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[en] The transient behavior of the TRIGA Mark-III reactor has been studied for the step reactivity insertion of 2.1% delta k/k. Its transient behavior is evaluated by the Fuchs model with the average fuel heat capacity. The peak power, asymptotic period, total energy release, final core-averaged fuel temperature, andd pulse width by the Fuchs model are compared with those of the safeguards. Analysis report for the KAERI and it is found that the values by the Fuchs model with the variable fuel heat capacity are in good agreement with them. In the transient state of 2.1% delta k/k step reactivity insertion, the values obtained are: a peak power of 2200Mw, an asymptotic period of 2.79 msec, a total energy release of 26.47 Mw-sec, a final core-averaged fuel temperature of 291.9 deg C, and a pulse width of 10.60 msec. (Author)
[en] The D and d work requires worker's safety and high reliability of operation because it has been processing in high radioactive environment. Therefore, it is necessary to select the dismantling items and applicable dismantling technologies and analyze the scenarios for selected items. In this paper, the main dismantling items were selected by the consideration of several factors, their 3D CAD models were constructed as well. The applicable dismantling technologies for each dismantling items were selected and their dismantling scenarios were setup. Finally the 3D graphic simulations for the shielding concrete, the RSR, and the core are performed
[en] According to the KRR-1 and 2 decommissioning project, the KRR-2 bio-shielding concrete was dismantled. Total 1,913 tons of concrete, which both activated and non-activated concrete was raised than the estimation as volume of 650 m3 from the size of 9.7 m (W) x17.4 m (L) x 7.8 m (H). The density of the normal concrete is around 2.4 Ton/m3 and it's of heavy concrete is around 3.0 Ton/m3. Before the main activities, the radiation characterization was evaluated for making the mapping between the activated and non-activated concrete. For dismantling, the technologies of the core boring, diamond wire sawing and hydraulic crushing were applied. During 6 months, total 1,964 man-days were consumed. Among the dismantled waste, only 13.2 % of concrete waste was classified as radioactive waste than which were temporally store in the KRR-2 reactor hall as of 38 EA, 4m3 containers and 59 EA. 200 liter drums
[en] This book starts the background of this writing, the letter to his father, a brief summary of his career. It is Dr. Kim Dong Hun's an autobiographical report about introduction into nuclear power, building TRIGA Mark-III and propel the business of research reactor, establishing nuclear safe center, beginning and president Lee, Seung Man, passion over TRIGA. It deals with carrying out building the HANARO about background, the process of the business.
[en] According to the KRR-1 and 2 decommissioning project, the KRR-2 bio-shielding concrete was dismantled. Total 1,913 tons of concrete, where both the activated and non-activated concrete dismantle was more than the estimation with a volume of 650 m3 from the size of 9.7 m (W) x 17.4 m (L) x 7.8 m (H). The density of the normal concrete was around 2.4 Ton/m3 and that the heavy concrete was around 3.0 - 3.2 Ton/m3. Before the main activities, the radiation was evaluated to create a boundary between the activated and non-activated concrete. For the dismantling, the technologies of a core boring, diamond wire sawing and hydraulic crushing were applied. During 6 months, a total of 1,964 mandays were consumed. Among the dismantled waste, only 13.2 % of the concrete waste was classified as radioactive waste which is temporally being stored in the KRR-2 reactor hall as 38 EA, 4m3 containers and 59 EA, 200 liter drums
[en] Characteristics of heat release process, while the Wigner energy was drawn off the graphite during DSC(Differential Scanning Calorimenter) measurement as an example of annealing process which is one of release methods of Wigner energy that is contained in the irradiated graphite, was studied. Linear temperature rise method in DSC operation was selected to estimate the total Wigner energy content and the heat release rate of each graphite samples, which were located in several positions in the thermal column in KRR-2 research reactor. As an annealing process in DSC operation Wigner energy of the irradiated graphite samples were totally released by heat supplying to the graphite from room temperature to 500 .deg., in DSC. Characteristics of Wigner energy release from the graphite sample was well correlated with the various activation energy model of the kinetic equation.
