• 방사성폐기물학회지
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• 제6권2호
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• pp.141-145
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• 2008

후행 핵연료주기 경제성 평가는 추정 비용의 불확실성, 평가 대상기간의 장기성, 적용 할인율에 따른 계산결과의 변동성 등 많은 불확실성을 내포하고 있기 때문에 평가기관 또는 평가자에 따라 그 결과가 서로 상이하다. 본고에서는 지금까지 수행된 주요 경제성 평가 연구들을 조사/분석하여 그 특징과 한계를 알아봄으로써 현재 국내에서 추진되고 있는 사용후핵연료 공론화 및 후행 핵연료주기 정책 연구 추진에 기초자료로 활용될 수 있도록 하고자 하였다. 분석 결과 사용후핵연료 재활용 옵션에 비해 직접처분 옵션이 유리하나, 입력 자료로 사용된 파라미터 값에 따라 결과의 불확실성이 많이 나타나 이 부분에 대한 추가적인 연구가 필요하다는 사실을 알 수 있었다.

• 방사성폐기물학회지
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• 제8권4호
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• pp.269-277
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• 2010

원자력의 중흥기를 맞이하여 민감한 핵연료주기 기술의 무분별한 확장을 억제하고자 다양한 핵연료주기 다자 방안이 제시되고 있다. 현재 원자력 공급국 위주의 핵연료주기 다자화가 추진되고 있는 실정에서 후행 핵연료주기 기술의 다자화 추진 추이를 파악하고자 사용후핵연료 공동 관리 시설에 대한 분석 결과를 검토하였다. 또한 후행 핵연료주기 연구개발 시설의 다자화를 제안하고 기대효과와 문제점을 검토한 후 이를 실현하기 위한 추진방안을 도출하였다.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2104-2125
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• 2021

This paper presents the verification and validation (V&V) of a calculation module for isotope inventory prediction to control the back-end cycle of spent nuclear fuel (SNF). The calculation method presented herein was implemented in a two-step code system of a lattice code STREAM and a nodal diffusion code RAST-K. STREAM generates a cross section and provides the number density information using branch/history depletion branch calculations, whereas RAST-K supplies the power history and three history indices (boron concentration, moderator temperature, and fuel temperature). As its primary feature, this method can directly consider three-dimensional core simulation conditions using history indices of the operating conditions. Therefore, this method reduces the computation time by avoiding a recalculation of the fuel depletion. The module for isotope inventory calculates the number densities using the Lagrange interpolation method and power history correction factors, which are applied to correct the effects of the decay and fission products generated at different power levels. To assess the reliability of the developed code system for back-end cycle analysis, validation study was performed with 58 measured samples of pressurized water reactor (PWR) SNF, and code-to-code comparison was conducted with STREAM-SNF, HELIOS-1.6 and SCALE 5.1. The V&V results presented that the developed code system can provide reasonable results with comparable confidence intervals. As a result, this paper successfully demonstrates that the isotope inventory prediction code system can be used for spent nuclear fuel analysis.

• Journal of Radiation Protection and Research
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• 제28권4호
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• pp.361-368
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• 2003

The economic and environmental friendliness analysis of the nuclear fuel cycle options that can be expected in Korea were performed. Options considered are direct disposal, reprocessing and DUPIC (Direct Use of Spent PWR Fuel In CANDU Reactors). By considering the result of calculation of the annual uranium requirement and nuclear spent fuel generation by analysis of nuclear fuel material flows in the nuclear fuel cycle options, we decided the time of back-end nuclear fuel cycle processes and the volume. Then we can analyze the economic and environmental friendliness by applying the unit cost and unit value of each process, respectively.

• 방사성폐기물학회지
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• 제19권4호
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• pp.435-446
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• 2021

This article examines the consequences of a significant spent fuel management decision or event in the United States, South Korea and Taiwan. For the United States, it is the financial impact of the Department of Energy's inability to take possession of spent fuel from commercial nuclear power companies beginning in 1998 as directed by Congress. For South Korea, it is the potential financial and socioeconomic impact of the successful construction, licensing and operation of a low and intermediate level waste disposal facility on the siting of a spent fuel/high level waste repository. For Taiwan, it is the operational impact of the Kuosheng 1 reactor running out of space in its spent fuel pool. From these, it draws six broad lessons other countries new to, or preparing for, nuclear energy production might take from these experiences. These include conservative planning, treating the back-end of the fuel cycle holistically and building trust through a step-by-step approach to waste disposal.

