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At least 145 records · Page 8

Qualification of an Additively Manufactured Irradiation Capsule for the High Flux Isotope Reactor

As part of the Advanced Materials and Manufacturing Technologies (AMMT) Program’s work package Component Manufacturing and Demonstrations from AM 316 SS, irradiation capsules have been additively manufactured (AM) from 316H stainless steel for insertion into the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). The irradiation capsules (commonly referred to as “rabbits”) have been successfully designed, fabricated, pressure tested, qualified, and inserted into the HFIR for irradiation and post-irradiation evaluation. Each rabbit consists of an AM housing and two standard AM end caps. The design is simple and amenable to geometric and material customization. This demonstration helps pave the way for acceptance of AM safety-critical components for nuclear energy applications.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

The Off-Site Source Recovery Program Capabilities in Recovering Transuranic Sealed Sources - 17599

Over the past 16 years, the mission of the Off-Site Source Recovery Program (OSRP) has been recovering disused radioactive sealed sources in the interest of national security, public health and safety. This program, which is sponsored by the National Nuclear Security Administration's Office of Global Material Security's Office of Radiological Security, is managed at Los Alamos National Laboratory and Idaho National Laboratory and has recovered sources worldwide. To date, OSRP has recovered more than 38,000 sources from over 1,300 locations worldwide. Since its inception, OSRP has grown from recovering only sealed sources containing one transuranic (TRU) isotope, Pu-239, in the early days of the program, to recovering sealed sources containing several other TRU and non-TRU isotopes. Primarily, OSRP's mission includes Pu-238, Pu-239, Am-241, Cf-252, Cm-244, Sr-90, Cs-137, Co-60, Ir-192 and Ra-226 sources that are US-origin, defense related and not commercially disposable. Over the lifetime of this program the types of recoveries performed have expanded from a single site to multi-site round-up recoveries. An additional approach, referred to as self-ship recoveries, is also used in cases where only a few sources may be present at a licensee's site. In these situations, the licensee ships their source(s) to an OSRP staging facility for ultimate consolidation and disposal. OSRP recovers sources from many types of licensees, with the majority of sources being removed from industry, universities and hospitals. These include sealed sources used in industrial radiological devices like moisture-density gauges and thickness gauges, medical devices such as blood irradiators and radiotherapy devices and sealed sources from nuclear power plants, among others. The recovery and management of sealed sources is a complex process covering multidisciplinary areas, including source construction, characteristics of the radioactive material, source packaging and transportation per DOT regulations, safe and secure storage, and final disposition per waste acceptance criteria of repository sites. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

Postirradiation Examination of HFIR-Irradiated Yttrium Hydrides

The US Department of Energy Microreactor Program is developing compact, high-temperature microreactors that require robust neutron moderators. Known for its high hydrogen retention and structural stability, YH x is a leading candidate for this purpose. As part of an ongoing evaluation, Oak Ridge National Laboratory conducted post-irradiation examinations on YH x specimens irradiated in the High Flux Isotope Reactor under the legacy Transformational Challenge Reactor program, focusing on their structural integrity, hydrogen retention, and thermal properties. The post-irradiation examination campaign primarily examined specimens from two irradiation campaigns, covering a range of hydrogen-to-yttrium atomic ratios (H/Y), neutron damage levels (0.1–2 displacements per atom), and targeted irradiation temperature of 600°C. The investigations included electron microscopy, high-energy x-ray diffraction, laser flash analysis, differential scanning calorimetry, and SiC thermometry analysis.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Search for New Isotope Production Pathways

The isotope group at Jefferson Lab is carrying out R&D for producing medically interesting radioisotopes, especially those with theranostic (therapeutic and diagnostic) attributes. Here the search for viable production mechanisms has been expanded to multi-step reactions where a daughter is produced from the target and decays into a medically interesting granddaughter radioisotope. It is difficult to find efficient production routes when investigating both the initial excitation reaction as well as the decay routes leading to medically interesting isotopes. The overall goal of this project is to create a structured code in Python to find these decay routes by automatically exploring the large number of isotopes and their possible decay modes. The program structure is described, and preliminary results are presented.

