KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

Background : Ginseng rain cover farming is expanding around Jinan county and Jangsu country of North Jeolla Province. Some farmers doing ginseng rain cover farming have suffered from difficulties due to hot weather damages. However, it is a situation that the study on mitigation techniques for high temperature damage do not exist with ginseng rain cover farming. Methods and Results : The test covering work was firstly done on April 28th for heat block film+90% black light blocking net, blue double sided film, and PE film+75% black light blocking net and when it comes to second treatment, 30% and 40% shading were implemented for heat block film group and blue double sided film group respectively and 75% black light blocking net was installed on PE film+75% shading group. When it comes to micro-climate measurement in rain cover facility, temperature, humidity and light intensity were measured during the growing period of ginseng. The results are as follows. Regarding the light transmittance (per PAR, 10 am in clear day) in facility with 1st covering, light block film covered group (LBF), blue double sided film group (BDF) and PE film group have 12.9±1.8%, has 11.6±1.0% and 27.1±1.1% respectively and after 2nd covering, in LBF groups, 30% blocking, 40% blcoking and no blocking have 10.6±1.3%, 8.2±0.9% and 12.9±1.8% and in BDF groups, 30% blocking, 40% blcoking and no blocking have 9.4±0.8%, 7.9±0.7% and 11.6±1.0 respectively and PE film group has 10.6±0.7%. Relative humidity also showed the same trend as temperature. The average monthly amount of light and maximum light intensity were lower in 30% and 40% light blocking groups of LBF and BDF and a little higher in no light blocking group compared to PE film group. The degree of high temperature damage was 1 in no LBF of BDF, but no LBF of LBF was so bad like 3. However, there was no high temperature damage in the test groups of blocking films or BDF with 30% and 40% light blocked light screens. Regarding root weight, all secondly treated groups of LBF group and BDF group were lighter compared to 4.36g of PE film group and especially, prism sheetof no light blocking group has 2.5g and BDF of of no light blocking group has 3.21g. 30 % and 40% light blocking groups of LBF group and BDF group were light with 3.20~4.07g. Conclusion : Regarding the analysis result on micro-climate in facility with different cover materials for 2 years old ginseng in ginseng rain cover farming of Gyeonggi Province, the covering method suitable for high temperature damage mitigation in ginseng rain cover farming was that 1st covering was done by PE film+75% black light blocking net and then 75% black light blocking net is additionally covered at a time when outside temperatures reaches 30℃.