Engineering topics

Taleyarkhan, Rusi P.

Publications and source records attributed to Taleyarkhan, Rusi P..

6 records

DOE OSTI2024

Tensioned metastable fluid detector sensing technology for multifarious-multiscale applications in the nuclear fuel cycle

The nuclear fuel cycle presents formidable 10 30+ multiscale challenges for high-efficiency spectroscopic sensing of alpha-neutron-fission radiation signatures amidst extreme gamma-beta radiation backgrounds at various stages of the cycle; it involves diverse arenas ranging from continuous/pulsed power production, security/safeguards, spent fuel, environmental remediation, and personnel health-dosimetry. This paper discusses the novel tensioned metastable fluid detector (TMFD) sensor technology. It discusses the results of studies demonstrating extreme (10 4 Sv/h) gamma-beta field blind high intrinsic efficiencies (80–100%) for neutron-alpha-fission radiation spectrometric detection. Example studies discussed in this paper include Neutron detection with spectroscopy; H*10 neutron radiation dosimetry upwards from ultra-low10 −2 µSv/h levels; Air and/or liquid-borne trace (10 –3 Bq/mL) quantity, 1 keV energy resolved alpha/fission spectroscopy for Rn/Po/U/Pu/Am environmental isotope assays at 106:1 (β:α) ratios; Directional-position enabled extended standoff tracking of neutron emitting (shielded/unshielded) special nuclear materials while stationary or moving at highway speeds; and, U.S. Department of Energy nuclear complex wide nuclear waste reprocessing, criticality safety, health physics, and environmental applications.

Alpha-fission-neutron spectrometry↗

DOE OSTI2022

PLA Renewable Bio Polymer Based Solid-State Gamma Radiation Detector-Dosimeter for Biomedical and Nuclear Industry Applications

Polylactic acid (PLA) as a “green,” renewable corn-soy based polymer resin was assessed as a novel solid-state detector for rapid-turnaround gamma radiation dosimetry in the 1–100 kGy range–of significant interest in biomedical and general nuclear industry applications. Co-60 was used as the source of gamma photons. It was found that PLA resin responds well in terms of rheology and porosity metrics with an absorbed gamma dose (Dg). In this work, rheological changes were ascertained via measuring the differential mass loss ratio (MLR) of irradiated PLA placed within PTFE-framed (40 mm × 20 mm × 0.77 mm) cavities bearing ~0.9 g of PLA resin and pressed for 12–16 min in a controlled force hot press under ~6.6 kN loading and platens heated to 227 °C for the low Dg range: 0–11 kGy; and to 193 °C for the extended Dg range: 11–120 kGy. MLR varied quadratically from 0.05 to ~0.2 (1σ ~ 0.007) in the 0–11 kGy experiments, and from 0.05 to ~0.5 (1σ ~0.01) in the 0–120 kGy experiments. Rheological changes from gamma irradiation were modeled and simultaneously correlated with void-pocket formations, which increase with Dg. A single PLA resin bead (~0.04 g) was compressed 5 min at 216 °C in 0–16 kGy experiments, and compressed 2 min at 232 °C in the 16–110 kGy experiments, to form sturdy ~100 µm thick wafers in the same press. Aggregate coupon porosity was then readily measurable with conventional optical microscope imaging and analyzed with standard image processing; this provided complementary data to MLR. Average porosity vs. dose varied quadratically from ~0 to ~15% in the 0–16 kGy range and from ~0 to ~18% over the 16–114 kGy range. These results provide evidence for utilizing “green”/renewable (under $0.01) PLA resin beads for rapid and accurate (+/-5–10%) gamma dosimetry over a wide 0–120 kGy range, using simple to deploy mass and void measuring techniques using common laboratory equipment.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2021

Actinide in Air (Rn-Progeny Rejected) Alpha Spectroscopy With Tensioned Metastable Fluid Detectors

Here, this article discusses outcome of research for deriving a methodology and apparatus for ascertaining for the presence of ultratrace-level actinides in air from their alpha emission signatures, while remaining blind to the relatively large (1000× higher activity) alpha emissions from Rn-progeny. Apparatus and techniques were developed to collect and characterize alpha-emitting nuclides of Rn-progeny and actinides in air on a polycarbonate 3 μm pore size continuous air monitor (CAM) filter. A wet-chemistry approach was developed and validated for successfully separating the Rn-progeny alpha emitting isotopes of Po-214 and Po-218, while extracting the actinides (U, Pu, Am) in a fluid mixture that is suitable for conduct of alpha spectroscopy with a centrifugally tensioned metastable fluid detector (CTMFD). The resulting α-TMFD technology was compared against the state-of-art “Alpha-Sentry™” Continuous Air Monitor (CAM) system commonly utilized world-wide. Results indicate that the α-TMFD technology can potentially offer complementary and superior performance in multiple performance categories, and ∼18× improvement in the time to detect (e.g., at 0.02 derived air concentration (DAC) within ∼3 h, versus ∼70 h for Alpha-Sentry) for actinides of interest while also remaining ∼100% blind to ∼10 3 × higher Rn-progeny background—with the added potential for offering few keV scale energy resolution without resorting to peak shape fitting, versus ∼300–400 keV for existing CAM systems.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2019

