Optimal Main Heat Transport system configuration for a nuclear power plant

• Published in: Nuclear engineering and design 2020-04, Vol.359, p.110474, Article 110474
• Main Authors: Gaikwad, Avinash J., Maheshwari, Naresh K., Obaidurrahman, K., Gupta, Aniket, Pradhan, Santosh K.
• Format: Article
• Language: English
• Subjects: ATWS; Boiling; Boiling water reactors; Configurations; Cooling; Cooling systems; Heat; Heat transport; Loss of coolant accidents; NCABWR; NPP Safety Improvements; Nuclear energy; Nuclear engineering; Nuclear fuels; Nuclear power plants; Nuclear safety; Optimal Main Heat Transport system configuration; Optimization; Performance enhancement; Pies; Prevention of DEC; Public domain; Reactors; Safety; Safety systems; Shutdowns; Transportation systems; Water circulation
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2019.110474

•Selection of an optimal Main Heat Transport (MHT) system configuration for a nuclear power plant (NPP) is an activity of high significance, as it influences the safety and the operational aspects.•Paper brings out methodology and criterion for selection of an optimal MHT configuration for NPPs which provides enhanced safety along with ease of operation.•The optimal NCABWR MHT configuration has performed for the enveloping DEC scenario (LOCA without any reactor trip) and it avoided progression into severe accident. Selection of an optimal Main Heat Transport (MHT) system configuration for a nuclear power plant (NPP) is an activity of high significance, as it influences the safety and operational aspects. This paper brings out the methodology for selection of optimal MHT configuration of NPPs which provides enhanced safety along with ease of operation. The criterion for selection of NPP-MHT configuration have been developed for enhancing safety and ease of operation. As a case study, an innovative MHT configuration has been arrived for a channel type Boiling Water Reactor (BWR) which further improves safety. Some of the multiple failure Design Extension Conditions (DEC) scenarios without SCRAM which lead to severe core damage, for commonly deployed MHT configurations, do not encounter any core heat up with this optimal MHT configuration, for a prolonged duration with Emergency Core Cooling System (ECCS). To demonstrate the effect of MHT system configuration on safety, the Natural Circulation Advanced Boiling Water Reactor (NCABWR) has been considered in this study. Though NCABWR is considered for demonstration purpose, similar methodology can be used for devising or conceptualizing an optimal MHT system configuration for any other NPP. The NCABWR is a four inter-connected loop channel type BWR with natural circulation based passive MHT cooling at all power levels. Following the recent DEC events, more emphasis is laid on very low or no radiological impact in the public domain and no requirement of evacuation in the spirit of “more good than harm”. New NPPs like NCABWR come closer to these requirements. With the mostly passive safety systems, NCABWR can avoid and mitigate DEC. The MHT system configuration for such NPPs need to be selected optimally based on the safety enhancement. In this study, optimal NCABWR MHT configuration has been further evolved based on all the Postulated Initiating Events (PIEs) including multiple failures, such as Anticipated Trans