Water inventory calculation for the shutdown boiling water reactors

• Published in: Nuclear engineering and design 2023-07, Vol.408, p.112315, Article 112315
• Main Authors: Chen, Yen-Shu, Huang, Li-Ying, Lin, Ansheng
• Format: Article
• Language: English
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2023.112315

During a shutdown of a Boiling Water Reactor, if a leakage event occurs, it is necessary to take action before the water level drops below the top of the active fuel. A simplified method to calculate the transient water level response is proposed in this study. Transient water level behaviors for the Chinshan (Mark I containment) and Kuosheng (Mark III containment) units are calculated using this method. Although both plants are in the decommissioning process, there are still fuel assemblies residing in the reactor pressure vessels. The results from the simplified method are compared with those using the GOTHIC program. For the Mark I unit, the calculated water level drops faster than the GOTHIC result due to the drywell pressurization. For the Mark III unit, the comparison results are in very good agreement. It is also found that higher decay heat power will result in faster drain time in small leakage accidents.