Compositions and methods for detecting radiation

Tensioned metastable fluid detectors are disclosed that minimize false positive detection events. The methods involve the use of new fluids that provide improved neutron-alpha fission detection at reduced tension states. The rate of spin is also increased using a new protocol that avoids the creation of liquid imbalances in the arms of a CTMFD (centrifugally tensioned metastable fluid detector). The disclosed CTMFD radiation detection system includes a detector assembly containing a detection fluid, a base, a safety enclosure, a motor and motor mounting bracket, speed sensors, a cooling system that includes an air inlet and outlet and a safety enclosure. The CTMFD radiation detection system can include a plurality of independent detector arms having fluids with distinct Pneg requirements such that the range of detectable radiation is increased. Also disclosed are methods for detecting radiation using the disclosed CTMFD radiation detection system. Motor speed calibration procedures are also disclosed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2019

Radiation detector

Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water. When the fluid is tensioned the presence of radon can be determined by the formation of bubbles which give off detectable signals including a shock wave, light-beam cutoff, or a light burst, any of which can be measured to derive information on radon and progeny radioactivity levels in air or water.

Taleyarkhan, Rusi P.↗

DOE OSTI2019

Novel, Low-Cost, Light-Weight High Efficiency (H*10 Capable) Neutron Detector-Dosimeter

The goal of this project was to design, develop and validate a novel, spectroscopy enabled H*(10) neutron dosimetry system based on the tensioned metastable fluid detector (TMFD) sensor technology. The project team consisted of staff from Oak Ridge National Laboratory (ORNL), Purdue University (PU) and Sagamore Adams Laboratories, LLC (SAL). PU-SAL staff were tasked with the design, development, construction and testing of the H*TMFD hardware and software, along with developing the control and data acquisition software for comparison of predictions from H*TMFD against a commonly accepted and widely used industry standard system; for this project, the Li-I detector coupled to bonner spheres (LiI-BSS) system manufactured by Ludlum, Inc. was utilized as the reference (“gold”) standard – similar in terms of neutron spectroscopy enablement to another industry recognized, albeit, significantly higher cost (est. $300K) system referred to as “ROSPEC” (from BTI, Inc., which was not available for this project). ORNL staff were tasked with providing field-relevant guidance, apparatus and facilities for acquiring data against calibrated neutron sources, and comparing results of H*TMFD against LiI-BSS system predictions in a series of blind-tests conducted at ORNL. Over the course of 12 months, the PU-SAL-ORNL staff successfully accomplished the proposed technical and administrative tasks, inclusive of engaging in outreach to potential users of this technology in the DOE-wide infrastructure. The proposed tasks were successfully accomplished in timely manner; the follow-up type tasks pertaining to SBIR type Phases 2-3 were discussed and are initiated, inclusive of filing for intellectual property (IP) disclosures and possible patent filings by PU’s Office of Technology Commercialization (OTC). Two H*TMFD system architectures (see Exhibits 1 & 2 in the report) were developed and constructed for hand-portability by health-physicists (HPs) – the HP-H*TMFD, and the H*TMFD system which consists of a side-by-side mounted array of 4 TMFDs of 3 different sizes in sensitive volume (including one with borated fluid) that now simultaneously enables neutron energy spectroscopy: single bin for < 0.1 MeV, and 152 energy bins in the 0.1-15.2 MeV range; H*(10) dosimetry from ~5 μRem/h towards 10 R/h ranges. Several experiments were conducted using neutron sources in various configurations (shielded and unshielded). In direct comparison against the LiI-BSS industry standard (acquiring data for 26h each source), the H*TMFD system (acquiring data for ~6h for each source) offered H*(10) dose predictions for the most part accurate to within +/-10% for dose rates in the 100-300 μRem/h range. The LiI-BSS was impractical to use under ultra-low (~10 μRem/h) dose rate space, as also another metering device used at ORNL (Ludlum 4241L non-spectroscopy enabled) for which the lower limit is set by the manufacturer at 100 μRem/h. The enablement for efficient use in timely manner at the 10 μRem/h levels is deemed to be a strong enabling factor for H*TMFD for use in the DOE-nuclear laboratory arena. In terms of weight, the HP-H*TMFD weighs under ~5-7 lb.; the H*TMFD system weighs ~35-lb. As such, it is ~1/4 the weight of an LiI-BSS system weighing ~120 lb (LiI detector with 6 bonner spheres) and, ~1/2 the weight of ROSPEC. As a result of this activity, two involved post-doctoral student staff have now transitioned their knowledge and experiences to DOE’s Pacific Northwest National Laboratory (PNNL). A PU graduate student has also benefited from this project work which formed a principal basis for his Ph.D. dissertation work (in progress).

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