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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
Journal Basic Information
Journal DOI :
The Korean Radioactive Waste Society
Editor in Chief :
Volume & Issues
Volume 8, Issue 4 - Dec 2010
Volume 8, Issue 3 - Sep 2010
Volume 8, Issue 2 - Jun 2010
Volume 8, Issue 1 - Mar 2010
Selecting the target year
Effect of a Hydrothermal Reaction on the Expandibility, Layer Charge, and CEC of Smectite Clay
Lee, Jae-Owan ; Cho, Won-Jin ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 173~179
In a HLW repository, the buffer is exposed to an elevated temperature due to a radioactive decay and geochemical conditions for a long time and such a hydrothermal condition may cause a significant loss of its barrier function. This study carried out hydrothermal tests with a domestic smectite clay to investigate the changes in the expandibility, layer charge, and cation exchange capacity of the smectite. When the temperature and potassium concentration in solution was increased for the hydrothermal treatments, the expandibility decreased, the layer charge negatively increased, and the CEC also decreased.
Decontamination Characteristics of 304 Stainless Steel Surfaces by a Q-switched Nd:YAG Laser at 532 nm
Moon, Jei-Kwon ; Baigalmaa, Byambatseren ; Won, Hui-Jun ; Lee, Kune-Woo ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 181~188
Metal surface decontamination characteristics were investigated by using a laser ablation method. A second harmonic generation of a Q-switched Nd:YAG laser with a wave length of 532 nm, a pulse energy of 150 mJ and a pulse width of 5 ns was employed to assess the decontamination performance for metal surfaces contaminated with
. The ablation behavior was investigated for the decontamination variables such as a number of laser shots, laser fluence and an irradiation angle. Their optimum values were found to be 8, 13.3 J/
, respectively. The decontamination efficiency was different depending on the kinds of the contaminated ions, due to their different melting and boiling points and was in the order: $CsNO_3>Co(NH_4)_2(SO_4)_2>Eu_2O_3>CeO_2$. We also evaluated a correlation between the metal ablation thickness and the number of laser shots for the different laser fluences.
A Study on the Determination of the Seasonal Heat Transfer Coefficient in KURT Under Forced Convection
Yoon, Chan-Hoon ; Kwon, Sang-Ki ; Hwang, In-Phil ; Kim, Jin ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 189~199
In a high-level waste (HLW) repository, heat is generated by the radioactive decay of the waste. This can affect the safety of the repository because the surrounding environment can be changed by the heat transfer through the rock. Thus, it is important to determine the heat transfer coefficient of the atmosphere in the underground repository. In this study, the heat transfer coefficient was estimated by measuring the indoor environmental factors in the Korea Atomic Energy Research Institute Underground Research Tunnel (KURT) under forced convection. For the experiment, a heater of 5 kw capacity, 2 meters long, was inserted through the tunnel wall in the heating section of KURT in order to heat up the inside of the rock to
, and fresh air was provided by an air supply fan connected to the outside of the tunnel. The results showed that the average air velocity in the heating section after the provision of the air from outside of the tunnel was 0.81 m/s with the Reynolds number of 310,000~340,000. The seasonal heat transfer coefficient in the heating section under forced convection was
in the summer and
in the winter.
X-ray Absorption Spectra Analysis for the Investigation of the Retardation Mechanism of Iodine Migration by the Silver Ion Added to Bentonite
Kim, Seung-Soo ; Kim, Min-Gue ; Baik, Min-Hoon ; Choi, Jong-Won ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 201~205
Most of iodine was captured by the block when NaI solution flowed through a bentonite block sorbed silver to retard the migration of iodine released from high-level radioactive wastes. In order to understand in detail the mechanism for the retardation of the iodine by the silver ion, X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) spectra of the silver sorbed bentonite before and after the contact with iodide were compared with those of AgO,
and AgI as references. This examination suggests that the silver ion sorbed on the bentonite is desorbed, and then it retards the migration of iodine by forming the cluster of AgI precipitate.
Temperature Effect on the Swelling Pressure of a Domestic Compacted Bentonite Buffer
Lee, Ji-Hyeon ; Lee, Min-Soo ; Choi, Heui-Joo ; Choi, Jong-Won ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 207~213
The effect of temperature on swelling pressure was observed with a Korean domestic Ca-bentonite which has been considered as a potential buffer material in the engineering barrier of a high level radioactive waste (HLW) disposal system. The Ca-bentonite was compacted to a dry density of 1.6 g/
, and then de-ionized water was supplied into it with a constant pressure of 0.69 MPa. The equilibrium swelling pressures were measured with different temperatures of
, respectively. The Ca-bentonite showed a sufficiently high swelling pressure of 5.3 MPa at room temperatures. Then it was clearly showed that the equilibrium swelling pressure was decreased with an increase of temperature. Interestingly, there were some differences in temperature effect on the equilibrium swelling pressure when the environmental temperature is increasing or decreasing. For further clarifying the swelling behaviour of a Korea domestic Ca-bentonite, the change of a compaction level, and the composition variation of a supplied water would be needed to use in conceptual design of HLW disposal system.
