According to NSSC Notice No. 2021-10, safety analysis needs to be introduced in the decommissioning plan. Public and occupational dose analyses should be conducted, specifically for unexpected radiological accidents. Herein, based on the risk matrix and analytic hierarchy process, the method of selecting accident scenarios during the decommissioning of nuclear power plants has been proposed. During decommissioning, the generated spent resin exhibits relatively higher activity than other generated wastes. When accidents occur, the release fraction varies depending on the conditioning method of radioactive waste and type of radioactive nuclides or accidents. Occupational dose analyses for 2 (fire and drop) among 11 accident scenarios have been performed. The radiation doses of the additional exposures caused by the fire and drop accidents are 1.67 and 4.77 mSv, respectively.

Nuclear power plants decommissioning is planned to be started in middle of the 2020. It is necessary to develop safety evaluation and verification technology during decommissioning to ensure the safety of security monitoring measures and maintenance measures, appropriate emergency plans and preparations for decommissioning, and the use of proven engineering when establishing decommissioning plan. For this purpose, a nuclear power plant decommissioning plan is prepared in several stages before decommissioning. When a lifetime of a nuclear power plant has reached, it needs to be decommissioned and therefore operator company should submit decommissioning plans to the National Safety and Security Commission. And safety analysis should be included in this document and it is explained in chapter 6. According to the NSSC Notice No. 2021-10, it is largely divided into principles and standards, exposure scenarios, dose assessment, residual radioactivity, abnormal events, and risk analysis. When unexpected radiological accident is happened, both public and occupational dose analysis should be conducted. However, research on the former can be found easily on the other hands, research on the latter is not active. In this paper, method of choosing scenarios of accidents during the decommissioning the nuclear power plants is briefly introduced. Accidents during nuclear power plants decommissioning cases in USA is chosen and its risk is evaluated by using risk matrix and ranked by AHP method. During the decommissioning phases, varieties of radioactive waste is expected to be generated such as contaminated concrete and metal. On the other hand, Dry Active Waste (DAW) is generated and its amount is and its amount is 7,353 drums. Characteristic of DAW is highly flammable compared to concrete or metal. Moreover, depending on method of radioactive waste conditioning and type of radioactive nuclides, release rate of the nuclides varies. Thus this type of radioactive waste is critical to fire accidents and such accident can occur extra dose exposure which exceeds the guideline of the regulatory body to workers. Therefore, in this paper, occupational dose exposure during the fire accident is conducted.

The purpose of this work was to study the effects of electron beam irradiation on development and reproduction and evaluate the DNA damage in Plutella xylostella. Adults and pupae of P. xylostella were irradiated with 30, 50 and 100 Gy electron beam. Hatchability and fecundity of adults declined as increased irradiation doses. When pupae were irradiated with 100 Gy, fecundity of emerged adults significantly decreased and no eggs hatched. However, the adults longevity and emergence of pupae did not change. Assessment of DNA damage in cells obtained from adults and pupae of P. xylostella was carried out using single-cell electrophoresis (comet assay). Electron beam-radiated adults and pupae showed that tail length and percentage of DNA damage at all the doses were significantly larger than the control batch. Our results suggest that electron beam induces sterility through the DNA damage and this technique could contribute to analytical identification of an effective disinfestation and quarantine treatment.

This study was performed to investigate attraction effect of spearmint oil and to confirm their EAG response against lantern fly, Lycorma delicatula nymphs and adult. In dose responses to spearmint oil, 2nd ∼ 4th nymphs and adult were significantly attracted at a dose of 5㎕. Attraction effect was showed highest (84.8%) at a 4th instar nymph, and mild effect (approximately 60%) was observed at 2nd∼3rd instar nymphs, but the others are not showed the significance. At a dose of 10㎕, 4th instar nymph and adult were significant and only 4th instar nymph was significantly attracted at a dose of 2.5㎕ but the others are not. Carvone, a constituent of spearmint oil, exhibited significantly attraction effect on nymphs and adult except 1st and 2nd instar nymphs. But limonene did not show any attraction effect. The attraction assay of L. delicatula to the mixtures of constituents appeared to be efficient additively. In EAG response to spearmint oil which exhibited attraction effect, antennae of 4th instar nymph and adult responded to only carvone. In conclusion, attraction effect of spearmint oil was more effective in 4th instar nymph and adult than 1st ∼ 3rd instar nymphs.

