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DOE OSTI2015

The first operation of 56 MHz SRF cavity in RHIC

A 56 MHz superconducting RF cavity has been designed, fabricated and installed in the Relativistic Heavy Ion Collider (RHIC). The cavity operates at 4.4 K with a “quiet helium source” to isolate the cavity from environmental acoustic noise. The cavity is a beam driven quarter wave resonator. It is detuned and damped during injection and acceleration cycles and is brought to operation only at store energy. For a first test operation, the cavity voltage was stabilized at 300 kV with full beam current. Within both Au + Au and asymmetrical Au + He3 collisions, luminosity improvement was detected from direct measurement, and the hourglass effect was reduced. One higher order mode (HOM) coupler was installed on the cavity. We report in this paper on our measurement of a broadband HOM spectrum excited by the Au beam.

43 PARTICLE ACCELERATORS↗

DOE OSTI2015

Measurement of the plutonium hold-up in glove box before dismantling - 15111

The French Bruyeres-Le-Chatel CEA (Commissariat a l'Energie Atomique et aux Energies Alternatives - French Alternatives Energies and Atomic Energy Commission) research center is going through a period of cleaning and dismantling of theses old treatment facilities on fissile materials and others associated nuclides. Some very large glove boxes contained some machines like melting furnace which can't be moved and are dismantled in situ. We need to evaluate the quantity of fissile materials to prevent criticality risk, to bring the evidence to the safety authority, to manage for the best the radioprotection of the workers and to manage waste production. A melting furnace in a glove box was dismantled. Measurements by gamma spectrometry with an HPGe detector (High Purity Germanium) and passive neutron counting (coincidence counting with shift register) are done in situ (furnace in the glove box). In order to refine the measurements, some data acquisitions by sector of glove box were carried out. In view of the geometries to characterize, some modelings have been created, in order to correct the different attenuations and to determine the plutonium masses content in the glove box, including the use of infinite energy technique. For the measurement by passive neutron counting (coincidence counting with shift register), we have used two slabs in high density polythene including nine He3 counters in each slab. This measurement technique is complementary to gamma spectrometry, and allows quantizing the fissile material which would be included in interstice of high Z material. The 100-L and 200-L drums produced during the dismantling were also measured. Based on simplified assumptions to analyze in situ measurements, plutonium weight could be evaluated. This approach of measurement in amount, during and after dismantling, has allowed to quantize the fissile material mass present in the glove box and didn't produce waste package which wouldn't respected the technical specifications of storage outlets. The results show good agreement between in situ and waste measurements. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2011

Neutron Detection Gamma Ray Sensitivity Criteria

The shortage of 3He has triggered the search for effective alternative neutron detection technologies for national security and safeguards applications. Any new detection technology must satisfy two basic criteria: (1) it must meet a neutron detection efficiency requirement, and (2) it must be insensitive to gamma-ray interference at a prescribed level, while still meeting the neutron detection requirement. It is the purpose of this paper to define measureable gamma ray sensitivity criteria for neutron detectors. Quantitative requirements are specified for: intrinsic gamma ray detection efficiency and gamma ray absolute rejection. The ratio GARRn is defined, and it is proposed that the requirement for neutron detection be 0.9 < GARRn < 1.1 at a 10 mR/h exposure rate. An example of results from a 3He based neutron detector are provided showing that this technology can meet the stated requirements. Results from tests of some alternative technologies are also reported.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2014

Why New Neutron Detector Materials Must Replace Helium-3

This is an article for the European Physics Journal on the status of the He-3 problem. Alan Hurd from LANL is the main author.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2010

