• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.155-159
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• 2013

Late effects of chronic exposure to gamma radiation are potential hazards to worker in radiation facilities as well as to the general public. Recently, chronic gamma radiation exposure effects have become a serious concern. Using a total of 60 mice, we studied the biological effects of medium-dose chronic exposure to gamma radiation. Sixty female 6-week-old specific pathogen free Balb/c mice were randomly divided into six groups (five groups irradiated and one non-irradiated control group). Irradiation was carried out for 7 days using gamma rays at dose rates of 119.65, 238.10, 357.14, 476.19 and $595.24mGy\;h^{-1}$ with total doses 20, 40, 60, 80 and 100 Gy. After irradiation, we determined survival rate of gamma radiation exposed mice during 1 week and 476.19 and $595.24mGy\;h^{-1}$ exposed group mice showed less 10% of survival rate. Otherwise, 119.65, 238.10 and $357.14mGy\;h^{-1}$ exposed group mice were survived each 100%, 80% and 70%. Half of survived mice after 1 week are immediately sacrifice and counted body and spleen weights. Compared with control non-irradiated group, total body weights and spleen weights isolated from 119.65, 238.10 and 357.14 irradiated group mice showed significant decreased. However, no significant alteration was observed between 119.65, 238.10 and $357.14mGy\;h^{-1}$ irradiated group. Overall, our results show for the first time that medium-dose chronic gamma radiation has the potential to stimulation of biological effects.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.11-15
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• 2014

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for freeze dried fruits which are not allowed to be irradiated in Korea. Apples and persimmons samples that had been dried with a freeze drier were irradiated at a dose of 1, 3, 5, 7, and 10 kGy, using a gamma radiator with a cobalt-60 source. With the PSL method, the dried apples showed photon counts of less then 700 counts/60 s (negative) in all the samples, whereas the dried persimmons that were gamma-irradiated above 3 kGy yielded photon counts of between 700 and 5,000 counts/60 s (intermediate). The TL results showed that this technique is useful for detecting irradiated samples; the TL ratios ($TL_1/TL_2$) measured for the food samples at an irradiation dose of 1 kGy were 0.13 for dried apples and 0.79 for dried persimmons. With regard to the results of ESR spectroscopy, the strength of the ESR signals from the dried fruits increased linearly in a dosedependent manner. However, the characteristic signal was not found in all the samples. In conclusion, the TL methods only can be used for the detection of gamma-irradiated dried apples and persimmons.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.31-40
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• 2012

There are two methods to fabricate the readout electronic to a large-area CMOS image sensor (LACIS). One is to design and manufacture the sensor part and signal processing electronics in a single chip and the other is to integrate both parts with bump bonding or wire bonding after manufacturing both parts separately. The latter method has an advantage of the high yield because the optimized and specialized fabrication process can be chosen in designing and manufacturing each part. In this paper, LACIS chip, that is optimized design for the latter method of fabrication, is presented. The LACIS chip consists of a 3-TR pixel photodiode array, row driver (or called as a gate driver) circuit, and bonding pads to the external readout ICs. Among 4 types of the photodiode structure available in a standard CMOS process, $N_{photo}/P_{epi}$ type photodiode showed the highest quantum efficiency in the simulation study, though it requires one additional mask to control the doping concentration of $N_{photo}$ layer. The optimized channel widths and lengths of 3 pixel transistors are also determined by simulation. The select transistor is not significantly affected by channel length and width. But source follower transistor is strongly influenced by length and width. In row driver, to reduce signal time delay by high capacitance at output node, three stage inverter drivers are used. And channel width of the inverter driver increases gradually in each step. The sensor has very long metal wire that is about 170 mm. The repeater consisted of inverters is applied proper amount of pixel rows. It can help to reduce the long metal-line delay.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.135-139
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• 2013

Recently, chronic gamma radiation exposure on biological effects in middle dose-rates have become a serious concern. We investigated the biological effects of middle dose chronic exposure to gamma ray. Fifty male 6-week-old specific free Balb/c mice were randomly divided into five groups (four groups irradiated and one non-irradiated control group). Gamma radiation exposed in Gamma phytotron on Advanced Radiation Technology Institute (Jeongeup, Korea). Irradiation was carried out for 1 or 2 weeks using gamma rays at dose rates of 45 and $50mGy\;h^{-1}$ with total doses 7.56 Gy ($45mGy\;h^{-1}$, 1 week), 8.4 Gy ($50mGy\;h^{-1}$, 1 week), 15.12 Gy ($45mGy\;h^{-1}$, 2 weeks) and 16.8 Gy ($50mGy\;h^{-1}$, 2 weeks). After irradiation, immediately we sacrificed and counted body and organ weights. Moreover we counted spleen cell numbers. Compared with control non-irradiated group, all irradiated groups of body and spleen weights showed significant decreased. However, no significant alteration was observed between same irradiated period groups. In spleen cell numbers, reduced compared to the control group. However, significant alteration was observed between same irradiated period groups ($45mGy\;h^{-1}$, $50mGy\;h^{-1}$). These results demonstrated biological effects according to the radiation dose rate and irradiated period.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.279-298
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• 2019

