New reactor cavity cooling system (RCCS) with passive safety features; A Comparative methodology between a real RCCS and a scaled-down heat-removal test facility

Takamatsu, Kuniyoshi; Matsumoto, Tatsuya*; Morita, Koji*

Annals of Nuclear Energy, 96, p.137 - 147, 2016/10

https://doi.org/10.1016/j.anucene.2016.05.012

After Fukushima Daiichi nuclear disaster by TEPCO, a cooling system to prevent core damage became more important from the perspective of defense in depth. Therefore, a new, highly efficient RCCS with passive safety features without a requirement for electricity and mechanical drive is proposed. Employing the air as the working fluid and the ambient air as the ultimate heat sink, the new RCCS design strongly reduces the possibility of losing the heat sink for decay heat removal. The RCCS can always stably and passively remove a part of the released heat at the rated operation and the decay heat after reactor shutdown. Specifically, emergency power generators are not necessary and the decay heat can be passively removed for a long time, even forever if the heat removal capacity of the RCCS is sufficient. We can also define the experimental conditions on radiation and natural convection for the scale-down heat removal test facility.

New reactor cavity cooling system having passive safety features using novel shape for HTGRs and VHTRs

Takamatsu, Kuniyoshi; Hu, R.*

Annals of Nuclear Energy, 77, p.165 - 171, 2015/03

https://doi.org/10.1016/j.anucene.2014.11.011

A new, highly efficient reactor cavity cooling system (RCCS) with passive safety features without a requirement for electricity and mechanical drive is proposed. The RCCS design consists of continuous closed regions; one is an ex-reactor pressure vessel (RPV) region and another is a cooling region having heat transfer area to ambient air assumed at 40 (C). The RCCS uses a novel shape to efficiently remove the heat released from the RPV with radiation and natural convection. Employing the air as the working fluid and the ambient air as the ultimate heat sink, the new RCCS design strongly reduces the possibility of losing the heat sink for decay heat removal.

Sensitivity analysis of thermal-hydraulic behavior in a containment at a core meltdown accident

; *; ; *

Nihon Genshiryoku Gakkai-Shi, 27(1), p.56 - 65, 1985/00

https://doi.org/10.3327/jaesj.27.56

no abstracts in English

Fission Rate and Sample Worth Measurements in Simulated LMFBR Meltdown Cores

; *;

JAERI-M 9090, 34 Pages, 1980/09

JAERI-M-9090.pdf:1.06MB

no abstracts in English

New Reactor Cavity Cooling System (RCCS) having passive safety features, 1; Experimental conditions of a scale-down heat removal test facility for comparison with a real RCCS

Takamatsu, Kuniyoshi; Matsumoto, Tatsuya*; Morita, Koji*

no journal, , 

After Fukushima Daiichi nuclear disaster by TEPCO, a cooling system to prevent core damage became more important from the perspective of defense in depth. Therefore, a new, highly efficient RCCS with passive safety features without a requirement for electricity and mechanical drive is proposed. Employing the air as the working fluid and the ambient air as the ultimate heat sink, the new RCCS design strongly reduces the possibility of losing the heat sink for decay heat removal. Now, we conduct experiments with the scale-down heat removal test facility to understand the heat-transfer characteristics and assessed effect of radiation quantitatively. Moreover, after considering experimental conditions for the scale-down heat removal test facility to reproduce radiation and natural convection in the new RCCS, we can also find decision technique for the experimental conditions.