• 제목/요약/키워드: Nuclear security

검색결과 391건 처리시간 0.027초

Calculation of preliminary site-specific DCGLs for nuclear power plant decommissioning using hybrid scenarios

  • Seo, Hyung-Woo;Sohn, Wook
    • Nuclear Engineering and Technology
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    • 제51권4호
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    • pp.1098-1108
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    • 2019
  • Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and is currently in transition stage. Preparatory activities for decommissioning such as historical site assessment, characterization, and dismantling design are being actively carried out for successful D&D (Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensure the safety of workers and residents that may arise during the decommissioning of nuclear facilities and, thereby finally returning the site to its original status in accordance with the release criteria. Upon completion of decommissioning, the resident's safety at a site released will be assessed from the evaluation of dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria, most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been set to 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult to measure, measurable concentration guideline levels for residual radionuclides that result in dose equivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selection of potential radionuclides, and systematic methodology should be developed in planning stage of Kori site decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels (DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflect practical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially, thereby striking a remarkable distinction with conventional approaches which considers only a single site scenario.

The regulatory system for imported-cargo radiation monitoring in Korea and a proposal for its improvement

  • Wo Suk Choi ;Tae Young Kong ;Hee Geun Kim;Eun Ji Lee ;Seong Jun Kim ;Jin Ho Son ;Chang Ju Song;Hwa Pyoung Kim;Cheol Ki Jeong
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.1-11
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    • 2023
  • To protect people and the environment from environmental radiation, the Act on Protective Action Guidelines against Radiation in the Natural Environment was formulated in Korea in 2011. This law regulates matters related to radiation safety that can be encountered in life. In accordance with this law, radiation monitoring equipment is operated at major airports and ports across the country, ensuring radiation monitoring of imported cargo. Currently, six ministries conduct radiation monitoring of imported cargo: the Nuclear Safety and Security Commission; the Korea Customs Service; the Ministry of Food and Drug Safety; the Ministry of Environment; the Ministry of Agriculture, Food and Rural Affairs; and the Korea Forest Service. Each ministry designates the relevant cargo items for radiation monitoring. The objective of this study was to comprehensively review the Korean radiation monitoring system for imported cargo and identify the areas and scopes of improvement. This paper also proposes a new law and an integrated supervision plan, which involves establishing a dedicated department to enhance the efficiency and professionalism of the national radiation monitoring system for imported cargo. The review will contribute to the development of a more sophisticated national radiation monitoring system for imported cargo.

Conceptual design of a dual drum-controlled space molten salt reactor (D2 -SMSR): Neutron physics and thermal hydraulics

  • Yongnian Song;Nailiang Zhuang;Hangbin Zhao;Chen Ji;Haoyue Deng;Xiaobin Tang
    • Nuclear Engineering and Technology
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    • 제55권6호
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    • pp.2315-2324
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    • 2023
  • Space nuclear reactors are becoming popular in deep space exploration owing to their advantages of high-power density and stability. Following the fourth-generation nuclear reactor technology, a conceptual design of the dual drum-controlled space molten salt reactor (D2-SMSR) is proposed. The reactor concept uses molten salt as fuel and heat pipes for cooling. A new reactivity control strategy that combines control drums and safety drums was adopted. Critical physical characteristics such as neutron energy spectrum, neutron flux distribution, power distribution and burnup depth were calculated. Flow and heat transfer characteristics such as natural convection, velocity and temperature distribution of the D2-SMSR under low gravity conditions were analyzed. The reactivity control effect of the dual-drums strategy was evaluated. Results showed that the D2-SMSR with a fast spectrum could operate for 10 years at the full power of 40 kWth. The D2-SMSR has a high heat transfer coefficient between molten salt and heat pipe, which means that the core has a good heat-exchange performance. The new reactivity control strategy can achieve shutdown with one safety drum or three control drums, ensuring high-security standards. The present study can provide a theoretical reference for the design of space nuclear reactors.

사용후핵 연료 관리 이슈 공론장과 그 갈등구조에 관한 소고 (The Public Sphere and the Conflict-Structure in Spent Nuclear Fuel Management)

  • 조성경
    • 방사성폐기물학회지
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    • 제7권1호
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    • pp.49-62
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    • 2009
  • 사용후핵 연료 관리 정책 결정 에 있어 사회적 수용성은 중요한 의미를 갖는다. 본고에서는 그 역동적 과정을 담아낼 그릇으로서 공론장을 제안한다. 즉, 사용후핵 연료 관리 정책에 대한 공론장은 무엇이고, 공론장의 주체인 이해관계자들은 누구이며 또 공론장에 내재된 갈등구조는 어떠한지에 대해 살펴보고, 바람직한 공론장의 조건에 대해 논의한다. 공론장은 다양한 이해관계자와 시민이 스스로의 의지를 바탕으로 정책의 결정과정에 영향을 미칠 수 있는 기제와 제도를 의미한다. 현실성 있고 효과적인 공론장을 구축하고 운영하기 위해서는 사용후핵 연료 관리를 둘러싼, 정치, 외교안보, 경제, 사회문화, 법과 제도에 관한 면밀한 분석과 대응방안 마련이 필요하다.