This study comprehensively addresses recent progress at KAERI in waste treatment technology to cope with waste produced by pyroprocessing, which is used to effectively manage spent fuel. The goal of pyroprocessing waste treatment is to reduce final waste volume, fabricate durable waste forms suitable for disposal, and ensure safe packaging and storage. KAERI employs grouping of fission products recovered from process streams and immobilizes them in separate waste forms, resulting in product recycling and waste volume minimization. Novel aspects of KAERI approach include high temperature treatment of spent oxide fuel for the fabrication of feed materials for the oxide reduction process, and fission product concentration or separation from LiCl or LiCl-KCl salt streams for salt recycling and higher fission-product loading in the final waste form. Based on laboratory-scale tests, an engineering-scale process test is in progress to obtain information on the performance of scale-up processes at KAERI.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.15-20
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• 2019

Background and Objectives : The goal of this study is to present a strategy for improving the self-regulation (SR) ability and facilitating the change of vocal behavior by applying voice therapy using the SR concept to the patients with vocal cord nodule and muscle tension dysphonia. Materials and Method : The subjects were 80 patients and 80 patients who were diagnosed with muscle tension dysphonia and vocal nodules. As a control group, the results were compared among patients with the same dysphonia without using SR strategies. The concept of SR before voice therapy was explained to the patients, and the treatment was divided into three stages according to the goal of voice therapy. The treatment stages consist of 1) skill acquisition, 2) habit formation, and 3) habit changes. voice therapy was performed by applying SR strategies such as goal implementation intentions and a less routine behavior. Patient's dropout rates were measured to compare the adherence of voice therapy. Results : Significant improvement was seen in all groups receiving voice therapy. However, in the group using the SR strategy, the voice analysis results showed a relatively low dropout rate of voice therapy. In the generalization confirmation stage, patients who applied SR concept showed better results. SR strategy did no longer be necessary to maintain newly adopted vocal behavior. Conclusion : The results of this study show that SR is one of the cognitive factors that can have a significant impact on the outcome of voice therapy, and also has a positive impact on the acquisition and generalization of new skills. A better understanding of SR and the development of therapeutic strategies using it will play an important role in solving voice problems in clinical settings.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.5
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• pp.384-389
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• 2014

In this paper, the result of an ultrasonic performance demonstration are analyzed. The requirements for an ultrasonic performance demonstration (PD) for a nuclear power plant were first described in ASME B&P Code Section XI, Appendix VIII (1989 winter addenda). In order to establish the performance demonstration scheme in Korean nuclear power plants, the Korea Hydro & Nuclear Power Co. Ltd (KHNP) has developed the Korean Performance Demonstration (KPD) system for the for the ultrasonic examination of nuclear power plants. An analysis of the ultrasonic performance demonstration results from 2004 through 2013 will improve the detection of flaws in an ultrasonic examination, as well as the further development of the KPD training system.

• Journal of Korea Technology Innovation Society
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• v.18 no.1
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• pp.126-150
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• 2015

Korea's experiences in the use and development of nuclear energy are recognized as a successful model as a developing country in the international nuclear community. With these experiences, Korea is able to contribute to the progress of Korean nuclear industry and international society as a nuclear advanced country. This paper reviews and analyzes the current situation and major issues in securing the international legal status of RCA Regional Office hosted by Korean Government since 2002. In this connection, major political environments and relevant issues in facilitating the revision of RCA Agreement and securing legal status of the RCARO are also investigated. It is essential to amend the 1987 RCA Agreement or to conclude the its supplementary agreement for the securing of the international legal status of RCA Regional Office at the RCA policy meeting prior to extension of the agreement in 2017 and after. It is recommended for the Korean Government to establish and operate the inter-ministry governmental task force teams to facilitate and support the required actions in the national and diplomatic actions in the regional level for the sustainable development of the RCA and RCA Regional Office.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.317-323
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• 2010

The manual ultrasonic examination for the nuclear power plant piping welds has been demonstrated by using KPD(Korean Performance Demonstration) generic procedure. For automated ultrasonic examination, there is no generic procedure and it should be qualified by using applicable automated equipment. Until now, most of qualified procedures used pulse-echo technique and there is no qualified procedure using phased array technique. In this study, data acquisition and analysis software were developed and phased-array transducer and wedge were designed to implement phased array technique for nuclear power plant in-service inspection. The developed procedure are qualified for performance demonstration for the flaw detection, length sizing and depth sizing. The qualified procedure will be applied for the field examination in the nuclear power plant piping weld inspection.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.51-57
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• 2007

In this study, We analyzed change of sea surface temperature due to cooling water around nuclear power station. Study area is around of Uljin nuclear power station, which is relatively large power station. There are many problems in monitering environmental change around of nuclear power station, because area is relatively large. We used Landsat 5, 7 Imagery which are useful in temperature analysis and can be easily obtained. After we georeferenced Landsat Imagery, radiance and sea surface temperature were calculated. As a result, As we compared sea surface temperature of surrounding area of nuclear power station with same area located 3 km east, there are $2.049^{\circ}C$ temperature difference.