Title: FINAL SAFETY ANALYSIS REPORT ON THE ZERO POWER PLUTONIUM REACTOR (ZPPR) FACILITY.

Results are presented for the ZPPR-15B, 15C and 15D assemblies. These assemblies were part of the IFR Physics Test Program to provide modern integral physics data for metallic-fuelled LMRs. The ZPPR-15B assembly had a ternary fuel alloy of plutonium, depleted uranium and zirconium. In ZPPR-15C, about half of the fuel elements were converted to {sup 235}U fuel, while in ZPPR-15D about 90% of the fuel was {sup 235}U. Results from ZPPR-15D include foil reaction rates, control rod worths, sodium void worths, gamma ray dose distributions and noise coherence measurements. Multigroup cross section data processing and calculation models are presented formore » the assemblies containing {sup 235}U fuel.« less

The Zero Power Physics Reactor (ZPPR) facility is a Department of Energy facility located in the Idaho National Laboratory’s (INL) Materials and Fuels Complex. It contains various nuclear and non-nuclear materials that are available to support many radiation measurement assessments. User-selected, single material, nuclear and non-nuclear materials can be readily utilized with ZPPR clamshell containers with almost no criticality concerns. If custom, multi-material configurations are desired, the ZPPR clamshell or an approved aluminum Inspection Object (IO) Box container may be utilized, yet each specific material configuration will require a criticality assessment. As an example of the specialized material configurations possible,more » the National Nuclear Security Agency’s Office of Nuclear Verification (NNSA/NA 243) has sponsored the assembly of six material configurations. These are shown in the Appendixes and have been designated for semi-permanent storage that can be available to support various radiation measurement applications.« less

BS>The organization and administration within the division of the Lewis Flight Propulsion Laboratory which is concerned with the reactor facility are included. Operating procedures, fuel handling procedures, experimental procedures, and health physics procedures are discussed. Design changes made since the initial hazards summary was submitted are given. (M.H.R.)

A fuel element rupture testing facility is being installed in the PRTR, with a test section in process channel 1946. The loop will be used to study the effect of jacket ruptures in a variety of fuel elements, including metallic uranium, ceramic, and plutonium-enriched fuels in light water at 600 deg F and 2100 psig maximum conditions, while the elements are generating at rates up to their full design power. The high coolant temperature is to be achieved by regenerative heat exchange, supplemental electric heat, and heater fuel eleraents if required. The coolant is circulated by positive displacement pumps. Themore » effluent passes through an ion exchange system to remove particulate and dissolved radioactive materials. Equipment is provided for circulation of decontaminating solutions through the loop. The loop is provided with a safety circuit to protect both the loop and the reactor from off-standard conditions in the loop. The safety circuit is tripped by coolant storage low level, coolant low flow rate in the test section, high or low coolant pressure at the test section inlet, high differential pressure between test section inlet and outlet, or high coolant temperature at the test section outlet. Each function is signaled by three independent sensors, and coincident signals from two are required to trip the safety circuit which scrams the reactor. Other design safety features are provision of a basket tube to contain the intentionally ruptured fuel element and prevent it from damaging the pressure tube, and multiple electrical power and coolant supply backups to ensure an adequate coolant supply to the test section under all emergency conditions. Installation of the rupture test loop in the reactor in place of a PRTR pressure tube and fuel element has a small positive reactivity effect with fuel in place, and a small negative reactivity effect with no fuel. Loss of light water coolant gives a small, readily controllable, positive reactivity increment of about 0.5 milli-k. The loop can not cause a reactor excursion, and a reactor excursion would not cause an accident in the loop. The loop would have a negligible effect on a reactor maximum credible accident. Rupture of the test section pressure tube is the maximum credible accident to the rupture test loop. This accident does not affect the nuclear safety of the reactor, nor change the radiological consequences of a reactor accident. It could, however, result in some damage to the calandria, and could release contaminants through the calandria vents into the containment vessel. The rupture testing facility was designed to avoid such an accident, and several unusual circumstances must occur sequentially or simultaneously to cause one to occur. (auth)« less