The objective of this production test is to demonstrate the feasibility of a Hanford reactor operating economically as a plutonium-tritium producer to increase the over-all conversion ratio and diversify the useful product output.

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Radiation damage may occur to the lithium hydride shields as a result of the reaction Li{sup 6}(n, {alpha})H{sup 3}. There is evidence in the literature indicating both the existence and absence of radiation damage to the SNAP shields. It is believed that there is a high probability that there will be damage and that it will adversely affect the properties of the shield. This damage may take the form of: (1) volume expansion of the hybrids, (2) void formation within the hybrids, and (3) gas pressure build-up in the shield container. Based upon the results of experiments with lithium fluoride, which may serve as a model for the hydride, there appears to be a threshold neutron dose which volume expansion effects can not be removed by annealing. Similarly, above the threshold dose, intercrystalline voids, formed as a result of radiation damage, appear to increase in size with increasing temperature. It has been established that at the SNAP shield operating conditions, essentially all of the hydrogen formed will recombine with free lithium. The helium atoms, however, remain trapped interstitially, in intercrystalline voids, or along subgrain boundaries. Appreciable amounts of helium gas are not released until the melting point of the hydride …

Accelerated alpha particles from the Berkeley heavy-ion linear accelerator were used in a series of experiments designed to elucidate the conditions by which radiation can stimulate or modify nerve action in mammals. Single millisecond pulses in excess of 40,000 radsor pulse trains of less than 1 sec duration elicited the corneal blinking reflex when delivered to the cornea of unanesthetized rabbits. The lowest threshold dose was observed when the Bragg ionization peak was placed at 140 {mu} depth.