Operational Probabilistic Safety Analysis of a Nuclear Power Plant Operating under Extreme Conditions

Authors

Andrii O. Kostikov, Anatolii Pidhornyi Institute of Power Machines and Systems of NAS of Ukraine (2/10, Komunalnykiv str., Kharkiv, 61046, Ukraine), e-mail: kostikov@ipmach.kharkov.ua, ORCID: 0000-0001-6076-1942

Leonid I. Zevin, Anatolii Pidhornyi Institute of Power Machines and Systems of NAS of Ukraine (2/10, Komunalnykiv str., Kharkiv, 61046, Ukraine)

Abstract

The problem of rapid risk assessment for nuclear power plant operation under extreme conditions, which may significantly affect nuclear and radiation safety, is considered. Based on a probabilistic safety analysis approach, a methodology has been developed to evaluate accident risk. Its application enables plant personnel to quickly make decisions on the need to reduce the reactor power or shut down the power unit in the event of circumstances that could seriously compromise operational safety. A formula for calculating the maximum permissible reactor power at which the plant can continue to operate in extreme conditions is obtained. It is shown that in cases of events posing substantial risk and potentially leading to accidents, shutting down the unit is advisable, as safety limits may otherwise be exceeded.

Keywords: nuclear power plant, probabilistic safety analysis, maximum allowable reactor power, reactor shutdown.

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References

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Received 04 September 2025

Accepted 06 October 2025

Published 30 December 2025