• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
• /
• pp.690-695
• /
• 1998

원자력시설에서 배출되는 고준위 방사선 페기물이나 TRU 둥의 심지층처분의 보완책으로서 핵변환 (Transmutation) 처리방안이 연구되고 있다 이 핵변환시스템의 냉각재로서 액체금속류가 고려되고 있다. 본 연구에서는 핵변환로에 적합한 냉각물질을 도출하기 위해서 보다 합리적인 선정방법으로서 의사결정방법을 이용하여 중점비교 대상인 나트륨(Na), 나트륨-칼륨 합금(Na-K alloy), 납(Pb), 납-비스므스 합금(Pb-Bi alloy)에 대한 정량적 평가를 시도하였다. 아울러 이 냉각재 후보물질에 대한 냉각재로서의 적합성 여부를 비교 검토하였다. 본 방법을 이용한 결과 핵 변화로의 냉각재로서는 납-비스므스 합금이 가장 적합한 것으로 평가되었다.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2005년도 Proceedings of The 6th korea-china joint workshop on nuclear waste management
• /
• pp.280-289
• /
• 2005

A pyrochemical process has been introduced and utilized so that the transmutation of spent PWR fuel in PEACER can produce mainly low and intermediate level waste for near surface disposal. Major radioactive nuclides from PEACER pyroprocessing are composed of TRU and LLFP. In this study, the requirement for the final waste from PEACER is evaluated based on the methodology for establishment of waste acceptance criteria. Also, sensitivity analysis for several input parameters is conducted in order to determine acceptable decontamination factor (DF) and LLFP removal efficiency and to find out input parameter that extremely have an effect on DE As a result of the study, LLFP removal efficiency, especially Sr-90 and Tc-99, is proved to be a major nuclide which contributes to annual dose by human intrusion scenario rather than TRU DF. More than $98.5\%$ of LLFP have to be removed to meet below dose constraint within the DF more than 5.0E+03. Besides, because of the relative short half-life of Sr-90, the increasing of the institutional control period is recommended for most important input parameter to determine DF.

• Nuclear Engineering and Technology
• /
• 제47권1호
• /
• pp.47-58
• /
• 2015

Four recycling scenarios involving pyroprocessing of spent fuel (SF) have been investigated for a 600-MWe transmutation sodium-cooled fast reactor (SFR), KALIMER. Performance evaluation was done with code system REBUS connected with TRANSX and TWODANT. Scenario Number 1 is the pyroprocessing of Canada deuterium uranium (CANDU) SF. Because the recycling of CANDU SF does not have any safety problems, the CANDU-Pyro-SFR system will be possible if the pyroprocessing capacity is large enough. Scenario Number 2 is a feasibility test of feed SF from a pressurized water reactor PWR. Thefsensitivity of cooling time before prior to pyro-processing was studied. As the cooling time sensitivity of cooling time before prior to pyro-processing was studied. As the cooling time increases, excess reactivity at the beginning of the equilibrium cycle (BOEC) decreases, thereby creating advantageous reactivity control and improving the transmutation performance of minor actinides. Scenario Number 3 is a case study for various levels of recovery factors of transuranic isotopes (TRUs). If long-lived fission products can be separated during pyroprocessing, the waste that is not recovered is classified as low- and intermediate-level waste, and it is sufficient to be disposed of in an underground site due to very low-heat-generation rate when the waste cooling time becomes >300 years at a TRU recovery factor of 99.9%. Scenario Number 4 is a case study for the recovery factor of rare earth (RE) isotopes. The RE isotope recovery factor should be lowered to ${\leq}20%$ in order to make sodium void reactivity less than <7$, which is the design limit of a metal fuel.

• 한국에너지공학회:학술대회논문집
• /
• 한국에너지공학회 2000년도 추계 학술발표회 논문집
• /
• pp.127-137
• /
• 2000

Accelerator Driven System (ADS) named HYPER(Hybrid Power Extraction Reactor) is being developed for the transmutation of nuclear waste in Korea Atomic Energy Research Institute(KAERI). The concept of the HYPER is using 1GeV proton to drive a subcritical core. HYPER system is believed to have much more stable dynamics than the critical system in terms of neutronics. However, the HYPER system is supposed to have some drawbacks for the cooling system accidents. Loss of Flow(LOF) and Loss of Heat Sink (LOHS) cause a strong damage. As results, those accidents would stop the power production in the critical system. On the other hand, the negative reactivity feedback could not stop the HYPER system because the HYPER is driven by an accelerator rather than reactivity.(omitted)