PASI – A test facility for research on passive heat removal

• Published in: Nuclear engineering and design 2021-11, Vol.383, p.111417, Article 111417
• Main Authors: Kouhia, Virpi, Riikonen, Vesa, Kauppinen, Otso-Pekka, Telkkä, Joonas, Hyvärinen, Juhani
• Format: Article
• Language: English
• Subjects: Containment; Containment cooling; Design; Heat; Heat exchangers; Measurement techniques; Natural circulation; Nuclear reactor components; Nuclear reactor containment; Nuclear reactors; Open-loop passive heat removal system; PASI test facility; Pressure vessels; Test facilities; Thermal-hydraulics
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2021.111417

•PASI facility tests provide beneficial data on passive open loop system behaviour.•The height ratio between the PASI facility and the reference system is 1:2.•Open passive heat removal system operation is dynamic and quasi-steady.•Undamped flow rate oscillations emerge as the loop approaches saturated conditions.•Studies with PASI continue within the national and EU Horizon 2020 programs. The PASI test facility has been designed and constructed at LUT University for the thermal–hydraulic studies of an open-loop passive containment heat removal system for nuclear reactors. The PASI facility consists of a pressure vessel that simulates containment conditions and a loop comprising of a heat exchanger, interconnecting pipelines, and a water reservoir. The research work with the PASI test facility aims to study the system performance characteristics and detect issues disturbing or preventing the designed operation of an open naturally circulating system. The PASI facility offers flexible structural features, traditional measurements, and the possibility to utilize advanced measurement techniques. It provides a new perspective for phenomena studies and experimental data useful for code validation. The PASI facility was taken into operation in 2018 with the characterizing experiments. The facility worked as expected, exhibiting two typical operational modes: stable and oscillatory. This paper presents the background for the chosen design of the PASI facility, summarizing the scaling and practical constraints considered in the design process. The details about the construction of the PASI facility with characteristic parameters and figures are presented. In addition, the characterizing experiments and the future research activities utilizing the PASI facility are discussed.