Dabill, L.↗

First Report of the Nuclear Data Subcommittee of the Nuclear Science Advisory Committee

Accurate, reliable nuclear data is essential for the success of Federal missions such as nonproliferation, nuclear forensics, homeland security, national defense, space exploration, clean energy generation, and scientific research. Data access is also key to innovative commercial developments such as new medicines, automated industrial controls, energy exploration, energy security, nuclear reactor design, and isotope production. The United States Nuclear Data Program (USNDP) is the domestic custodian of nuclear data. In its April 2022 meeting, the DOE/NSF Nuclear Science Advisory Committee was charged with preparing two reports on nuclear data. In this first report, we review recent accomplishments of the USNDP and discuss complementary and collaborative international efforts. Detailed descriptions of nuclear data needs for basic science, nonproliferation, national security, nuclear energy together with medical and space applications are also presented. Lastly, a set of specific cross-cutting nuclear data needs with relevance for multiple applications areas are also identified for further discussion in a follow-on report planned for release at the end of January 2023.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

ORNL Report for the Preparation and Verification of a U-233 Spike Solution

In response to a Letter Request from the International Atomic Energy Agency to the United States Support Program, the NNSA’s Nuclear Reference Material Program (NRMP) tasked the Material Signatures and Isotopic Standards (MSIS) group at Oak Ridge National Laboratory to prepare 50 units of a U-233 CRM standard with a unit size of approximately 10 µg of U-233.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Space exploration and the history of solar-system volatiles

The thermochemical history of volatile substances in all solar-system planets, satellites, and planetoids is discussed extensively. The volatiles are viewed as an interface between the abiotic and biotic worlds and as a key to the history of bodies of the solar system. A flowsheet of processes and states is exhibited. Differences in bulk volatiles distribution between the planetary bodies and between the interior, surface, and atmosphere of each body are considered, as well as sinks for volatiles in degassing. The volatiles-rich Jovian and Saturnian satellites, the effect of large-planet magnetosphere sweeps on nearby satellites, volatiles of asteroids and comets, and the crucial importance of seismic, gravity, and libration data are treated. A research program encompassing analysis of the elemental and isotopic composition of rare gas in atmospheres, assay of volatiles-containing phases in regoliths, and examination of present or past atmospheric escape/accretion processes is recommended.

Fanale, F. P.↗

Disposition Options for Mk-42 Materials - 17072

In the late 1980s, the DOE Defense Programs identified a need to recover special isotopes of americium, curium, and plutonium (Am/Cm/Pu) from Mark-42 (Mk-42) targets that had been irradiated at the SRS. Eighty Mk-42 target segments were transferred from SRS to ORNL for recovery of these special isotopes. Approximately 65% of the target materials has been processed and converted to solids. The remaining Mk-42 materials are either targets stored in their irradiated forms or target material stored from various stages of processing. The Pu, Am-243 and Cm-244 in these targets are valuable materials; for example, the Am/Cm materials are potential feedstocks for production of heavy actinides (Cf-252, Bk-249, etc.). Although the isotopes in the Mk-42 materials have value, there is continual pressure to look at de-inventorying material in storage to only retain the most valuable materials needed to meet mission needs and to allow other materials to be added to the inventory as they become available. Evaluations are underway for potential disposition options for the Mk-42 materials. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Evaluation of Options for Disposition of Mk-42 Materials - 18034

In the late 1980's, the DOE defense programs identified a need to recover special isotopes of americium, curium, and plutonium from Mark-42 (Mk-42) targets that had been irradiated at the SRS. Eighty Mk-42 target segments were transferred from SRS to ORNL for recovery of these special isotopes. Approximately 65% of the target material has been processed, and the recovered material converted to solids. The remaining Mk-42 materials are stored either as targets in their irradiated forms or as target material from various stages of processing. The Pu, Am-243 and Cm-244 in these targets are valuable materials; for example, the Am/Cm materials are potential feedstocks for production of heavy actinides (Cf-252, Bk-249, etc.). In addition, rare long-lived fission product (LLFP) isotopes present in the targets in much smaller quantities, such as Zr-93, also have value to the research community. Although the isotopes in the Mk-42 materials have value, there is continual pressure to de-inventory the material in storage and only retain the most valuable materials needed to meet mission needs and provide inventory space for other materials to be added as they become available. Evaluations are underway for potential disposition options for the Mk-42 materials. Previous studies have included identification and evaluation of disposition options for the various Mk-42 materials in storage at ORNL [1]. Evaluations have included options for recovering the major isotopes and evaluating the waste that would be sent to disposal facilities. This paper summarizes the next steps in the evaluation process to develop an optimum path forward for the disposition of the Mk-42 materials. It includes an evaluation of the future programmatic need for the materials, the impact of storage on facility operations, and additional evaluations of options for dispositioning the materials. In addition to recovery of the major isotopes previously evaluated, it also looks at the potential to recover rare LLFP isotopes present in the targets in small quantities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Molecular Weight Calculator

