Vol. XVIII, No. 1, Pp. 1-50
June 2003
UDC 621.039+614.876:504.06
YU ISSN 1451-3994

Pages: 3-15

Author: Milan Pesić

Abstract

The RB reactor is a uranium fuel heavy water moderated critical assembly that has been put and kept in operation by the Vinca Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro since April 1958. The first complete Safety Analysis Report of the RB reactor was prepared in 1961/62; yet, the first accident analysis had been made in late 1958 with the aim to examine a power transition and the total equivalent doses received by the staff during the reactivity accident that occurred on October 15, 1958. Since 1960, the RB reactor has been modified a few times. Beside the initial natural uranium metal fuel rods, new types of fuel (TVR-S types of Russian origin) consisting of 2% enriched metal uranium and 80% enriched UO2, dispersed in aluminium matrix, have been available since 1962 and 1976, respectively. Modifications of the control and safety systems of the reactor were made occasionally. Special reactor cores were designed and constructed using all three types of fuel elements, as well as the coupled fast-thermal ones. The Nuclear Safety Committee of the Vinca Institute, an independent regulatory body, approved for usage all these modifications of the RB reactor on the basis of the Preliminary Safety Analysis Reports, which, beside proposed technical modifications and new regulation rules, included safety analyses of various possible accidents. A special attention was given (and a new safety methodology was proposed) to thorough analyses of the design-based accidents related to the coupled fast-thermal cores that included central zones of the reactor filled by the fuel elements without any moderator. In this paper, an overview of some accidents, methodologies and computation tools used for the accident analyses of the RB reactor is given.

Key words: accidents, final safety analysis report, RB reactor, HERBE

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