• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.3-6
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• 2013

Purpose: The treatment of thyroid cancer patients was continuously increased. According to the increment of thyroid cancer patients, the establishment of iodine therapy site was also increased in each hospital. This treatment involves the administration of radioactive iodine, which will be given in the form of a capsule. Therefore, protections and managements for radioactive source pollution and radiation exposure should be necessary for radiation safety. Among the many problems, the problem of disposing the radioactive wastes was occurred. In this study, The date for self-disposal for radioactive wastes, which were contaminated in clothes, bedclothes and trash, were calculated. Materials and Methods: The number of iodine therapy ward was 15 in Korea Institute of Radiological Medical and Sciences. Recently, 8 therapy wards were operated for iodine therapy patients and others were on standby for emergency treatment ward of any radiation accidents. Radioactive wastes, which were occurred in therapy ward, were clothes, bedclothes, bath cover for patients washing water and food and drink which was leftover by patients. Each sample was hold into the marinelli beaker (clothes, bedclothes, bath covers) and 90 ml beaker (food, drink, and washing water). The activities of collected samples were measured by HpGe MCA device (Multi Channel Analysis, CANBERRA, USA) Results: The storage period for the each kind of radioactive wastes was calculated by equation of storage periods based on the measurement outcomes. The average storage period was 60 days for the case of clothes, and the maximum storage period was 93 days for patient bottoms. The average storage period and the maximum storage period for the trash were 69 days and 97 days, respectively. The leftover foods and drinks had short storage period (the average storage period was 25 days and maximum storage period was 39 days), compared with other wastes. Conclusion: The proper storage period for disposing the radioactive waste (clothes, bedclothes and bath cover) was 100 days by the regulation on self-disposal of radioactive waste. In addition, the storage period for disposing the liquid radioactive waste was 120 days. The current regulation for radioactive waste self-disposing was not suitable for the circumstances of each radioactive therapy facility. Therefore, it was necessary to reduce the leftover food and drinks by adequate table setting for patients, and improve the process and regulation for disposing the short-half life radioactive wastes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.172-179
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• 2003

Various type of tritium wastes can be produced from nuclear fuel cycle process satisfying non-proliferation, CANDU reactors, and nuclear industry. Activities of tritium processing in the world were surveyed to develope the processing technologies of tritium wastes. The tritium wastes were classified into gas phase, liquid phase, and organic phase. And the treatment techniques for the tritium wastes are analyzed. Development of tritium processing technologies is essential to finding public acceptance of radioactive wastes and forming a solid foundation to foster the growth of nuclear industry in Korea.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2261-2267
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• 2021

This paper evaluates the efficacy of magnesium potassium phosphate cements (MKPCs) as waste forms for the solidification of radioactive concrete powder wastes produced by the decommissioning of nuclear power plants. MKPC specimens that contained up to 50 wt% of simulated concrete powder wastes (SCPWs) were evaluated. We measured the porosity and compressive strength of the MKPC specimens, observing them using scanning electron microscopy and X-ray diffraction. The addition of SCPWs reduced the porosity and increased the compressive strength of the MKPC specimens. Struvite-K crystals were well-synthesized, and no additional crystal phase was formed. After thermal cycling and after immersion, MKPC specimens with 50 wt% SCPWs satisfied the waste-acceptance criteria (WAC) for compressive strength. Semi-dynamic leaching tests were performed using the ANS 16.1 method; the leachability indices of Cs, Co, and Sr were 11.45, 17.63, and 15.66, respectively, which also satisfy the WAC. Thus, MKPCs can provide stable matrices to immobilize radioactive concrete wastes generated by the decommissioning of nuclear power plants.

• Journal of radiological science and technology
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• v.44 no.5
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• pp.481-487
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• 2021

This study was conducted for the purpose of efficient radioactive waste disposal and management. Experiment was evaluated the decontamination efficiencies of the four types decontamination materials(Water, Alcohol, Decontamination Water, Decontamination Gel) with radioactive wastes generated during radio-pharmaceutical production process at Korea Institute Radiological and Medical Sciences(KIRAMS). The radioactive waste sample used in experiment is a lead plate of the fume hood that was disposed in April, 2019. In the experimental method, radioactive waste was measured before and after decontamination using a HPGe semiconductor detector and Gamma survey meter. The measured values before and after decontamination were evaluated for decontamination efficiency as a percentage. As a result, it was confirmed that a lot of specific activity and surface dose rate was removed from the radioactive wastes. In particular, when decontamination water was used, most of the radioactivity of radioactive wastes was removed. Considering these results, if decontamination water is used in decontamination of radioactive waste, decontamination efficiency equivalent to the disposition criteria can be expected with just one decontamination treatment. In addition, in the case of water and alcohol, only on decontamination was effective in approximately 75% and 95%. Otherwise, when decontamination gel was used, it was confirmed that the largest deviation occurred among all experimental results.

