Graphite fast neutron irradiation

Brocklehurst, J.E. and Kelly, B.T., Analysis of the dimensional changes and structural changes in polycrystalline graphite under fast neutron irradiation. Carbon, 1993, 31, 155 178. 

Taylor, R., Kelly, B.T., and Gilchrist, K.E., The thermal conductivity of fast neutron irradiated graphite. J. Phys. Chem. Solids, 30, 1969, 2251 2267. 

Fast neutron irradiation of graphite causes displacement of lattice atoms and leads to graphite growth and distortion. The Wigner effect in graphite is also a problem in some high power research reactors. For these reactors, embrittlement of beryllium components must also be considered. 

The diffusion of HOmAg fn as-received, oxidized and fast neutron-irradiated graphitic matrix (A3-3) and in original (A3-27) material was studied in vacuum by measuring the release kinetics from cylindrical specimens. The latter had previously been doped with carrier-free HOm g it lOOOC. Concentration profiles were measured after the release of part of the 1 lOm g which was initially present. It was found that the release kinetics and the concentration profiles satisfied Pick s second law. At temperatures ranging from 800 to 1300C, and for Ag concentrations of less than 4 x 10" at%, the diffusion data could be described by ... 

During reactor operation, fast neutron irradiation significantly changes both the graphite component dimensions and the graphite material properties [9,10]. Of paramount interest to the reactor designer are the dimensional change and the property... 

Historically, within the literature, there is a variety of irradiation units used to describe the aging of graphite due to fast neutron irradiation [10]. Some of the units are based on the bum-up of fuel adjacent to the graphite sample or component. Others are based on the activation of metal foils such as cobalt or nickel. Yet, other units are based on neutron energy above a certain level. 

G. Haag, Properties of ATR-2E Graphite and Property Changes Due to Fast Neutron Irradiation, 2005. 

XV-9] INTERNATIONAL ATOMIC ENERGY AGENCY, Irradiation damage in graphite due to fast neutrons in fission and fusion systems, IAEA-TECDOC-1154, Vienna (September 2000). 

J. E. Brocklehurst and B. T. Kelly, The dimensional changes of highly-oriented pyrolytie graphite irradiated with fast neutrons at 430 C and 600 C, Carbon, 31(1), 179-183 (1993). 

IAEA, Irradiation Damage in Graphite Due to Fast Neutrons in Fission and Fusion Systems, IAEA-TECDOC-1154, 2000. 

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