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Effects of heat and gamma radiation on the degradation behaviour of fluoroelastomer in a simulated severe accident environment

  • Inyoung Song (Department of Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST)) ;
  • Taehyun Lee (Department of Reliability Assessment, Mechanical System Safety Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Kyungha Ryu (Department of Reliability Assessment, Mechanical System Safety Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Yong Jin Kim (Department of Ultra-Precision Machines and Systems, Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Myung Sung Kim (Department of Ultra-Precision Machines and Systems, Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Jong Won Park (Department of Reliability Assessment, Mechanical System Safety Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Ji Hyun Kim (Department of Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST))
  • 투고 : 2022.04.20
  • 심사 : 2022.08.08
  • 발행 : 2022.12.25

초록

In this study, the effects of heat and radiation on the degradation behaviour of fluoroelastomer under simulated normal operation and a severe accident environment were investigated using sequential testing of gamma irradiation and thermal degradation. Tensile properties and Shore A hardness were measured, and thermogravimetric analysis was used to evaluate the degradation behaviour of fluoroelastomer. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the structural changes of the fluoroelastomer. Heat and radiation generated in nuclear power plant break and deform the chemical bonds, and fluoroelastomer exposed to these environments have decreased C-H and functional groups that contain oxygen and double bonds such as C-O, C=O and C=C were generated. These functional groups were formed by auto oxidation by reacting free radicals generated from the cleaved bond with oxygen in the atmosphere. In this auto oxidation reaction, crosslinks were generated where bonded to each other, and the mobility of molecules was decreased, and as a result, the fluoroelastomer was hardened. This hardening behaviour occurred more significantly in the severe accident environment than in the normal operation condition, and it was found that thermal stability decreased with the generation of unstable structures by crosslinking.

키워드

과제정보

This work was supported by the Korea Institute of Machinery & Materials (KIMM) (NK238C) and the Ministry of Oceans and Fisheries (MOF) (No. 20220603).

