Lori A. Metz's research while affiliated with Pacific Northwest National Laboratory and other places

Publications (33)

Article
The Source Term Analysis of Xenon (STAX) project has been installing stack detectors at medical isotope production facilities to measure radioxenon emissions to investigate the effect of radioxenon releases on nuclear explosion monitoring. This paper outlines the installation of the first STAX detection system at the National Institute for Radioele...
Article
The purpose of this work was to evaluate the ability of cation and actinide resins to isolate Be, Mn, Ni, and Cs from a mixed activation and fission product sample. Overall, the isolation of three fractions (Be/Mn, Cs, and Ni) was achieved via sequential cation and Actinide resin columns using non-radioactive surrogates and would potentially allow...
Article
The quantification of uranium (U) by Kinetic Phosphorescence Analysis (KPA) is negatively impacted by the presence of silver (Ag). KPA can be combined with gamma spectroscopy to determine recovery of short-lived uranium isotopes after radiochemical purification in nuclear forensics relevant samples. Fission products can impact accurate gamma spectr...
Article
An overview of the hardware and software developed for the Source Term Analysis of Xenon (STAX) project is presented which includes the data collection from two stack monitoring systems installed at medical isotope production facilities, infrastructure to transfer data to a central repository, and methods for sharing data from the repository with u...
Article
Sequential separation methods are key for rapid determination of multiple radionuclides. Seven different activation and fission products were isolated by two different sized anion exchange columns after a UTEVA/ TRU double stack. First, a 6 mL column of AG1-x8 separated Cd, Zn, Co, and Ir. The Cd recoveries were quantitative, with a decontamination...
Article
The noble gas collection and measurement stations in the International Monitoring System (IMS) are heavily influenced by releases from medical isotope production facilities. The ability to reliably model the movement of radioxenon from the points of release to these IMS samplers has improved enough that a routine aspect of the analysis of IMS radio...
Article
This work focused on the experimental analysis of depleted uranium irradiated with 14 MeV neutrons to obtain fission yields for 20 fission products with half-lives ranging from 16.8 h to 30.1 years. Several analytes were identified where improvements to the available nuclear data would be beneficial. The results obtained from this experiment could...
Article
This work describes a radiochemical separation procedure for the determination of gold (Au), platinum (Pt), tantalum (Ta), and tungsten (W) activation in the presence of fission products. Chemical separations result in a reduction in the minimum detectable activity by a factor of 287, 207, 141, and 471 for ¹⁸²Ta, ¹⁸⁷W, ¹⁹⁷Pt, and ¹⁹⁸Au respectively...
Conference Paper
Full-text available
The sixth workshop on the signatures of man-made isotope production (WOSMIP) was held November 28 through December 2nd in Bariloche, Argentina. CTBTO, PNNL and INVAP jointly organized the event, where 81 participants representing 27 countries took part. More than 60 contributions, among oral presentations and posters were submitted. This workshop...
Article
Determination of environmental tungsten (W) is inhibited by a lack of reference materials and practical methods to remove isobaric and radiometric interferences. We present a method that evaluates the potential use of commercially available sediment, Basalt Columbia River-2 (BCR-2), as a quality control standard for W. Tungsten concentrations deter...
Article
Prior work has demonstrated the use of a natural B4C capsule for spectral-tailoring in a mixed spectrum reactor as an alternate and complementary method to critical assemblies for performing nuclear data measurements at near 235U fission-energy neutron spectrum. Previous fission product measurements showed that the neutron spectrum achievable with...
Article
This work expands the availability of energy-resolved short-lived cumulative fission product yields for 235,238,233U, 239Pu, and 237Np subjected to a 2$ pulse in the Washington State University TRIGA reactor. A boron carbide capsule tailored the neutron spectrum, creating a spectrum with an average energy of 700 keV, similar to fast reactor spectra...
Article
Full-text available
The fission products from HEU formed under a fast-pooled neutron spectrum generated using a boron carbide shield were analyzed at Pacific Northwest National Laboratory and the Atomic Weapons Establishment. The results from each laboratory using chemical separation, high-purity germanium gamma spectroscopy and/or Compton suppression gamma spectrosco...
Article
Full-text available
Quantifying the iron (Fe) isotopes 55Fe and 59Fe radiometrically can be difficult due to emission interferences or high spectral backgrounds in the presence of other activation products or fission products. The purpose of this work was to demonstrate a separation procedure for Fe activation product analysis for complex samples that contain either a...
