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Yang B, Zheng J, Yang G, Qin N, Tagami K, Uchida S. Characterization of typical transuranic nuclides in a reference fallout material using SF-ICP-MS. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 278:107506. [PMID: 39053127 DOI: 10.1016/j.jenvrad.2024.107506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/17/2024] [Accepted: 07/21/2024] [Indexed: 07/27/2024]
Abstract
For the quality control in determining transuranic nuclides in fallout samples, this work first reported the 237Np activity concentration in a reference fallout material and further calculated the activity ratios of 237Np/239+240Pu and 237Np/241Am, and the atom ratio of 237Np/239Pu in it. The reference fallout material prepared by the Meteorological Research Institute was collected at 14 stations throughout Japan in 1963-1979. The 237Np and Pu isotopes (239Pu and 240Pu) were separated and purified using AG MP-1M anion-exchange resin, quantified using 242Pu as an isotope dilution tracer, and determined by the SF-ICP-MS. The analytical method was validated by the analysis of 4 sediment reference materials. The activity concentrations of 237Np, 239Pu and 240Pu were (25.9 ± 0.6) × 10-3, 4.10 ± 0.01 and 2.89 ± 0.04 Bq/kg, respectively, in the investigated reference fallout material. The activity ratio of 237Np/239+240Pu (3.7 ± 0.1) × 10-3 was consistent with the global fallout evaluation value. The 237Np/239Pu atom ratio of 0.561 ± 0.014 was higher than the average global fallout value of 0.41 ± 0.010, indicating the necessity of establishing regional characteristic global fallout value of 237Np/239Pu atom ratio for assessment of radioactive contamination. Comparison of the 237Np/239+240Pu activity ratios between in the reference fallout material and in soils over several decades indicated that 237Np has stronger migration capability than Pu isotopes in soils because 237Np was depleted compared to reference fallout material.
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Affiliation(s)
- Bo Yang
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan; East China University of Technology, No. 418 Guanglan Avenue, Nanchang, Jiangxi, 330013, China
| | - Jian Zheng
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan.
| | - Guosheng Yang
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Ning Qin
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan; University of Science and Technology Beijing, Beijing, 100083, China
| | - Keiko Tagami
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Shigeo Uchida
- Institute of Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 263-8555, Japan
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Qin N, Zheng J, Guosheng Yang, Tagami K. A comprehensive survey of reference materials for their use in quality assurance for the determination of Np-237 in environmental samples. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 271:107328. [PMID: 37951039 DOI: 10.1016/j.jenvrad.2023.107328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 11/13/2023]
Abstract
Neptunium-237 (237Np) is one of the most hazardous radionuclides of public concern due to its radiological toxicity, long half-life and high environmental mobility. Standard reference materials (SRMs) with well characterized 237Np activity concentrations are valuable for method development and validation of 237Np determination in environmental samples. In this study, a comprehensive literature survey of 237Np activity concentrations in 25 SRMs was carried out covering the various matrices of sediment, soil, seawater, atmospheric particles, and biota. After data screening, arithmetic mean of the activity concentrations of 237Np in literatures were calculated as statistical values (SVs). Then, accuracies of different instrument analyses and acid digestion methods were evaluated based on the SVs. Finally, by optimizing the sector field ICP-MS analytical method, 237Np activity concentration in JSAC-0471 soil SRM was measured. The application of SVs provides 237Np activity concentration information in more SRMs. Besides SRMs certified by technically validated procedures, SRMs with SVs and the measurement of JASC-0471 provide more options for suitable selection of SRMs for 237Np determination.
