EDN: XTFIUV
Authors & Affiliations
Devkina E.V.
A.I. Leypunsky Institute of Physics and Power Engineering, Obninsk, Russia
Devkina E.V. – Researcher. Contact: 1, pl. Bondarenko, Obninsk, Kaluga region, 249033. Tel.: +7 (484) 399-42-16; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Abstract
The paper is dedicated to the calculation of nuclear hazardous areas (NHA) in the course of handling spent removable parts (SRP) of liquid metal cooled reactors. The main principle of nuclear safety assurance is elimination of self-sustaining chain reaction (SCR) initiation during normal operation and in emergency. In the course of SRP handling, process flowsheets and equipment are developed that meet the nuclear safety standards. Despite the measures taken to ensure nuclear safety, the risk of SCR exists. Instantaneous radiation in case of SCR is most hazardous for the personnel, therefore, it is important to correctly determine the boundaries of the nuclear hazardous area and the location of the self-sustaining chain reaction alarm system (SCR AS). In the course of SCR AS designing, calculations of neutron and gamma radiation fields are performed.
The dose distribution of neutrons and gamma quanta should be obtained over a sufficiently extended area with a detailed description of the geometry and strong attenuation of particles. Structural materials attenuate the fluxes of gamma rays and neutrons by 10 and more orders of magnitude. Variance reduction methods should be used in order to obtain reliable data by the Monte Carlo method. Weight windows obtained by the MAGIC (Method of Automatic Generation of Importances by Calculation) method were used as a variance reduction method. The use of weight windows made it possible to obtain calculated data with a reliable statistical error. Based on the calculation results, the boundaries of nuclear hazardous areas and the SCR DU location were determined.
Keywords
nuclear hazardous area, spent removable part of the reactor, self-sustaining chain reaction, self-sustaining chain reaction alarm system, self-sustaining chain reaction detection unit, Monte Carlo method, weight windows, MAGIC method, relative error, absorbed dose
Article Text (PDF, in Russian)
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Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2024, no. 3, 3:5
