• Title, Summary, Keyword: radioactive concentration

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Determination of Radionuclide Concentration Limit for Low and Intermediate-level Radioactive Waste Disposal Facility I : Application of IAEA Methodology for Underground Silo Type Disposal Facility (중저준위 방사성폐기물 처분시설의 처분농도제한치 설정에 대한 고찰 I : IAEA 방법론의 동굴처분시설 적용)

  • Hong, Sung-Wook;Kim, Min Seong;Jung, Kang Il;Park, Jin Beak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.15 no.3
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    • pp.257-264
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    • 2017
  • For the safe disposal of intermediate level radioactive waste according to the Nuclear Safety and Security Commission's notice and KORAD's management plan for low and intermediate level radioactive waste, the disposal concentration limit was derived based on the IAEA methodology. The evaluation of the derived disposal concentration limit revealed that it is not suitable as a practical limit for intermediate level radioactive waste. This is because the disposal concentration limit according to the IAEA methodology is derived using a single value of radioactive waste density and the disposal facility's volume. The IAEA methodology is suitable for setting the concentration limit for vault type disposal, which consists of a single type of waste, whereas an underground silo type disposal facility is composed of several types of radioactive waste, and thus the IAEA methodology has limitations in determining the disposal concentration limit. It is necessary to develop and apply an improved method to derive the disposal concentration limit for intermediate level radioactive waste by considering the radioactivity of various types of radioactive waste, the corresponding scenario evaluation results, and the regulatory limit.

Determination of Radionuclide Concentration Limit for Low and Intermediate-Level Radioactive Waste Disposal Facility II: Application of Optimization Methodology for Underground Silo Type Disposal Facility (중저준위방사성폐기물 처분시설의 처분농도제한치 설정에 대한 고찰 II: 최적화 방법론 개발 및 적용)

  • Hong, Sung-Wook;Kim, Min Seong;Jung, Kang Il;Park, Jin Beak
    • 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 $^{14}C$.

The Analysis of radioactivity Concentration in drainage when using a radioactive Iodine (방사성옥소 사용 시 배수 중 방사능농도 분석)

  • Lee, Kyung-Jae;Sul, Jin-Hyung;Park, Young-Jae;Lee, In-Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.22 no.1
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    • pp.28-34
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    • 2018
  • Purpose With regard to the use of radioiodine in domestic medical institution, the case of exceeding the allowance of nuclear safety Act about radioactive concentration in drainage was found. Through understanding the cause of exceeding case and analyzing radioactive concentration in drainage, evaluating the relationship of the public waters in surroundings and usefulness. Materials and Methods From November 1, 2014 to April 30th, 2015, the research is aiming at domestic twenty hospitals for six months. By using a HPGe gamma-ray spectrometer(Canberra DSA-1000) and GENIE-2000 Analysis software for comparative analysis, measuring a radioactive concentration of radioiodine in drainage. Consequently, we confirm the excess of radioactive concentration of radioiodine in seven medical institutions. Results Conducting a survey of twenty hospitals and average radioactive concentration of radioiodine in drainage appears $42,100Bq/m^3$. The features of domestic hospitals where show a high radioactive concentration are a number of medical treatment patient when using radioactive iodine and the absence of private rest room. During I-131 whole body scan, the pretreatment procedure of urinating is considered emission of residual Iodine. In public waters, the cause of exceeding detect on radioactive concentration in drainage suppose a diagnostic radioactive iodine. Conclusion We confirm the importance of enhanced education, providing a safety control instructions and installing a private rest rooms for patients who injected a low capacity radioiodine. Also, constructing institutional and legal management system is considered about the Emission management standard in drainage.

