Reactivity determination in a subcritical reactor: Computational, analytical and experimental methods

摘要

In this paper, an analysis of reactivity determination methods at Jordan Subcritical Assembly (JSA), which is driven by an external neutron source, is presented. Results from previous computational analysis estimate the effective multiplication factor, k(eff) to be 0.96553 +/- 0.00004. Calculations of reactivity in a subcritical system predicts the source multiplication factor, k(s), to be 0.9637 +/- 0.0007, which is very close to the computed value of k(eff). The experimental values of the prompt neutron decay constant (alpha) using Rossi-alpha and Feynman-alpha methods, were 551.5 +/- 8.0 (s(-1)) and 555.5 +/- 9.8 (s(-1)), respectively. Using the values for effective delayed neutron fraction, beta(eff) and the mean neutron generation time, Lambda, from the computational analysis, give estimations for k(eff) by Rossi-alpha and Feynman-alpha to be 0.9548 +/- 0.0009 and 0. 9544 +/- 0.0011, respectively, which are lower than the computed value by 1.1%. (C) 2021 Elsevier Ltd. All rights reserved.