Review on the Possibility of Distinguishing Between Packaging Container and Transport Container in Domestic Nuclear Regulations

Moonoh Kim,Jihoon Lee,Nakhoon Sung 한국방사성폐기물학회 2019 한국방사성폐기물학회 학술논문요약집 Vol.2019 No.05

Review for Disposal Suitability of Drums Compressed With Super-High Pressure

Moonoh Kim,Hyun Woo Song,Sang June Park,Jun-gi Yeom 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Radioactive waste (hereinafter referred to as mixed waste) containing hazardous substances (heavy metals, organic and inorganic waste liquids, asbestos, etc.) has been continuously generated from domestic nuclear power plants, nuclear facilities, and other industrial facilities, and heavy metals were released during the dismantlement of Kori Unit 1 and Wolseong Unit 1. Lead, cadmium, mercury, arsenic), asbestos, decontamination waste liquid (organic/inorganic waste liquid), etc. may be generated. Although hazardous waste related to the nuclear industry continues to be generated, only the regulation direction for hazardous substances is presented in the provisions related to hazardous substances in the delivery regulations for low and intermediate-level radioactive waste and the acceptance criteria for low and intermediate-level radioactive waste disposal facilities. In particular, because there is no clear definition of “hazardousness” and specific standards such as concentration and characteristics for classification of hazardous substances, as well as hazard removal procedures when the hazardousness of radioactive waste is confirmed, no hazardous substances have been delivered in Korea to date and many mixed wastes are stored at each generation facility or at the NPP. As a plan to improve delivery standards related to mixed waste is being prepared recently, it is believed that if the acceptance standards are revised accordingly, it will be possible to confirm the suitability for disposal of drums produced after the establishment of the acceptance standards in 2015. However, it is believed that securing disposal suitability for waste that was packed in 200L drums and compressed under super high pressure in the absence of specific technical standards and regulatory guidelines for the disposal of radioactive waste containing hazardous substances would still remain a difficult problem. In this report overseas acceptance standards related to hazardous waste were reviewed and a plan to secure the disposal suitability of 200 L drums compressed with of super high pressure was proposed.

Review of Foreign Management and Disposal Policies for Intermediate-Level Waste

Moonoh Kim,Yoonji Choi,Jeonghyun Yoon 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1

When the decommissioning of a nuclear power plant begins in earnest, starting with Kori Unit 1, it is necessary to dispose of intermediate-level wastes such as high-dose waste filters and waste resin stored in the power plant, as well as the internal structures of the reactor. However, there are no intermediate-level waste disposal facilities in Korea, and the maintenance of acceptance criteria considering the physical, chemical, and radiological characteristics of intermediate-level waste is insufficient. In this paper, in preparation for the establishment of domestic intermediate-level waste treatment/disposal and acceptance standards, the following major foreign countries’ legal and institutional standards for intermediate-level waste are reviewed, and based on this, factors to be considered when establishing domestic intermediate-level waste treatment/disposal standards were derived. First, although the USA does not define and manage intermediate-level wastes separately, low-level wastes were separated into Class A, B, and C, where land disposal is allowed, and GTCC, which does not allow land disposal. However, it was recently confirmed that the position was changed to recognize the possibility of land disposal of GTCC waste under the condition that the dose to inadvertent intruders does not exceed 5 mSv·yr?1 and a barrier against inadvertent intrusion valid for 500 years is installed. Second, Sweden classifies intermediate-level wastes into short-lived and longlived intermediate-level wastes. The maximum dose rate permitted on packages are different for each vault and a silo of the SFR where short-lived wastes; 100 mSv·h?1 or less is disposed of in BMA, 10 mSV·h?1 or less in BTF, 2 mSv·h?1 or less in BLA and 500 mSv·h?1 or less in silo. Meanwhile, a repository for long-lived low and intermediate level waste, SFL, which could contains significant amounts of nuclides with a half-life greater than 31 years, operations are planned to commence in 2045. Third, France also manages short-lived intermediate-level wastes and long-lived intermediatelevel wastes separately, and the short-lived intermediate-level wastes were disposed of together with short-lived low-level wastes at the La Manche and L’Aube repository. France announced the Cig?o Project, a high- and medium-level long-lived waste plan in 2012, and submitted the creation authorization application for in 2021 with the goal of operating a repository in 2025. Finally, the UK defines intermediate-level waste as “waste whose activity level exceeds the upper limit for low-level waste but does not require heating, which is considered in the design of storage or disposal facilities” and established NIREX to provide deep disposal of intermediate-level radioactive waste. In Finland, wastes with radioactive concentrations of 1 MBq/kg to 10 GBq·kg?1 are classified as intermediatelevel wastes, and a repository was constructed and operated in a bedrock of about 110 m underground. Because the domestic classification standard simply classifies intermediate-level waste as waste exceeding the activity level of low-level waste limit, not high-level wastes, it is necessary to establish treatment and disposal standards by subdividing them by dose rate and long-lived radionuclides concentration to safely and efficiently dispose of intermediate-level waste for. Additionally, there is a need to decide whether or not to reflect safety by inadvertent intruders when evaluating the safety of intermediate-level disposal.

