High temperature graphite irradiation creep experiment in the Dragon Reactor. Dragon Project report

Technical Report · Sat May 15 04:00:00 EDT 1971

OSTI ID:4953648

Manzel, R.; Everett, M. R.; Graham, L. W.

The irradiation induced creep of pressed Gilsocarbon graphite under constant tensile stress has been investigated in an experiment carried out in FE 317 of the OECD High Temperature Gass Cooled Reactor ''Dragon'' at Winfrith (England). The experiment covered a temperature range of 850 dec C to 1240 deg C and reached a maximum fast neutron dose of 1.19 x 10²¹ n cm^-2 NDE (Nickel Dose DIDO Equivalent). Irradiation induced dimensional changes of a string of unrestrained graphite specimens are compared with the dimensional changes of three strings of restrained graphite specimens stressed to 40%, 58%, and 70% of the initial ultimate tensile strength of pressed Gilsocarbon graphite. Total creep strains ranging from 0.18% to 1.25% have been measured and a linear dependence of creep strain on applied stress was observed. Mechanical property measurements carried out before and after irradiation demonstrate that Gilsocarbon graphite can accommodate significant creep strains without failure or structural deterioration. Total creep strains are in excellent agreement with other data, however the results indicate a relatively large temperature dependent primary creep component which at 1200 deg C approaches a value which is three times larger than the normally assumed initial elastic strain. Secondary creep constants derived from the experiment show a temperature dependence and are in fair agreement with data reported elsewhere. A possible determination of the results is given.

• Research Organization: UKAEA Reactor Group, Winfrith (United Kingdom). Atomic Energy Establishment
• Sponsoring Organization: OECD High Temperature Reactor Project Dragon
• NSA Number: NSA-32-026153
• OSTI ID: 4953648
• Report Number(s): DP-Report--752
• Country of Publication: United Kingdom
• Language: English

Related Subjects

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DRAGON REACTOR
GRAPHITE
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Ceramics
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Non-breeding
Graphite Moderated
PHYSICAL RADIATION EFFECTS
STRESS RELAXATION
VERY HIGH TEMPERATURE