In-Pile Loop Cryogenic Refrigerator

Abstract

Under contract with the National Aeronautics and Space Administration, Lockheed Nuclear Products is investigating the synergistic effects of nuclear radiation and cryogenic temperatures on nuclear missile materials. As a part of this contract, a refrigerator is being designed to furnish the cryogenic environment for the in-pile loop samples during reactor irradiation. This refrigerator has the following design objectives:

• 1. Supply 1150 w of refrigeration at the transfer-line manifold with a minimum of 950 w at the entrance to the in-pile test loops while maintaining a test-sample temperature within the range of 30° to 540°R to ±1°R.

• 2. Be capable of holding concurrently any single sample temperature in this range of 30° to 540°R in separate test loops (one under irradiation and another in the pool not under irradiation) provided that the total heat load of the test loops does not exceed 950 w at 24° R under steady-state conditions.

• 3. The refrigeration system must provide for three interchangeable test loops to be connected at one time.

• 4. The transfer lines must be sufficiently flexible to permit insertion of a test loop into the reactor beam port and 180° rotation, then translation into a hot cave port which is used for removal of test samples from the loops.

This work was accomplished under contract with the National Aeronautics and Space Administration, Office of Advanced Research and Technology, Contract No. NASw-114.