Title:
Development of Structural Integrity Assessment Technologies for a Concrete Containment Structure under Ultimate Pressure Condition
Author(s):
Minkyu Kim, Tae-Hyun Kwon, Gyeonghee An, and Habeun Choi
Publication:
Symposium Paper
Volume:
364
Issue:
Appears on pages(s):
40-51
Keywords:
containment structure; crack; external leakage; nuclear power plant; prestressed concrete
DOI:
10.14359/51745455
Date:
12/1/2024
Abstract:
The containment structure of a nuclear power plant is the last barrier of defense to maintain safety in the event of a severe accident, and the integrity of the containment building is the last line of defense against the release of radioactive material. Nuclear power plant containment buildings are most commonly constructed of prestressed concrete, but there are also some constructed of steel. In the case of PS concrete containment building, in order to prepare for the increase in internal pressure in the event of a severe accident, compression force is applied using a tendon in advance to secure sufficient safety, but due to the characteristics of concrete, cracks may occur, and these cracks may become a pathway for external leakage of radioactive materials in the event of a severe accident. In addition, a number of corroded cavities and degradation of liner plates have been found in recent Korean nuclear power plants. Therefore, a study to evaluate the safety of PS concrete containment buildings began in 2022, started by the Korea Atomic Energy Research Institute, and will be conducted for eight years until 2029. The purpose of the research can be categorized into two main areas. The first is to derive the probability of failure of concrete containment buildings due to an increase in internal pressure in the event of a severe accident. The second objective is to estimate the amount of radioactive material leakage through cracks in the containment building when cracks occur. The current methods for calculating the amount of leakage are approximate and based on many assumptions, and therefore contain too much uncertainty. The results of this study will be used to determine the probability of damage to the containment building in the event of a severe accident at a nuclear power plant, and to quantitatively evaluate the amount of radioactive material leakage to the outside, thereby quantitatively evaluating the amount of external exposure. This paper describes progress to date and potential outcomes rather than highly technical results.