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Development of a novel reconstruction method for two-phase flow CT with improved simulated annealing algorithm

  • Yan, Mingfei;Hu, Huasi;Hu, Guang;Liu, Bin;He, Chao;Yi, Qiang
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1304-1310
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    • 2021
  • Two-phase flow, especially gas-liquid two-phase flow, has a wide application in industrial field. The diagnosis of two-phase flow parameters, which directly determine the flow and heat transfer characteristics, plays an important role in providing the design reference and ensuring the security of online operation of two-phase flow system. Computer tomography (CT) is a good way to diagnose such parameters with imaging method. This paper has proposed a novel image reconstruction method for thermal neutron CT of two-phase flow with improved simulated annealing (ISA) algorithm, which makes full use of the prior information of two-phase flow and the advantage of stochastic searching algorithm. The reconstruction results demonstrate that its reconstruction accuracy is much higher than that of the reconstruction algorithm based on weighted total difference minimization with soft-threshold filtering (WTDM-STF). The proposed method can also be applied to other types of two-phase flow CT modalities (such as X(𝛄)-ray, capacitance, resistance and ultrasound).

뉴스초점 - 북한의 미사일 발사 그리고 핵실험 (North's Launching Their Missile and Nuclear Test)

  • 주승환
    • 기술사
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    • 제42권3호
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    • pp.35-40
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    • 2009
  • After the yield of North Korea conducted underground the first nuclear test in 2006, which was less than a kiloton, it launched a vehicle on this April 9 again, which is believed to be a Taepo-dong 2 missile, defying international warnings that the move would violate U.N. resolutions, from Musudan-ni, North Korea. Its development and proliferation of ballistic missile and nuclear bomb technology pose a threat to the northeast Asian region and to international peace and security. In the other launching the missile, a newspaper reported that "While the launch was dubbed a failure by the U.S., it was an improvement over the North Koreans' July 2006 test of the Taepodong-2, said Green of the Center for Strategic and International Studies. "It was definitely better than last time, but it's still not an operational system," Green said.

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원자력시설의 사이버보안 검사를 위한 점검툴 활용에 관한 연구 (A Study on Inspection Tools for Cyber Security on Nuclear Facilities)

  • 변예은;김현두
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2016년도 춘계학술발표대회
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    • pp.274-276
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    • 2016
  • 2014년 12월, 한국수력원자력의 사이버테러, 이란의 원자력 농축시설을 대상으로 한 사이버공격 등 국내외에서 원자력시설을 대상으로 한 사이버공격이 발생하고 있다. 이에 따라, 사이버보안 중요성이 증가하면서 방사선 재해방지와 공공의 안전을 위한 효과적인 규제체계의 필요성이 증가하였다. 한국원자력통제기술원은 개정된 방사능방재법에 따라 2014년부터 사이버보안 정기검사를 수행하고 있으며, 정기검사에 활용할 취약점 점검툴을 통해 정기검사의 효과성 및 수행능력을 향상시키고자 한다.

Prediction of Possible Intercept Time by Considering Flight Trajectory of Nodong Missile

  • Lee, Kyounghaing;Oh, Kyunngwon
    • International Journal of Aerospace System Engineering
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    • 제3권2호
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    • pp.14-21
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    • 2016
  • This paper presents research on predicting the possible intercept time for a Nodong missile based on its flight trajectory. North Korea possesses ballistic missiles of various ranges, and nuclear warhead miniaturization tests and ballistic missile launch tests conducted last year and in previous years have made these missiles into a serious security threat for the international community. With North Korea's current miniaturization skills, the range of the nuclear capable Nodong missiles can be adjusted according to their use goals and operating environment by using a variety of adjustment methods such as payload, fuel mass, Isp, loft angle, cut-off, etc., and therefore precise flight trajectory prediction is difficult. In this regards, this research performs model simulations of the flight trajectory of North Korea's domestically developed Nodong missiles and uses these as a basis for predicting the possible intercept times for major ballistic missile defense systems such as PAC-3, THAAD, and SM-3.