• Nuclear Engineering and Technology
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• 제40권1호
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• pp.9-20
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• 2008

Since plutonium accounts for 40-50% of the power produced by uranium fuels, spent fuel contains only residual plutonium. Management of this plutonium is one of the aspects influencing the choice of a fuel cycle back-end option: reprocessing, direct disposal or wait-and-see. Different grades and qualities of plutonium exist depending from their specific generation conditions; all are valuable fissile material. Safeguard authorities watch the inventories of civil plutonium, but access to those data is restricted. Independent evaluations have led to an estimated current inventory of 220t plutonium in total (spent fuel, separated civil plutonium and military plutonium). If used as MOX fuel, it would be sufficient to feed all the PWRs and BWRs worldwide during 7 years or to deploy a FBR park corresponding to 150% of today' s installed nuclear capacity worldwide, which could then be exploited for centuries with the current stockpile of depleted and spent uranium. The energy potential of plutonium deteriorates with storage time of spent fuel and of separated plutonium, due to the decay of $^{241}Pu$, the best fissile isotope, into americium, a neutron absorber. The loss of fissile value of plutonium is more pronounced for usage in LWRs than in FBR. However, keeping the current plutonium inventory for an expected future deployment of FBRs is counterproductive. Recycling plutonium reduce the required volume for final disposal in an underground repository and the cost of final disposal. However, the benefits of utilizing an energy resource and of reducing final disposal liabilities are not the only aspects that determine the choice of a back-end policy.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.392-395
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• 1998

This paper suggests the“infinite-retailer model”to approximate expected backorders per cycle of the One-warehouse N-retailer distribution system where the warehouse holds back some of the replenishment quantity to satisfy retailer backorders at the end of the cycle through direct shipping to customers. The main objective is to show the functional relationship between the warehouse inventory and the expected backorders per cycle. We illustrate the relationship using a uniform demand case.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.150-164
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• 2004

According to the Korean long-term plan for nuclear technology development, KAERI is conducting a few R&D projects related to the proliferation-resistant back-end fuel cycle. The R&D activities for the back-end fuel cycle are reviewed in this work, especially focusing on the study of the partitioning and transmutation(P&T) of long-lived radionuclides. The P&T study is currently being carried out in order to develop key technologies in the areas of partitioning and transmutation. The partitioning study is based on the development of pyroprocessing such as electrorefining and electrowinning because they can be adopted as proliferation-resistant technologies in the fuel cycle. In this study, various behaviors of the electrodeposition of uranium and rare earth elements in the LiCl-KCl electrorefining system have been examined through fundamental experimental work. As for the transmutation system, KAERI is studying the HYPER (HYbrid Power Extraction Reactor), a kind of subcritical reactor which will be connected with a proton accelerator. Up to now, a conceptual study has been carried out for the major elemental systems of the subcritical reactor such as core, transuranic fuel, long-lived fission product target, and the Pb-Bi cooling system, etc. In order to enhance the transmutation efficiency of the transuranic elements as well as to strengthen the reactor safety, the reactor core was optimized by determining its most suitable subcriticality, the ratio of height/diameter, and by introducing the concepts of optimum core configuration with a transuranic enrichment as well as a scattered reloading of the fuel assemblies.

• 산업경영시스템학회지
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• 제18권36호
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• pp.341-348
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• 1995

The AHP is a good methodology for the multicriterion decision-making process such as nuclear fuel cycle technology selection, which requires consideration of international circumstances, social factors, economic factors as well as technological factors. This paper presents the prioritization of technologies using AHP at back-end fuel cycle development strategy and it would be useful for the national nuclear development planners.

• Nuclear Engineering and Technology
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• 제37권1호
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• pp.91-100
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• 2005

Kyung-hee Thorium Fuel (KTF), a heterogeneous thorium-based seed and blanket design concept for pressurized light water reactors, is being studied as an alternative to enhance proliferation resistance and fuel cycle economics of PWRs. The proliferation resistance characteristics of the KTF assembly design were evaluated through parametric studies using neutronic performance indices such as Bare Critical Mass (BCM), Spontaneous Neutron Source rate (SNS), Thermal Generation rate (TG), and Radio-Toxicity. Also, Fissile Economic Index (FEI), a new index for gauging fuel cycle economy, was suggested and applied to optimize the KTF design. A core loaded with optimized KTF assemblies with a seed-to-blanket ratio of 1: 1 was tested at the Korea Next Generation Reactor (KNGR), ARP-1400. Core design characteristics for cycle length, power distribution, and power peaking were evaluated by HELIOS and MASTER code systems for nine reload cycles. The core calculation results show that the KTF assembly design has nearly the same neutronic performance as those of a conventional $UO_2$ fuel assembly. However, the power peaking factor is relatively higher than that of conventional PWRs as the maximum Fq is 2.69 at the M$9^{th}$ equilibrium cycle while the design limit is 2.58. In order to assess the economic potential of a heterogeneous thorium fuel core, the front-end fuel cycle costs as well as the spent fuel disposal costs were compared with those of a reference PWR fueled with $UO_2$. In the case of comprising back-end fuel cycle cost, the fuel cycle cost of APR-1400 with a KTF assembly is 4.99 mills/KWe-yr, which is lower than that (5.23 mills/KWe-yr) of a conventional PWR. Proliferation resistance potential, BCM, SNS, and TG of a heterogeneous thorium-fueled core are much higher than those of the $UO_2$ core. The once-through fuel cycle application of heterogeneous thorium fuel assemblies demonstrated good competitiveness relative to $UO_2$ in terms of economics.