System of computation of the reactivity balance for the BOR-60 reactor

Abstract

One of the most effective techniques of diagnosing the stateof a fast reactor involves computation of the reactivity balance (CRB). The technique has given satisfactory results in the course of experiments with a breadboard model of the CRB system on the BOR-60 reactor. This paper describes a digital CRB system that uses the special-purpose control computer Electronika D3-28 as the base. This desk-top minicomputer combines high-precision computation by decimal arithmetic and a sufficiently high speed of binary operation (addition time for two-byte format numbers is 0.12 msec) with ease of programming. The features of the device are described in detail. The CRB system has been on trial operation on the BOR-60 reactor for two years. The tests have shown that the real sensitivity to abnormal reactivity changes in the rated reactor operating conditions is (1-2) /SUP ./ 10/sup -5/ delta-k/k. The main contribution to the error is the ambiguity of reactivity effects and their variation with time which requires a correction of the coefficients introduced into the system at intervals.