• Nuclear Engineering and Technology
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• v.39 no.6
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• pp.731-736
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• 2007

Radioactive organic wastes containing acetone, alcohol, and particularly tributyl phosphate (TBP)/dodecane contaminated with uranium are extracted from the PUREX process and the decontamination of related equipment. An evaporation method that utilizes existing DU oxidation apparatuses and ventilation systems and a typical muffle furnace installed with an aspirating system are adopted. A separation method using phosphoric acid especially for the TBP/dodecane waste is also studied and evaluated. The results show that a simple evaporation process is utilizable for wastes containing acetone or alcohol with a lower boiling point. A modified muffle furnace is more appropriate to dispose directly of organic wastes having a higher boiling point, such as TBP/dodecane, without generating a condensed waste solution. It is recommended that, when the uranium concentration of TBP/dodecane waste is much higher than stipulated levels, separation technology should be applied to remove uranium from the mixture. Each type of solvent after separation can then be considered disposable below the regulatory limit in the modified furnace discussed in this study.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.3
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• pp.265-279
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• 2017

The Gyeongju underground silo type disposal facility, approved for use in December 2014, is in operation for the disposal of low and very low-level radioactive wastes, excluding intermediate-level waste. That is why the existing low-level radioactive waste level has been subdivided and the concentration limit value for intermediate-level waste has been changed in accordance with Nuclear Safety Commission Notice 2014-003. For the safe disposal of intermediate-level wastes, new optimization methodology for calculating the concentration limit of intermediate radioactive level wastes at an underground silo type disposal facility was developed. According to the developed optimization methodology, concentration limits of intermediate-level wastes were derived and the inventory of radioactive nuclides was evaluated. The operation and post closure scenarios were evaluated for the derived radioactive nuclide inventory and the results of all scenarios were confirmed to meet the regulatory limit. However, in case of $^{14}C$, it was confirmed that additional radioactivity limitation through a well scenario was needed in addition to the limit of disposal concentration. It was confirmed that the derived intermediate concentration limit of radioactive waste can be used as the intermediate-level waste concentration limit for the underground disposal facility. For the safe disposal of intermediate-level wastes, KORAD plans to acquire additional data from the radioactive waste generator and manage the cumulative radioactivity of $^{14}C$.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.10a
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• pp.552-553
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• 2011

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.220-225
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• 2003

Generally, liquid radioactive wastes generated in nuclear power plant exist in powder form which do not contain moisture through the evaporating process of the Liquid Waste Management System and drying process of the Concentrated Waste Drying System. This powder form wastes are blended homogeneously with paraffin solidification agent and packed in metal drum to ensure its stability during handling and disposal. However, it was experienced that the powder form wastes were not blended homogeneously and separated into two layers in metal drum, on the other hand, a Portion of powder was adhered and solidified to the Inside parts of facility during the blending process. And the flaw of blending process above would come in case the mole ratio of Boron to Sodium in liquid radioactive wastes exceeds 0.2.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.336-336
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• 2004

EDTA contained in decontamination wastes can cause complexation of radioactive captions resulting from its various treatment process such as chemical precipitation, and ion exchange etc. It might also import for elevated teachability and higher mobility of cationic contaminants from conditioned wastes such as waste immobilized in cement or other matrices. Therefore, various cheated or unchlelated EDTAS must be treated to environmentally safe materials.(omitted)

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.347-356
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• 2008

The purpose of Radioactive Waste Acceptance Criteria(WAC) is to verify a radioactive waste compliance with radioactive disposal facility requirements in order to maintain a disposal facility's performance objectives and to ensure its safety. To develop WAC which is conformable with domestic disposal site conditions, we furthermore analysed the WAC of foreign disposal sites similar to the Kyung-Ju disposal site and the characteristics of various wastes which are being generated from Korea nuclear facilities. Radioactive WAC was developed in the technical cooperation with the Korea Atomic Energy Research Institute in consideration of characteristics of the wastes which are being generated from various facilities, waste generators' opinions and other conditions. The established criteria was also discussed and verified at an advisory committee which was comprised of some experts from universities, institutes and the industry. So radioactive WAC was developed to accept all wastes which are being generated from various nuclear facilities as much as possible, ensuring the safety of a disposal facility. But this developed waste acceptance criteria is not a criteria to accept all the present wastes generated from various nuclear facilities, so waste generators must seek an alternative treatment method for wastes which were not worth disposing of, and then they must treat the wastes more to be acceptable at a disposal site. The radioactive disposal facility WAC will continuously complement certain criteria related to a disposal concentration limit for individual radionuclide in order to ensure a long-term safety.