Evaluation of 18F Radioactive Concentration in Exhaust at Cyclotron Facility at Chosun University

  • Jeong, Cheol-ki;Jang, Han;Lee, Goung-jin
    • Journal of Radiation Industry
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    • v.10 no.1
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    • pp.37-41
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    • 2016
  • The recent prevalence of PET examinations in Korea has led to an increase in the number of cyclotrons. The medical isotope $^{18}F$ produced in most cyclotron facilities currently operating in Korea is emitted into the environment during the production of [$^{18}F$]FDG, a cancerdiagnosis reagent. The amount of [$^{18}F$]FDG synthesized determines the radioactive concentration of $^{18}F$ in the exhaust. At some facilities, this amount temporarily exceeds the emission limit. In this study, we evaluated the $^{18}F$ radioactivity concentration in the exhaust from the cyclotron facility at Chosun University. The $^{18}F$ radioactivity concentration was measured using an air sampler and a HPGe semiconductor detector. The measurements showed that the radioactive concentration of $^{18}F$ in the exhaust at the cyclotron facility at Chosun University was the highest during [$^{18}F$]FDG synthesis but remained under the legal limit of $2,000Bq\;m^{-3}$.

Effectsof absorbed radioactive sulfur $S^35$ in plant cell. II. Effects of sulfur on the growth and tissue respiration of rye seedlings (식물에 미치는 방사성 동위원소 $S^35$의 영향에 대하여 (제2보) 발아호밀의 생장 및 조섬호흡에 미치는 영향)

  • 홍순우
    • Journal of Plant Biology
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    • v.8 no.1_2
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    • pp.5-10
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    • 1965
  • The effect of radioactive sulfur-35 on the growth and tissue respiration in rye, Secale cereale L., seedlings were studied in this investigation. The growth and respiration rate of the materials treated with the different intensities of radioactivity, represented by the different concentration(${\mu}c$) of radioactive sulfur were shown similar effects in treated groups as those of Gamma-ray or X-ray irradiation on plant materials. However, in the groups of ($0.1{\mu}c$ and ($0.4{\mu}c$ S35-solution, the growth and respiration rate were stimulated somewhat more clearly than in case of control. And the higher concentration groups, $1.6{\mu}c$, $6.4{\mu}c$, and $25.6{\mu}c$ were depressed of the growth and tissue respiration rate. The present data could be explained on the basis that the higher concentration treatments with the radioactive isotope did produce injury to the plant metabolism generally, but the moderate treatment would stimulate to the plant growth and tissue respiration.

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Practical Radiation Safety Control: (I) Application of Annual Limit on Intake and Derived Air Concentration (방사선안전관리 실무: (I) 연간섭취한도와 유도공기중농도의 적용)

  • Kim, Hyun Kee
    • Journal of Radiation Protection and Research
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    • v.38 no.4
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    • pp.234-236
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    • 2013
  • Some of radioactive contamination is unavoidable in the facilities using the unsealed radioactive material. The primary purpose of radioactive contamination control in the workplace with contamination concern is the effects from the potential intake of radioactive material into the body. This paper provides procedures to estimate the level of internal exposure for the worker based on the conservative assumptions and simple calculations. They consist of two processes; to calculate air concentration of radioactive material and annual intake by inhalation with contaminated air and to compare each of them to Derived Air Concentration and Annual Limit on Intake mentioned in the related notification. The procedures are applicable to make a decision on practical requirements for monitoring air contamination and internal exposure of worker as follows; needs for measurement of air contamination and internal exposure and acquisition of information on the design of the ventilation system.

Leaching Characteristic Analysis of Cement Solidified Radioactive Waste Attached by Yellow Sand Rain (황사빗물의 영향에 의한 방사성 폐기물 시멘트 고화체의 침출특성 분석)

  • 김혜진;이수홍;황주호;이재민
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • pp.244-250
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    • 2003
  • With a recent public concern rising on the radioactive waste, it is disclosed that the problem is more serious than expected. This research has been conducted to find effects of yellow sandy rainwaters on the solidified cement of mid-and-low level radioactive waste. The ANS 16.1 standard test method was chosen for this leaching experiment. Make a cement solidified radioactive waste that contains Co nuclide, and fabricate it for over 28 days. Then, decide on the volume of leaching water and the concentration of ion and metal in leachate from the mass concentration of yellow sands in atmosphere. In this paper, we have taken a short look at characteristics of yellow sand. Before going into the leaching experiment, we decided experimental conditions first. Then, it was evaluated and analyzed how sandy rainfalls have impact on the cement solidified radioactive waste based on data from 90 days of leaching experiment.

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