• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.77-85
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• 2004

Regulations and guidelines for radioactive waste disposal require detailed information about the characteristics of radioactive waste drums prior to transport to the disposal sites. However, estimation of radionuclide concentrations in the drummed radioactive waste is difficult and unreliable. In order to overcome this difficulty, scaling factor (SF) method has been used to assess the activities of radionuclides, which could not be directly analyzed. A radioactive waste assay system has been operated at Korean nuclear power plant (KORI site) since 1996 and consolidated SF concept has played a dominant role in the determination of radionuclide concentrations. However, SFs are somewhat dispersive and limited in KORI site. Therefore establishment of the assay system using more improved SFs is planned and progressed. In this paper, the scope of research is briefly introduced. For the selection of more reliable activity determination method, the accuracy of predicted SF values for each activity determination method is compared. From the comparison of each activity determination method, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system. And, this change of SF determination method will prevent an inordinate over-estimation of radionuclide inventory in radwaste drum.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1148-1155
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• 2020

This work presents two different methods for quantifying and propagating the uncertainty associated with fuel composition at end of life for cask criticality calculations. The first approach, the computational approach uses parametric uncertainty including those associated with nuclear data, fuel geometry, material composition, and plant operation to perform forward depletion on Monte-Carlo sampled inputs. These uncertainties are based on experimental and prior experience in criticality safety. The second approach, the data-driven approach relies on using radiochemcial assay data to derive code bias information. The code bias data is used to perturb the isotopic inventory in the data-driven approach. For both approaches, the uncertainty in k_eff for the cask is propagated by performing forward criticality calculations on sampled inputs using the distributions obtained from each approach. It is found that the data driven approach yielded a higher uncertainty than the computational approach by about 500 pcm. An exploration is also done to see if considering correlation between isotopes at end of life affects k_eff uncertainty, and the results demonstrate an effect of about 100 pcm.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.2
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• pp.117-123
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• 2012

In order to dispose of the LILW(low and intermediate level radioactive waste) stored at KAERI, the radwaste drum assay system will be introduced to evaluate the radioisotopes inventory of stored drums. At present, the construction project of the dedicated assay facility to operate it and carry out routine maintenance of that equipment has been conducting at the radwaste treatment facility. Since that facility will be constructed in front of a 1st radwaste storage facility as well as the radwaste drums to be assayed and the transmission source in the radwaste drum assay system are in that facility, they could act as the radioactive sources and then, would affect the dose rate at the inside and the outside of the facility. Therefore, the radiation shielding should be evaluated through the concrete wall near to the radioactive sources whether the wall thickness is sufficient against the regulations. In this study, the radiation safety for the concrete wall around the radiation controlled area in the radwaste drum assay facility was evaluated by the MCNP code. From the evaluation results, the thickness of those concrete walls which are under consideration of about 30 cm was enough to shield the radiation from the radioactive sources.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.2
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• pp.194-202
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• 2001

Objectives : Many studies have shown an association between serum lipid concentrations and psychologic characteristics. However, conflicting results have also been reported. This study was designed to find the relationship between serum lipid levels(cholesterol and triglycerides) and psychologic characteristics(impulsiveness, aggressiveness, depressiveness) in adolescents. Methods : Serum cholesterol concentration, serum triglycerides concentration, complete blood count, electrolytes, liver function test, and blood sugar level were measured by overnight fasting blood sampling and urinalysis was also conducted in 407 high school students. Impulsiveness level was measured by Barratt Impulsiveness Scale(BIS). Aggressiveness level was measured by Buss-Durkee Hostility Inventory(BDHI). Depressiveness level was measured by Beck Depression Inventory(BDI). Serum cholesterol was measured by standard enzymatic assay and serum triglycerides was measured by Boehringer Mannheim method. Results : 1) Low cholesterol group(<15 percentile) were found to have significantly higher BIS score than high cholesterol group(>85 percentile) in female. Female low cholesterol group were also found to have significantly higher motor impulsivity score, a subscale of BIS, than high cholesterol group. 2) High triglycerides group(>85 percentile) were found to have significantly higher BDI score than low triglycerides group(<15 percentile) in male and female separately. Especially, male high triglycerides group were also found to have significantly higher BIS and motor impulsivity score than low triglycerides group. Conclusion : These results support the previous hypothesis that serum lipid levels(cholesterol and triglycerides) affect human psychologic characteristics.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1226-1233
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• 2017