The Measurement of Radionuclides Concentration Ratio of the Aquatic Animal using the Chinese Minnow(Rhynchocypris Oxycephalus)
Jun, In ; Lim, Kwang-Muk ; Choi, Yong-Ho ; Keum, Dong-Kwon ; Park, Doo-Won ; Han, Mun-Hee ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 215~220
An experiment measuring the concentration ratios of
in fish as an index aquatic animal was performed. The species was Chinese minnow (Rhynchocypris Oxycephalus), a Korean native freshwater species. Chinese minnows were reared in acryl aquarium which was 45 cm wide, 85 cm long and 50 cm high. Water in the aquarium was successively purified using filtering devices attached on the floor and the wall. Fish powder in a particulate form was supplied twice a day for feeding. After a radioactive solution was added to make the initial water concentrations approximately
, respectively, the fish and water were sampled 10 times for a month. The concentration ratios were measured to be
Study on Pre-treatment Method for Vitrification of Concentrated Wastes
Cho, Hyun-Je ; Kim, Deuk-Man ; Park, Jong-Kil ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 221~227
The solidification methods for powder wastes dried at CWDS(Concentrate Waste Drying System) in PWR have been studied in a variety of ways both at home and abroad. The solidification for these wastes has been performed using stabilization agents such as cement, paraffin and polymer. The applicability studies to maximize the reduction ratio of wastes and operational effectiveness for wastes treatment have been carried out, recently. It is necessary to pretreat the powder wastes before feeding wastes to vitrification facility because the fines flying brings about clogging of feeding pipes and off-gas treatment system or workers' exposure to radiation during maintenance. This paper describes an effective method for treatment of powder wastes to improve safety and stability of vitrification facilities.
Analysis of Case Studies on Experimental Research of Gas Generation in Foreign Countries for Low- and Intermediate-level Radioactive Waste Disposal
Park, Jin-Beak ; Lee, Sun-Joung ; Kim, Suk-Hoon ; Kim, Ju-Youl ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 229~238
In order to acquire a realistic forecast for the lifetime and post-closure period of the LILW (Low- and Intermediate-Level Radioactive Waste) repository and to establish the overall management plan associated gas issues. it is essential to carry out the long-term experimental research in a similar condition to actual disposal environment. Regarding this, as a part of the following-up actions on a construction and operation license for the first stage of the LILW repository at Gyeongju city, a large-scale in-situ experiment is being planned. For securing basic data on the experiment, the experimental researches related to gas generation previously performed in foreign countries are reviewed in detail. Consequently, it is judged that data on the gas generation experiment in Finland could be practically applied as the benchmark for our large-scale in-situ experiment because the same disposal concept as the Korean repository is adopted and the experiment is performed in a scale large enough to allow the use of regular waste packages.
Development of a Simplified Source Term Estimation Model for a Spent Fuel from Westinghouse-type Reactors
Cho, Dong-Keun ; Kook, Dong-Hak ; Choi, Heui-Joo ; Choi, Jong-Won ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 239~245
There are 11,811 LWR spent fuels stored at reactor sites, as of 2009. Source terms based on reference spent fuel which represents entire spent fuels with bounding values in the aspect of source term has been applied to a design of nuclear installations, instead of those which are generated by weighting respective source term for each spent fuel. Simplified regression models to estimate total decay heat, radioactivity, and ingestion hazard index for spent fuel from Westinghouse-type reactors were developed in this study, because it can be used as a fundamental model for weighting source term for respective spent fuel to exclude conservativeness in source terms. It was found that the estimated source terms agreed with calculated value from ORIGEN-ARP within 5%. It was also found that the conservativeness could be excluded if the weight source terms were used as reference source term in the design. Therefore, it is expected that the developed regression model could be widely used in the conceptual design process of nuclear facilities related with storage and disposal of spent nuclear fuel.
Crevice Corrosion Evaluation of Cold Sprayed Copper
Lee, Min-Soo ; Choi, Heui-Joo ;
Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT), volume 8, issue 3, 2010, Pages 247~260
The developement of a HLW disposal canister is under way in KAERI using Cold Spray Coating technique. To estimate corrosion behavior of a cold sprayed copper, a creivice corrosion test was conducted at Southwest Research Institute(SWRI) in the United State. For the measurement of repassivation potential needed for crevice corrosion, three methods such as (1) ASTM G61-86 : Cyclic Potentiodynamic Polarization Measurements, (2) Potentiodynamic Polarization plus intermediate Potentiostatic Hold method, and (3) ASTM G192-08 (THE method) : Potentiodynamic- Galvanostatic-Potentiostatic Method, were introduced in this report. In the crevice corrosion test, the occurrence of corrosion at crevice area was optically determined and the repassivation potentials were checked for three kind of copper specimens in a simulated KURT underground water, using a crevice former dictated in ASTM G61-86. The applied electrochemical test techniques were cyclic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy. As a result of crevice corrosion tests, every copper specimens including cold sprayed one did not show any corrosion figure on crevice areas. And the open-cell voltage, at which corrosion reaction initiates, was influenced by the purity of copper, but not their manufacturing method in this experiment. Therefore, it was convinced that there is no crevice corrosion for the cold sprayed copper in KURT underground environment.