Article
Mixed fission and activation materials resulting from various nuclear processes and events contain a wide range of isotopes for analysis spanning almost the entire periodic table. This work describes the production of a complex synthetic sample containing fission products, activation products, and irradiated soil, and determines the percent chemica...
Article
Full-text available
A novel reaction pathway for production of 240Am is reported. Models of reaction cross-sections in EMPIRE II suggest that deuteron-induced activation of a 240Pu target produces maximum yields of 240Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A 240Pu target was activated under the modeled...
Article
The purpose of this work was to determine polonium losses from a variety of sample types (soil, cotton fiber, and air filter) due to digestion technique, chemical separation, and deposition method for alpha energy analysis. Results demonstrated that yields from a perchloric acid wet-ash (87 +/- A 5 %) were similar to that from a microwave digestion...
Article
A boron carbide capsule highly enriched in 10B has been designed and used for spectral-tailoring experiments at the TRIGA reactor at Washington State University. New experiments show that enriching the boron to 96% B-10 results in additional absorption of neutrons in the resonance region thereby producing a neutron spectrum that is much closer to a...
Article
The monitoring of the radioactive xenon isotopes (131m)Xe, (133)Xe, (133m)Xe, and (135)Xe is important for the detection of nuclear explosions. While backgrounds of the xenon isotopes are short-lived, they are constantly replenished from activities dominated by the fission-based production of (99)Mo used for medical procedures. At present, one of t...
Article
A boron carbide capsule was previously designed and tested by Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) for spectral-tailoring in mixed spectrum reactors. The presented work used this B4C capsule to create a fission product sample from the irradiation of highly enriched uranium (HEU) with a fast fission neut...
Article
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...
Article
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 agr...
Article
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 g...
Article
Low-level analysis of radioiodine performed by TIMS requires an initial chemical separation from interfering higher electron-affinity halogens. Experiments using 125I and 36Cl tracers have shown that iodide can be selectively oxidized and purged from solution while the chloride remains in the solution. A systematic investigation of the experimental...
Article
Full-text available
A unique set of fission product gamma spectra was collected at short times (4 minutes to 1 week) on various fissionable materials. Gamma spectra were collected from the neutron-induced fission of uranium, neptunium, and plutonium isotopes at thermal, epithermal, fission spectrum, and 14-MeV neutron energies. This report describes the experimental m...
Article
Fission yields are especially well characterized for long-lived fission products. Modeling techniques incorporate numerous assumptions and can be used to deduce information about the distribution of short-lived fission products. This work is an attempt to gather experimental (model-independent) data on short-lived fission products. Fissile isotopes...
Article
Full-text available
Washington State University’s 1MW TRIGA reactor has a long history of utilization for neutron activation analysis (NAA). TRIGA reactors have the ability to pulse, reach supercritical (k>1) for short bursts of time (~50ms). At this high power and fast time the energy spectrum and neutron fluence are largely uncharacterized. The pulse neutron energy...
Article
A novel device has been fabricated for the electrodeposition of technetium metal onto platinum filaments for thermal ionization mass spectrometric (TIMS) measurements. The ability of the device to focus the deposition to diameters of hundreds of micrometers on pre-mounted TIMS filaments coupled with the ease of use and simplicity of design permit f...
Article
Two methods capable of near complete recovery of technetium adsorbed on charcoal are presented. The first involves liquid extraction of the technetium from the charcoal by hot 4M nitric acid. An average recovery of 98% (n=3) is obtained after three rounds of extraction. The second method involves dry ashing with air in a quartz combustion tube at 4...
Article
Summary Two methods capable of near complete recovery of technetium adsorbed on charcoal are presented. The first involves liquid extraction of the technetium from the charcoal by hot 4M nitric acid. An average recovery of 98% (n=3) is obtained after three rounds of extraction. The second method involves dry ashing with air in a quartz combustion t...

Citations

... Detection of minor components of complex mixtures of radionuclides is challenging due to detection interferences caused by Compton backscatter [1][2][3][4][5][6][7]. Chemical isolation of the minor radionuclides is often required for quantitative analysis via gamma spectroscopy [1][2][3][4][5][6]. ...
... For Te, in addition to the 125 Te and 126 Te isotopes recommended by Fillela and Roduskhin (2018), we also tested the more abundant 128 Te isotope recently used for Te analysis in lake sediments from Canada (Wiklund et al. 2018). For W, the most abundant isotope 184 W, previously used for analysis of geological samples, was chosen (Morrison et al. 2017). Recoveries for these elements in three different CRMs (Table 2) showed that for Ga both isotopes 69 Ga and 71 Ga can be used on MR, for Ge either 74 Ge on MR or 72 Ge on HR, while 93 Nb can be measured on both LR and MR. ...