Measurements of the isotopic contents of spent nuclear fuel provide experimental data that are a prerequisite for validating computer codes and nuclear data for many spent fuel applications. Under the auspices of the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) and guidance of the Expert Group on Assay Data of Spent Nuclear Fuel of the NEA Working Party on Nuclear Criticality Safety, a new database of expanded spent fuel isotopic compositions has been compiled. The database, Spent Fuel Compositions (SFCOMPO) 2.0, includes measured data for more than 750 fuel samples acquired from 44 different reactors and representing eight different reactor technologies. Measurements for more than 90 isotopes are included. This new database provides data essential for establishing the reliability of code systems for inventory predictions, but it also has broader potential application to nuclear data evaluation. The database, together with adjoint based sensitivity and uncertainty tools for transmutation systems developed to quantify the importance of nuclear data on nuclide concentrations, are described.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.322-327
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• 2003

It is important to know the accurate radionuclide inventory of radioactive waste for the reliable management. However, estimation of radionuclide concentrations in drummed radioactive waste is difficult and unreliable because of difficulties of direct detection, high cost, and radiation exposure of sampling personnel. In order to overcome these difficulties, scaling factors (SFs) have been used to assess the activities of radionuclides that could not be directly analyzed. A radionuclide assay system has been operated at KORI site since 1996 and consolidated scaling factor method has played a dominant role in determination of radionuclides concentrations. However, some problems are still remained such as uncertainty of estimated scaling factor values, inaccuracy of analyzed sample values, and disparity between the actual and ideal correlation pairs and the others. Therefore, it needs to improve the accuracy of scaling factor values. The scope of this paper is focused on the improvement of accuracy and representativeness of calculated scaling factor values based on statistical techniques. For the selection of reliable activity determination method, the accuracy of estimated SF values for each activity determination method is compared. From the comparison of each activity determination methods, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.345-355
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• 2019

Use of the reconstructed fuel assemblies from partially burnt nuclear fuel pins is analyzed. This reutilization option is a potential candidate technique to make better use of the nuclear resources. Standard two step method is used to calculate node i.e. fuel assembly average burnup and then pin by pin ${\eta}$ values are reconstructed to ascertain the residual reactivity in the used fuel pins. Fuel pins with ${\eta}$ > 1:0 are used to reconstruct to-be-reused fuel assemblies. These reconstructed fuel assemblies are burnt during the cycle 3, 4, 5 and 6 of a 1000 MW PWR core by replacing fresh, once burnt and twice burnt fuel assemblies of the reference core configurations. It is concluded that using reconstructed fuel assemblies for the fresh fuel affect dearly on the cycle length (>50 EFPD) when more than 16 fresh fuel assemblies are replaced. However, this loss is less than 20 days if the number of fresh fuel assemblies is less than eight. For the case of replacing twice burned fuel, cycle length could be increased slightly (10 days or so) provided burnt fuel pins from other reactors were also available. Reactor safety parameters, like axial off set (< ${\pm}10%$), Doppler temperature coefficient (<0), moderator temperature coefficient at HFP (<0) are always satisfied. Though, 2D and 3D pin peaking factors are satisfied (<1:55) and (<2:52) respectively, for the cases using eight or less reconstructed fuel assemblies only.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.35-40
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• 2004

Final disposal of radioactive waste generated from Nuclear Power Plant (NPP) requires the detailed information about the characteristics and the quantities of radionuclides in waste package. Most of these radionuclides are difficult to measure and expensive to assay. Thus it is suggested to the indirect method by which the concentration of the Difficult-to-Measure (DTM) nuclide is estimated using the correlations of concentration - it is called the scaling factor - between Easy-to-Measure (Key) nuclides and DTM nuclides with the measured concentration of the Key nuclide. In general, the scaling factor is determined by the log mean average (LMA) method and the regression method. However, these methods are inadequate to apply to fission product nuclides and some activation product nuclides such as 14$^{C}$ and 90$^{Sr}$ . In this study, the artificial neural network (ANN) method is suggested to improve the conventional SF determination methods - the LMA method and the regression method. The root mean squared errors (RMSE) of the ANN models are compared with those of the conventional SF determination models for 14$^{C}$ and 90$^{Sr}$ in two parts divided by a training part and a validation part. The SF determination models are arranged in the order of RMSEs as the following order: ANN model

