http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Luksic, Steven A. (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Effect of Technetium-99 sources on its retention in low activity waste glass
Luksic, Steven A.,Kim, Dong-Sang,Um, Wooyong,Wang, Guohui,Schweiger, Michael J.,Soderquist, Chuck Z.,Lukens, Wayne,Kruger, Albert A. Elsevier 2018 JOURNAL OF NUCLEAR MATERIALS Vol.503 No.-
<P><B>Abstract</B></P> <P>Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO<SUB>2</SUB>∙2H<SUB>2</SUB>O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. We postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.</P>
-
Enhanced <sup>99</sup>Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals
Um, Wooyong,Luksic, Steven A.,Wang, Guohui,Saslow, Sarah,Kim, Dong-Sang,Schweiger, Michael J.,Soderquist, Chuck Z.,Bowden, Mark E.,Lukens, Wayne W.,Kruger, Albert A. Elsevier 2017 JOURNAL OF NUCLEAR MATERIALS Vol.495 No.-
<P><B>Abstract</B></P> <P>Technetium (<SUP>99</SUP>Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tc oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (∼10%) than in glass prepared using KTcO<SUB>4</SUB> because of limited and delayed Tc volatilization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Reduced Tc(IV) can be incorporated within an Fe oxide mineral structure. </LI> <LI> Tc-incorporated Fe minerals can increase Tc retention in glass waste forms. </LI> <LI> Increased Tc retention in glass can reduce the cost of waste treatment. </LI> </UL> </P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
