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Krebs, John F.

Publications and source records attributed to Krebs, John F..

11 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Persistent Acoustic Sensing for Monitoring A Reactor Facility - Oral Presentation

Measurements over the past few years, taking place within the Multi-Informatics for Nuclear Operations Scenarios (MINOS) project, show that infrasound and low-frequency acoustic monitoring can detect, and often quantify, activities that occur on-site at a large research reactor. Observable activities include: crane translation, lifting, and lowering; differentiation between loaded and unloaded crane operations; access door opening and closing; vehicle operations; and cooling tower fan operation. Advanced data analytic and spectral feature extraction methods can be used to interpret selected signatures to reach a deeper understanding of different reactor activities. These measurements are being conducted using a network of smartphones that continuously operate in conjunction with cloud-based architectures. A recent addition to the system is the development and deployment of a real-time, cloud-based analytic framework that supports near-real-time alarming which can facilitate tip-and-cue protocols. This paper will present recent research advances in this area including studies to explore the transferability of learned parameters from one smartphone to another, the detectability of events from multiple sensors at different locations simultaneously, and the feasibility of porting analytical tools directly to the smartphones to allow edge computing with optimized configurations.

42 ENGINEERING↗
DOE OSTI2021

Persistent Acoustic Sensing for Monitoring A Reactor Facility

Measurements over the past few years, taking place within the Multi-Informatics for Nuclear Operations Scenarios project, show that infrasound and low-frequency acoustic monitoring can detect, and often quantify, activities that occur on-site at the High Flux Isotope Reactor. Observable activities include: crane translation, lifting, and lowering; differentiation between loaded and unloaded crane operations; access door opening and closing; vehicle operations; and cooling tower fan operations. Advanced data analytic and spectral feature extraction methods can be used to interpret selected signatures to reach a deeper understanding of different reactor activities. These measurements are being conducted using a network of smartphones that continuously operate in conjunction with cloud-based architectures. A recent addition to the system is the development and deployment of a real-time, cloud-based analytic framework that supports near-real-time alarming which can facilitate tip-and-cue protocols. This paper presents recent research in this area including the use of low-frequency acoustics to tip-off transfer operations and cue a more comprehensive analysis by other sensor networks.

42 ENGINEERING↗
DOE OSTI2018

AMORE Mo-99 Spike Test Results

As a first step to produce Mo-99 in phase 2 of the Argonne Molybdenum Research Experiment (AMORE), we are performing a series of tests in which Mo-99 and natural Mo are added to a target vessel and the target solution is processed to recover Mo. This report describes a Mo-99 spike test with pH 1 sulfuric acid that was performed with an electron beam on a depleted uranium (DU) target.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2017

AMORE Mo-99 Spike Test Results

With funding from the National Nuclear Security Administrations Material Management and Minimization Office, Argonne National Laboratory (Argonne) is providing technical assistance to help accelerate the U.S. production of Mo-99 using a non-highly enriched uranium (non-HEU) source. A potential Mo-99 production pathway is by accelerator-initiated fissioning in a subcritical uranyl sulfate solution containing low enriched uranium (LEU). As part of the Argonne development effort, we are undertaking the AMORE (Argonne Molybdenum Research Experiment) project, which is essentially a pilot facility for all phases of Mo-99 production, recovery, and purification. Production of Mo-99 and other fission products in the subcritical target solution is initiated by putting an electron beam on a depleted uranium (DU) target; the fast neutrons produced in the DU target are thermalized and lead to fissioning of U-235. At the end of irradiation, Mo is recovered from the target solution and separated from uranium and most of the fission products by using a titania column. The Mo is stripped from the column with an alkaline solution. After acidification of the Mo product solution from the recovery column, the Mo is concentrated (and further purified) in a second titania column. The strip solution from the concentration column is then purified with the LEU Modified Cintichem process. A full description of the process can be found elsewhere [1–3]. The initial commissioning steps for the AMORE project include performing a Mo-99 spike test with pH 1 sulfuric acid in the target vessel without a beam on the target to demonstrate the initial Mo separation-and-recovery process, followed by the concentration column process. All glovebox operations were tested with cold solutions prior to performing the Mo-99 spike tests. Two Mo-99 spike tests with pH 1 sulfuric acid have been performed to date. Figure 1 shows the flow diagram for the remotely operated Mo-recovery system for the AMORE project. There are two separate pumps and flow paths for the acid and base operations. The system contains three sample ladders with eight sample loops per ladder for target mixing; column loading, including acid and water washes; and column stripping, including the final water wash.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2016