On the development and reproduction of four major agricultural insect pests including B. tabaci, M. persicae, P. xylostella and T. urticae, electron-beam was irradiated with different doses of 30, 50, 70, and 100 Gy. The effect of electron beam was investigated with respect to the longevity, egg hatching, emergence, and fecundity. Eggs hatching of B. tabaci, P. xylostella and T. urticae were more inhibited as increased irradiation doses. Especially B. tabaci and T. urticae eggs were perfectly inhibited to hatch at a dose of 100 Gy. However, these pests showed no lethal effect on the nymph/larva, pupa, and adult stages. When irradiated on the eggs of B. tabaci, P. xylostella and T. urticae, the emergence was inhibited from nymphs/larvae to adults. Individually, B. tabaci emerged adult did not lay eggs at a dose of 70 Gy. Besides, fecundity of P. xylostella emerged adult decreased at a dose of 100 Gy. On the contrary, irradiation did not affect the longevity of P. xylostella adult. When irradiated on B. tabaci, P. xylostella, Myzus persicae and T. urticae nymphs/larvae, emergence was inhibited at doses of 70 and 100 Gy, and decreased the fecundity and inhibited the hatching of laid eggs. However, the longevity of adults did not affect

This study was performed to investigate attraction effect of six plant essential oils and to confirm their electrophysiological response against Lycorma delicatula. Among the tested oils, spearmint oil (94.1%) significantly attracted L. delicatula at a dose of 1.25㎕/cm2 by using an olfactometer. In dose response to spearmint oil, a dose of 2.5㎕/cm2 was very effective. GC-MS analysis revealed that the active components responsible for the effective attraction effect of spearmint oil were carvone (70.6%) and limonene (54.8%). Of the two active components, carvone was more significant than limonene with reference to attraction activity against L. delicatula. Analysis by GC-EAD showed, major components of spearmint oil that elicited response in L. delicatula antennae, indicating the potential role of the essential oil as attractant that determine the choice of the attraction material. In the field test, spearmint oil exhibited attraction effect up to 5 days. This effect was different in accordance with test places and treatment dose.

Twospotted spider mite, Tetranychus urticae was collected from the rose greenhouse in Gimhae, Gyeongnam province in Jan, 2001. Resistant strain was reared over nine years treated with Acequinocyl (over 400 times), and increased 614 folds as compared to susceptible strain (S). Cross resistance of acequinocylresistant strain adults to eight acaricide was showed high in Cyflumetofen (108 folds) and expressed low in Abamectin (16 folds), Tebufenpyrad (7.6 folds), Fenpyroximate (6.1 folds). Against Chlorfenapyr (0.5 folds), however, showed negatively correlated cross resistance. Synergistic effects with PBO (piperonyl butoxide), an oxygenase inhibitor, DEF (S,S,S-tributyl phosphorotrithioate), an esterase inhibitor, and DEM (diethymaleate), an inhibitor of glutathion S-transferase were also investigated. Synergistic effect showed low in DEM (4.2 folds) but showed high in PBO (12 folds) and DEF (23 folds).

Using thirty-one essential oils with different manufactured T-tube olfactometers, attraction and repellent efficacy were proved against ggot-mae-mi, Lycorma delicatula. Among tested essential oils, spearmint was selected to have attraction efficacy (94.1%; P<0.001). Spearmint was also showed attraction efficacy in 10 and 2.5 ul, but did not showed in 1 ul. GC analyzed chemical constituents of spearmint were tested with different concentations (10, 5, 2.5, 1 ul). Carvone were showed activity in 10 and 5 ul, but limonene did not showed the activity. When mixing two compounds were showed activity in 10, 5, 2.5 ul as 78.8, 73.5, and 69.7%, respectively. Lavender was selected to have repellent efficacy (86.7%; P<0.001). Lavender was also showed repellency in 10 and 2.5 ul, but did not showed in 1ul. GC analyzed chemical constituents of lavender were tested with different concentrations, results have the activity linalool and terpinen-4-ol in 10 and 5 ul, but linalyl acetate and caryophyllene oxide did not have the activity. Spearmint and lavender showing attraction and repellency, respectively, were keep in lure during 24 hr for penetration with different concentration(30, 20, 10 ul), and attached to the center of Fly catcher, fly sticky trap. The trap was set in the field that founded frequently the L. delicatula. The number of L. delicatula caught in the traps were counted after 5, 10, and 15 days. In attraction efficacy of 20 ul concentration wㄷre high attracted the insect(P<0.001). 30 ul concentration were also have the high attraction (P<0.01). We are now tested the control efficacy in grapevine orchard using these materials.

