Investigation of the Character of Stored-Energy Release from Graphite Irradiated at High Temperature
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The results of an investigation of the stored energy in GR-280 graphite irradiated at 560°C to neutron fluence ~3·1026 m–2 are presented. The measurements were performed by means of differential scanning calorimetry with constant heating rate 20°C/min. The release of the stored energy reaches a maximum at annealing temperature 1100°C. The maximum output is equal to 0.34–0.48 J/(g·°C). The total stored energy released in the annealing temperature range 560–1300°C does not exceed 183 J/g. A kinetic analysis of the spectrum of the stored energy was performed. This analysis established that increasing the radiation temperature from 450 to 560°C results in almost complete vanishing of individual vacancies, redistribution of the migration of di-vacancies, and evolution of a cluster structure upon post-radiation annealing in the range 560–1300°C in the direction of processes with lower activation energy.
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- 1.T. Burchell, “Irradiation damage in graphite – from the nano- to the mille-metric scale,” Techn. Meeting on High-Temperature Qualification of High-Temperature Gas Cooled Materials, IAEA, Vienna (2014).Google Scholar
- 2.N. Gallego, “A review of stored energy release of irradiated graphite,” Milestone Report on the Workshop on HTGR Graphite Stored Energy Release, ORNL/TM-2011/378.Google Scholar
- 3.A. S. Pokrovsky, E. P. Belan, and D. V. Kharkov, “Stored energy in graphite irradiated to high neutron fluences,” Fund. Issled, No. 5-1, 130–136 (2015).Google Scholar
- 4.A. S. Pokrovsk, E. P. Belan, and A. V. Avdonin, “Changes in the thermophysical properties of irradiated reactor graphite during high-temperature annealing,” in: Collection of Works of GNTs NIIAR (2015), Iss. 1, pp. 3–10.Google Scholar
- 5.S. E. Vyatkin, A. E. Deev, V. G. Nagornyi, et al., Nuclear Graphite, Atomizdat, Moscow (1967).Google Scholar
- 6.R. Nightingale, Nuclear Graphite, Academic Press, London (1962).Google Scholar
- 9.A. El-Barbary, First Principles Characterization of Defects in Irradiated Graphitic Materials: A Thesis Submitted Towards Fulfilment of the Requirement for the Degree of Doctor of Philosophy, Sussex (2005).Google Scholar