Boron-Lined Straw-Tube Neutron Detector Test

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2012

Uranium Neutron Coincidence Collar Model Utilizing 3 He

The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube based alternative system in a configuration typically used for 3 He-based coincidence counter applications. The specific application selected for boron-lined tube replacement in this project was one of the Uranium Neutron Coincidence Collar (UNCL) designs. This report, providing results for model development of a UNCL, is a deliverable under Task 2 of the project. The current UNCL instruments utilize 3 He tubes. As the first step in developing and optimizing a boron-lined proportional counter based version of the UNCL, models of eight different 3 He-based UNCL detectors currently in use were developed and evaluated. A comparison was made between the simulated results and measured efficiencies for those systems with values reported in the literature. The reported experimental measurements for efficiencies and die-away times agree to within 10%.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2012

Neutron Coincidence Counting Studies

The efficiency comparison for measured and simulated responses of a 10 B-lined proportional counter and a 3 He proportional counter in a close, symmetrical geometry are presented. The measurement geometry was modeled in MCNPX to validate the methods used for simulating the response of both the 3 He and 10 B-lined tubes. The MCNPX models agree within 1% with the 3 He tube measurements and within 3% for the 10 B-lined tubes when a 0.75-µm boron-metal lining is used.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2012

Uranium Neutron Coincidence Collar Model Utilizing Boron-10 Lined Tubes

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3 He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10 B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report, providing results for model development of Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) designs, is a deliverable under Task 2 of the project.

boron-10↗

DOE OSTI2012

Boron-10 Lined Proportional Counter Model Validation

The Department of Energy Office of Nuclear Safeguards (NA-241) is supporting the project “Coincidence Counting With Boron-Based Alternative Neutron Detection Technology” at Pacific Northwest National Laboratory (PNNL) for the development of an alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a boron-lined proportional tube-based alternative system in the configuration of a coincidence counter. This report discusses the validation studies performed to establish the degree of accuracy of the computer modeling methods current used to simulate the response of boron-lined tubes. This is the precursor to developing models for the uranium neutron coincidence collar under Task 2 of this project.

born lined tubes↗

DOE OSTI2013

Boron-10 ABUNCL Prototype Models And Initial Active Testing

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.

coincidence counter↗

DOE OSTI2013

Boron-10 ABUNCL Models of Fuel Testing

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNP simulations of the General Electric Reuter-Stokes Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) active configuration model with fuel pins previously measured at Los Alamos National Laboratory. A comparison of the GE-ABUNCL simulations and simulations of 3He based UNCL-II active counter (the system for which the GE-ABUNCL was targeted to replace) with the same fuel pin assemblies is also provided.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2010

Alternative Neutron Detection Testing Summary

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. Most currently deployed radiation portal monitors (RPMs) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large area neutron detector. This type of neutron detector is used in the TSA and other RPMs installed in international locations and in the Ludlum and Science Applications International Corporation RPMs deployed primarily for domestic applications. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated wavelength-shifting plastic fibers. Reported here is a summary of the testing carried out at Pacific Northwest National Laboratory on these technologies to date, as well as measurements on 3He tubes at various pressures. Details on these measurements are available in the referenced reports. Sponsors of these tests include the Department of Energy (DOE), Department of Homeland Security (DHS), and the Department of Defense (DoD), as well as internal Pacific Northwest National Laboratory funds.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2010

Lithium and Zinc Sulfide Coated Plastic Neutron Detector Test

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. In addition, a few other companies have detector technologies that might be competitive in the near term as an alternative technology. Reported here are the results of tests of 6Li/ZnS(Ag)-coated scintillator paddles. This testing measured the required performance for neutron detection efficiency and gamma ray rejection capabilities of a system manufactured by Symetrica.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2010

Alternatives to 3He for Neutron Detection for Homeland Security

Neutron detection is an essential aspect of interdiction of radiological threats for national security purposes, since plutonium, a material used for nuclear weapons, is a significant source of fission neutrons. Radiation portal monitoring systems, of which there are thousands deployed for homeland security and non-proliferation purposes, currently use 3He gas-filled proportional counters for detecting neutrons. Because of the high usage of 3He for neutron scattering science and national security, the supply has dwindled, and can no longer meet the demand. Consequently, a replacement technology for neutron detection is required in the very near future.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