A Procedure for Evaluating Modified Pulsed-Neutron- Source Experiments in Subcritical Nuclear Reactors

Journal Article · Sat May 13 04:00:00 EDT 2017 · Nuclear Science and Engineering

DOI:https://doi.org/10.13182/nse67-3· OSTI ID:4234697

Masters, Christopher F. ^[1]; Cady, K. B. ^[1]

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1. Cornell Univ., Ithaca, NY (United States)

A theoretical interpretation of the modified pulsed-neutron-source experiments of Sjöstrand, Gozani, and Garelis and Russell is given using exact steady-state Boltzmann equations. Here, interpretation is based on a phenomenological description of the experiments and is patterned after work done on the Garelis-Russell method by Corngold. The basic approximation made is that the fundamental prompt-mode decay constant is much larger than any delayed-neutron precursor decay constant. The theoretical interpretation allows the reactivities measured by the above three modified pulsed-source techniques to be easily calculated and compared to more conventional definitions of reactivity. The calculations can be performed by any standard source-iteration code that has been modified to solve the inhomogeneous problem. Experiments were performed on the Cornell University Critical Assembly and interpreted with the aid of the above theory. Calculations and experiments agree to within 20%. Sjöstrand's method is found to give the best result for this reactor.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); US Atomic Energy Commission (AEC)
• NSA Number: NSA-21-040687
• OSTI ID: 4234697
• Journal Information: Nuclear Science and Engineering, Journal Name: Nuclear Science and Engineering Journal Issue: 2 Vol. 29; ISSN 0029-5639
• Publisher: Taylor & Francis
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
CRITICAL ASSEMBLIES
EXPONENTIAL PILES
MEASUREMENT
NEUTRON SOURCES
Nuclear Criticality Safety Program (NCSP)
PULSES
REACTIVITY
REACTORS
SUBCRITICAL ASSEMBLIES