• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
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• pp.403-414
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• 2003

Periodic safety review on Kori Unit 1 has been successfully done for the first time in Korea. 11 safety factors of the review were fully evaluated in accordance with the domestic legal system. Although it is the oldest nuclear power plant in Korea, Kori Unit 1 was found to have maintained good operating conditions and continuously enhanced its safety by implementing post-TMI action plans and other safety issues, such as replacing steam generators and process/control system. It can be therefore confirmed that safe operation of Kori Unit 1 is guaranteed until next periodic safety review. Nevertheless, some corrective action items were recommended to enhance further its safety level, such as equipment qualification, additional ageing management program, strengthening of some procedures related to administration and human factor. The results of PSR can be utilized for the continued operation beyond the design life as long as the plant safety is maintained and improved. Experiences of the PSR on Kori Unit 1 can be also applied to PSR on other plants.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.104-104
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• 2018

Kori Unit 1 is the first permanent shutdown nuclear power plant in Korea and it is on June 18th, 2017. Spent fuel assemblies began to be discharged from the reactor core to the spent fuel pool(SFP) within one week after shutdown of Kori unit 1 and the campaign was completed on June 27th, 2017. The total number of spent nuclear fuel assemblies in SFP of Kori Unit-1 is 485 and their discharging date is different respectively. So, decay heat was evaluated considering the actual enrichment, operation history and cooling time of the spent fuel assemblies stored in SFP of the Kori Unit-1. The code used in the evaluation is the ORIGEN-based CAREPOOL system developed by KHNP. Decay heat calculation of PWR fuel is based on ANSI/ANS 5.1-2005, "Decay heat power in light water reactors" and ISO-10645, "Nuclear energy - Light water reactors - Calculation of the decay heat power in nuclear fuels. Also, we considered the contribution of fission products, actinide nuclides, neutron capture and radioactive material in decay heat calculation. CAREPOOL system calculates the individual and total decay heat of all of the spent fuel assemblies in SFP of Kori Unit-1. As a result, the total decay heat generated in SFP on June 28th, 2017 when the spent fuel assemblies were discharged from the reactor core, is estimated to be about 4,185.8 kw and to be about 609.5 kw on September 1st, 2018. It was also estimated that 119.6 kw is generated in 2050 when it is 32 years after the permanent shutdown. Figure 1 shows the trend of total decay heat in SFP of Kori Unit-1.

• 방사성폐기물학회지
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• 제14권3호
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• pp.289-295
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• 2016

국내 최초로 건설된 가압경수로형 발전소인 고리1호기는 1978년 4월 첫 상업운전을 개시하였고, 2017년 6월 18일 영구정지 될 계획이다. 고리1호기에서는 사용후핵연료가 사용후핵연료저장조로 모두 이송된 이후, 계통 표면의 선량율을 감소시키기 위한 목적으로 전계통 제염을 실시할 계획이다. 이 논문에서는 해외 원전의 계통제염 사례분석을 통해 국내 최초로 시행될 예정인 고리1호기의 계통제염 운전개념을 기술하고자 하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
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• pp.515-519
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• 1997

The purpose of this study is to reduce the fast neutron fluence at the reactor pressure vessel(RPV) and to provide a basis for plant-life extension. In this study, different neutron absorbers were employed in the core outer assemblies of Kori Unit 1 Cycle 14. The modified assemblies were used to calculate fast neutron fluence at the RPV and to evaluate reduction of outer assembly power and total power in core. By comparison with the case of no suppression fixture, the fast neutron fluence of a case with two rows stainless steel around the assembly with natural uranium pins is decreased by 85.8%. It is noted that the modification of outer assembly is more efficient than the previous low leakage loading pattern (LLLP) applied to Kori Unit 1. Also, compared fast neutron fluence in Cycle 1 with Cycle 14, fast neutron fluence at the RPV between Cycle 1 and Cycle 14 is not significantly different. It is found that LLLP applied to the Kori Unit 1 has not contributed to fast neutron fluence reduction at the RPV.

• Nuclear Engineering and Technology
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• 제29권5호
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• pp.375-384
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• 1997

Relative power density distributions of the Kori Unit 1 pressurized water reactor are calculated by Monte Carlo modeling with the MCNP code. The Kori Unit 1 core is modeled on a three-dimensional representation of the one-eighth of the reactor in-vessel component with reflective boundaries at 0 and 45 degrees. The axial core model is based on half core symmetry and is divided into four axial segments. Fission reaction density in each rod is calculated by following 100 cycles with 5,000 test neutrons in each cycle after starling with a localized neutron source and ten noncontributing settle cycles. Relative assembly power distributions are calculated from fission reaction densities of rods in assembly. After 100 cycle calculations, the system converges to a k value of 1.00039 $\geq$ 0.00084. Relative assembly power distribution is nearly the same with that of the Kori Unit 1 FSAR. Applicability of the full-scope Monte Carlo simulation in the power distribution calculation is examined by the relative root moan square error of 2.159%.

