중수로 압력관 재료의 조사 열화에 따른 인장거동 특성

Tensile Behavior Characteristics of CANDU Pressure Tube Material Degraded by Neutron Irradiations

  • 발행 : 2002.01.01


To investigate the degradation of mechanical properties induced mainly by neutron irradiation, the tensile tests were conducted from room temperature to 300\\`c using the irradiated and the unirradiated Zr-2.5Nb pressure tube materials. The irradiated longitudinal and transverse specimens were collected from the coolant inlet, middle, and outlet parts of M-11 tube which had been operated in Wolsung CANDU Unit-1 and exposed to different operating temperatures and irradiation fluences. The different tensile behavior was characterized not by the fluences of irradiation but by the tensile loading direction. The transverse specimen showed the higher strength and lower elongation than those of the longitudinal one. It was believed that these phenomena resulted from the microstructure anisotropy caused by the extrusion process. The increased strength hardening and decreased elongation embrittlement of the irradiated material were compard to those of the unirradiated one. While the tensile strength of the inlet was higher than that of the outlet, the elongation of the inlet was lower than that of outlet. Considering the operation condition, it was proposed that the operating temperature could be a more effective parameter than the irradiation fluence for long-time life. Through the TEM observation, it was found that while the a-type dislocation density was increased, the c-type dislocation was not changed in the irradiated. The fact that the higher dislocation density was sequentially distributed over the inlet, the middle, and the outlet parts was consistent with the distribution of the tensile strength.


핫셀;조사;비조사;중성자;압력 관;조사경화 및 취화


  1. Hosbons, R. R., Davies, P. H., Griffiths, M., Sagat, S. and Coleman, C. E., 2000, 'Effect of Long-term Irradiation on the Fracture Properties of Zr-2.5Nb Pressure Tubes,' Zirconium in the Nuclear Industry : Twelfth International Symposium, ASTM STP 1354, pp. 122-138
  2. Davies, P.H., Hosbons, R. R., Griffitth, M. and C, K. Chow, 1994, 'Correlation between Irradiated and Unirradiated Fracture Toughness of Zr-2.5Nb Pressure Tubes,' Zirconium in the Nuclear Industry: Tenth International Symposium, ASTM STP 1245, pp. 135-167
  3. Ibrahim, E. F., 1987, 'Mechanical Properties of Cold Drawn Zr-2.5Nb Pressure Tubes After up to 12 years in CANDU Reactors,' Materials for Nuclear Reactor Core Applications, BNES, London, pp. 73-78
  4. Nah, B. K., 2001, Private communications, CANDU Reactor Design Group in KOPEC Co
  5. Griffith, M., 1998, 'A Review of Microstructure Evolution in Zirconium Alloys during Irradiation,' Journal of Nuclear Materials, Vol. 159, pp. 190-218
  6. Northwood, D. D., 1977, 'Comments on In-pile Dimensional Changes in Neutron-Irradiated Zr-base Alloys,' Journal of Nuclear Materials, Vol. 64, pp. 316
  7. Cheadle, B. A., Ellis, C. E. and J. van der Kurr, 1974, 'Plastic Instability in Irradiated Zr-Sn and Zr-Nb Alloys,' Zirconium in Nuclear Applications, ASTM STP 551, pp. 370-384
  8. Tenckoff, E., 1988, 'Deformation Mechanism, Texture, and Anisotropy in Zirconium and Zircaloy,' ASTM STP 966, pp. 1-77
  9. Jensen, J. A. and Backofen, W. A., 1972, 'Deformation and Fracture of Alpha Zr Alloys,' Can. Metall. Q., Vol. 11(1), pp. 39-51
  10. Parry, G. W., 1966, 'The Effect of Fast Neutron Irradiation on the Tensile Properties of Specimens from Cold-Worked Zirconium-2.5 wt% Niobium Pressure Tubes,' Chalk River, Ontario, AECL-2625
  11. 지세환, 김영진, 1993, 'CANDU 압력관의 건전성 평가,' 대한기계학회지, 제 33권, 제5호, pp. 449-455
  12. Davies, P. H., Shewfelt, R. S. W.and Jaevine, A. K., 1995, 'Constraint Effects in Testing Different Curved Geometries of Zr-2.5Nb Pressure Tube Material,' Constraint Effects in Fracture: Theory and Application, ASTM STP 1244, pp. 392-424
  13. 오동준, 안상복, 박순삼, 안창윤, 김영석, 2000, 'Zr-2.5Nb 압력관의 수화물에 의한 파괴인성 취화에 관한연구, 대한기계학회 2000년도 추계 학술대회 논문집 A, pp. 93-98
  14. Himbeault, D. D., Chow, C. K., and Pulse, M. P., 1996, 'Deformation Behavior of Irradiated Zr-2.5Nb Pressure Tube Materials,' Metallurgical and Materials Transaction A, Vol. 25A, pp. 135-145
  15. Lee, D., 1968, 'Dutility of Textured Zircalcy-2,' Trans. ASM, Vol.61, pp. 742-749
  16. Ells, C. E., 'The pressure in the CANDU reactors,' AECL-Report, AECL-7344
  17. 이기순, 1997, '조사공학,' 문경출판사, pp. 119-126

피인용 문헌

  1. Delayed Hydride Cracking Velocity of Irradiated Zr-2.5Nb Tubes after a 30-Year Operation in the Wolsong Unit 1 vol.475-479, pp.1662-9752, 2005,