This study was performed to analyze the sugar contents from six kinds of plant and investigate their effect on the life span of ggot-mae-mi, Lycorma delicatula. Part of plants were methanol extracted from host plants such as Ailanthus altissima, Vitis vinifera and non-host plants such as Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora, and concentrated the water layer and then analyzed the sugar contents using HPLC. Ailanthus altissima existed high in sugar contents and followed by Fructose>Glucose, Vitis vinifera was analyzed by an order of Glucose>Fructose>Maltose>Sucrose>Rhamnose; Malus pumila was as Glucose>Fructose; Pyrus calleryana was as Glucose>Unknown>Fructose; Hibiscus syriacus was as Sucrose>Glucose; Pinus densiflora was as Fructose>Glucose>Sucrose. A parafilm bioassay was used to investigate the longevity of L. delicatula nymphs to the sugar contents. Nymphs of L. delicatula was lived as long as 13.1 days in 5% Sucrose solution, but lived as short as 6.0 days in 5% Glucose solution. When provided with only water, L. delicatula lived for 5.4 days. Life span to the each sugar contents were longer lived in an order of Sucrose>Fructose>Rhamnose>Maltose>Glucose. As investigated the life span of L. delicatula nymph according to the combination of sugar contents founded in original plants were lived longer in 5% sugar combination solution of Ailanthus altissima. Analyzed original sugar contents from Malus pumila, Pyrus calleryana, L. delicatula was lived as 7.8, and 7.1 days, respectively, comparing to the Hibiscus syriacus, and Pinus densiflora lived as 6.0, and 4.7 days, respectively. This result were judged that sugar contents affected on choosing the host plants.

This study was performed to compare the host preference, survivorship and feeding behavior using EPG against ggot-mae-mi, Lycorma delicatula against seven plants such as Ailanthus altissima, Vitis vinifera, Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora. In host preference. L. delicatula was most preferred the Ailanthus altissima, Vitis vinifera and was not preferred the other plants. Survival rate of 3rd Nymph was recorded from Ailanthus altissima, Vitis vinifera as 15.0, and 15.4 days, respectively, it showed longest period. However, Malus pumila, Pyrus calleryana, Hibiscus syriacus, were survived within 6 days and Pinus densiflora was within 5 days. Moreover, L. delicatula was survived within 2 days to the three kinds of fruits. Ecdysis rate from 3rd to 4th nymph also high from Ailanthus altissima, Vitis vinifera as 63.3, 63.0 % and the order was followed as Malus pumila(17.7%) > Pyrus calleryana(9.3%) > Hibiscus syriacus(7.8%) > Pinus densiflora(5.9%). Especially, ecdysis rate was recorded 0% to the three kinds of fruits. Feeding behavior was analyzed using EPG and compared the differences their waveform from seven kinds of plants and three kinds of fruits. Non-probing time was short in host plants, reversely, Phloem-feeding time was recorded longer in Ailanthus altissima, Vitis vinifera as 45.7 and 13.7 min, respectively. And other plants and fruits were not showed feeding behavior.

This study was performed to investigate the correlation between changes of feeding behavior of green peach aphid, Myzus persicae and residual effect of an insecticide, Pyrifluzuinazon, using EPG technique. Pyrifluquinazon was showed the insecticidal activity until three days (72h) after treatment, and the activity was high in nymph than adult of GPA. There was no difference among treatment methods. Lethal sign was observed the slimed the abdomen of GPA after 3 days that rises the insecticidal activity, and dieㅇ as being sticked and/or pulled out the needle. Residual efficacy from 1, 3, 5, 7 to 20 days after treatment, insecticidal activity was showed 70% in 50 ppm, recommended concentration, until 5 days. And waveforms relating to non-probe time and phloem phase time using EPA, feeding inhibition efficacy was showed during 5 days after treatment, but showed similar level with control after 13 days. These results show that the change of feeding behavior of GPA is correlated with the change of residual effect of pyrifluzuinazon.

