From abstract: An estimate is presented of the radioactivity in the helium coolant of the high-temperature gas-cooled reactor, GCR-2, due to entry into the coolant of recoil nuclei from neutron-induced reactions which take place in the fuel element cladding, type 304 stainless steel. Two systems were considered: one without a filter and the other utilizing a by-pass filter designed to reduce the concentration of contaminants in the coolant.

The following report describes a study by the M.I.T. Metallurgical Project to pursue the quest of producing ductile beryllium, as beryllium has a relatively high strength, good corrosion resistance to water and air and a melting point of about 1230 C, features that make it a great potential value among being one of the most effective of all materials for slowing down neutrons with little tendency to absorb them.

From summary: Report on the location, final design, and hazards analysis of the Massachusetts Institute of Technology Reactor Facility. It is hoped that the reactor plans described in this report may be approved from the safety standpoint, so that a license and construction permit for the facility may be granted and construction started.