• Title/Summary/Keyword: Nuclear safety regulation

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Radiation Safety Consideration Regarding the Treatment which uses the Radioactive Substance (방사성물질을 이용한 치료의 안전관리 고찰)

  • Lim, Cheong-Hwan;Kim, Seung-Chul;Lee, Gui-Won
    • The Journal of the Korea Contents Association
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    • v.8 no.11
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    • pp.217-224
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    • 2008
  • Is trend that treatment that use isotope of radioactive substance increases from 1964 to now steadily. Bursting tube state solidified accordingly. But, do not establish treatment ward in presence at a sickbed by means that present regulation and system escape this as well as possession that exert negative impact in treatment action preferably is and is treating by radioactivity of small quantity, treatment air by that do not detain many sickers without equaling the institution although there is treatment ward keeps fair death anniversary and is in reservation stand-by status. To possess about 10 therapy rooms including existing sickroom in the institute of nuclear energy recently is looked but is waiting for an opportunity for treatment during suitableness time yet indeed even as that operate 57 radiation isotope therapy rooms all in about 28 hospitals in present domestic state is solveded. Therefore, radiation safety supervision by medical treatment action that treat as radioactive substance may need more active effort. Make mandatory to equipment that hospital which correspond to present the third medical examination and treatment must equip, or effort about more active system improvement may have to be about equipment that enforce this.

Investigation on Natural Radioactivity of Environmental Samples Near the Bauxite Processing Facility (보오크사이트 사용업체 주변 환경시료의 자연방사능 조사)

  • Moon, Dong-Hyeok;Koh, Sang-Mo;Chang, Byung-Uck;Kim, Tong-Kwon;Kim, Yong-Ug
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.4
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    • pp.347-356
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    • 2010
  • Bauxite is a main raw material for the production of alumina and aluminum hydroxide in the processing plant of KC company. It is a NORM (Naturally Occurring Radioactive Materials), and its waste, red mud, is a TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials). The purpose of the geochemical and mineralogical investigations of the bedrock and soils in and around the plant, a large NORM source, was to provide basic data for measuring the radiation dose and protecting from radioactive hazards. Soils were mixtures of minerals derived from the country rock (quartz, feldspar, mica, kaolin, gibbsite, and sepiolite) and bauxite (hematite, boehmite, and calcite) of open-air storage. Average U and Th contents of the soil samples were 4.7 ppm and 23 ppm, respectively, indicating somewhat Th anomaly. The average concentrations of radionuclides are $^{40}K$ 100~1,433 Bq/kg, $^{226}Ra$ anomaly in the red mud open-air storage. Soil external hazard indices range from 0.10 to 1.66 with an average of 0.63. Although most of the indices are below 1.0 that is a regulation value, those of 4 samples of total 41 soil samples exceed 1.0, requiring further detailed investigation.

A Study on Improvement of Test Method of Nuclear Power Plant ESF ACS by applying Regulatory Guide 1.52 (Rev.3) (Reg. Guide 1.52(Rev.3)를 적용한 원전 ESF 공기정화계통 성능시험법 개선 연구)

  • Lee, Sook-Kyung;Kim, Kwang-Sin;Sohn, Soon-Hwan;Song, Kyu-Min;Lee, Kae-Woo;Park, Jeong-Seo;Cho, Byoung-Ho;Yoo, Byeang-Jea;Hong, Soon-Joon;Kang, Sun-Haeng
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.4
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    • pp.311-318
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    • 2010
  • U. S. NRC Regulation Guide 1.52 regulating ESF ACS in nuclear power plants has been revised to revision 3. To apply reduction of operability test time, allowance of alternative challenge agents for in-place leak test of HEPA filters, and upgrade of Methyl Iodide penetration acceptance criterion in activated carbon performance test suggested in Reg. Guide 1.52(Rev.3) on Yonggwang units 5 and 6 ESF ACSes, technical feasibility study was carried out with on-site experiments as well as experiments with a lab-scale model. It was confirmed that the moisture in the system returned to the level before the test in 1 or 4 days even though the moisture was removed during the operability test lasting more than 10 hours. Therefore, it is appropriate to perform monthly operability test in 15 minutes just long enough to check the operability of equipment. To change challenge material for in-place HEPA filter leak test, size of aerosol, production rate, and leak detection capability were compared for DOP and PAO. It was concluded that PAO can be substituted for DOP in nuclear power plants. The upgrade of Methyl Iodide penetration acceptance criterion from 0.175 % to 0.5 % in active carbon filter bed deeper than 4 inches was to conform to the change of activated carbon performance test method to ASTM D3803(1989). It was confirmed that Methyl Iodide penetration acceptance criterion of 0.5 % under $30^{\circ}C$, relative humidity 95 % condition was conservatively good enough for testing performance of active carbon insitu. The licence change of Yonggwang units 5 and 6 has been completed based on this study.

A Study on the Thermo-Mechanical Fatigue Loading for Time Reduction in Fabricating an Artificial Cracked Specimen (열-기계적 피로하중을 받는 균열시편 제작시간 단축에 관한 연구)

  • Lee, Gyu-Beom;Choi, Joo-Ho;An, Dae-Hwan;Lee, Bo-Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.1
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    • pp.35-42
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    • 2008
  • In the nuclear power plant, early detection of fatigue crack by non-destructive test (NDT) equipment due to the thermal cyclic load is very important in terms of strict safety regulation. To this end, many efforts are exerted to the fabrication of artificial cracked specimen for practicing engineers in the NDT company. The crack of this kind, however, cannot be made by conventional machining, but should be made under thermal cyclic load that is close to the in-situ condition, which takes tremendous time due to the repetition. In this study, thermal loading condition is investigated to minimize the time for fabricating the cracked specimen using simulation technique which predicts the crack initiation and propagation behavior. Simulation and experiment are conducted under an initial assumed condition for validation purpose. A number of simulations are conducted next under a variety of heating and cooling conditions, from which the best solution to achieve minimum time for crack with wanted size is found. In the simulation, general purpose software ANSYS is used for the stress analysis, MATLAB is used to compute crack initiation life, and ZENCRACK, which is special purpose software for crack growth prediction, is used to compute crack propagation life. As a result of the study, the time for the crack to reach the size of 1mm is predicted from the 418 hours at the initial condition to the 319 hours at the optimum condition, which is about 24% reduction.