This study was performed to investigate the seasonal occurrence, developmental characteristics of each nymphal stages with different temperatures (20, 25, 30℃), longevity and fecundity of ussur brown katydid, Paratlanticus ussuriensis, damaging by outbreaks in the orchard areas of Bitan-ri, Yeongdong, Chungbuk. Paratlanticus ussuriensis occurred from late-March to late-August with peak of mid-May. Newly emerged nymphs appeared from March and do damaged fruit orchards with peak of mid-May when P. ussuriensis existed as 4th and 5th nymphal stages. P. ussuriensis adult occurred from early-June to mid-Aug. with peak of mid-July. Total density of P. ussuriensis was showed highest in mid-May. P. ussuriensis goes through nymphal stages to 7th nymph, the ovipositor began exposed to outside from the 4th instar and the body weight increased heavily from this stage and the wings were observed from 6th instar. Developmental period was longer as increased the nymphal stages. Sex ratio of collected insect was showed as 0.57; females more than males. As increased the temperature, developmental period was to be short. Preoviposition was also to be short as 5.0, 4.3, and 3.4 days at 20, 25, 30℃, respectively, and fecundity increased as 69.0, 87.1, and 104.3 at 20, 25, 30℃, respectively. Longevity of male and female at 25℃ was showed the longest with 35.7, and 32.9 days and showed the shortest with 30.1 and 28.1 days at 30℃, respectively. The difference of developmental period in male and female were showed longer in female without relation of temperature. The eggs laid were frequently distributed 3 to 4 cm from soil surface, and showed the behavior laying eggs intensively when early oviposition period.

Recently, Ussur brown katydid outbreaks caused a serious pest problem in areas of Yeongdong, Chungbuk. This study was performed to control the pest with environment-friendly method. Trap was made of PET plastic bottles that easily found near farmhouse. Attractant materials such as oak (Quercus acutissima) leaf, fruits (peach, apple, grapefruit and pear) sarcocarp or its juices, rice wine (makgeolli) and fish meal were directly applied into the manufactured trap and investigated for the attraction efficacy compared with the funnel trap. During one day, manufactured trap (fish trap) attracted the Ussur brown katydid more than funnel trap. The efficacy of attractant materials were as follows: peach juice (32.7 adults)> rice wine+fish meal (31.3 adults) > rice wine (27.0 adults) > pear juice (19.0 adults) > apple juice (17.2 adults) > fish meal (16.7 adults) > grapefruit juice (14.4 adults) > oak leaf (2.3 adults). The attractive efficacy of fruit juices to ussur brown katydid was more than fruit carcocarps, and the trap hangover 1m in height more than that on ground. The composition of rice wine and fish meal prolonged its efficacy when treated with disinfectant.

Biotype Q of Sweetpotato whitefly, Bemisia tabaci (Homoptera: Aleyrodidae) was raised in seven tomatoes and eight red pepper varieties; however, biotype B did not grow in red pepper varieties. Rokkusanmaru variety of tomato and Cheongpungdaegun variety of red pepper showed the highest susceptibility to biotype B and Q. HPLC (ELSD Detector) analysis showed that the presence of sugars such as erythritol, xylose, xylitol, fructose, glucose, mannitol, and sucrose in red pepper varieties; erythritol, xylose, fructose, glucose, and mannitol was in tomato varieties. Tomato varieties lacks xylitol and sucrose, which were present in the red pepper varieties. Subsequent bioassay with these two sugars, sucrose did not show significant difference between two biotypes; however, xylitol was showed only repellent effect against B biotype. Therefore, it seems that xylitol may play a key role in the selection of host plant by biotype B of sweetpotato whitefly.

This study was performed to investigate the feeding behavior of Bemisia tabaci B- and Q-biotypes using EPG technique against seven tomato and eight red pepper commercial varieties. EPG waveforms was recorded during three hours compare with the characteristic patterns of feeding behaviors between two biotypes such as total duration of non-probing times, the time taken until stylet activities changed after reaction, number of probes, and total duration of phloem phase. In comparing the effect of the varieties between the two biotypes, biotype Q showed the feeding behavior against all pepper varieties in the total duration of phloem feeding. Daeshin variety has the longest feeding time. However in total duration of phloem feeding, biotype B was observed in hanyeoreumbigarim and Daeshin varieties, but feeding time was very short. Biotype B was longer in total duration of non-probing, and showed lower number of probes, and total duration of probing phase. However, biotype Q was shorter time in total duration of non-probing phase than biotype B, but showed more aggressive probing and stylet pathway pattern. These results suggest that biotype Q are more preferred the pepper host than biotype B. However, tomato varieties between the two biotypes did not show the difference.