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Conference Article: Gaseous diffusion and pore structure in nuclear graphites

Mays, T.J.; McEnaney, B.; Kelly, B.T. (Bath Univ. (United Kingdom). School of Materials Science)

Abstract

With the incentive of providing more information for oxidation and lifecycle studies of moderators in thermal reactors, a new method has been developed to estimate power structure in nuclear graphites. This method involves the measurements of room-temperature binary gas diffusion in graphite samples using an apparatus that was specially-built to operate at pressures below 100 Torr. In these conditions diffusion in graphite pores is in the transition regime between Knudsen and bulk or molecular diffusion. Transition diffusion measurements are analyzed for nuclear-grade graphites to yield pore size distributions. Results from the new method are compared with pore structure data obtained using porosimetry, pycnometry and established gas flow techniques.

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key words: Gas Cooled Reactor, Nuclear Technology
Reference:
Specialists meeting on graphite moderator lifecycle behaviour. Bath (United Kingdom). 24-27 Sep 1995.
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--901, pp:329-335