Influence of Microbial Activity on the Long-Term Alteration of Compacted Bentonite/Metal Chip Blocks

다국어 초록 (Multilingual Abstract)

Safe storage of spent nuclear fuel in deep underground repositories necessitates an understanding of the long-term alteration of metal canisters and buffer materials. A small-scale laboratory alteration test was performed on metal (Cu or Fe) chips embedded in compacted bentonite blocks placed in anaerobic water for 1 year. Lactate, sulfate, and bacteria were separately added to the water to promote biochemical reactions in the system. The bentonite blocks immersed in the water were dismantled after 1 year, showing that their alteration was insignificant. However, the Cu chip exhibited some microscopic etch pits on its surface, wherein a slight sulfur component was detected. Overall, the Fe chip was more corroded than the Cu chip under the same conditions. The secondary phase of the Fe chip was locally found as carbonate materials, such as siderite (FeCO3) and calcite ((Ca, Fe)CO3). These secondary products can imply that the local carbonate occurrence on the Fe chip may be initiated and developed by an evolution (alteration) of bentonite and a diffusive provision of biogenic CO2 gas. These laboratory scale results suggest that the actual long-term alteration of metal canisters/bentonite blocks in the engineered barrier could be possible by microbial activities.

참고문헌 (Reference)

1 이승엽, "황산염환원미생물에 의한 금속재료의 부식 특성" 한국광물학회 26 (26): 219-228, 2013

2 오종민, "한국원자력연구원 지하심부 미생물에 의한 용존우라늄 제거 및 광물화 특성" 한국광물학회 23 (23): 107-115, 2010

3 이승엽, "토착미생물의 생지화학적 활동에 의한 지하수의 산화/환원전위 변화 특성" 대한자원환경지질학회 47 (47): 61-69, 2014

4 이승엽, "지하수 용존 우라늄의 수착 및 침전 거동에서 수소 가스의 생지화학적 영향" 대한자원환경지질학회 51 (51): 77-85, 2018

5 이민수, "저온분사코팅구리의 틈새부식 특성 평가" 한국방사성폐기물학회 8 (8): 247-260, 2010

6 이승엽, "국내 지하수에 서식하는 바쿨라텀(baculatum)에 의한 용존우라늄 제거 및 미량 중금속 원소들의 영향" 한국광물학회 24 (24): 83-90, 2011

7 이지영, "고준위폐기물 완충재로 사용되는 벤토나이트의 미생물의 존재 및 특성" 한국방사성폐기물학회 11 (11): 95-102, 2013

8 B. Rosberg, "Tafel Slopes Used in Monitoring of Copper Corrosion in a Bentonite/Groundwater Environment" 47 (47): 3267-3279, 2005

9 M. Kamrunnahar, "Prediction of Corrosion Behaviour of Alloy 22 Using Neural Network as a Data Mining Tool" 53 (53): 961-967, 2011

10 J. Pena, "Kinetic Modelling of the Attenuation of Carbon Steel Canister Corrosion due to Diffusive Transport Through Corrosion Product Layers" 50 (50): 2197-2204, 2008

11 이승엽, "KURT 암반단열 내 미생물의 생지화학적 활동과 방사성 우라늄의 수착거동 특성 변화" 한국자원공학회 53 (53): 452-462, 2016

12 K. O. Konhauser, "Introduction to Geomicrobiology" Blackwell Publishing 2007

13 H. L. Ehrlich, "Geomicrobiology" CRC Press 2009

14 최희주, "Development of Geological Disposal Systems for Spent Fuels and High-level Radioactive Wastes in Korea" 한국원자력학회 45 (45): 29-40, 2013

15 이민수, "Design, Manufacturing, and Performance estimation of a Disposal Canister for the Ceramic Waste from Pyroprocessing" 한국방사성폐기물학회 10 (10): 209-218, 2012

16 J. Lee, "Concept of a Korean Reference Disposal System for Spent Fuels" 44 (44): 1565-1573, 2007

17 이민수, "APPLICATION OF COLD SPRAY COATING TECHNIQUE TO AN UNDERGROUND DISPOSAL COPPER CANISTER AND ITS CORROSION PROPERTIES" 한국원자력학회 43 (43): 557-566, 2011

18 L. Wu, "A Model for the Influence of Steel Corrosion Products on Nuclear Fuel Corrosion Under Permanent Disposal Conditions" 61 : 83-91, 2012