Report documenting the systems, operating procedures, and design of the Oak Ridge National Laboratory's gas-cooled reactor.

A capital cost breakdown of the Idaho Chemical Processing Plant, a directly maintained remotely operated plant for processing spent enriched uranium fuel assemblies from reactors, is presented. The capital investment in the plant, including design, construction, training, and preoperational costs, an estimate of the direct costs incurred by the Atomic Energy Commission, and a proportional part of the costs of Central Facilities, including the value of the land and improvements theorem when acquired by the Commision, was $31,105,899. The cost of design and construction was $25,212,231, of which $3,773,357 was expanded on design and inspection.

In order to evaluate the behavior of an APPR type absorber rod, an irradiation test program has been established. Approximately 21 more samples are planned for testing under this request. The request proposes testing a full size APPR-1 type control rod in the MTR. The objective of the test is to better evaluate the neutron absorbing material proposed for the APPR-1 control rod.

The operation and design of a high pressure recombination loop for the recombination of H2, D2, and O2 produced by the radiolytic decomposition of water which is used a solvent for fuel in the homogeneous reactors are presented.

Startup accident and pump run-down on the ORR have been simulated on the Reactor Controls Analog Facility. At full flow the 150% level scram (45 Mv) easily terminates the startup accident before the metal temperature gets above 180°F. For very low flows typical of criticality runs, temperature coefficients turn the excursion before it reaches 150% of full power, and temperatures climb to boiling, a potentially hazardous condition. (This same behavior can occur at full flow is the power is increased to the point where the level scram must be set above 50 Mw).