• Economic and Environmental Geology
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• v.56 no.5
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• pp.565-580
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• 2023

In this study, we reviewed and summarized comprehensive roles and importance of natural analogue studies for demonstrating the safety and improving the reliability of the safety for the deep geological disposal of high-level radioactive waste. We also investigated domestic and foreign status of natural analogue studies in order to study and substantiate complex and various radionuclide behaviors in subsurface disposal environments. In addition, we investigated and uranium behaviors in groundwater and rock in uranium deposits including domestic uranium deposits in Ogcheon Metamorphic Belt and biogeochemical interactions in geological environments. Although there are many limitations and uncertainties in directly using the information and data for uranium behaviors obtained from uranium deposits in the disposal safety assessment, the information and data can be utilized in the disposal safety assessment and safety case construction both in qualitative and partly quantitative ways.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.1-24
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• 1982

Several recent advances in our knowledge of thyroid physiology have broad application to the diagnosis and management of thyroid disorders. For in the thyroid, more than other endocrine organs, pathophysiology can be translated directly into the diagnosis and management of thyroid disease. Graves' disease is a syndrome including goiter with hyperthyroidism, exophthalmos and dermopathy. The pathogenesis of Graves' disease is not yet clearly identified, but various autoantibodies to the thyroid gland and immunopathologic studies indicate that autoimmune processes are involved in the pathogenesis of the disease. The diagnosis and management of Graves' disease are largely dependent on radionuclide techniques as radioimmunoassay, radioactive iodine therapy and so on. Several laboratory tests are also developed to determine the remission of this disase including TRH stimulation test, $T_3$ suppression test and detection of thyroid stimulating immunoglobulins. Autoimmune thyroiditis is almost certainly a primary immunologic disease and the incidence tends to increase recently, mainly due to the application of biopsy technique in thyroid diseases. Thyroid nodules have been a great challenge to physicians because of the possibility of malignancy. But recently, cytologic examination of thyroid aspirate provides a very simple and also reliable diagnostic method in patients with thyroid nodules. In 163 patients with thyroid nodules, only 19.3% was revealed to be malignant. Therefore cytologic examination of thyroid aspirate and thyroid biopsy should be included in the diagnosis of nodular patients prior to surgical intervention. In this paper, a comprehensive review is presented on the pathogenesis, clinical features, laboratory findings and therapeutic modalities of various thyroid diseases on the basis of over 80 researches performed during the past 20 years at radioisotope clinic, Seoul National University Hospital.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.133-141
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• 2012

The impacts influenced on the performance and safety of a repository are classified as units of Features, Events, and Processes (FEP), for the total system performance assessment (TSPA) related to the permanent disposal of HLW. The importance is evaluated in consideration of the frequency, consequence, regulation, suitability of a specific site, etc. and then these are grouped as a similar FEP. A scenario describing the migration of radionuclide from the repository to the biosphere is derived from understanding the interaction among these groups. KAERI has developed the KAERI FEP lists by review and collation of the foreign studies. The KAERI FEP list has been reviewed by several Korean experts. The five major scenarios describing possible future evolutions of the geological disposal system have been developed by RES and PID methods. Also the CYPRUS which is a KAERI integrated database management system for the total system performance assessment (TSPA) related to the permanent disposal of HLW has been developed and the results of the FEP and scenario development have been uploaded in this system.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.132-145
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• 2001

The purpose and need of the study is to quantify the advantage or disadvantage of the environmental friendliness of the partitioning of nuclear fuel cycle. To this end, a preliminary study on the quantitative effect of the partition on the permanent disposal of spent PWR and CANDU fuel (HLW) was carried out. Before any analysis, the so-called reference radionuclide release scenario from a potential repository embedded into a crystalline rock was developed. Firstly, the feature, event and processes (FEPs) which lead to the release of nuclides from waste disposed of in a repository and the transport to and through the biosphere were identified. Based on the selected FEPs, the ‘Well Scenario’which might be the worst case scenario was set up. For the given scenario, annual individual doses to a local resident exposed to radioactive hazard were estimated and compared to that from direct disposal. Even though partitioning and transmutation could be an ideal solution to reduce the inventory which eventually decreases the release time as well as the peaks in the annual dose and also minimize the repository area through the proper handling of nuclides, it should overcome major disadvantages such as echnical issues on the partitioning and transmutation system, cost, and public acceptance, and environment friendly issues. In this regard, some relevant issues are also discussed to show the direction for further studies.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.492-496
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• 1995

To evaluate the usefulness of hepatic uptake in neonatal jaundice, Tc-99m-DISIDA cholescintigraphy was reviewed for 13 infants with prolonged mired jaundice and no demonstrable excretion into bowel,even after 24hr. Five patients proved to have biliary atresia. The remainder had neonatal hepatitis. There was no distinct differentiation of the hepatic uptake of tracer at 5 and 10 minutes between biliary atresia and neonatal hepatitis. The consideration of hepatic uptake rate of the tracer is not useful in differentiating neonatal hepatitis from biliary atresia.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.277-285
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• 2018

