Various disposal methods for spent nuclear fuels (SNFs) are being researched, and one of these methods involves separating high heat-generating nuclear isotopes such as Strontium-90 (90Sr) and Cesium-137 (137Cs) for deep disposal. These isotopes has relatively short half-lives and substantial decay energies. Especially, 90Sr undergoes decay through Yttrium-90 to Zirconium-90, emitting intense heat with beta radiation. Therefore, the removal of these high heat-generating isotopes will significantly contribute to reducing disposal site area. To remove 90Sr from SNFs, molten salt was utilized in KAERI. During this process, it was discovered that 90Sr dissolves in the molten salt in the form of SrCl2 and/or Sr4OCl6. Afterwards, it is crucial to recover 90Sr in the form of oxide from the salt to create immobilized forms for disposal. This can be achieved by reactive distillation with K2CO3. However, the amount of 90Sr within the SNFs is only 0.121wt%, and even if all the 90Sr in the SNFs were to leach into the molten salt, the quantity of 90Sr in the molten slat would still be very small. Therefore, adding K2CO3 to the molten salt for reactive distillation could result in significant possibilities of side reactions occurring. In this study, a two-step process was employed to mitigate the side reactions: the 1st step involves evaporating the all molten salts and the 2nd step includes adding K2CO3 to make oxides through solid-solid reaction. Eutectic LiCl-KCl, which is the most commonly used salt, was employed. The eutectic LiCl-KCl with SrCl2 was heated at 850°C for 2 h to evaporate the salts under a vacuum (> 0.02 torr). However, after examining the distillation product before the solid-solid reaction, it was observed that SrCl2 reacted with KCl in the salt, resulting in the formation of KSr2Cl5. It means that salts containing KCl are not suitable candidates for reactive distillation aimed at producing immobilized forms. As an alternative, MgCl2 could be a highly promising candidate because it is inert to SrCl2 and according to a recent study in KAERI, MgCl2 exhibited the most efficient separation of Sr among various salts. Therefore, we plan to proceed with the two-step reactive distillation using MgCl2 for the future work.

The purpose of this study is to identify differences in the Systemic reaction, Vertical jump and Side step of Judo, Taekwondo, Kendo elite athletes The Total Health Promotion Plan was used to measure systemic reactions, vertical jump and side steps. In the results of the study, systemic reaction was significantly different between Judo player and Taekwondo player (p<0.05). Vertical jump did not differ between groups. Side step was significantly different between Kendo player, Judo player, Judo player and Taekwondo player, Taekwondo player and Kendo player (p<0.05). This study suggests that systemic reaction, vertical jump and side step are different for each sport.

마이크로파를 열원으로 이용하는 화학반응은 어려운 반응을 활성화시킬 수 있고 반응시간과 속도를 가속화하여 고수득율 및 높은 분자량을 얻는 고분자를 합성하는데 유용하게 쓰일 수 있다. 본 연구에서는마이크로파를 이용하여 Diels-Alder 반응을 실시하고 열적으로 안정한 측사슬계 2차 비선형광학고분자를 합성하였다. 일반적인 수열반응을 통해 얻어진 고분자와 물리적, 열적, 광학적 특성을 비교 분석하였으며 마이크로파 가열을 활성화하기 위해 용매를 달리하고 이온성액제를 첨가하여 반응을 조절하였다. PAMID시리즈의 다양한 고분자를 합성하였으며 이중에서 PAMID-M2는 10분간 120W의 전력을 사용하여 얻어졌으며 이 때 사용한 용매는 이온성액제가 소량 첨가된 trichloroethane을 사용하였다. 얻어진PAMID-M2의 무게평균 분자량은 18,300이었으며 분포도는 1.3이었고 높은 유리전이온도 (123oC)를 나타냈다.