This program can calculate the molecular weight and percent composition of chemical formulas and amino acids, providing a graphical user interface to edit the formulas and parsing options. It recognizes user-definable abbreviations, custom elemental isotopes, and can display up to 20 compounds simultaneously. It also includes a Mole/Mass Converter, Formula Finder, Capillary Flow Modeller, Amino Acid Notation Converter, Peptide Sequence Fragmentation Modeler, Isotopic Distribution Calculator, and built-in calculator. Full program documentation is available by pressing F1 during program operation.

Monroe, Matthew↗

TUNABLE IRRADIATION TESTBED

PNNL has developed and continues to develop innovative methods for characterizing irradiated materials from nuclear reactors and particle accelerators for various clients and collaborators around the world. The continued development of these methods, in addition to the ability to perform unique scientific investigations of the effects of radiation on materials could be greatly enhanced with easy access to irradiation facilities. A Tunable Irradiation Testbed with customized targets (a 30 MeV, 1mA cyclotron or similar coupled to a unique target system) is shown to provide a much more flexible and cost-effective source of irradiating particles than a test reactor or isotopic source. The configuration investigated was a single shielded building with multiple beam lines from a small, flexible, high flux irradiation source. Potential applications investigated were the characterization of radiation damage to materials applicable to advanced reactors, fusion reactor, legacy waste, (via neutron spectra tailored to HTGR, molten salt, LWR, LMR, fusion environments); 252Cf replacement; characterization of radiation damage to materials of interest to High Energy Physics to enable the neutrino program; and research into production of short lived isotopes for potential medical and other applications.

Wootan, David W.↗

TUNABLE IRRADIATION TESTBED

PNNL has developed and continues to develop innovative methods for characterizing irradiated materials from nuclear reactors and particle accelerators for various clients and collaborators around the world. The continued development of these methods, in addition to the ability to perform unique scientific investigations of the effects of radiation on materials could be greatly enhanced with easy access to irradiation facilities. A Tunable Irradiation Testbed with customized targets (a 30 MeV, 1mA cyclotron or similar coupled to a unique target system) is shown to provide a much more flexible and cost-effective source of irradiating particles than a test reactor or isotopic source. The configuration investigated was a single shielded building with multiple beam lines from a small, flexible, high flux irradiation source. Potential applications investigated were the characterization of radiation damage to materials applicable to advanced reactors, fusion reactor, legacy waste, (via neutron spectra tailored to HTGR, molten salt, LWR, LMR, fusion environments); 252Cf replacement; characterization of radiation damage to materials of interest to High Energy Physics to enable the neutrino program; and research into production of short lived isotopes for potential medical and other applications.

Wootan, David W.↗

Production rates of neon xenon isotopes by energetic neutrons

As a first step in an experimental program to study the behavior of noble gases produced in situ in minerals, a suite of minerals and pure chemicals were irradiated with 14.5 MeV neutrons at LLNL's Rotating Target Neutron Source (RTNS-II) and production rates for noble gases were determined. While neutron effects in meteorites and lunar samples are dominated by low-energy neutron capture, more energetic cosmic-ray secondary neutrons can provide significant depth-dependent contributions to production of cosmogenic nuclides through endothermic reactions such as (n,2n), (n,np), (n,d) and (n,alpha). Production rates for nuclides produced by cosmic-ray secondary neutrons are therefore useful in interpreting shielding histories from the relative abundances of cosmogenic nuclides. Absolute production cross sections were calculated from isotope dilution analyses of NaCl, Mg, CsCl, and Ba(NO3)2 samples, assuming purity, stoichiometry, and quantitative noble gas retention and extraction. Relative production cross sections determined from neon isotopic ratios in the mineral samples were also considered in evaluating the neon production cross sections. Results are presented.

