[en] Japan has systematically revamped its technical standards for nuclear reactor facilities by formulating various performance regulations. Being part of a trend toward deregulation, such efforts toward social regulation is aimed at effectively operating administrative procedural laws to keep pace with global trends and enhance the benefits of deregulation under the principle of self-responsibility. Based on the collection of public opinions in February and March 2005, the Nuclear and Industrial Safety Agency(NISA) presented its position that it was required to promptly perform a flexible assessment of the technical feasibility of formulated society and association standards. Current, pressing issues are summarized as an early revision of technical standards regarding nuclear facilities for power generation, use of society and association standards, and the overhaul of nuclear safety regulations subject to performance regulations. Subjecting technical standards to performance regulations means stipulating the qualitative aspects of performance and the targets that certain facilities must achieve, which are not specific standards, but general compulsory standards. This study examines the early revision of technical standards on nuclear facilities for power generation and the status of the use of society and association standards, as well as introducing the details of revisions in the concrete containment vessel standards as specific examples

[en] Two dimensional slices of the cross-sectional distributions of fuel images in the combustion chamber were visualized quantitatively using a laser-induced exciplex (excited state complex) fluorescence technique. A new exciplex visualization system consisting of 5%DMA (N, N-dimethylaniline) · 5%1, 4,6-TMN (trimethylnaphthalene) in 90% isooctane (2,2,4-trimethylpentane) fuel was employed. In this method, the vapor phase was tagged by the monomer fluorescence while the liquid phase was tracked by the red-shifted exciplex fluorescence with good spectral and spatial resolution. The direct calibration of the fluorescence intensity as a function of the fluorescing dopant concentrations then permitted the determination of quantitative concentration maps of liquid and vapor phases in the fuel. The 308 nm (XeCl) line of the excimer laser was used to excite the doped molecules in the fuel and the resulting fluorescence images were obtained with an ICCD detector as a function time. In this paper, the spectroscopy of the exciplex chemical sensors as well as the optical diagnostic method of the fluid distribution is discussed in detail.

[en] Before May 17, 2005, Korea's nuclear power plant (hereinafter referred to as 'NNP') regulation system was two-pronged. Every NPP system consists of primary or secondary system, and each type was respectively regulated by the Atomic Energy Act(hereinafter referred to as 'AEA') and the Electric Utility Act(hereinafter referred to as 'EUA'). This unusual regulatory regime gave rise to a number of problems with respect to operation and safety. For this reason, the Enforcement Regulation of AEA and applicable Notice were revised on May 17, 2005 to the effect that all regulation on NPPs subject to EUA was brought under the purview of AEA, except regulation on business license for nuclear power generation under Article 7 of EUA and approval of plan of works for setting up electric installations (hereinafter referred to as 'construction plan') (including approval of any changes; the same shall apply hereinafter) under Article 61 thereof. From the point of view of the Ministry of Science and Technology, the regulation of NPPs by a single law has enhanced their safety. However, the Ministry of Commerce, Industry and Energy retains regulatory authority regarding NPPs. It reviews and approves construction plans for secondary system pursuant to Article 61 of EUA and Article 28 of the Enforcement Regulation thereof. This situation arose because Article 28 of the Enforcement Regulation of EUA continues to provide for matters related with nuclear power. Therefore, continued control of NPPs under EUA ignores the relationship and respective nature of AEA and EUA. There is also possibility of violation of a superseding law. Even if said provision is not in violation of a superseding law, Article 28 of the Enforcement Regulation of EUA poses the possibility of overlapping regulation, which may violate the principle of prohibiting excessive regulation, one of the principles of the Korean Constitution. Assessment of the dual regulatory system for review of secondary system requires (i) identifying problems by analyzing the nature of AEA and EUA and the regulatory law system on NPPs and (ii) ascertaining the legitimacy of the dual regulatory system according to the legal principles of the Constitution and administrative law

[en] With regard to the nuclear reactor permission system under the Atomic Energy Act of the Republic of Korea, two types of permits must be obtained for nuclear power reactors under Article 11 and Article 21 of the Atomic Energy Act: construction permits and operation permits. Concerning nuclear reactors for research, however, only one permit is required: a dual permit that authorizes both construction and operation, under Article 33 of said act. This permit can be obtained by submitting an application for a dual construction and operation permit to the regulatory authority. The question is whether a dual permit can be issued for nuclear reactors for research under any circumstances. If the literal provisions of the Atomic Energy Act are applied rigorously even in cases where it is realistically difficult to submit a dual permit application or issue a dual permit for construction and operation considering the power output, usage, and design complexity of nuclear reactors for research, separate permits for construction or operation shall never be issued, with only dual permits for construction and operation issued. For the Hanaro research reactor, a dual permit was issued with a condition attached thereto based on the literal provisions of the Atomic Energy Act at the time of its construction, although an application for and issuance of a dual permit for its construction and operation were impossible at the time. This is in violation of the purport of the law that provides for a dual permit