• Journal of Korean Biological Nursing Science
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• v.12 no.3
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• pp.133-139
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• 2010

Purpose: The purpose of this study was to evaluate the effectiveness of aromatherapy on headache, anxiety, and serum cortisol level in middle-aged women with recurrent headaches. Methods: Nineteen patients in the intervention group and 21 in the control group participated in the exercise. They were randomly selected volunteers whose average headache score over 6 months with above 4 points on the visual analogue scale (VAS). The experimental group received aromatherapy for 5 days; inhalation (3 times per day) and an application on the neck and both shoulders (one time per day). Prior and post treatment scores in headache, anxiety, and measurement of serum cortisol in experimental group were measured. Then, these were compared with the control group. The headache score was measured by VAS; anxiety score was measured by State Trait Anxiety Inventory; serum cortisol was measured by Radio-Immune-Assay method. Results: Decrease in headache, anxiety, and serum cortisol level in the experimental group was greater than those in the control group. Conclusion: It confirmed aromatherapy is effective in reducing headache, anxiety, and serum cortisol level.

• Natural Product Sciences
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• v.8 no.1
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• pp.1-15
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• 2002

An International Cooperative Biodiversity Group (ICBG) program based at the University of Illinois at Chicago initiated its activities in 1998, with the following specific objectives: (a) inventory and conservation of of plants of Cuc Phuong National Park in Vietnam and of medicinal plants of Laos; (b) drug discovery (and development) based on plants of Vietnam and Laos; and (c) economic development of communities participating in the ICBG project both in Vietnam and Laos. Member-institutions and an industrial partner of this ICBG are bound by a Memorandum of Agreement that recognizes property and intellectual property rights, prior informed consent for access to genetic resources and to indigenous knowledge, the sharing of benefits that may arise from the drug discovery effort, and the provision of short-term and long-term benefits to host country institutions and communities. The drug discovery effort is targeted to the search for agents for therapies against malaria (antimalarial assay of plant extracts, using Plasmodium falciparum clones), AIDS (anti-HIV-l activity using HOG.R5 reporter cell line (through transactivation of the green fluorescent protein/GFP gene), cancer (screening of plant extracts in 6 human tumor cell lines - KB, Col-2, LU-l, LNCaP, HUVEC, hTert-RPEl), tuberculosis (screening of extracts in the microplate Alamar Blue assay against Mycobacterium tuberculosis $H_{37}Ra\;and\;H_{37}Rv),$ all performed at UIC, and CNS-related diseases (with special focus on Alzheimer's disease, pain and rheumatoid arthritis, and asthma), peformed at Glaxo Smith Kline (UK). Source plants were selected based on two approaches: biodiversity-based (plants of Cuc Phuong National Park) and ethnobotany-based (medicinal plants of Cuc Phuong National Park in Vietnam and medicinal plants of Laos). At mc, as of July, 2001, active leads had been identified in the anti-HIV, anticancer, antimalarial, and anti- TB assay, after the screening of more than 800 extracts. At least 25 biologically active compounds have been isolated, 13 of which are new with anti-HIV activity, and 3 also new with antimalarial activity. At GSK of 21 plant samples with a history of use to treat CNS-related diseases tested to date, a number showed activity against one or more of the CNS assay targets used, but no new compounds have been isolated. The results of the drug discovery effort to date indicate that tropical plant diversity of Vietnam and Laos unquestionably harbors biologically active chemical entities, which, through further research, may eventually yield candidates for drug development. Although the substantial monetary benefit of the drug discovery process (royalties) is a long way off, the UIC ICBG program provides direct and real-term benefits to host country institutions and communities.