Leich, D. A.↗

The oceanographic toolbox for the collection of sinking and suspended marine particles

Marine particles play a central role in controlling the transport, cycling, and inventories of many major elements and trace elements and isotopes throughout the oceans. Studies seeking to elucidate the biogeochemical roles of marine particles often require reliable ways to collect them from the ocean. Here, we review the oceanographic toolbox of techniques and instrumentation that are employed to collect both suspended and sinking particles. With these tools, it is possible to determine both the concentrations and vertical fluxes of important elements and individual particle types. We describe the various methods for quantifying the concentrations of particulate matter with in situ pumps, towed sampling devices, bottle collectors, and large volume capture devices. The uses of various types of flux collection platforms are discussed including surface tethered, neutrally buoyant, and bottom moored devices. We address the issues of sediment trap collection biases and the apparent inconsistencies that can arise due to differences in the temporal and spatial scales sampled by the various methodologies. Special attention is given to collection considerations made for the analysis of trace metals and isotopes, as these methodologies are of high importance to the ongoing GEOTRACES program which seeks to identify the processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean. With the emergence of new particle collection methodologies and the continued reliance on traditional collection methods, it is imperative that we combine these multiple approaches in ways that will help improve their accuracy and precision while enhancing their utility in advancing understanding of the biogeochemical and ecological roles of marine particles.

58 GEOSCIENCES↗

The isotopic record of lunar volcanism

Some fundamental aspects of lunar history which have been established as a result of the Apollo program of lunary exploration and contemporaneous Soviet lunar missions are summarized, with emphasis on the isotopic data which record lunar global evolution most directly. It is shown that some lunar anorthosites formed about 4.45 Ga ago, consistent with the early formation of an anorthositic lunar crust. Some 'Mg-suite' norites, troctolites, and dunites also formed approximately contemporaneously with the oldest anorthosites, but others are up to 200-300 Ma younger. More evolved rocks (granites and quartz-monzodiorites) also formed between about 4.4 and 4.0 Ga ago. KREEP basalt volcanism began at least 4.1 Ga ago, approximately contemporaneously with that of the ancient, mare-like basalts, and continued during the cataclysm. The isotopic data record an early primary lunar differentiation during which mare basalt sources formed, probably by crystallization of cumulus minerals from a lunar magma ocean.

Nyquist, L. E.↗

American Chemical Society's summer school in nuclear and radiochemistry. Final report

The ACS Summer Schools in Nuclear and Radiochemistry (herein called “Summer Schools”) were held each year at San Jose State University (SJSU) and Brookhaven National Laboratory (BNL). The Summer Schools are an intensive, six-week program that includes both a lecture component covering fundamental principles of nuclear chemistry and radiochemistry and a laboratory component providing hands-on experience for the students to observe and test many of the basic principles that they learn about in lecture and in the special seminars. Each site hosts 12 undergraduate students annually. Participants are selected from a nation-wide pool of applicants who are currently enrolled as undergraduates seeking bachelors’ degrees, preferably in disciplines of physical sciences or engineering. To broaden the students’ perspectives on nuclear science, prominent research scientists active in nuclear and/or radiochemical research participate in a Guest Lecture Series. Symposia emphasizing nuclear security, nuclear medicine, and career opportunities are conducted as a part of the program.

07 ISOTOPE AND RADIATION SOURCES↗

Current cosmic-ray programs in the United States

Approved NASA cosmic ray programs for the next five years are reviewed. In deep space, four new missions are planned. The first two, Helios A and B, will go inwards to approximately 0.3 AU, and the second two, Mariner Jupiter-Saturn, will go outwards to Saturn at 9.5 AU. Two missions in the earth orbital program promise to provide major new information on cosmic ray isotopes and on very heavy cosmic rays. These are the C mission of the International Sun-Earth Explorer, and the C mission of the High Energy Astronomy Observatory. The balloon research program is also mentioned.

Opp, A. G.↗

Measuring Neptunium Concentration using Optical Spectrometry for the Pu-238 Supply Program

Targets containing 237 Np are irradiated at the High Flux Isotope Reactor at Oak Ridge National Laboratory to produce 238 Pu, as plutonium dioxide (PuO 2 ), a heat source material for use in future NASA space missions. Kilogram quantities of Np are processed yearly and developing methods to efficiently characterize and monitor the Np processing streams with optical spectroscopy and real-time monitoring software is a critical aspect of this effort. Here, we evaluate how ultraviolet/visible/near-infrared (UV-Vis-NIR) absorbance and Raman spectroscopic techniques are applicable to characterizing concentrated Np solutions and provide proof-of-principle and proof-of-concept results for each technique. Both techniques were tested in lab-scale studies and should improve the timeliness of production efforts. However, spectrophotometry is the more mature option and has been successfully demonstrated in a hot cell environment. An overview of the initial findings, a brief demonstration, and areas for future work will be highlighted in this report.

07 ISOTOPE AND RADIATION SOURCES↗