[en] The additional clauses refer to 'subordinate regulations applied to primary acts in order to limit the effect of administrative acts (conditions and time limits), impose special obligations (burden) or complement requirements (reservation of the right to withdrawal and reservation of posterior changes).' Its merits include the following: i) it is possible to work out a compromise between accepting and rejecting applications by attaching additional clauses to certain measures (flexibility in permitting administrative acts); ii) it is possible to prevent re-applications and re-examinations after rejection of applications (pursuit of economy of the proceedings); and iii) it is possible to take appropriate actions to protect the interest of third parties or the public interest. Its detriment is that any rescinding additional clauses including rescission conditions, time limit(expiring time) and reservation of the right to withdrawal may generate results where the costs incurred for adaptation of posterior changes after administrative act(measures taken) are transferred to the counter-party

[en] Technical standards by legal term in Korea are the mandatory requirements which are prescribed in nuclear laws and Notices of the MOST (Minister of Science and Technology). Regulations on Technical Standards for Nuclear Reactor Facilities, etc. (Ministerial Ordinance No.31) prescribes the technical standards on the location, structure, installation, performance, operation, and quality assurance for the design, construction and operation of reactor facilities and nuclear fuel cycle facilities. Although the ordinance was wholly amended in July 2001, the technical standards by the ordinance should be improved in a way because they do not have separate and detail standards for different type of reactor, and still have some mutatis mutandis regulations and so on. Recently, globalization for the safety standards has been pursued. In this environment, technical standards have to be improved to meet the concept of the Atomic Energy Act and the international safety level. In this paper, the structure and components of the technical standards for reactor facilities were reviewed and evaluated comparing with foreign standards such as IAEA safety standards, and considering current regulatory position. Also, the components and contents of the new requirements were suggested

[en] The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual (10 μSv/y) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard

[en] The Atomic Energy Act (hereinafter referred to as 'the Act') contains no provision that sanctions the retroactive application of new safety standards to nuclear facilities in operation to satisfy the development of technology (hereinafter referred to as 'new safety standards'). In addition, the periodic safety review under Article 23-3 of the Act does not set forth application of, nor assessment under, new safety standards. When the fatal and overwhelming impact of nuclear accidents is taken into account, it is advisable to apply the new safety standards retroactively to nuclear facilities in operation. However, retroactive application of new safety standards to nuclear facilities in operation would entail a modification in the standards for permits, etc. Therefore, there exists a risk of violating the principles of the Constitution and administrative laws, namely the principles of the prohibition of retroactive application, safeguarding of good faith and so forth. Accordingly, this report scrutinizes the possibility of introducing retroactive application of new safety standards under the Act (hereinafter referred to as 'retroactive application'), based on the theories of Constitution and administrative laws

[en] The synchrotron-radiation interferometer has been employed to measure the beam size in the storage ring at the 2.5 GeV Pohang Light Source [PLS]. We discuss the optical system of the interferometer and analysis methods to measure the beam size. The PLS has used a Min/Max method to measure the beam size in the ring. In our studies, we also investigated ways in which to optimize the measured results on the beam sizes in the vertical and the horizontal directions by using fitting methods with both Mathematica and Root. We examined the variations in the background by passing time and their effects on the measured beam sizes. In this paper, we present methods for analyzing the measured data that result in improvement the measurement of the beam size in the PLS.

[en] Most of them are contaminated with radionuclides with short half-lives, so they are characterized by a sufficiently safe level of radioactivity when stored for a certain period of time. In 1992, the International Atomic Energy Agency (IAEA) proposed limits for individual dose (10 uSv / y) and collective dose (1 man-Sv / y) for nearby residents on its disposal basis. In addition, the standard concentration of self-disposal was presented through RS-G-1.7 ^Application of the Concepts of Exclusion, Exemption and Clearance^. In order to apply this, there is inconvenience that dose assessment or concentration of radionuclides should be measured. In order to derive such international practices as international standards, it is necessary to set the appropriate storage period for the radioactive waste for medical use up to the concentration level of the IAEA's disposal, to measure and analyze the radioactive contamination of the radioactive waste generated after use at the medical institution, We want to estimate the date of disposal. When radioactive waste samples with natural radiation dose rate status are analyzed by nuclide analysis, the radioactivity exceeding the allowable concentration limit of self-disposal is detected.