Engineering topics

Friese, Judah I

Publications and source records attributed to Friese, Judah I.

7 records

DOE OSTI2013

Identifying and quantifying short-lived fission products from thermal fission of HEU using portable HPGe detectors

Due to the emerging potential for trafficking of special nuclear material, research programs are investigating current capabilities of commercially available portable gamma ray detection systems. Presented in this paper are the results of three different portable high-purity germanium (HPGe) detectors used to identify short-lived fission products generated from thermal neutron interrogation of small samples of highly enriched uranium. Samples were irradiated at the Washington State University (WSU) Nuclear Radiation Center’s 1MW TRIGA reactor. The three portable, HPGe detectors used were the ORTEC MicroDetective, the ORTEC Detective, and the Canberra Falcon. Canberra’s GENIE-2000 software was used to analyze the spectral data collected from each detector. Ultimately, these three portable detectors were able to identify a large range of fission products showing potential for material discrimination.

detectors↗

DOE OSTI2012

Design and Testing of a Boron Carbide Capsule for Spectral Tailoring in Mixed-Spectrum Reactors

A boron carbide capsule has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. Irradiations were conducted in pulsed mode and in continuous operation for up to 4 hours. A cadmium cover was used to reduce thermal heating. The neutron spectrum calculated with MCNP was found to be in good agreement with reactor dosimetry measurements using the STAY'SL computer code. The neutron spectrum resembles that of a fast reactor. Design of a capsule using boron carbide enriched in {sup 10}B shows that it is possible to produce a neutron spectrum similar to {sup 235}U fission.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2012

Short-lived fission product measurements from >0.1 MeV neutron-induced fission using boron carbide.

A boron carbide shield was designed, custom fabricated, and used to create a fast fission energy neutron spectrum. The fissionable isotopes 233, 235, 238U, 237Np, and 239Pu were separately placed inside of this shield and irradiated under pulsed conditions at the Washington State University 1 MW TRIGA reactor. A unique set of fission product gamma spectra were collected at short times (4 minutes to 1 week) post-fission. Gamma spectra were collected on single-crystal high purity germanium detectors and on Pacific Northwest National Laboratory's (PNNL's) Direct Simultaneous Measurement (DSM) system composed of HPGe detectors connected in coincidence. This work defines the experimental methods used to produce and collect the gamma data, and demonstrates the validity of the measurements. It is important to fully document this information so the data can be used with high confidence for the advancement of nuclear science and non-proliferation applications. The gamma spectra collected in these and other experiments will be made publicly available at https://spcollab.pnl.gov/sites/gammadata or via the link at http://rdnsgroup.pnl.gov. A revised version of this publication will be posted with the data to make the experimental details available to those using the data.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2011

Investigation of Gravity Lanthanide Separation Chemistry

Lanthanides are common fission products and the ability to separate and quantify these elements is critical to rapid radiochemistry applications. Published lanthanide separations using Eichrom Ln Spec resin utilize an HCl gradient. Here it is shown that the efficacy and resolution of the separation is improved when a nitric acid gradient is used instead. The described method allows parallel processing of many samples in 1.5 hours followed by 60 minute counting for quantification of 9 isotopes of 7 lanthanide elements.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2011

A Discussion of Procedures and Equipment for the Comprehensive Test Ban Treaty On-Site Inspection Environmental Sampling and Analysis

This paper is intended to serve as a scientific basis to start discussions of the available environmental sampling techniques and equipment that have been used in the past that could be considered for use within the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on-site inspections (OSI). This work contains information on the techniques, equipment, costs, and some operational procedures associated with environmental sampling that have actually been used in the past by the United States for the detection of nuclear explosions. This paper also includes a discussion of issues, recommendations, and questions needing further study within the context of the sampling and analysis of aquatic materials, atmospheric gases, atmospheric particulates, vegetation, sediments and soils, fauna, and drill-back materials.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2010

Isotopic Measurements: Interpretation and Implications of Plutonium Data

One of the fundamental activities within the field of nuclear forensics is the laboratory analysis of nuclear material; one aspect is providing the isotopic composition of the material under investigation. For both plutonium and uranium, this includes a unique suite of isotopes that, individually and collectively (i.e. an isotopic vector), will help characterize these materials, and potentially provide insight into their mode of production, intended utilization, and processing history. A full understanding of how this information is used provides the basis for defining the need for these measurements and helps determine the precision and accuracy requirements for those measurements. This paper provides an overview of this process as it applies to plutonium, discussing how reactor design and operating parameters can impact the resultant plutonium vector, thereby giving us the ability to infer those reactor traits based on isotopic measurements.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2010

Nuclear Forensics: A Holistic Overview

Discussions of nuclear forensics are often restricted to work performed by radio-chemists measuring nuclear material attributes in the laboratory. However, this represents only one portion of the work required to answer critical questions. Laboratory analysis results in measurements that need to be evaluated. The results of those evaluations must be put into their proper context in order for them to be useful to others and often require merging those results with additional information. This may contribute to attribution, by virtue of inclusion or exclusion. Finally, the end product must be presented such that appropriate actions can be taken. This could include prosecution by law enforcement, policy initiatives on the part of legislative bodies, or military action in the case of nuclear attack (whether that attack is preempted or not). Using the discovery of a sample of plutonium during cleanup activities at Hanford in 2004, we will step through the process of discovery (representing an interdiction), initial field analysis, laboratory analysis, data evaluation and merging with additional data (similar to law enforcement and/or all source), thereby providing an example of an integrated approach.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