A quasi-static Monte Carlo algorithm for the simulation of sub-prompt critical transients

Journal Article · Wed Dec 19 00:00:00 EST 2018 · Annals of Nuclear Energy (Oxford)

DOI:https://doi.org/10.1016/j.anucene.2018.11.055· OSTI ID:1494480

Trahan, Travis John ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

A pseudo-time-dependent Monte Carlo algorithm suitable for simulating thermal reactor transients with timescales on the order of seconds is presented. An initial experimental implementation has been written into the Monte Carlo Application ToolKit (MCATK) developed at Los Alamos National Laboratory. The algorithm is essentially a combination of the fully time-dependent Monte Carlo algorithm, including the explicit simulation of delayed neutron precursors, and a quasi-static algorithm that does not use the point-kinetics equations. The fully time-dependent calculation is performed for some number of inactive and active micro time steps. The dynamic reactor time constant and delayed neutron precursor production rates are calculated directly from the active cycles, rather than from point-kinetics parameters. These quantities are then used to advance the neutron population and delayed neutron precursors forward in time across a macro time step. As a result, the method is applied to the C5G7-TD benchmark operating in steady state and in transient mode.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1494480
• Report Number(s): LA-UR-18-28351
• Journal Information: Annals of Nuclear Energy (Oxford), Vol. 127, Issue C; ISSN 0306-4549
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
Monte Carlo Time-dependent Quasi-static Reactor transient Delayed neutrons