• 방사성폐기물학회지
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• 제18권3호
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• pp.347-354
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• 2020

Site characterization for decommissioning Kori Unit 1 is ongoing in South Korea after 40 years of successful operation. Kori Unit 1's containment building is assumed to be mostly radioactively contaminated, and therefore radiation exposure management and detailed contamination investigation are required for decommissioning and dismantling it safely. In this study, site-specific Derived Concentration Guideline Levels (DCGLs) were derived using the residual radioactivity risk evaluation tool, RESRAD-BUILD code. A conceptual model of containment building for Kori Unit 1 was set up and limited occupational worker building inspection scenario was applied. Depending on the source location, the maximum contribution source and exposure pathway of each radionuclide were analyzed. The contribution of radionuclides to dose and exposure pathways, by source location, is expected to serve as basic data in the assessment criteria of survey areas and classification of impact areas during further decommissioning and decontamination of sites.

• Nuclear Engineering and Technology
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• 제38권7호
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• pp.665-674
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• 2006

Three-dimensional neutron flux and fluence of Kori Unit 3 were evaluated using the synthesis technique described in Regulatory Guide 1.190 for all reactor geometry. For this purpose DORT neutron transport calculations from Cycle 1 to Cycle 15 were performed using BUGLE-96 cross-section library. The calculated flux and fluence were validated by comparing the calculated reaction rates to the measurement data from the dosimetry sensor set of the $5^{th}$ surveillance capsule withdrawn at the end of cycle 15 of Kori Unit 3. And then the best estimation of the neutron exposures for the reactor vessel beltline region was performed using the least square evaluation. These results can be used in the assessment of the state of embrittlement of Kori Unit 3 pressure vessel.

• 방사성폐기물학회지
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• 제14권2호
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• pp.123-134
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• 2016

최근 국내에서는 월성 1호기 및 고리 1호기를 포함하여 운영 중인 원자력발전소가 노후화함에 따라 원전 해체에 대한 관심이 많이 증대되고 있다. 이와 관련하여 월성 1호기의 계속운전이 최근 결정되었으며, 고리 1호기의 경우 2017년 6월 영구정지하기로 결정되었다. 이에 본 논문에서는 상업용 원자로로서는 국내 최초로 해체가 예정된 고리 1호기에 대해, 원자로 압력용기 자체의 해체로 인해 발생하는 방사성폐기물 최종 처분량을 원자로 압력용기 절단 방법 및 방사성폐기물 처분용기를 고려하여 산정하였다. 처분용기를 고려한 방사성폐기물 처분량을 산정한 결과 원자로 압력용기 몸통 부위보다는 반구 형태의 헤드 부분을 작게 절단할수록 최종 처분량이 감소하는 것으로 예측되었다. 또한 경주 방폐장의 200 L 및 320 L 드럼 처분용 처분용기의 경우 무게 제한으로 인해 적재효율이 좋지 못한 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제26권1호
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• pp.41-53
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• 1994

1991년 2월 미하마원전에서 발생한 증기발생기 세관 파열사고에 대한 경험을 바탕으로, 본 사고에 대한 고리 1호기의 대처능력을 평가하기 위하여 해석을 수행하였다. 고리 1호기의 계통설계 및 운전조건은 미하마 2호기와 아주 유사하기 때문에 고리 1호기에서 발생한 가상의 증기발생기 세관 파열사고시의 사고경위 및 전개에 대한 평가가 필요하였다. 해석은 고리 1호기 EOP를 근거로 현실적으로 가능하게 수행되었다. 해석결과, 파열된 세관을 통한 누출은 사고후 약 40분 후에 정지되었으며, 고리 1호기는 유사한 증기발생기 세관 파열사고의 경우 충분한 대처능력이 있음을 보였다. 그러나, SI 신호작동후 소외전원으로 부터의 비안전등급 AC전원으로 단절되는 설계에 대한 재고가 필요하며, EOP의 운전절차가 운전원의 적절한 판단을 요구하기에는 다소 충분치 못함을 보였다. 또한 미하마 원전의 사고를 실험적으로 모사한 LSTF의 실험결과를 이용 해석코드인 RELAP5/MOD3의 평가능력에 대하여 해석을 수행하였다. 해석결과 코드는 사고 초기의 누설량 예측을 제외하고는 일반적으로 실험결과와 잘 일치하고 있음을 보였다.

• 방사성폐기물학회지
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• 제18권2_spc호
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• pp.247-260
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• 2020

본 논문에서는 고리 1호기 해체 비용 추정을 위해 외국 원자력발전소 해체 비용 데이터를 현가화한 후 원자력발전소 해체 비용 추정 회귀 분석모델을 개발하였다. 이 모델 개발에 사용된 데이터는 해체 또는 진행 중인 BWR 13기, PWR 16기의 해체 비용 데이터이다. 회귀 분석모델 도출을 위해, 해체 비용을 종속변수로 정하고, 해체 원전의 운전 특성을 반영할 수 있게 고안된 Contamination factor와 해체 기간을 독립변수로 선정하였다. 빅데이터 분석 도구인 R language의 통계패키지를 이용하여 회귀 분석모델을 도출하였다. 이 회귀 분석 모델을 적용하여 고리 1호기 해체 비용을 예측한 결과, 미화 663.40~928.32백만 달러, 한화 약 7,828.12억~1조 954.18억 원이 소요될 것으로 예측되었다.