Examination for Repackaging Method of Intermediate Level Waste

Moonoh Kim,Yoonji Choi,Jeonghyun Yoon 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

Treatment methods such as interim storage and immobilization are being considered to dispose of intermediate level waste (ILW), but some wastes that have been treated in the past may require repackaging. Re-packaging means to cover repackaging of waste that has already been packaged in a waste container and re-packaging is required for the following reasons: loss of shielding or containment, damage to external handling features, package out-of-specification, insufficient records and external policy. The re-packaging includes various methods such as non-intrusive treatment, overpacking of waste package, external treatment of waste container, repair waste container, injection of stabiliser, disassemble waste package, high temperature process, and dissolve waste package. The purpose of this paper is to evaluate the re-packaging possibility for various wastes by identifying the main repackaging methods among the above various re-packaging methods. 1) Disposal outside of the waste container is a viable technique for most packages, as coating with a portable spray gun for low dose rate packages or remotely using a robotic arm for high dose rate packages. 2) Waste container repair is divided into welding repair and patching of waste container according to the degree of damage. Weld repair and patching are important techniques that can be used to add additional shielding, repair damaged areas, and improve the integrity of lifting gears that may not be compliant. 3) In general, disassembly of waste packages has been applied to loose drummed waste. Packages and waste forms are physically disassembled, reduced in size, and placed in different new packages. For practical solution, grouted waste is repackaged by cutting using proprietary equipment such as diamond saws, wire saws, core drilling and rupture techniques. 4) High-temperature process involves cutting the waste package and placing the pieces in a hot bath of inorganic liquid or molten metal, and the process is applicable to all waste types. However, treatment of all gases produced, compliance with waste types and acceptance criteria. Finally, dissolving waste packages, which is generally considered impractical due to the variety of chemicals and radionuclides present in ILW, is a process that is easier to perform on raw ILW than conditioned waste. An example of waste being re-packaged is when old drummed waste is recovered from an old storage facility and the waste needs to be repackaged into a form that meets modern standards for interim storage and disposal.

Benefit Analysis for Melting of Metallic Intermediate Level Waste

Moonoh Kim,Yoonji Choi,Jeonghyun Yoon 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

The treatment of radioactive waste by melting has been mainly discussed with low-level waste (LLW). Considering that a large amount of waste in RV or RVI is intermediate-level waste (ILW), however, it is necessary to examine the possibility of treatment by melting of ILW. Different from LLW, melting of ILW with a high content of long-lived nuclides would lead to no free releasee, but has advantages in volume reduction, homogenization, and delay of release. In this paper, the possibility of melting as an alternative technology for the treatment of ILW in the future is reviewed by analyzing the benefits generated by melting ILW in the following aspects: 1) Similar to melting techniques of LLW, them of ILW are mostly based on well-known techniques, but it is necessary to review the feasibility of performing operations such as removal of solidified melt using remote equipment in abnormal situations such as loss of electricity. 2) It is necessary to specify radiation limits for the melting operation unless the ILW melting operation technique can guarantee that the risk of abnormal occurrence is very low. The main quantified radiation parameter is the ingot dose rate, which of 10 mSv/h is considered more reasonable. 3) Although the treatment of ILW by melting leads to a reduction in volume, the main characteristics of the waste still remain, and no waste can be disposed of for free release. Thus, the main potential benefits are improved long-term safety and reduced waste volume. 4) Reducing the surface-to-volume ratio of the molten material could reduce the amount of corrosive material per unit time and, consequently, increase long-term safety. Its effect on long-term safety is difficult to quantify precisely as it depends on several factors, such as the geometry of the original component or whether radionuclides were distributed on the surface of the original component or the induced radioactivity. 5) The volume reduction of ILW is estimated to be reduced by about 1/4 compared to the generated amount when assuming a disposal volume reduction factor of 3 and considering the dose reduction due to radioactive decay after long-term storage, however, due to the lack of knowledge about non-hazardous facility alternatives, it is difficult to evaluate cost-benefit. This is heavily influenced by both the final volume reduction and the potential to reduce the complexity of the repository’s technical barriers.

