Safety assessment calculation procedure for operating VVER unit in maneuvering regimes

摘要

This paper presents a test safety assessment calculation technique for operating high power VVER units in daily maneuvering regimes. The test of maneuvering operation is an actual problem of VVER reactors exploitation. Corresponding tests are classified as nuclear hazardous procedures which are accompanied by power variations, regulators actions and continuous space power field fluctuations. As a result a lot of possible reactor plant conditions can occur. This fact is taken into account during the safety assessment of such tests. The proposed technique is based on a conservative approach. The paper contains a step-by-step structure of the method, the description of the calculation procedures and the applied models for each step. Initial conditions for selected RIA accidents are given and justified. Conclusions important for the practice are supported by method application results analysis for assigned task. All calculations are conducted using the KORSAR/GP programming code with 3D-neutrion kinetic model.