and experimentally determining the parameters in the critical equation, are also performed. Experiments performed with 27-in.- and 48-in.-diam spheres, and 5-ft- and 9-ft-diam cylinders yield consistent values of eta. Measurements of the non-leakage probability in cylindrical geometry give values consistent with those predicted by a two-group model in which the theoretical value of the age is used. Within the experimental error no differences are found in the ages of fission neutrons for U²³³ and U²³⁵. The average thermal values of eta determined are 2.292 ± 0.015 for U²³³ and 2.076 ± 0.015 for U²³⁵. The 2200 meters/sec values are the same since the g-factors for eta are unity. The value of the neutron age to the indium resonance energy for U²³⁵ fission neutrons in water is found to be 25.6 ± 1.3 cm². The minimum U²³³ and U²³⁵ critical densities for these nitrate solutions are found to be 11.25 ± 0.10 and 12.30 ± 0.10 gm/liter for U²³³ and U²³⁵, respectively.

• 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)
• DOE Contract Number: W-7405-ENG-26
• NSA Number: NSA-16-012326
• OSTI ID: 4805366
• Journal Information: Nuclear Science and Engineering, Journal Name: Nuclear Science and Engineering Vol. 12; ISSN 0029-5639
• Publisher: Taylor & Francis
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CRITICALITY
CROSS SECTIONS
CYLINDERS
DENSITY
ENERGY
EQUATIONS
ERRORS
FERMI AGE
FISSION
GROUP THEORY
HOMOGENEOUS REACTORS
INDIUM
LIQUIDS
MEASURED VALUES
NEUTRONS
Nuclear Criticality Safety Program (NCSP)
RESONANCE
SOLUTIONS
SPHERES
URANIUM 233
URANIUM 235
URANIUM NITRATES
WATER