In 2017, a decision was made to permanently shut down Kori Unit 1, and preparations began to be made for its decontamination and decommissioning. The dismantling of the biological shields concrete, reactor vessel (RV), and reactor vessel internals (RVI) is crucial to the nuclear decommissioning process. These components were radiologically activated by the neutron activation reaction occurring in the reactor during its operational period. Because of the radioactivity of the RV and RVI of Kori Unit 1, remotely controlled systems were developed for cutting within the cavity to reduce radiation exposure. Specialized equipment was developed for underwater cutting operations. This paper focuses on modeling related to RVI operations using the MAVRIC code and the dose calculation for a diver entering the cavity. The upper and lower parts of the RVI are classified as low-level radioactive waste, while the sides that came into contact with the fuel are classified as intermediate-level radioactive waste. Therefore, the modeling presented in this paper only considers the RVI sides because the upper and lower parts have a minimal impact on the radiation exposure. These research findings are anticipated to contribute to enhancing the efficiency and safety of nuclear reactor decommissioning operations.

Ms. Hee Choon Oh was a Jeju Haenyeo(woman diver) and one of the few surviving victims of the Jeju 4.3 (1948). As a Haenyeo: Jeju society was very poor at the time during the Japanese colonial period and the division of the two Korea, especially after the Korean War, so she had to work regardless of gender. It was hard to go into the sea, but it was the only thing to support my family. In retrospect, Going out to work in the sea was like a life-threatening adventure every day. While there were many emergency moments, She becomes one with the sea and forgot all the pain. After having spent a lot of time together with the sea, I had to stop working as a Haenyeo because it was hard to take care of nine children after having heart surgery. I was able to receive Honorary Haenyeo through continuous exchanges and dedication to the society. As a victim of the Jeju 4.3: I had no choice but to explain it why I had to do work as a Haenyeo and to understand my life. I am a woman who chose the job of Haenyeo, but I have lived through the pain of the dark modern and contemporary history of Korea. The unfair one-year prison life that I wanted to hide even from my children hurt me all my life. Over the past 70 years, sharing pain with the sea, neighbors, and family, serving the region, and hopefully waiting for a better society and justice to come. and finally It was not until 2019, 70 years after 1948, that I was officially acquitted by a Korean court. I regained my honor as a Haenyeo and was able to get rid of my deep sadness.

본 연구는 수중 및 여가활동에 대한 수요 증가에 따른 다이버들을 위한 보트의 구조 건전성에 관한 것이다. 대상 선박은 선체 중앙부에 Moon Pool 구조를 갖추고 있는 소형 쌍동선이며, 연구수행은 ISO Rule 기반의 허용응력 산정을 통한 유한요소 해석법을 이용하여 연구를 수행하였다. 연구수행 방법은 ISO 12215-5와 TC118.1225-7에서 정의하고 있는 계수를 산정하고, 종방향굽힘 모멘트, 비틀림 모멘트, 선저슬래밍 하중 등을 적용하여 ISO 기준과 허용응력 설계법(ASD)에 의한 적합성 여부를 판정하고 유한요소해석(FEA)를 활용한 극한강도 설계법을(LFRD)를 적용하여 수행하였다. 연구결과 문풀형 구조를 가진 선박도 ISO규정, KR규정을 적용하여 설계시 구조적 건전성을 확보 하는 것으로 사료된다.