Pressurization Analysis for Heating of a Screw Top Utility Can Loaded With Plutonium Oxide Powder by a 1273 K Fire

The documented safety analysis for the Savannah River National Laboratory (SRNL) evaluates the consequences of a postulated 1273 K fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage containers. The oxide storage configuration selected for analysis is can/bag/can, comprised of oxide powder inside an 8.38 × 10−6 m3 stainless steel B vial inside 0.006 kg of polyethylene bagging inside a one-quart screw top utility can of the type commonly used to package solvents or rubber cements. To enable evaluation of the dose consequences, temperature and pressure transients have been calculated for exposure of a typical set of storage containers to the fire. The pressurization analysis credits venting to and from the B vial but does not credit venting or leakage from the can. Due to the low rate of venting from the B vial into the can gas space, the can pressure is nearly independent of the B vial pressure. Calculated maximum pressures are compared to the utility can burst pressure. In lieu of a structural analysis of the utility cans, burst pressures and leakage rates were measured using compressed nitrogen gas. The measured gauge burst pressure was 0.250 ± 0.043 MPa. The measured burst pressures are lower than the calculated maximum pressure due to fire exposure, indicating that the utility cans could burst during exposure to a 1273 K fire.

Thermal Aspects of Safety Analysis for Shipment of West Valley Melter

The thermal aspects of a safety analysis for shipment of the West Valley melter are presented. The West Valley melter was used from 1996 to 2002 to vitrify regionally sourced high level radioactive waste. The U.S. Department of Energy (DOE) set up the West Valley Demonstration Project to encase this melter and grout it in low density cellular concrete, for disposal. DOE-West Valley requested the Savannah River National Laboratory to prepare a Safety Analysis Report. The thermal portion of the safety analysis covers Normal Conditions of Transport (NCT) and Hypothetical Accidents Conditions (HAC), as defined in the Code of Federal Regulations. For NCT, it is assumed that the encased melter is stored in either shade or direct sunlight at an ambient temperature of 311 K (100 °F). The defining HAC is exposure to a 1075 K (1475 °F) fire for 30 minutes. Finite element computer models were used to compute temperature profiles for NCT and HAC, given the thermal properties of the melter and its contents and tabulated radiolytic heating source concentrations. The resulting temperature conditions were used to estimate the pressurization due to evaporation of water from the concrete. The maximum calculated gauge pressures were determined to be 81 kPa (12 psig) for NCT and 580 kPa (84 psig) for HAC.

Radiochemical and analytical methods of analysis of radiological dispersal devices

The events on September 11th 2001 and subsequent attacks in America and around the world have brought a renewed interest in the nation's security including the concern over the use of a nuclear or a radiological dispersal device (RDD). Research has been done in two separate projects in order to help address some of these concerns. A research assistantship from Savannah River National Laboratory was granted in order to identify the unique characteristics of radioactive 192Ir materials (chapters 2-4). A method for the dissolving of the iridium with electrochemistry was developed and used for sample preparation for analysis. Mass spectrometry (ICP-MS) analysis was then used to identify and quantify impurities and isotope ratios in iridium from various locations across the country. The second research project has developed a series of nanoparticles for use as tagging and tracking explosives (chapters 5-7). The composition of the nanoparticles were created with lanthanides with varying composition to provide a unique signature that can be rapidly and precisely measured in the field via neutron activation analysis. The nanoparticles could be used as a real-time in the field method for tracking and identifying materials such as explosives in a post detonation scenario.

Hydrogen Concentrations During Storage of 3013 Oxide Samples

As part of a surveillance program intended to ensure the safe storage of plutonium bearing nuclear materials in the Savannah River Site (SRS) K-Area Materials Storage, samples of these materials are shipped to Savannah River National Laboratory (SRNL) for analysis. These samples are in the form of solids or powders which will have absorbed moisture. Potentially flammable hydrogen gas is generated due to radiolysis of the moisture. The samples are shipped for processing after chemical analysis. To preclude the possibility of a hydrogen deflagration or detonation inside the shipping containers, the shipping times are limited to ensure that hydrogen concentration in the vapor space of every layer of confinement is below the lower flammability limit of 4 volume percent (vol%) [1]. This study presents an analysis of the rate of hydrogen accumulation due to radiolysis and calculation of allowable shipping times for typical K-Area materials.

Preshipment Leak Testing of 9977 Containment Vessels With the TM Electronics Solution Model S1A-L2-V Leak Tester

Pacific Northwest National Laboratory (PNNL) is replacing its 6M nuclear shipping fleet with 9977 shipping packages, which were designed by Savannah River National Laboratory (SRNL). The new packages require PNNL to perform a preshipment leak test on the lid seals of the containment vessel before the package is shipped on public roads. Savannah River National Laboratory (SRNL) developed a preshipment leak test using a TM Electronics Solution leak tester for PNNL. The Solution is an automatic vacuum leak tester that uses the Gas Pressure Rise leak test method to check the O-ring lid seals and the test port plug seal. The two tests take three minutes each to perform. Because the Solution is fully automatic, the leak test can be done by operators after a few hours of training. This paper describes the test equipment and the testing sequence.