Heat Transfer Modeling by the Contact Condition and the Hole Distance for A-KRS Vertical Disposal (A-KRS 수직 처분공 접촉 조건 및 처분공 간의 거리에 따른 열전달 해석)

  • Kim, Dae-Young;Kim, Seung-Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.3
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    • pp.313-319
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    • 2019
  • The A-KRS (Advanced Korean Reference Disposal System) is the disposal concept for pyroprocessed waste, which has been developed by the Korea Atomic Energy Research Institute. In this disposal concept, the amount of high-level radioactive waste is minimized using pyrochemical process, called pyroprocessing. The produced pyroprocessed waste is then solidified in the form of monazite ceramic. The final product of ceramic wastes will be disposed of in a deep geological repository. By the way, the decay heat is generated due to the radioactive decay of fission products and raises the temperature of buffer materials in the near field of radioactive waste repository. However, the buffer temperature must be kept below $100^{\circ}C$ according to the safety regulation. Usually, the temperature can be controlled by variation of the canister interdistance. However, KAERI has modelled thermal analysis under the boundary condition, where the waste canisters are in direct contact with each other. Therefore, a reliable temperature analysis in the disposal system may fail because of unknown thermal resistence values caused by the spatial gap between waste canisters. In the present work, we have performed thermal analyses considering the gap between heating elements and canisters at the beginning of canister loading into the radioactive waste repository. All thermal analyses were performed using the COMSOL software package.

Recent Developments in Space Law (우주법(宇宙法)의 최근동향(最近動向))

  • Choi, June-Sun
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.223-243
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    • 1989
  • The practical application of modern space science and technology have resulted in many actual and potential gains of mankind. These successes have conditioned and increased the need for a viable space law regime and the challenge of space has ultimately led to the formation of an international legal regime for space. Space law is no longer a primitive law. It is a modern law. Yet, in its stages of growth, it has not reached the condition of perfection. Therefore, under the existing state of thing, we could carefully say that the space law is one of the most newest fields of jurisprudence despite the fact that no one has so far defined it perfectly. However, if space law can be a true jurisprudential entity, it must be definable. In defining the space law, first of all, the grasp of it's nature iis inevitable. Although space law encompasses many tenets and facets of other legal discriplines, its principal nature is public international law, because space law affects and effects law relating intercourse among nations. Since early 1960s when mankind was first able to flight and stay in outer space, the necessity to control and administrate the space activities of human beings has growingly increased. The leading law-formulating agency to this purpose is the United Nation's ad hoc Committee on Peaceful Uses of Outer Space("COPUOS"). COPUOS gave direction to public international space law by establishing the 1963 Declaration of Legal Principles Governing the Activities of the States in the Exploration and Use of Outer Space("1963 Declaration"). The 1963 Declaration is very foundation of the five international multilateral treaties that were established successively after the 1963 Declaration. The five treaties are as follows: 1) The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space including Moon and other Celestial Bodies, 1967. 2) The Agreement on the Rescue of Astronauts, the Return of Astronauts, and the Return of Objects Launched into Outer Space, 1968. 3) The Convention on International Liability for Damage Caused by Space Objects, 1972. 4) The Convention on Registration of Objects Launched into Outer Space, 1974. 5) The Agreement Governing Activities of States on the Moon and Other Celestial Bodies: Moon Treaty, 1979. The other face of space law is it's commercial aspect. Space is no longer the sole domination of governments. Many private enterprise have already moved directly or indirectly into space activities in the parts such as telecommunications and space manufacturing. Since space law as the public international law has already advanced in accordance with the developments of space science and technology, there left only a few areas untouched in this field of law. Therefore the possibility of rapid growth of space law is expected in the parts of commerical space law, as it is, at this time, in a nascent state. The resources of the space environment are also commercially both valuable and important since the resources include the tangible natural resources to be found on the moon and other celestial bodies. Other space-based resources are solar energy, geostationary and geosynchronous orbital positions, radio frequencies, area possibly suited to human habitations, all areas and materials lending themselves to scientific research and inquiry. Remote sensing, space manufacturing and space transportation services are also another potential areas in which commercial. endeavors of Mankind can be carried out. In this regard, space insurance is also one of the most important devices allowing mankind to proceed with commercial space venture. Thus, knowlege of how space insurance came into existence and what it covers is necessary to understand the legal issues peculiar to space law. As a conclusion the writer emphasized the international cooperation of all nations in space activities of mankind, because space commerce, by its nature, will give rise many legal issues of international scope and concern. Important national and world-community interests would be served over time through the acceptance of new international agreements relating to remote sencing, direct television broadcasting, the use of nuclear power sources in space, the regularization of the activities of space transportation systems. standards respecting contamination and pollution, and a practical boundary between outer space and air space. If space activity regulation does not move beyond the national level, the peaceful exploration of space for all mankind will not be realized. For the efficient regulation on private and governmental space activities, the creation of an international space agency, similar to the International Civil Aviation Organization but modified to meet the needs of space technology, will be required. But prior to creation of an international organization, it will be necessary to establish, at national level, the Office of Air and Space Bureau, which will administrate liscence liscence application process, safety review and sale of launch equipment, and will carry out launch service.

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