참고문헌

  1. Y.H. Seo, W.S. Jeong, Y.T. Moon, Equipment Survivability Assessment in APR1400, Korea Nuclear Society, 2012. 
  2. K. Ryu, I. Song, T. Lee, S. Lee, Y. Kim, J.H. Kim, Survivability assessment of Viton in safety-related equipment under simulated severe accident environments, Nuclear Engineering and Technology 50 (2018) 683-689.  https://doi.org/10.1016/j.net.2018.02.009
  3. INTERNATIONAL ATOMIC ENERGY AGENCY, Assessment of Equipment Capability to Perform Reliably under Severe Accident Conditions, 2017. IAEA-TECDOC-1818. 
  4. INTERNATIONAL ATOMIC ENERGY AGENCY, Safety Assessment and Verification of Nuclear Power Plants, Safety Standard Series, 2002. No. NS-G-1.2. 
  5. L.S. Fifield, M.P. Westman, A. Zwoster, B. Schwenzer, Assessment of Cable Aging Equipment, Status of Acquired Materials, and Experimental Matrix at the Pacific Northwest National Laboratory, 2015. PNNL-24198. 
  6. S.W. Glass, L.S. Fifield, G. Dib, J.R. Tedeschi, A.M. Jones, T.S. Hartman, State of the Art Assessment of NDE Techniques for Aging Cable Management in Nuclear Power Plants FY2015, M2LW-15OR0404024, 2015. PNNL-24649. 
  7. M. Celina, K.T. Gillen, R.A. Assink, Accelerated aging and lifetime prediction: review of non-Arrhenius behaviour due to two competing processes, Polymer Degradation and Stability 90 (2005) 395-404.  https://doi.org/10.1016/j.polymdegradstab.2005.05.004
  8. ASTM International, Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers-Tension, 2021, p. D412. -16. 
  9. ASTM International, E1641-18 Standard Test Method for Decomposition Kinetics by Thermogravimetry Using the Ozawa/Flynn/Wall Method, 2018, p. E1641. -18. 
  10. KAERI, Accelerated Ageing Test of Cable Materials Used in Nuclear Power Plants for the Evaluation of Lifetime, vol. 2424, KAERI/TR, 2003. 
  11. INTERNATIONAL ATOMIC ENERGY AGENCY, IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Station, 2003. IEEE Std 323-2003. 
  12. KIMM, Development of Emerging Core Technique of Equipment Qualification on Design Based Events and SAs of NPPs, 2016. TR-2016-195. 
  13. Kyungha Ryu, Taehyun Lee, Sanghyuk Lee, Youngjoong Kim, Dae Hwan Kim, Inyoung Song, Ji Hyun Kim, Numerical Analysis of Thermal Lag with Various Convection Heat Transfers Coefficient in Severe Accident Environment, Korean Nuclear Society, 2017. 
  14. S.I. Lee, H.K. Jung, Development of the NPP instrument requirements for highly survivability under severe accidents, in: Conference on Korea Society for Energy Engineering, 2013, 121-121. 
  15. F.I. Rojas Rodriguez, J.R. d'Almeida Moraes, B.A. Marinkovic, Natural Aging of Ethylene-Propylene-Diene Rubber under Actual Operation Conditions of Electrical Submersible Pump Cables, Materials 14 (19) (2021) 5520. 
  16. Y.D. Seo, H.S. Lee, Y.S. Kim, C. Song, A Study on the Aging degradation of ethylene-propylene-diene monomer (EPDM) under LOCA condition, Nuclear Engineering and Technology 43 (3) (2011) 279-286.  https://doi.org/10.5516/NET.2011.43.3.279
  17. A. Taguet, Bruno ameduri, Bernard Boutevin, crosslinking of vinylidene fluoride-containing fluoropolymers, Advances in polymer science 184 (2005) 127-211.  https://doi.org/10.1007/b136245
  18. Yuanyuan Zhang, Zongke Hou, Kangning Wu, Shihang Wang, Jianying Li, Shengtao Li, Influence of oxygen diffusion on thermal ageing of cross-linked polyethylene cable insulation, Materials 13 (2020) 2056. 
  19. Inyoung Song, Seung Chang Yoo, Taehyun Lee, Kyungha Ryu, Ji Hyun Kim, Evaluation of degradation effect on fluoroelastomer in simulated severe accident environment of nuclear power plants, in: 2018 International Congress on Advances in Nuclear Power Plants, 2018, pp. 262-266. 
  20. Inyoung Song, Taehyun Lee, Kyungha Ryu, In Cheol Bang, Ji Hyun Kim, Degradation behavior of fluoroelastomer under simulated severe accident environment, in: Proceedings of ANS 2019 Annual Meeting, vol. 120, 2019, pp. 422-425, 1. 
  21. Ganna Gryn'ova, Jeninfer L. Hodgson, Michelle L. Coote, Revising the mechanism of polymer autooxdiation, Organic & Biomolecular Chemistry 9 (2011) 480. 
  22. S.H. Kalfayan, R.H. Silber, A.A. Mazzeo, S. T Liu, Long-term aging of elastomers: chemoheology of viton B fluorocarbon elastomer, JPL Quarterly Technical Review 2 (3) (1972). 
  23. S.J. Lim, K.K. Gleason, D.J. Edell, E.F. Gleason, Flexible fluorocarbon wire coatings by pulsed plasma enhanced chemical vapor deposition, Journal of Vacuum Science & Technology A 15 (1997) 1814-1818.  https://doi.org/10.1116/1.580796
  24. C. Biloiu, I.A. Biloiu, Y. Sakai, Y. Suda, A. Ohta, Amorphous fluorocarbon polymer (a-C: F) films obtained by plasma enhanced chemical vapor deposition from perfluoro-octane (C8F18) vapor I: deposition, morphology, structure and chemical properties, Journal of Vacuum Science & Technology A 22 (2004) 13-19.  https://doi.org/10.1116/1.1624284
  25. A.N. Theodore, M. Zinbo, R.O. Carter III, Characterization of fluoroelastomer networks: II. SEC, FTIR, and ODR analysis, Journal of Applied Polymer Science 61 (1996) 2065-2073.  https://doi.org/10.1002/(SICI)1097-4628(19960919)61:12<2065::AID-APP3>3.0.CO;2-8
  26. M. Hedenqvist, Diffusion of small-molecule penetrants in semicrystalline polymers, Progress in Polymer Science 21 (2) (1996) 299-333.  https://doi.org/10.1016/0079-6700(95)00022-4
  27. Pierangiola Bracco, Luigi Costa, Maria Paola Luda, Billingham Norman, A review of experimental studies of the role of free-radicals in polyethylene oxidation, Polymer Degradation and Stability 155 (2018) 67-83.  https://doi.org/10.1016/j.polymdegradstab.2018.07.011
  28. Sung Young Lee, Seo Bin Eom, Jong Sung Won, Jong Woo Bae, Seong Han Park, Seung Goo Lee, Evaluation of aging behavior of nitrile Butadiene rubber via oxygen-consumption experiments, Fibers and Polymers 22 (3) (2021) 639-646.  https://doi.org/10.1007/s12221-021-0345-y
  29. S. Mittra, A. Chanbari-Siahkali, P. Kingshott, K. Almdal, H.K. Rehmeier, A.G. Christensen, Chemical Degradation of Fluoroelastomer in an Alkaline Environment, vol. 83, 2004, pp. 195-206. 
  30. I. Banik, A.K. Bhowmick, S.V. Raghavan, A.B. Majali, V.K. Tikku, Thermal degradation studies of electron beam cured terpolymeric fluorocarbon rubber, Polymer Degradation and Stability 63 (1999) 413-421.  https://doi.org/10.1016/S0141-3910(98)00122-0
  31. G.J. Knight, W.W. Wright, The thermal degradation of some fluorine containing elastomers, Thermochimca Acta 60 (1983) 187-194.  https://doi.org/10.1016/0040-6031(83)80269-X
  32. Shuaishuai Liu, Stephen W. Veysey, Leonard S. Fifield, Nicola Bowler, Qualitative analysis of changes in antioxidant in crosslinked XLPE cable insulation material exposed to heat and gamma radiation, polymer degradation and stability 156 (2018) 252-258.  https://doi.org/10.1016/j.polymdegradstab.2018.09.011
  33. Inyoung Song, Taehyun Lee, Kyungha Ryu, Sangkyo Kim, Young Joong Kim, Ji Hyun Kim, Investigation of thermal stability of fluoroelastomer in simulated severe accident environment of nuclear power plants, Proceedings of the KNS 2018 Fall Meeting 50 (40) (2018).