[en] At present, two research reactors are operated at the Korea Atomic Research Institute, namely, one being a TRIGA Mark-II reactor of 250-kW power rating and the other a TRIGA Mark-III reactor of 2 MW, both of General Atomic design. Design characteristics and operations for the reactors are reviewed
[en] The practical decommissioning work was started from June 2001 in accordance with the approval of licensing documents for KRR-1 and 2 decommissioning project from government. In the first plan, reactor room of the KRR-2 was planed to decommission at first, but in order to acquire experience for decommissioning of nuclear facilities radioisotopes production facilities and laboratories was almost finished except some area in Dec. 2002, from 2003 reactor room of KRR-2 will be decommissioning for about 2 years. During the accomplished decommissioning work, exposure dose for work was very low compared with regulatory level, and total wastes produced by decommissioning was about 67 ton, which was almost nonradioactive waste
[en] KAERI is performing research to calculate a coefficient for decommissioning work unit productivity to calculate the estimated time decommissioning work and estimated cost based on decommissioning activity experience data for KRR-2. KAERI used to calculate the decommissioning cost and manage decommissioning activity experience data through systems such as the decommissioning information management system (DECOMMIS), Decommissioning Facility Characterization DB System (DEFACS), decommissioning work-unit productivity calculation system (DEWOCS). In particular, KAERI used to based data for calculating the decommissioning cost with the form of a code work breakdown structure (WBS) based on decommissioning activity experience data for KRR-2.. Defined WBS code used to each system for calculate decommissioning cost. In this paper, we developed a program that can calculate the decommissioning cost using the decommissioning experience of KRR-2, UCP, and other countries through the mapping of a similar target facility between NPP and KRR-2. This paper is organized as follows. Chapter 2 discusses the decommissioning work productivity calculation method, and the mapping method of the decommissioning target facility will be described in the calculating program for decommissioning work productivity. At KAERI, research on various decommissioning methodologies of domestic NPPs will be conducted in the near future. In particular, It is difficult to determine the cost of decommissioning because such as NPP facility have the number of variables, such as the material of the target facility decommissioning, size, radiographic conditions exist
[en] As the number of obsolete research reactors and nuclear facilities increases, dismantling nuclear facilities has become an influential issue. During the decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete wastes are generated. In Korea, the decontamination and decommissioning of the retired TRIGA MARK II and III research reactors and a uranium conversion plant at KAERI has been under way. By dismantling KRR-2, more than 260 tons of radioactive concrete wastes were generated among the total 2,000 tons of concrete wastes and more than 60 tons of concrete wastes contaminated with uranium compounds have been generated. Typically, the contaminated layer is only 1∼10mm thick because cement materials are porous media, the penetration of radionuclides may occur up to several centimeters from the surface of a material. Concrete is a structural material which generally consists of a binder (cement), water, and aggregate. The binder is typically a portland cement which comprises the four principal clinker phases tricalcium silicate (Ca3SiO5) and constitutes 50-70%, decalcium silicate (Ca2SiO4), tricalcium aluminate (Ca3Al2O6), and calcium aluminoferrite (Ca4Al2Fe2O10). Cement powder (anhydrous cement) created from the co-grinding of clinkers and gypsum is mixed with waster and hydrate phase are formed. The interaction between highly charged C-S-H particles in the presence of divalent calcium counter ions is strongly attractive because of ion-ion correlations and a negligible entropic repulsion. In the temperature range 100-300 .deg. C, these evolutions are mainly attributed to the loss of the bound water from the C-S-H gel. Similar consequences have been reported for mortars and concretes enhanced sometimes by the appearance of micro-cracks related to the strain incompatibilities between the aggregates and the cement paste. Concrete aggregates are combined mutually strongly by hydrated cement paste. Radionuclides may be found in cement-base materials. The cement fine powder should be stabilized for disposal criteria in a final disposal repository. The aim of this study was to establish the optimized solidification conditions for the treatment of concrete paste contaminated with radioniclides. The solidification tests had been performed using the pastes which were contaminated with the radionuclide generated from TRIGA MARK II and uranium conversion plant.