Patients administered radioisotope for medical purposes are regulated by each country to quarantine them until their body's radioactivity contents decrease below release criteria. To predict the quarantine period and provide it to medical staffs and patients, it is necessary to approach the assessment of the exposure dose of persons due to patients in a realistic manner. For this purpose, a whole-body effective half-life should be applied to the dose assessment equation instead of the physical half-life. In this study, we constructed a bio-kinetic model for each nuclear species based on the ICRP publication to obtain a whole-body effective half-life of 10 unsealed gamma-ray emitting nuclei from the notification of Nuclear Safety and Security Commission, and calculated the effective half-life mathematically by simulating the distribution of the radioisotope administered in the whole body as well as each organ scale. The whole-body effective half-life of $^{198}Au$, $^{67}Ga$, $^{123}I$, $^{111}In$, $^{186}Re$, $^{99m}Tc$, and $^{201}TI$ were 1,93, 2.57, 0.295, 2.805, 1.561, 0.245, and 2.397 days respectively. However, it was found to be undesirable to offer a single value of the effective half-life of $^{125}I$, $^{131}I$, and $^{169}Yb$ because the changes in the effective half-life show no linearity. A bio-kinetic model created for the internal exposure assessment has been shown to be possible to calculate the effective half-life of radioisotopes administered in the patient's body, but subsequent studies of radiolabeled compounds are required as well.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.507-513
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• 2022

When X-ray energy above 8 MV is used, photoneutrons are generated by the photonuclear reaction, which activates the components of linear accelerator (linac). Safely managing the radioactive material, when disposing linac or replacing components, is difficult, as the standards for the radioactive material management are not clear in Korea. We surveyed the management status of radioactive components occurred from medical linacs in Korea. And we also measured the activation of each part of the discarded Elekta linac using a survey meter and portable High Purity Germanium (HPGe) detector. We found that most medical institutions did not perform radiation measurements when disposing of radioactive components. The radioactive material was either stored within the institution or collected by the manufacturer. The surface dose rate measurements showed that the parts with high surface dose rates were target, primary collimator, and multileaf collimator (MLC). ⁶⁰Co nuclide was detected in most parts, whereas for the target, ⁶⁰Co and ¹⁸⁴Re nuclides were detected. Results suggest that most institutions in Korea did not have the regulations for disposing radioactive waste from linac or the management procedures and standards were unclear. Further studies are underway to evaluate short-lived radionuclides and to lay the foundation for radioactive waste management from medical linacs.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.3034-3042
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• 2022

The results of radioecological monitoring of the cooling pond Beloyarsk NPP (Russia) have been presented. The influence of waste technological waters of thermal and fast NPP reactors on the content of artificial radionuclides in surface waters and bottom sediments of the Beloyarsk reservoir has been studied. The long-term dynamics of the specific activity of ⁶⁰Co, ⁹⁰Sr, ¹³⁷Cs and ³H in the main components of the freshwater ecosystem at different distances from the source of radionuclide discharge has been estimated. Critical radionuclides (⁶⁰Co and ¹³⁷Cs), routes of their entry and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at Beloyarsk NPP, based on fast reactors, has a much smaller effect on the flow of artificial radionuclides into the freshwater ecosystem of the reservoir. During the entire period of monitoring studies, the decrease in the specific activity of radionuclides from NPP origin in surface waters was 4.3-74.5 times, in bottom sediments 10-505 times. The maximum discharge of artificial radionuclides into the reservoir was noted during the period of restoration and decontamination work aimed at eliminating emergencies at the AMB thermal reactors of the first stage of the Beloyarsk NPP.

• Economic and Environmental Geology
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• v.56 no.5
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• pp.501-514
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• 2023

Forest fires can generate numerous pollutants through the combustion of vegetation and cause serious environmental problems. The global warming and climate change will increase the frequency and scale of forest fires across the world. In Korea, many nuclear power plants (NPPs) are located in the East Coast where large-scale forest fires frequently occur. Therefore, understanding the sorption and transport characteristics of radionuclides in the forest fire areas is required against the severe accidents in NPPs. This article reviewed the physiochemical changes and contamination of groundwater and soil environments after forest fires, and discussed sorption and transport of radionuclides in the subsurface environment of burned forest area. We considered the geochemical factors of subsurface environment changed by forest fire. Moreover, we highlighted the need for studies on changes and contamination of subsurface environments caused by forest fires to understand more specific mechanisms.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3815-3821
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• 2023

Dosimetric studies in Nuclear Medicine are very important, especially with new therapeutic methods, the number of which has increased significantly with the Theranostic approach (determining diagnostic-therapeutic pairs where similar molecules are labelled with different isotopes in order to diagnose and treat malignant diseases). Peptide receptor radionuclide therapy (PRRT) has been used successfully for many years to treat neuroendocrine tumors (NET). ⁹⁰Y-DOTATOC is one of the radiopharmaceuticals used frequently in this type of therapy. In this work, blood and urine samples from 13 patients treated with ⁹⁰Y-DOTATOC were measured by a liquid scintillation beta counter (LSC). Calibration of the beta counter for this type of measurement was done and all results are presented in the paper. The presented paper also provides a methodology for determining the measurement uncertainty for this type of measurement. Immediately after the administration of radiopharmaceuticals, the activity in the blood was different from 6.31% to 88.9% of the applied radioactivity, while 3 h after the termination of the application, the average value of radiopharmaceuticals in the blood was only 3.84%. The activity in the excreted urine depended on the time when the patients urinated after the therapy. It was measured that as much as 58% of the applied radioactivity was excreted in the first urine after the therapy in a patient who urinated 4.5 h after the completed application of the therapy. In most patients, the highest urine activity was in the first 10 h after the application, while the activities after that time were negligibly low. The described methodology of measuring and evaluating activity in blood and excreted urine can be applied to other radiopharmaceuticals used in nuclear medicine. It could be useful for researchers for dosimetric assessments in clinical application of PRRT.