The moderator fluid will be injected into the PRTR calandrin through injectors located between the shroud tubes and at the bottom of the calandrin. It is important that the size and arrangement of the injectors be such that complete mixing of the moderator will occur and prevent hot sports from forming in the moderator. Such hot spots could lead to undesired changes in the moderating characteristics due to boiling within the moderator. Also of importance is the requirement that the injector should not produce excessive turbulence at the moderator surface thereby complicating moderator level control. To determine the extent of moderator mixing within the calandrin, experimental studies were made employing a full scale PRTR calandrin mockup.

The small amount of irradiation tenting experience on the plutonium-aluminum type elements planned for the Plutonium Recycle Test Reactor (PRTR) has made such testing of great importance. The high temperature pressurized recirculating water 1706 KER facility is one possible place for conducting investigations of the irradiation behavior of this type fuel element. To obtain the maximum information from the in-reactor testing and to detect possible problems, out-of-reactor test both at room and anticipated operating temperatures must be made. Room temperature pressure drop measurements and high temperatures performance of two prototypical fuel element designs proposed for KER testing are reported in this document.

Several tests are being performed and others being planned to investigate the role of heat transfer in corrosion processes. These tests are measuring both corrosion rates of metals (Zr-2 and X-8001 aluminum) under heat transfer, and the temperature rise associated with the buildup of the corrosion product. A brief description of these tests is given in this report.