Evaluating the performance of passive second-stage hydro accumulators to enhance safety margins at Bushehr NPP

IF 3.3 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Progress in Nuclear Energy Pub Date : 2025-03-27 DOI:10.1016/j.pnucene.2025.105744

Mehdi Yarizadeh-Bene , Mahdi Zangian , Abdolhamid Minuchehr , Hamed Kargaran

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引用次数: 0

Abstract

Following the Fukushima accident, the nuclear industry acknowledged the significance of passive safety systems that may function autonomously without relying on external power sources or operator involvement. These systems are engineered to deliver reliable and automated safety operations, even in severe circumstances. The Second Stage Hydro accumulator (HA-2) is an autonomous safety system that autonomously introduces coolant into a nuclear reactor during emergencies, without the need for external power. It plays a vital role in the safety architecture of sophisticated VVER reactors. The objective of this study is to examine the influence of the new type of second-stage hydro accumulators (HA-2) compared to the second-stage accumulators (Bushehr) that are only in Bushehr NPP on the occurrence of design extension condition (DEC) during a station blackout and a small break in the coolant pipeline along with an SBO accident. For this purpose, a VVER-1000 thermal hydraulic model for RELAP5 code has been modified to include the HA-2 system. After analyzing the results, it has been concluded that the passive part of the safety system, together with the accumulators (ACCs), performs well enough to prevent core damage in small Loss of Coolant Accident (SB-LOCA) scenarios larger than 70 mm, as well as in Station Blackout (SBO) situations, for a minimum of 13 h. Furthermore, in circumstances including a severe blackout (SBO), the system exhibits adequate performance to prevent any damage to the core for 24 h. These results are based on assessing the system's autonomous capacity, without considering supplementary managerial interventions.

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来源期刊

Progress in Nuclear Energy 工程技术-核科学技术

CiteScore

5.30

自引率

14.80%

发文量

331

审稿时长

3.5 months

期刊介绍： Progress in Nuclear Energy is an international review journal covering all aspects of nuclear science and engineering. In keeping with the maturity of nuclear power, articles on safety, siting and environmental problems are encouraged, as are those associated with economics and fuel management. However, basic physics and engineering will remain an important aspect of the editorial policy. Articles published are either of a review nature or present new material in more depth. They are aimed at researchers and technically-oriented managers working in the nuclear energy field. Please note the following: 1) PNE seeks high quality research papers which are medium to long in length. Short research papers should be submitted to the journal Annals in Nuclear Energy. 2) PNE reserves the right to reject papers which are based solely on routine application of computer codes used to produce reactor designs or explain existing reactor phenomena. Such papers, although worthy, are best left as laboratory reports whereas Progress in Nuclear Energy seeks papers of originality, which are archival in nature, in the fields of mathematical and experimental nuclear technology, including fission, fusion (blanket physics, radiation damage), safety, materials aspects, economics, etc. 3) Review papers, which may occasionally be invited, are particularly sought by the journal in these fields.