... 7 This helps to control physical properties such as viscosity, density, hydrophobicity, and solu-bility, as well as their biodegradation ability or toxicological features. 7 Due to these advantages, ILs are being used as novel solvents in organic synthesis, 8 catalysis, 9 electrochemistry, 10 electrocatalysts, 11 lubricants, 12 chemical separation, 13 chemical fixation of carbon dioxide, 14 synthesis of nanoparticles, 15 and metal extraction. 16 Phosphonium-based ILs exhibit enhanced thermal stability compared with ammonium-, imidazolium-, and pyridinium-based ILs [17][18][19] making them useful as solvents for reactions carried out at and above 100°C. ...
... The mercury desorption from silverloaded activated carbon fiber was achieved up to 94.73 %, whereas the same from activated carbon fiber was only 69.93 % (Table 1). Engelmann et al. (2006) found appreciable recovery of technetium (Tc) and suggested two methods for recovery of technetium adsorbed on charcoal. The first recovery method employed was liquid extraction method that involved extraction of 99 Tc from charcoal with a hot 4-M HNO 3 leaching, and the second method involved air ashing at elevated temperature of 400-450°C to recover 99 Tc from the charcoal. ...
... Figure 6 illustrates the variation of the fission yield of 143 Ce with neutron energy for 235 U(n, f) reaction (denoted Y 5 ) and for 238 U(n, f) reaction (denoted Y 8 ). Data points for 143 Ce in 235 U(n, f) reaction are from [43][44][45][46][47][48][49][50][51][52][53][54][55]. Data points for 238 U(n, f) reaction are from [47,48,50,51,[56][57][58][59]. ...
... Sequential separations maximize the amount of each analyte available for separation which is especially beneficial for analytes with low fission yields as well as samples with a low number of fissions. Previous work by Douglas et al. and Morley et al. demonstrate the use of sequential separation schemes for analysis of multiple fission and/or activation products from irradiated actinide targets [6,7]. The separation scheme employed for this work, Fig. 1, was designed to accommodate the large actinide targets required to obtain sufficient fissions to achieve good radiometric results. ...
... The digestion techniques were classified mainly in two ways including (1) acid digestion (Lin et al., 2009;Cunha et al., 2001;Swift et al., 1998;Ham et al., 1997;Martin et al., 1998;Cho et al., 2016;Prabhath et al., 2015;Sreejith et al., 2014;Jia et al., 2018;Chen et al., 2001; Szarlowicz e a 18 K ç 14 2018; Belivermis et al., 2019; Sanchez-Cabeza e a e a 1998 P aninšek e a 2013; Takizawa et al., 2000;Beals et al., 1989;Sadi et al., 2016) and (2) fusion method Sadi et al., 2016;Maxwell et al., 2019). Acid digestion has been limited to the effect of 210 Po volatilization under different temperature conditions (Martin et al., 1969;Heyraud et al., 1979;Mabuchi et al., 1963;Henricsson et al., 2011;Seiner et al., 2014). Meanwhile, the fusion method was presented to be a more active decomposition technique in completely dissolving various solid samples in the medium than acid digestion; ...
... Produksi topaz biru dari topaz putih dengan teknik iradiasi pertama kali dilaporkan oleh F. H. Pough pada tahun 1957 sebagai teknik pengubahan dalam skala besar [3]. Iradiasi topaz tanpa bahan filter penyerap neutron di teras reaktor merupakan pewarnaan dengan semua energi neutron [4]. Pewarnaan topaz dengan teknik iradiasi neutron menyebabkan terbentuknya isotop radioaktif dari atom yang merupakan bagian dari topaz dan atom dari pengotor. ...
... These levels are as large or larger than recent and historical releases from underground nuclear explosions which vary from less than 10 9 to 10 15 Bq (Saey et al. 2007;Ringbom et al. 2009;Becker et al. 2010;De Meutter et al. 2017;Kurzeja et al. 2018). The effect of new man-made sources can be of particular concern in locations such as around the Korean peninsula as outlined in Bowyer et al. (2014) and Lee et al. (2016). ...
... Detection of minor components of complex mixtures of radionuclides is challenging due to detection interferences caused by Compton backscatter [1][2][3][4][5][6][7]. Chemical isolation of the minor radionuclides is often required for quantitative analysis via gamma spectroscopy [1][2][3][4][5][6]. ...