Compendium of Phase-I Mini-SHINE Experiments

Argonne National Laboratory is assisting SHINE Medical Technologies in their efforts to develop the technology to become a domestic Mo-99 producer using low-enriched uranium (LEU). Mini-SHINE experiments are being performed with the high-current electron linear accelerator (linac) at Argonne. The target solution is a 90-150 g-U/L LEU uranyl sulfate at pH 1. In Phase 1, the convertor was tantalum with a maximum beam power on the convertor of 10 kW, and the target solution was limited to 5 L. This configuration generated a peak fission power density of 0.05 W/mL. Nine experiments were performed between February and October 2015. Results are reported and discussed for each experiment regarding the off-gas analysis system, the sampling and Mo-recovery operation, and the Mo-product concentration and purification system. In Phase 2, the convertor will be depleted uranium; beam power will increase to 20 kW; and the solution volume will be 18 L. This configuration will generate a fission power density of up to 1 W/mL.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Optimization of the dissolution of molybdenum disks. FY-16 results

Argonne National Laboratory is providing technical development assistance to NorthStar Medical Technologies LLC in its pursuit of two pathways for production of molybdenum-99: the 98 Mo(n,γ) 99 Mo reaction and the photonuclear reaction, 100 Mo(γ,n) 99 Mo. Processing of irradiated targets, from either production mode, requires dissolution of the target material in H 2 O 2 followed by a concentration step, addition of ferric ion to precipitate impurities, and conversion of the final solution to 5M potassium hydroxide solution of potassium molybdate. Currently, NorthStar is using pressed and sintered Mo disks as targets. Several options are being considered for the design of Mo targets for the production of 99 Mo using the (γ,n) reaction. In the current design, the target holder contains a series of sintered Mo disks lined up perpendicular to two incident electron beams, one entering from each side of the target stack. In this configuration, the front-most disks absorb most of the heat from the electron beam and need to be thinner to allow for better cooling, while the middle of the target can be thicker. Distribution of the total mass of Mo allows for larger masses of Mo material and thus larger production batches of 99 Mo. A limitation of the sintering approach is the production of very thin disks. Recent advances in 3D printing allow for much thinner target components can be achieved than when the traditional press-and-sinter approach is used. We have demonstrated that several factors can play important roles in dissolution behavior: particle size of Mo metal used for production of targets, sintering conditions, degree of open porosity, and thickness of the sintered Mo targets. Here we report experimental results from studies of small-scale dissolution of sintered Mo disks fabricated from various recycled and commercial Mo materials, and dissolution of 3D-printed Mo disks that were fabricated by Oak Ridge National Laboratory (ORNL). We also report on large-scale dissolution studies with 600 g batches of sintered Mo disks.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2015

UV-Vis Spectroscopy as a Tool for Safeguards; Instrumentation installation and fundamental data collection

Two spectrophotometric process monitors, one optimized for high concentration (approximately 10 g/L) and one for trace levels (approximately 10 ppm),were developed at Argonne and installed at the SRS H-Canyon facility for field testing. These systems were built of Commercial-Off-The-Shelf components utilizing a custom, facility-specific hardware interface. The systems directly provide a qualitative measurement of process chemistry (i.e. valence state). With appropriate calibrations the systems could provide quantitative data. Laboratory tests were performed to determine the spectrophotometric molar absorptivity coefficients for relevant actinide and transition metals of interest.

36 MATERIALS SCIENCE↗
DOE OSTI2014

FY13 Progress Report on the Phase I Mini-SHINE Water Irradiations and Micro-SHINE Irradiations

The original goal of the micro-SHINE experiments was to confirm that precipitation of uranyl peroxide can be prevented by adding a catalyst such as FeSO 4 to destroy peroxide. After successfully demonstrating that FeSO 4 is an effective catalyst for peroxide destruction, subsequent micro-SHINE solutions were used as tracers to perform a Mo-separation and recovery column experiment, a sulfate-to-nitrate conversion, and iodine speciation experiments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Documenting Dual-Column Experiment with Mini-SHINE Solution

Argonne National Laboratory (Argonne) is assisting SHINE Medical Technologies (SHINE) in developing a production method and recovery and purification processes for molybdenum 99 (Mo-99) using an accelerator-driven, subcritical target consisting of an aqueous uranyl-sulfate solution. An integral part of the process is the development of a column for the separation and recovery of Mo-99, followed by a concentration column to reduce the product volume from 15–25 L to <1 L prior to entry into the low-enriched uranium (LEU)-Modified Cintichem purification process. Argonne has developed plant-scale column designs for the initial Mo-recovery column and the concentration column.

Stepinski, Dominique C.↗