Analytical Science and Technology (분석과학)

The Korean Society of Analytical Sciences (한국분석과학회)
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Determination of Tritium in Spent Pressurized Water Reactor (PWR) Fuels

가압 경수로 사용후핵연료 중 삼중수소 분석

  • Lee, Chang Heon (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute) ;
  • Suh, Moo Yul (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute) ;
  • Choi, Kwang Soon (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute) ;
  • Jee, Kwang Yong (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute) ;
  • Kim, Won Ho (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute)
  • 이창헌 (한국원자력연구소, 원자력화학연구부) ;
  • 서무열 (한국원자력연구소, 원자력화학연구부) ;
  • 최광순 (한국원자력연구소, 원자력화학연구부) ;
  • 지광용 (한국원자력연구소, 원자력화학연구부) ;
  • 김원호 (한국원자력연구소, 원자력화학연구부)
  • Received : 2004.06.10
  • Accepted : 2004.09.09
  • Published : 2004.10.25
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Abstract

To characterize chemically a spent pressurized water reactor (PWR) fuel, an analytical method for trace amounts of tritium ($^3H$) in it has been established. Considering the effective management of radioactive wastes generated through the whole experimental process and the radiological safety for analysts, a separation condition under which $^{14}C$ and $^3H$ can be sequentially recovered from a single fuel sample was optimized using simulated spent PWR fuel dissolved solutions. $^{14}CO_2$ evolved during dissolution of the spent PWR fuels with nitric acid was trapped in an aliquot of 1.5 M NaOH. $^{129}I_2$ which was volatilized along with $^{14}CO_2$ was removed using a silver nitrate-impregnated silica gel absorbent. $^3H$ remaining in the fuel dissolved solution as $^3H_2O$ was selectively recovered by distillation. Its recovery yield was 97.9% with a relative standard deviation of 0.9% (n=3). $^3H$ in a spent PWR fuel with burnup value of 37,000 MWd/MtU was analyzed, reliability of this analytical method being evaluated by standard addition method.

가압 경수로 사용후핵연료의 화학특성을 규명하기 위하여 극미량 함유되어 있는 삼중수소 ($^3H$)의 정량기술을 확립하였다. 분석과정에서 발생하는 방사성 폐액의 양을 줄이고 분석자의 방사선 피폭을 줄이기 위하여 하나의 시료로부터 $^{14}C$과 $^3H$를 순차적으로 회수할 수 있도록 분리조건을 최적화하였다. 사용후핵연료를 질산으로 용해하는 과정에서 $^{14}CO_2$와 함께 휘발하는 $^{129}I_2$는 $AgNO_3$가 침윤되어 있는 흡착제로 제거하였다. $^{14}CO_2$는 1.5 M NaOH에 포집시키고 $^3H_2O$는 증류시켜 회수하였다. $^3H$의 평균 회수율은 97.9%, 상대표준편차는 0.9% (n = 3) 이었으며, 37,000 MWd/MtU 연소도의 사용후핵연료를 대상으로 $^3H$를 분석하고 표준물첨가법으로 분석신뢰도를 평가하였다.

Keywords

References

  1. G. F. Knoll, 'Radiation, Determination and Measurement', Wiley, Inc, New York, 1979.
  2. UNSCEAR, 'Sources and Effects of Ionizing Radiation', United Nations Publications, Vienna, Austria, 1977.
  3. BNFL 'Annual report on radioactive discharges and monitoring of the environment', Vol. 1, British Nuclear Fuels, Risely, Cheshire, UK, 1995.
  4. 'Dissolution studies of spent nuclear fuels', JAERI-M 91-010, 1991.
  5. M. A. Gautier, E. S. Gladney and D. R. Perrin, 'Quality assurance for Health and Environmental Chemistry: 1989', Los Alamos National Laboratory Report LA-11995-MS, 1990.
  6. J. A. Stone and D. R. Johnson, DP-MS-78-7, 1978.
  7. PNL-ALO-479 Technical Report, 1989.
  8. D. R. Johnson and J. A. Stone, DP-MS-77-77, 1978.
  9. E. W. Baumann and K. W. MacMurdo, CONF 771031-1, 1977.
  10. P. E. Warwick, I. W. Croudace, A. G. Howard, Anal. Chim. Acta, 382, 225(1999).
  11. G. L. Haag, J. W. Nehis, Jr. and G. C. Young, 'Carbon-14 immobilization via the Ba(OH)2.8 H2O process', In Proc. 17th DOE Nuclear Air Cleaning Conference, CONF-828033, U.S. DOE., pp 431-453, 1983.
  12. W. Davis, Jr., 'Carbon-14 Production in nuclear reactors', ORNL/NUREG/TM-12, Oak Ridge National Laboratory, Oak Ridge, TN, 1977.
  13. M. J. Kabat, 'Monitoring and removal of gaseous carbon-14 species', In Proc. 15th DOE Nuclear air Cleaning Conference, CONF-780819, National Technical Information Service, Springfield, 1979.
  14. C. O. Kunz, '14C release at light water reactors', In Proc. 17th DOE Nuclear air Cleaning Conference, CONF-820833, National Technical Information Service, Springfield, VA, pp 414-430, 1983.