Derived Improvements From the Experience in Development of NPP Decommissioning Waste Packaging and Transportation Containers

Moonoh Kim,Mi-Hyun Lee,Dae-Sub Choi,Ji-Hoon Lee,nakhoon Sung 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.06

Review of the Possibility of Disposing of High Activity Spent Resins Using Concentration Average Method

Moonoh Kim,Mi-Hyun Lee,Young-Hwan Hwang,Ji-hoon Lee 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.06

Proposal of Economical and Efficient Treatment Facility for Treating Pressurized Heavy Water Reactor Resin Mixture

Moonoh Kim,Young-Ku Choi,Kwang-Woo Jung,Su-Young Moon,Jongsoon Song 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

Pressurized Heavy Water Reactors (PHWR) have stored ion exchange resins, which are used in deuteration, dehydrogenation systems, liquid waste treatment systems, and heavy water cleaning systems, in spent resin storage tanks. The C-14 radioactivity concentration of PHWR spent resin currently stored at the Wolseong Nuclear Power Plant is 4.6×10E+6 Bq/g, which exceeds the limited concentration of low-level radioactive waste. In addition, when all is disposed of, the total radioactivity of C-14, 1.48×10E+15 Bq, exceeds the disposal limit of the first-stage disposal facility, 3.04×10E+14. Therefore, it is currently impossible to dispose of them in Gyeongju intermediate- and low-level disposal facilities. As to dispose of spent resins produced in PHWR, C-14 must be removed from spent resins. This C- 14 removal technology from the spent resin can increase the utilization of Gyeongju intermediate- and low-level disposal facilities, and since C-14 separated from the spent resin can be used as an expensive resource, it is necessary to maximize its economic value by recycling it. The development of C-14 removal technology from the spent resin was carried out under the supervision of Korea Hydro & Nuclear Power in 2003, but there was a limit to the C-14 removal and adsorption technology and process. After that, Sunkwang T&S, Korea Atomic Energy Research Institute, and Ulsan Institute of Science and Technology developed spent resin treatment technology with C-14-containing heavy water for the first and second phases from 2015 to 2019 and from 2019 to the present, respectively. The first study had a limitation of a pilot device with a treatment capacity of 10L per day, and the second study was insufficient in implementing the technology to separate spent resin from the mixture, and it was difficult to install on-site due to the enlarged equipment scale. The technology to be proposed in this paper overcomes the limitations of spent resin mixture separation and equipment size, which are the disadvantages of the existing technology. In addition, since 14CO2 with high concentration is stored in liquid form in the storage tank, only the necessary amount of C-14 radioactive isotope can be extracted from the storage tank and be used in necessary industrial fields such as labeling compound production. Therefore, when the facility proposed in this paper is applied for treating mixtures in spent resin tanks of PHWR, it is expected to secure field applicability and safety, and to reflect the various needs of consumers of labeled compound operators utilizing C-14.

A Proposal of "Innerpack" Design Concept for Efficient Transport and Disposal of Radioactive Waste

Moonoh Kim,Wooyoung Kim,Nakhoon Sung 한국방사성폐기물학회 2019 한국방사성폐기물학회 학술논문요약집 Vol.2019 No.10

A Study on the Applicability of Foreign Test Requirements for Type IP-2 Soft Bag Container

Hyosub Kim,Moonoh Kim,Jaewoo Park,Jihoon Lee,Dong-gyu Lee,Nakhoon Sung 한국방사성폐기물학회 2019 한국방사성폐기물학회 학술논문요약집 Vol.2019 No.05