• 제목/요약/키워드: U-phase

검색결과 1,026건 처리시간 0.036초

Proposal of Application Method for Concentration Averaging of Radioactive Waste in Korea by Using CA BTP of US NRC

  • Jiyoung Yi;Chang-Lak Kim
    • 방사성폐기물학회지
    • /
    • 제21권3호
    • /
    • pp.347-357
    • /
    • 2023

  • United States Nuclear Regulatory Commission (U.S. NRC) specifies regulations on obtaining licenses and describes the technical position on the average waste concentration, also known as Concentration Averaging and Encapsulation Branch Technical Position (CA BTP); CA BTP helps classify blendable waste and discrete items and address concentration averaging. The technical position details are reviewed and compared in a real environment in Korea. A few cases of concentration averaging based on the application of CA BTP to domestic radioactive waste are presented, and the feasibility of the application is assessed. The radioactive waste considered herein does not satisfy the Disposal Concentration Limit (DCL) of the second-phase disposal facility while applying the preliminary classification. However, if CA BTP is applied when the radioactive waste is mixed with other radioactive waste items in a large and heavy container, it can be disposed of at the second-phase disposal facility in Gyeongju Repository. To apply the CA BTP of the U.S. NRC, it is necessary to investigate the safety assessment conditions of the US and Korea.

  • https://doi.org/10.7733/jnfcwt.2023.024 인용 PDF

U-City 시스템 도입에 따른 탄소배출량 저감 효과 분석 (The Effect of Reducing Carbon Emissions, According to the Introduction of U-City System)

  • 정태웅;문수정;김윤관;구지희
    • Spatial Information Research
    • /
    • 제20권1호
    • /
    • pp.19-26
    • /
    • 2012

  • 기후변화의 원인 중 탄소배출이 가장 큰 비중을 차지하고 있어 탄소배출 감소의 필요성이 전 세계적으로 제기되고 탄소배출을 감소하기 위한 국제적 움직임이 가속화되고 있다. 선진국들은 녹색산업을 신성장동력 산업으로 활용하는 전략을 추진 중이며 탄소저감형도시(low carbon city)에 대한 관심이 높아지고 있다. 현재 우리나라에서 진행되고 있는 U-City 사업에 대하여 U-City 도입 이전 도시와 U-City 도입 도시의 탄소배출량 변화를 분석하여 이산화탄소 저감효과에 대한 분석이 필요하다. 본 연구에서는 U-City 도입 이전과 도입 이후의 이산화탄소 발생량을 비교, 분석하여 U-City 도입에 따른 탄소저감 효과를 정량화하고자 하였다. U-City 도입이전의 도시는 1기 신도시 중에 성남시 분당구와 고양시 일산구를 대상으로 하였으며, U-City 도입이후의 도시로는 화성동탄 U-City를 선정하여 비교한 결과 탄소배출량이 30%정도 줄어든 것으로 결과가 도출되었다.

  • https://doi.org/10.12672/ksis.2012.20.1.019 인용 PDF KSCI

${Bi_2}{Sr_2}{CaCu_2}{O_{8+x}}$와 ${Bi_2}{Sr_2}{Ca_2}{Cu_3}{O_{10+x}}$의 상 안정성에 대한 산소분압의 영향 (Effect of the Oxygen Partial Pressure on the Phase Stability of ${Bi_2}{Sr_2}{CaCu_2}{O_{8+x}}$ and ${Bi_2}{Sr_2}{Ca_2}{Cu_3}{O_{10+x}}$)

  • 박민수;이화성;안병태
    • 한국재료학회지
    • /
    • 제5권5호
    • /
    • pp.583-597
    • /
    • 1995

  • We investigated the effect of the oxygne partial pressure on the phase stability of B $i_{2}$S $r_{2}$Ca C $u_{2}$ $O_{8+x}$ and B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ at 82$0^{\circ}C$. As the oxygen pressure decreased, B $i_{2}$Sr/sb 2/CaC $u_{2}$ $O_{8+x}$ melted at 2.2$\times$10$^{-3}$ atm $O_{2}$. In the case of the B $i_{1.7}$P $b_{0.4}$S $r_{2}$C $a_{2}$ $O_{10+x}$, it started to decompose into theree phases of B $i_{2}$S $r_{2}$Cu $O_{6+y}$, $Ca_{2}$Cu $O_{3}$ and C $u_{4}$ $O_{3}$ and C $u_{4}$ $O_{3}$ at 8.0$\times$10$^{-3}$ atm $O_{2}$ and was completely decomposed at 4.3$\times$10$^{-3}$ atm $O_{2}$ B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ phase was not formed by the solid state reaction from the mixutre of $i_{2}$S $r_{2}$CaCu.sub 2/ $O_{8+x}$, $Ca_{2}$Cu $O_{3}$ and CuO down to 2.2$\times$10.sub -3/ atm O.sub 2/ but formed by the solidifciation of the formed from the mixture of the intermediate compounds in the Bi-Sr-Ca-Cu-O system and the fromation temperature of Bi.sub 2/S $r_{2}$C $a_{2}$Cu.$_{3}$ $O_{10+x}$ can be lowered by reducing oxygen partial pressure.e.e.ure.e.e.

  • PDF

BPSCCO System에서 2212 및 2223 phase의 생성.전이 (The Formation and Transition of 2212 and 2223 Phase in BPSCCO System)

  • 박용필;왕종배;김홍철;김왕곤;이준웅
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
    • /
    • pp.311-315
    • /
    • 1991

  • The formation and transition of 2212 and 2223 phase have been studied in BPSCCO system. The 2212 phase formed in early sintering state reacts on $Ca_2PbO_4,\;Ca_2CuO_3$ and CuO during sintering process and thus produces the 2223 phase. A long sintering period is need to fabricate the superconductor with large volume fraction of 2223 phase. Also, the thin plate-like grains composed of Bi, Sr, Ca and Cu contribute to 2223 phase formation. Though the sample has lower volume fraction of 2223 phase, the critical temperature is measured highly in case of the grain grown to plate-like shape. In this work, the critical temperature of the sample sintered for 264 hr in air was measured 108 K. Microstructure of the sample was varied with condition of heat treatment after sintering process and the sample annealed with $500^{\circ}C$ for 5 hr showed excellent charateristics of 2223 phase formation.

  • PDF