경주 벤토나이트의 수리-열-열할적 특성 및 핵종 유출 저지증

• 영문명: Hydraulic-Thermal-Mechanical Properties and Radionuclide Release-Retarding Capacity of Kyungju Bentonite
• 발행기관: 한국방사성폐기물학회
• 저자명: 이재완 조원진 한필수
• 간행물 정보: 『Journal of Nuclear Fuel Cycle and Waste Technology (JNFCWT)』Vol.2 No.2, 87~96쪽, 전체 10쪽
• 주제분류: 공학 > 공학일반
• 파일형태: PDF
• 발행일자: 2004.06.30

국문 초록

고준위방사성폐기물 처분장의 완충재 후보물질 선정을 위해 경주 벤토나이트를 대상으로 수리특성, 팽윤특성, 열적특성, 역학특성 및 핵종유출 저지특성을 조사하였다. 실험결과, 압축 벤토나이트의 수리전도도는 10-11 m/s 이하로 매우 낮았으며 건조밀도가 증가할수록 감소하였다. 팽윤압은 0.66 MPa - 14.4 MPa 사이의 값을 보였으며 건조밀도에 따라 증가하였다. 건조밀도가 1.4 Mg/m3 - 1.8 Mg/m3일 때, 열전도도, 일축압축강도 (unconfined compressive strength), 탄성계수 (Young’s modulus of elasticity), Poisson 비는 각각 0.80 kcal/mhoC - 1.52 kcal/mhoC, 0.55 MPa - 8.83 MPa, 59 MPa - 1275 MPa, 0.05 - 0.20의 값을 나타내었다. 압축벤토나이트 에 대한 핵종 확산계수는 산화환경에서 측정되었으며, 주어진 실험조건에서 삼중수소 (H-3)는 1.7 x 10-10 m2/s - 3.4 x 10-10 m2/s, 양이온 핵종 (Cs, Sr, Ni)은 8.6 x 10-14 m2/s - 1.3 x 10-12 m2/s, 음이온 핵종 (I, Tc)은 1.2 x 10-11 m2/s - 9.5 x 10-11 m2/s, 악티나이드 핵종은 3.0 x 10-14 m2/s - 1.8 x 10-13 m2/s 사이의 값을 나타내었다. 이 때 확산계수는 모든 핵종에 대해 압축벤토나이트의 건조밀도가 증가할수록 감소하는 경향을 보였다.

영문 초록

Studies were conducted to select the candidate buffer material for a high-level waste (HLW) repository in Korea. This paper presents the hydraulic properties, the swelling properties, the thermal properties, and the mechanical properties as well as the radionuclide release-retarding capacity of Kyungju bentonite as part of those studies. Experimental results showed that the hydraulic conductivities of the compacted bentonite were very low and less than 10-11m/s. The values decreased with increasing the dry density of the compacted bentonite. the swelling pressures were in the range of 0.66 MPa to 14.4 MPa and they increased with increasing the dry density. The themal conductivities were in the range of 0.80 kcal/mh℃ to 1.52 kcal/mh℃ . The unconfined compressive strenth, Young’s modulus and Poison’s ratio showed the range of 0.55 MPa to 8.83 MPa, 59 MPa to 1275 MPa, and 0.05 to 0.20, respectively, when the dry densities of the compacted bentonite were 1.4 Mg/㎥ to 1.8 Mg/㎥ . The diffusion coeffcients in the compacted bentonite were measured under and oxidizing condition. The values were 1.7 x 10-10 ㎡/s to 3.4 x 10-10 ㎡/s for electrically neutral tritium (H-3), 8.6 x 10-14 ㎡/s to 1.3 x 10-12 ㎡/s for cations (Cs, Sr, Ni), 1.2 x 10-11 ㎡/s to 9.5 x 10-11/s for anions (I, Tc), and 3.0 x 10-14 ㎡/s to 1.8 10-13 ㎡/s for actinides (U, Am), when the dry densities were in the range of 1.2 Mg/㎡ to 1.8 Mg/㎡ . The obtained results will be used in assessing the barrier properties of Kyungju bentonite as a buffer material of a repository in Korea.

키워드

방벽특성치 벤토나이트 완충재 고준위폐기물처분장 Barrier properties Bentonite Buffer HLW Repository