Calculation of the Probability of Coolant Flow Arising in the Collector of VVER Steam Generator Using the MAVR-4.1 Computer Program

The regulatory documentation establishes the maximum admissible fracture probability for the collector vessels of steam generators at 10 –7 yr –1 per unit, which cannot be compensated by regular accident localization systems. In this connection, it is important to calculate the probability of a uncompensated (Du43, Du100 for AES-2006) coolant leaks in the first loop a steam-generator collector. The MAVR 4.1 software system developed for such calculations is described. Procedures for calculating the probability of a leak in a steam-generator collector and the required initial data are presented. Methods for calculating the equivalent diameter and intensity of a leak and a calculation of the probability of a leak are examined in detail. It is shown that calculations performed with the MAVR 4.1 software based on failure data for PGV-1000 steam generators for 1978–1991 are valid. Translated from Atomnaya Énergiya, Vol. 114, No. 1, pp. 17–21, January, 2013.