Passive decay heat removal system design for the integral inherent safety light water reactor (I²S-LWR)

Journal Article · 22 August 2019 · Annals of Nuclear Energy

DOI: https://doi.org/10.1016/j.anucene.2019.106987 · OSTI ID:1848127

Wang, Mingjun ^[1]; Manera, Annalisa  ^[2]; Petrov, Victor  ^[2]; Memmott, Matthew J. ^[3]; Qiu, Suizheng ^[4]; Su, G. H. ^[4]

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1. Xi'an Jiaotong Univ., Shaanxi (China). Dept. of Nuclear Science and Technology; Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
2. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
3. Brigham Young Univ., Provo, UT (United States)
4. Xi'an Jiaotong Univ., Shaanxi (China). Dept. of Nuclear Science and Technology

The Integral, Inherently Safe Light Water Reactor (I²S-LWR) is an innovative Pressurized Water Reactor (PWR) concept being developed by a multi-institutional team led by Georgia Tech and in collaboration with Westinghouse, under the Department of Energy’s Nuclear Energy University Programs Integrated Research Projects (DOE NEUP IRP). The University of Michigan leads the design of the thermalhydraulic and passive safety systems, in collaboration with Westinghouse and Bringham Young University. The I²S-LWR features an integral primary system configuration and is more conducive to the implementation of inherent safety features by eliminating potential accidents. In this paper, a novel passive Decay Heat Removal System (DHRS), is presented, consisting of a primary loop, an intermediate loop and a cooling tower loop. This passive system is designed to remove the I²S-LWR decay heat in the case of emergency heat removal transients, without the need for external power or operator action. The proposed DHR uses atmosphere as ultimate heat sink, to achieve indefinite decay heat removal. In this paper, firstly, the design of primary and secondary DHRS heat exchangers is optimized. Then the DHR heat removal characteristics are studied using the best-estimate thermal hydraulic code RELAP5. In addition, CFD simulations have been performed in order to investigate the DRHS helical coil primary heat exchanger performance with different coil pipe arrangements, and optimize its design. The performance of the proposed DHRS concept is investigated in case of a Station Black-Out (SBO) scenario. Operation of two, three and four DHRS trains is studied respectively. The findings show that three out of four DHRS trains are sufficient to indefinitely remove the core decay heat successfully during a SBO, and keep the reactor in a safe state without the need of any other auxiliary active system.

• Research Organization: Univ. of Michigan, Ann Arbor, MI (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE
• Grant/Contract Number: NE0008697
• OSTI ID: 1848127
• Alternate ID(s): OSTI ID: 1632755
• Journal Information: Annals of Nuclear Energy, Vol. 145, Issue C; ISSN 0306-4549
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English