The Korea Atomic Energy Research Institute (KAERI) has facilities that are operated for the purpose of treating radioactive wastes and storing drums before sending them to a disposal site. Domestic regulations related to nuclear facility require radiological dose assessment resulting from release of gaseous radioactive effluent of nuclear facilities. In this study, ICRP-60-based dose conversion factors were applied to evaluate the radiation dose to residents in the event of operation and accident for the radioactive waste management facilities in KAERI. The radioactive gaseous effluent generated from each facility diffuse outside the exclusion area boundary (EAB), causing radiation exposure to residents. To evaluate the external exposure dose, the exposure pathways of cloudshine and radioactive contaminated soil were analyzed. The internal exposure dose was estimated by considering the exposure from respiration and ingestion of agricultural and livestock products. The maximum individual exposure dose was evaluated to be 1.71% compared to the dose limit. The assumed situation used for accidental scenarios are as follows; A fire inside the facility and falling of radioactive waste drum. It was a fire accident that caused the maximum exposure dose to individual and population living within an 80 km radius of the site. At the outer boundary of the low population zone (LPZ), the maximum effective dose and thyroid equivalent dose were estimated as 8.92 E-06% and 5.29 E-06%, respectively, compared to the dose limit. As a result of evaluating the radiological exposure dose from gaseous emissions, the radioactive waste treatment facilities and its supplementary facilities meet the regulations related to nuclear facility, and are operated safely in terms of radiological environmental impact assessment.

In case of Korea, unlike overseas nuclear power plants, adjacent units are located in permanently stopped nuclear power plants. Radioactive substances from airborne and liquid effluents are released into the environment from the NPP, and the radioactivity of the released substances must be reported to the regulatory authorities. Radioactive effluents are released into the environment not only in operation but also after permanent shutdown. Due to domestic conditions in which multiple units exist on the same site, it is necessary to consider radioactive effluents generated after permanent shutdown of NPPs. In particular, liquid effluent may have an increased tritium concentration due to draining the spent fuel pool. This paper summarizes the annual liquid emissions of PWR power plants that have been permanently shut down. The data was obtained from the Nuclear Regulatory Commission’s (NRC) annual radioactive effluent release report, which provides information on the annual emissions power plants into the environment. The liquid emissions of each plant were organized into an annual table, providing an overview of the amount of liquid released by each plant. This study aims to raise awareness about the potential environmental impact of permanently shut down nuclear power plants and the need for proper management of their liquid emissions. The findings of this study can used by operator, policymakers, and other stakeholders to make informed decisions regarding the decommissioning and management of nuclear power plants.

Barrier effect model developed by CRIEPI is used for the estimation of rate of radioactive material release from a transport cask submerged in the ocean. If the containment boundary of cask is broken in an accident during maritime transportation, the sea water comes into the cask cavity and the leaching of radioactive material occurs. If the release of radioactive material thorough the opening of the containment boundary of cask is less than the leaching rate of the radioactive material inside the cask, then the release rate is controlled by the saturation limit of the sea water inside the cask cavity. In this study, the release rate estimation using the barrier effect model is compared with the model used in other codes, such as MARINRAD. And by parameter study, important factors that affect the releaser rate are identified and prioritized. It is shown that the gap generated in the containment boundary is the key parameter that determine the release rate of the radioactive material and the leaching rate is the dominant parameter to determine the saturation time of the cavity sea water.

방사성물질의 대기 누출 사고시 환경에서 핵종 거동을 모사하는 동적 섭식경로모델 DYNACON을 개선하여, 가축 (육우)의 공기 흡입과 토양 섭취가 육류 (쇠고기)의 방사능 오염에 미치는 영향을 고찰하였다. 이들 두 오염경로는 누출이 육우의 비방목 기간에 일어나는 경우에 육류의 오염에 있어서 결코 무시될 수 없는 경로라는 사실을 확인하였다. 특히 누출 후 대부분 기간에 걸쳐 토양 섭취에 의한 육류의 오염 영향이 공기 흡입에 의한 영향에 비해 우세하였다. 누출 기간동안 강우는 토양 섭취에 의한 육류의 오염에 중요한 요소로 작용하였으며, 이러한 현상은 단반감기 핵종인 보다 장반감기 핵종인 의 경우에 보다 뚜렷하였다. 이전에 수행된 우유에 대한 분석 결과와 비교하여 공기 흡입과 토양 섭취는 육류에 대해 보다 중요한 오염경로로 나타났는데, 이는 상대적으로 육류에서 핵종의 긴 생물학적 반감기 때문이다. 방목기간에 방사성물질이 대기로 누출되는 경우 누출 기간동안 강우의 유무에 관계없이 목초 섭취에 의한 오염 영향이 지배적이었으며, 결과적으로 토양 섭취와 공기 흡입에 의한 오염 영향은 우유의 경우와 마찬가지로 무시할 수 있는 수준이었다.