After the major radioactivation structures (RPV, Core, SG, etc.) due to neutron irradiation from the nuclear fuel in the reactor are permanently shut down, numerous nuclides that emit alpha-rays, beta-rays, gamma-rays, etc. exist within the radioactive structures. In this study, nuclides were selected to evaluate the source term for worker exposure management (external exposure) at the time of decommissioning. The selection of nuclides was derived by sequentially considering the four steps. In the first stage, the classification of isotopes of major nuclides generated from the radiation of fission products, neutron-radiated products, coolant-induced corrosion products, and other impurities was considered as a step to select evaluation nuclides in major primary system structures. As a second step, in order to select the major radionuclides to be considered at the time of decommissioning, it is necessary to select the nuclides considering their half-life. Considering this, nuclides that were less than 5 years after permanent suspension were excluded. As a third step, since the purpose of reducing worker exposure during decommissioning is significant, nuclides that emit gamma rays when decaying were selected. As a final step, it is a material made by radiation from the fuel rod of the reactor and is often a fission product found in the event of a Severe accident at a nuclear power plant, and is excluded from the nuclide for evaluation at the time of decommissioning is excluded. The final selected Co-60 is a nuclide that emits high-energy gamma rays and was classified as a major nuclide that affects the reduction of radiation exposure to decommissioning workers. In the future, based on the nuclide selection results derived from this study, we plan to study the evaluation of worker radiation exposure from crud to decommissioning workers by deriving evaluation results of crud and radioactive source terms within the reactor core.

Narcissus (Narcissus spp.) bulbs were used to investigate contagious viral retention in the dormant stage. The amplified polymerase chain reaction (PCR) bands were screened using universal potyvirus primers and sequenced to identify specific viruses. To identify individual viruses, primers for specific viruses were designed, and reverse transcription (RT)-PCR was performed. The PCR fragments were sequenced and compared by phylogenetic analysis. Three potyviruses, cyrtanthus elatus virus A (CyEVA), narcissus yellow stripe virus (NYSV), and narcissus late season yellows virus (NLSYV) were singly or doubly detected in 18 samples from six cultivars of the 38 samples representing eight cultivars that were tested. Based on RT-PCR using specific primers, CyEVA was detected in the split corona daffodil cv. Orangery. NLSYV and NYSV frequently occurred as co-infections with each other in the double daffodil cv. Tahiti, and the N. cyclamineus daffodil cv. Tete-a-tete and cv. Tete Boucle. Results has shown that at least three potyviruses are present in imported Narcissus bulbs.

A one-year-old, female, Maltese dog was presented with head tilting, horizontal nystagmus, and tetraparesis. Blindness was first identified, and magnetic resonance imaging (MRI) scanning revealed diffuse lesion which was hyperintense on T2-weighted image over the cerebellum and brainstem. The immunosuppressive therapy had been administered, but the patient had no improvement. Re-performed MRI revealed the progression of the pre-existed inflammatory lesions. Treatment with prednisolone, leflunomide, cyclosporine, and cytosine arabinoside was initiated. However, neurological signs had been progressive, and the patient was euthanized. The histopathological examination revealed the disseminated granulomatous meningoencephalomyelitis (GME). This GME case suggests the importance of initiation of treatment at the appropriate time.

Zinc injection into the coolant system of nuclear power plants is an effective method for reducing corrosion and improving performance. The effectiveness of this method is influenced by various factors such as zinc concentration and injection rate. This paper provides an overview of the factors affecting the effectiveness of zinc injection in nuclear power plants, with a focus on zinc concentration and injection rate, and discusses various research results on the effects of these factors on corrosion reduction and coolant system performance. Zinc concentration is an important factor affecting the effectiveness of zinc injection. The research results show that gradual increases in zinc concentration are more effective for coolant system stability. However, the concentration should not exceed the recommended levels as high zinc concentrations can have negative effects on the system. Injection rate is also an important factor affecting the effectiveness of this method. The research results show that gradual increases in injection rate are more effective for coolant system stability. However, excessive injection rates can have negative effects on the system such as overload of the zinc injection facility and chemical shocks within the coolant system, and therefore, should be optimized. In conclusion, zinc concentration and injection rate are important factors affecting the effectiveness of zinc injection in nuclear power plants. The optimal concentration and injection rate should be determined based on specific reactor conditions and system requirements, and efforts should be made to maximize corrosion reduction and performance improvement.

