Neutron Noise Measurements of a Fast Heu Copper System

Abstract

In addition to nuclear data validation and criticality safety research, criticality experiments offer unique opportunities for investigations into fundamental reactor physics and measurement techniques. Unlike conventional light water research reactors where kinetics parameters do not significantly deviate from one reactor to another, critical experiments with neutron lifetimes from tens of nanoseconds to tens of microseconds can be constructed on vertical lift machines. Kinetics measurement of new fast reactors will be crucial for the validation of computational methods. In this work, we present the results of neutron noise measurements of a fast HEU fueled copper reflected critical system constructed on the Comet vertical lift assembly at the National Criticality Experiments Research Center (NCERC). Fluctuations in the systems neutron population were analyzed in the frequency domain by 3He proportional counters and organic scintillators in order to measure the prompt neutron decay constant, α, at delayed critical and four subcritical states. Agreement between the extrapolated αDC values of the two detector systems was within 1%. Additionally, α values at delayed critical were examined as a function of time in the presence of small power drifts. By comparing to the linear channel, it is shown these drifts did not cause a noticeable effect on α, but did inversely vary with the signal amplitude.

Department(s)

Nuclear Engineering and Radiation Science

Comments

National Nuclear Security Administration, Grant 89233218CNA000001

Keywords and Phrases

CPSD; Critical Experiment; Neutron Noise

International Standard Book Number (ISBN)

978-089448797-2

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Nuclear Society; Taylor and Francis; Taylor and Francis Group, All rights reserved.

Publication Date

01 Jan 2024

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