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Affiliation(s)
- Ning Qin
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan; University of Science and Technology Beijing, Beijing, 100083, China
| | - Jian Zheng
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan.
| | - Guosheng Yang
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan
| | - Keiko Tagami
- Institute for Radiological Science, National Institutes for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba, 266-8555, Japan
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Corcho Alvarado JA, Röllin S, Sahli H, McGinnity P. Isotopic signatures of plutonium and uranium at Bikar atoll, northern Marshall Islands. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 242:106795. [PMID: 34923320 DOI: 10.1016/j.jenvrad.2021.106795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/02/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
We present plutonium (Pu) and uranium (U) isotopic fingerprints (or signatures) in environmental samples collected at Bikar Atoll. Bikar is the second -most northern atoll of the Republic of the Marshall Islands, and therefore an important reference point to evaluate the extension of the regional fallout from the Pacific Proving Grounds (PPG) in Bikini and Enewetak Atolls. Previous studies have shown that regional fallout from atmospheric nuclear weapon testing (NWT) in Bikini and Enewetak has resulted in elevated levels of fallout radionuclides in this atoll. In order to optimally interpret the isotopic fingerprints, we compare our results with data obtained in eleven certified reference materials, representing different contamination sources. As well as 238Pu, 239Pu, 240Pu, 241Pu, 238U and 235U, this study also encompasses less commonly reported radionuclides such as 242Pu, 244Pu and 236U. We show the importance of combining numerous fingerprints for improved assessment of the source of a nuclear contamination. In samples from Bikar, Pu and U isotope ratios were found to vary within narrow ranges. Pu and U fingerprints suggest that regional fallout from the Castle Bravo test in March 1954 was the main source of the contamination. This was further confirmed by two different age dating approaches that estimated 1954 as the year of the contamination. We demonstrate that use of an exponential function to approximate the yield of heavy radionuclides in thermonuclear explosions with increasing mass is a valid approach for estimating the age of a contamination. We show that, if sufficient radionuclide activity concentration measurement results with low uncertainties are available, this method is robust.
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Affiliation(s)
- J A Corcho Alvarado
- Nuclear Chemistry Division, Spiez Laboratory, Federal Office for Civil Protection, CH-3700 Spiez, Switzerland.
| | - S Röllin
- Nuclear Chemistry Division, Spiez Laboratory, Federal Office for Civil Protection, CH-3700 Spiez, Switzerland
| | - H Sahli
- Nuclear Chemistry Division, Spiez Laboratory, Federal Office for Civil Protection, CH-3700 Spiez, Switzerland
| | - P McGinnity
- International Atomic Energy Agency, Environment Laboratories, Monaco
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Goldstein SJ, Price AA, Hinrichs KA, Lamont SP, Nunn AJ, Amato RS, Cardon AM, Gurganus DW. High-precision measurement of U-Pu-Np-Am concentrations and isotope ratios in environmental reference materials by mass spectrometry. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 237:106689. [PMID: 34298408 DOI: 10.1016/j.jenvrad.2021.106689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/13/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
We report results of precise and sensitive mass spectrometric measurements of uranium, plutonium, neptunium, and americium concentrations and isotope ratios in a variety of environmental reference materials. Most of our work has been done on NIST SRM 4350b, River Sediment, but we also present results for NIST SRM 4354, Lake Sediment; NIST SRMs 4355 and 4355a, Peruvian Soil; NIST SRM 4357, Ocean Sediment; NIST SRM 1648a, Urban Particulate Material; NIST SRM 1649b, Urban Dust; IAEA CRM 385, Ocean Sediment; USGS BCR-2, Columbia River Basalt; and USGS BHVO-2, Hawaiian Volcanic Observatory Basalt. These materials reflect a wide range in long-lived actinide concentrations (e.g. 1E4 to 1E10 atoms 239Pu/g) and isotope ratios. Measurements were performed in a clean laboratory by isotope dilution, multi-collector thermal ionization and multi-collector inductively coupled plasma mass spectrometry. In general, our results are in agreement with, but lower the uncertainty of, literature or certificate values for these reference materials. Our uranium results for the basalts also confirm previously reported high-precision mass spectrometric results from our laboratory. In many cases our measurements of U-Pu-Np-Am nuclides appear to be novel. Extensive results for NIST SRM 4350b, River Sediment, indicate that this material is heterogeneous for Pu-Np-Am concentrations and isotope ratios at a sample size of 5 g or lower. Pu-Np isotope ratios and a241Pu-241Am model age of 1954 reflect a mix of plutonium production operations at the nearby Hanford, Washington site, and global atmospheric fallout from nuclear weapons testing. Results for the oceanic sediment materials (NIST SRM 4357 and IAEA 385) collected near Sellafield, U.K. vary but are also indicative of local anthropogenic sources of varying Pu isotopic composition and a mean 241Pu-241Am model age of 1964. Large environmental fractionation between Pu and Np is observed for the ocean, river, and lake sediment reference materials. Novel measurements for the two air particulate SRMs indicate high U, Pu and Np concentrations for these collections in 1976-1977 with an anomalous regional fallout Pu isotopic signature. Results for BHVO-2 and other Hawaiian basalts indicate that those which erupted before or during the period of abundant atmospheric nuclear weapons testing (1950-1970) contain significant levels of Pu (on the order of 1E7 atoms 239Pu/g) with a global fallout Pu isotopic composition, compared to more recent eruptions which incorporated less Pu. Hence, Hawaiian basalts may provide an integrated temporal record of anthropogenic actinide fallout deposition from the atmosphere since eruption.