Radioactive waste generated during nuclear power plant decommissioning is classified as radioactive waste before the concentration is identified, but more than 90% of the amount generated is at a level that can be by clearance. However, due to a problem in the analysis procedure, the analysis is not carried out at the place of on-site but is transported to an external institution to identify concentration, which implies a problem of human error because 100% manual. As a way to solve this problem, research is underway to develop a mobile radioactive waste nuclide analysis facility. The mobile radionuclide analysis facility consists of a preparation room, a sample storage room, a measurement room, a pretreatment room, and a waste storage room, and is connected to an external ventilation facility. In addition, since the automation module is built-in from the sample pre-threatening step to the separation step, safety can be improved and rapid analysis can be performed by being located in the decommissioning site. As an initial study for the introduction of a mobile nuclide analysis facility, Visiplan, a preliminary external exposure evaluation code, was used to derive the analysis workload by a single process and evaluate the exposure dose of workers. Based on this, as a follow-up study, the amount of analysis work according to the continuous process and the exposure dose of workers were evaluated. As a result of the evaluation, the Regulatory dose limit was satisfied, and in future studies, internal and external exposure doses were evaluated in consideration of the route of movement, and it is intended to be used as basic data in the field introduction process.

n Korea, the decommissioning of nuclear power plants is being prepared, and a large amount of radioactive waste is expected to be generated. In particular, clearance level waste, which accounts for more than 90%, requires prevention of cross-contamination and prompt classification. In this study, the possible exposure route and the derivation of exposure dose for worker exposure management in a movable analysis system that can be analyzed onsite were studied. The movable radionuclide analysis system is divided into a preparatory room, a sample storage room, a radioanalysis room, a laboratory, and a waste storage room. It consists of one radioanalysis worker and one pre-treatment worker, and the main radiation exposure is expected to occur in the movement path in the sample storage room, radioanalysis room, and laboratory. The source term for the exposure evaluation, the annual usage dose presented in the radiation safety report in the movable radionuclide analysis system was used. The input data for the evaluation of the external exposure dose under normal circumstances (exposure situation, working hours, distance, etc.) is referenced at facility specifications. The internal exposure dose evaluation was assumed to be acute exposure (1 hour) assumed as internal pollution due to the drop in liquid sample during the pretreatment work. As an evaluation method, a method using a calculation formula and a method using an evaluation code was performed. For the evaluation of exposure dose using the calculation formula, a preliminary evaluation was performed using the point source method, the point kernel method, and intake and dose conversion factors. In addition, VISIPLAN and IMBA codes were used to evaluate exposure dose using the evaluation code, and the input data were supplemented for evaluation. As a result of the evaluation, the annual exposure dose limit of 20 mSv was satisfied for both normal and non-normal situations. In future research, it is planned to derive the evaluation results by particular scenarios for the detailed movement route and evaluation time according to the work process in the mobile radionuclide analysis.

