• Title/Summary/Keyword: 방사성입자

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Effect of Cetyltrimethyl Ammonium Bromide on Foam Stability and SiO2Separation for Decontamination Foam Application (거품제염을 위한 실리카 나노입자와 CTAB (Cetyltrimethyl Ammonium Bromide)의 거품안정성 및 분리특성 평가)

  • Choi, Mansoo;Kim, Seung-Eun;Yoon, In-Ho;Jung, Chong-Hun;Choi, Wang-Kyu;Moon, Jei-Kwon;Kim, Seon-Byeong
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.2
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    • pp.173-182
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    • 2018
  • As part of planning for waste minimization, decontamination foam has been considered as a potential application for the cleaning of radioactive contaminant. In this study, we synthesized silica particles to improve foam stability by varying synthesis parameters. Cetyltrimethylammonium bromide (CTAB) was found to influence the stability of the decontamination foam. The reason was that higher interaction between $SiO_2$ nanoparticles and surfactant at the air-water interface in aqueous solution is beneficial for foam stability. CTAB can also be used as an additive for the aggregation of silica nanoparticles. In the separation of $SiO_2$ nanoparticles, CTAB plays a critical role in the nanoparticles flocculation because of the charge neutralization and hydrophobic effects of its hydrocarbon tails.

KAERI 소각시설의 실용화를 위한 방사학적 안전성 분석

  • 양희철;김정국;김창회;박원만;김봉환;김준형;오원진;박현수
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.409-414
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    • 1998
  • 5 년간의 기술실증 및 안전성 검토를 거쳐 한국원자력연구소내 실증소각시설을 자체발생 가연성 $\beta$/${\gamma}$폐기물을 소각하는 시설로 인허가를 얻었다. 동위원소포함 모의폐기물 및 원전발생 가연성폐기물 실증소각 결과에 기준을 두고 연간 배출오염원 및 가상 사고시의 방사학적 위해성을 평가하여 저준위 폐기물을 부지내에서 소각처리할 때 그 위해성은 무시할 수 있을 것으로 미미함 을 확인하였다. 실증시험으로 주된 배출 방사선원은 고온의 소각로에서 휘발성이 크고 저준위 폐기물내 농도가 큰 반휘발성 Cs-137 및 Cs-134로, 발전소 가연성폐기물과 같은 핵종조성을 가진 0.109 mCi/kg 의 소각시 Cs-137 및 Cs-134의 배출농도가 공기중허용농도의 10%를 약간 상회하는 것으로 평가되었다. 비방사성 CsCI을 이용한 시험소각을 통하여 사용되는 저온배기체처리계통 에서의 휘발된 Cs의 배기체 냉각시 입자화 및 제거특성을 고찰한 결과 휘발된 기체상 Cs성분은 건식배기체 냉각공정을 거치면서 대부분 마이크론 크기이하의 입자로 생성되지만 5% 미만이 전이영역 크기에 분포하여 주여과장치인 여과포집진기에서 제거효율이 99.9% 이상이었다.

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Formation of Ultra fine Particle by the Polonium-218 Ions under Different Humidity Conditions (다른 습도조건하에서 Po-218 이온들의 극소입자형성에 관한 연구)

  • Yoon, Suk-Chul;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
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    • v.17 no.1
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    • pp.1-10
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    • 1992
  • A number of investigators have reported the formation of the radiolytic ultrafine particles produced by the interaction of ionizing radiation with water vapor. Previous studies have suggested that a very high localized concentration of the OH radical produced by the radiolysis of water can react with trace gas like organic vapors and produce lower vapor pressure compounds that can then nucleate. In order to determine water vapor dependence of the active, positively charged, first radon daughter(Po-218), an experiment was conducted using a well-controlled radon chamber. The activity size distribution of the radon daughter in the range of 0.5-100nm was measured using the parallel graded wire screens system. Measurements were taken for different relative humidity. The resultant activity size distributions were analyzed. The addition of water vapor to the radon carrier gases resulted in the formation of ultrafine particles by OH radicals formed by radon radiolysis. It may be due to the neutralization of charged Po-218 ion with water vapor through the radio lysis.

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Infrared Emissivity of Stainless Steel Coated with Composites of Copper Particle and m-Aramid Resin (구리입자/메타아라미드 수지 복합재료 도포 스테인리스 철판의 적외선 방사 특성)

  • Oh, Chorong;Kim, Sunmi;Park, Gyusang;Choi, Seongman;Lee, Dai Soo;Myoung, Rhoshin;Kim, Woncheol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.1
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    • pp.1-7
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    • 2017
  • As a part of studies to lower the infrared (IR) emissivity from the surface of exhaust nozzle in the turbo jet engine, stainless steel plate was coated with copper particle/meta-aramid resin composites and the IR emissivity of the plate were investigated. Binders of filler particles based on synthetic polymers generally undergo thermal decomposition before $300^{\circ}C$. It was found that the meta aramid resin was thermally stable after the test at $320^{\circ}C$, confirming the excellent thermal stability. Contents of copper particles in the composites were varied from 0 to 70% by volume. It was observed that the copper particle/meta aramid resin composites showed good adhesion after the tests at $320^{\circ}C$. The specimen coated with the composite containing 50 vol% of copper particles showed the lowest IR emissivity, 0.6, at $320^{\circ}C$.

토양제염 실증실험을 위한 세척수 재순환장치의 성능시험

  • 손중권;이강원;강기두;김학수;박경록;김경덕
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.242-242
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    • 2004
  • 원자력발전소의 운전과정에서 계획적 혹은 비계획적으로 방출되는 미량의 입자상 방사성 물질들은 대부분 원전 부지내 토양에 침적되게 된다. 이러한 과정 속에서 오염토양이 발생하게 되면 수거되어 단순 격리관리하고 있는 실정이지만 앞으로 원전의 해체과정 등으로 인한 오염토양이 상당량 발생할 것으로 예상되기 때문에 적절한 제염을 통하여 폐기물량을 최소화시킬 필요가 있다. 이를 위해 오염토양 제염공정으로 물을 이용한 토양세척법을 선정하여 제염장치를 제작하였으며 실증시험을 수행하였다.(중략)

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