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Affiliation(s)
- Steven J Goldstein
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
| | - Allison A Price
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Kimberly A Hinrichs
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Stephen P Lamont
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Andrew J Nunn
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Ronald S Amato
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Annelise M Cardon
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Daniel W Gurganus
- Group C-NR, MS J514, Nuclear and Radiochemistry Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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Yang G, Zheng J, Kim E, Zhang S, Seno H, Kowatari M, Aono T, Kurihara O. Rapid analysis of 237Np and Pu isotopes in small volume urine by SF-ICP-MS and ICP-MS/MS. Anal Chim Acta 2021; 1158:338431. [PMID: 33863417 DOI: 10.1016/j.aca.2021.338431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/11/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
Internal contamination with alpha-particle emitting actinides, such as 237Np, 239Pu, 240Pu, is likely to bring a large amount of dose to the tissues of persons even if the intake amount is small. To provide timely information for prompt decision-making in radiation emergency therapy, we developed a simple and rapid method for urinary bioassay to determine ultra-trace 237Np and Pu isotopes using SF-ICP-MS and ICP-MS/MS. To avoid polyatomic interferences and tailing effects from U, 237Np and Pu isotopes were collected after removing U effectively using a simple single chromatographic column packed with 2 mL AG MP-1M anion exchange resin, exhibiting a high decontamination factor of 108 for 238U. The overall chemical fractionation between 237Np and 242Pu for the whole analytical procedure was 0.974 ± 0.064 (k = 2), allowing us to measure 237Np and Pu isotopes using 242Pu as a yield tracer with yields of 76 ± 5%. Using ICP-MS/MS with low background provided the method detection limits for 237Np, 239Pu, 240Pu, and 241Pu of 0.025, 0.025, 0.015, and 0.020 fg mL-1, respectively, for 20 mL of urine sample. Those were comparable to detection limits of SF-ICP-MS with high sensitivity. Subsequently, three urine reference materials with Pu spike, provided by the Association for the PROmotion of Quality COntrol in RADiotoxicological Analysis (PROCORAD), France, were analyzed by the developed method and the conventional alpha spectrometry technique for validation. Finally, the developed method was successfully employed to measure the contamination level of 237Np, 239Pu, 240Pu, and 241Pu in urine samples collected during decorporation therapy using DTPA, after a Pu inhalation exposure accident in Japan. The high throughput (9 h for 12 samples), simplicity, low cost, and high sensitivity of the method will allow greater numbers of related laboratories to be involved in screening activities for unexpected actinide exposure, such as in the case of a large scale radiological disaster.
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Affiliation(s)
- Guosheng Yang
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Jian Zheng
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan.
| | - Eunjoo Kim
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Shuai Zhang
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan; School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
| | - Hatsuho Seno
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Munehiko Kowatari
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Tatsuo Aono
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Osamu Kurihara
- National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
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