Aster 속에 속하는 자생식물로는 눈갯쑥부쟁이, 개쑥부쟁이, 쑥부쟁이, 벌개미취, 참취 등이 있는데, 대부분 식용 또는 관상용 으로 많이 활용되고 있다. 특히 눈갯쑥부쟁이는 제주 한라산(표 고 1,200~1500m근처)에서 자생하는 한반도 특산식물로써, 다른 Aster 속과 다르게 포복성을 가지고 있고 개체당 소화의 수가 많아 관상가치가 매우 뛰어나다. 또한 파종 당해년에도 개화가 가능하기 때문에 유망한 관상식물 자원이라 할 수 있다. 본 연구 에서는, 한반도 특산 눈갯쑥부쟁이의 유전자원 보존 및 대량번 식을 위한 기초자료를 확보하고자 종자의 발아특성 및 휴면유형 을 분류하였다. 눈갯쑥부쟁이 종자는 형태적으로 완전하게 발달 된 배를 가지고 있고, 배양 72시간 내에 145%의 수분을 흡수하 였다. 4가지 온도조건(4°C, 15/6°C, 20/10°C, 25/15°C)에 배양한 결과, 광조건에서는 각각 67.0%, 58.9%, 62.2%, 71.6% 발아하였 고, 암조건에서는 각각 79.4%, 65.9%, 65.9%, 49.1% 발아하였 다. 저온층적처리(4°C) 실험 결과, 최종 발아율에는 큰 차이가 없었으나, 층적처리 기간 동안에도 발아하는 특성을 관찰하였 다. GA3처리 후 25/15°C에 배양한 결과, 0, 10, 100, 1000mg·L-1 처리에서 각각 57.9%, 68.3%, 74.9%, 63.9%의 발아율을 보였 다. 15/6°C에 배양한 경우에는 각각 78.3%, 62.8%, 72.2%, 55.9% 발아하였다. 본 연구에서는 위 실험들을 통하여, 약 80% 정도는 non-dormant 종자로, 나머지 약 20%는 생리적 휴면 (physiological dormancy)을 가지고 있는 것으로 판단되었다.

The antioxidant effects by pre-treatment of Hutgae fruit water and ethanol (30°, Soju) extract on refrigerated eels were analyzed. The antioxidant activities were measured through DPPH and ABTS scavenging effect, values of acidity, peroxide, carbonyl, and TBA. The peroxide prevention effects of linoleic acid and eel oil were also assessed. Regarding DPPH radical scavenging, Hutgae ethanol extract presented higher scavenging effects than vitamin C 5 mM solution (p<0.05). The eel’s peroxidation degree was measured through 21 days of refrigeration after cleaning and immersion into the extract solution for one hour. Upon measuring the values of four different peroxide indicators, those of eels pre-treated with Hutgae extracts were lower than those of eels untreated. The POV of Hutgae ethanol extract, vitamin C 5 mM, and the control was 11.1, 11.3, 15.5 meq/kg, respectively. Hutgae ethanol extract showed higher antioxidant activities in TBA value, and carbonyl value than other samples. In linoleic acid or eel oil, Hutgae extract was as superiorly effective in preventing peroxide generation of refrigerated eels as vitamin C 10 mM solution. In conclusion, pre-application of Hutgae water and ethanol (30°, Soju) extract on eels was proved to be competent in stopping peroxidation of eel in refrigeration.

Ms. Hee Choon Oh was a Jeju Haenyeo(woman diver) and one of the few surviving victims of the Jeju 4.3 (1948). As a Haenyeo: Jeju society was very poor at the time during the Japanese colonial period and the division of the two Korea, especially after the Korean War, so she had to work regardless of gender. It was hard to go into the sea, but it was the only thing to support my family. In retrospect, Going out to work in the sea was like a life-threatening adventure every day. While there were many emergency moments, She becomes one with the sea and forgot all the pain. After having spent a lot of time together with the sea, I had to stop working as a Haenyeo because it was hard to take care of nine children after having heart surgery. I was able to receive Honorary Haenyeo through continuous exchanges and dedication to the society. As a victim of the Jeju 4.3: I had no choice but to explain it why I had to do work as a Haenyeo and to understand my life. I am a woman who chose the job of Haenyeo, but I have lived through the pain of the dark modern and contemporary history of Korea. The unfair one-year prison life that I wanted to hide even from my children hurt me all my life. Over the past 70 years, sharing pain with the sea, neighbors, and family, serving the region, and hopefully waiting for a better society and justice to come. and finally It was not until 2019, 70 years after 1948, that I was officially acquitted by a Korean court. I regained my honor as a Haenyeo and was able to get rid of my deep sadness.