• Title/Summary/Keyword: Nuclear waste

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Review of the Acceptance Criteria of Very Low Level Radioactive Waste for the Disposal of Decommissioning Waste (극저준위 해체폐기물 처분을 위한 방사성폐기물 인수기준 분석)

  • Kim, Beomin;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.165-169
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    • 2014
  • In order to use the nuclear energy as the sustainable energy source, the safe and efficient management of radioactive wastes generated from the nuclear fuel cycle including NPP decommissioning is one of the most important factors. The establishment of acceptance criteria for very low level radioactive wastes generated from decommissioning of nuclear power plant in a large quantity is seemed to play a key role for developing a radioactive wastes disposal strategy as well as NPP decommissioning strategy. In this thesis, we want to review the acceptance criteria of low-and-intermediate-level radioactive wastes in this country through the analysis of other country's acceptance criteria.

Nuclear Criticality Analyses of Two Different Disposal Canisters for Deep Geological Repository Considering Burnup Credit

  • Hyungju Yun;Manho Han;Seo-Yeon Cho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.4
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    • pp.501-510
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    • 2022
  • The nuclear criticality analyses considering burnup credit were performed for a spent nuclear fuel (SNF) disposal cell consisting of bentonite buffer and two different types of SNF disposal canister: the KBS-3 canister and small standardized transportation, aging and disposal (STAD) canister. Firstly, the KBS-3 & STAD canister containing four SNFs of the initial enrichment of 4.0wt% 235U and discharge burnup of 45,000 MWD/MTU were modelled. The keff values for the cooling times of 40, 50, and 60 years of SNFs were calculated to be 0.79108, 0.78803, and 0.78484 & 0.76149, 0.75683, and 0.75444, respectively. Secondly, the KBS-3 & STAD canister with four SNFs of 4.5wt% and 55,000 MWD/MTU were modelled. The keff values for the cooling times of 40, 50, and 60 years were 0.78067, 0.77581, and 0.77335 & 0.75024, 0.74647, and 0.74420, respectively. Therefore, all cases met the performance criterion with respect to the keff value, 0.95. The STAD canister had the lower keff values than KBS-3. The neutron absorber plates in the STAD canister significantly affected the reduction in keff values although the distance among the SNFs in the STAD canister was considerably shorter than that in the KBS-3 canister.

Transport Risk Assessment for On-Road/Sea Transport of Decommissioning Waste of Kori Unit 1

  • Woo Yong Kim;Hyun Woo Song;Jisoo Yoon;Moon Oh Kim
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.2
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    • pp.255-269
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    • 2023
  • Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

A Study on the Evaluation of Radiological Effects on Workers from Air Contamination in Radioactive Waste Treatment Facilities (방사성 액체폐기물 처리 시설 내 공기오염에 의한 작업종사자 방사선학적 영향 평가에 대한 연구)

  • Min-Ho Lee;Woo-Beom Ha;Sang-Heon Lee;Jong-Soon Song
    • Journal of Radiation Industry
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    • v.18 no.2
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    • pp.147-153
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    • 2024
  • Radioactive liquid waste generated during operation and overhaul is collected and reused through the radioactive liquid waste treatment system and continuous monitoring system in the nuclear power plant or discharged to the outside if it satisfies the limit within the control and monitoring. However, there are concerns about boric acid management, which controls the power output of nuclear power plants in radioactive liquid waste. Due to the behavior of boric acid, it is difficult to remove it in the existing liquid radwaste system, and the concentration of boric acid water discharged tends to be higher than the natural state of 5 ppm, so additional facilities should be considered. Therefore, this study aims to evaluate the radiological effects of radioactive waste treatment facilities that are under development and use them as a basis for managing worker exposure and evaluating the safety of facilities in the future.