Since the commercial operation of Kori Unit #1 nuclear power plant(NPP) started in 1978, 23 units at present are operating in Korea. Radioactive wastes will be steadily generated from these units and accumulated. In addition, the life-extension of NPPs, construction of new NPPs and decontamination and decommissioning research facilities will cause radioactive wastes to increase. Recently, Korea has revised the new classification criteria as was proposed by IAEA. According to the revised classification criteria, low-level, very-low-level and exempt waste are estimated to about 98% of total disposal amount. In this paper, current status of overseas cases and disposal method with new classification criteria are analyzed to propose the most reasonable method for estimating the amount of decommissioning waste when applying the new criteria.

본 실험은 일당귀의 개화 후 일수에 따른 종자 등숙 특성을 알아보고자 수행하였다. 2019년 농촌진흥청 약용작물과 시험 포장에서 채종한 종자를 시험재료로 사용하였다. 개화 후 일수에 따라 종자 무게와 발아율이 조사되었고, 등숙 과정 동안 종자 내에서 배종비(E:S ratio)가 측정되었다. 결과적으로는 각 소화서마다 개화 후 일수가 증가할수록 종자 무게가 유의적으로 증가하였으며, 각 소화서에서 발아가 시작되는 시기는 차이가 있었다. 또한 종자 내에서 배의 길이는 계속해서 성장하여 배종비가 높아지는 것을 관찰하였다. 일당귀는 다양한 소화서에서 꽃이 피기 때문에 종자의 배종비가 종자 발아에 영향을 미칠 수 있다. 본 연구를 바탕으로 일당귀의 우량 종자 생산을 위해서는 개화 후 50일부터 70일경이 가장 적합한 것으로 사료된다.

This study was conducted to elucidate the effects of mulching materials on root growth characteristics and weed occurrence of Platycodon grandiflorum transplants (3 years old) in organic farming. After transplanting, roots were mulched with one of three mulching materials (biodegradable film, sawdust, or rice husks) or a control (no mulching). The average root diameter of all mulching groups was 28.1 mm, which was 5.1 mm thicker than the no-mulching treatment. Roots with the biodegradable film treatment were the thickest at 30.9 mm. Root length was the shortest, 22.0 cm, with rice husk mulching. The number of rootlets was the highest with film mulching (36.0 rootlets/root) and the lowest with no mulching. For root fresh weight, which directly affects yield, the average of treated and untreated roots was 100 and 56 g/root, respectively. The highest fresh weight was in the biodegradable film plot (130 g/root). The mulching treatment groups showed a weed inhibition effect compared with the no-mulching treatment. The dominant weeds with the no-mulching treatment were Setaria viridis and Digitaria ciliaris, and that with the mulching treatment was Setaria viridis. Average annual weed occurrence across all treatments was 72%. Weed occurrence was the highest with the no-mulching treatment (125 weeds/m 2 ), and there were no weeds with the biodegradable film treatment.

Adenophora triphylla var. japonica HARA is a herbaceous plant belongs to Campanulaceae. Adenophora root is mainly used for medicinal purpose. It is effective for lung cleaning, sputum remove, viscera strengthening, cough stopping and cancer treatments. Adenophora has about 70 species in the world and 17 of the species are distributed in Korea. Genetic resources of A. triphylla var. japonica HARA are valuable as the habitat is concentrated in East Asia. The intraspecies variation is very high according to the environmental conditions. A new A. triphylla var. japonica HARA variety, ‘Harang’, was developed through polyploid breeding in 2011. But, low domestic production and passive studies caused our country to rely on imports for almost all amount of the A. triphylla var. japonica HARA demands. In this experiment, genetic diversity between the collections were analyzed using 32 RAPD primers. Through this study, limit of morphologic classification could be solved and genetic diversity of this plant could be assured.