Distribution of plutonium isotopes in soils between two nuclear test sites: Semipalatinsk and Lop Nor. (February 2022)

• Record Type: Journal Article
• Authors: Feng, Dongxia; Yang, Fang; Wang, Xihuang; Zhou, Xingxuan; Liu, Zhiyong; Liao, Haiqing
• Is Part Of: Journal of environmental radioactivity. Volume 242(2022)
• Publication Date: 2022-02
• Subjects: Plutonium -- Spatial distribution -- Soil -- Nuclear weapons tests -- Global fallout; Plutonium Pu -- Semipalatinsk nuclear test site SNTs -- China's Lop Nor nuclear test site China's Lop Nor nuclear test site; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2021.106792
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: Plutonium (Pu) has attracted attention as an environmental tracer due to its radiotoxicity and the possibility of sources linked with nuclear accidents in recent years. Plutonium isotopes ( 239, 240 Pu) were detected at trace levels in soils collected from the Xinjiang region located between the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site. Little is known regarding the spatial variation of 239, 240 Pu in soils from this region. This study reports the use of Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) methods to distinguish between Pu isotopes derived from global fallout and nuclear weapon tests. We found that the 239, 240 Pu activity concentrations ranged from 0.035 to 1.338 mBq/g; the 240 Pu/ 239 Pu atomic ratios were 0.157–0.223 with a weighted average of 0.180 ± 0.002, corresponding with the expected average global fallout ratio of 0.180 ± 0.014. This indicated that global fallout is the major source of Pu in the study region. The 239, 240 Pu inventories in these soils ranged from 23.67 to 222.7 Bq/m 2, corresponding with those from other areas in China and other countries within the latitude range. Our Pu isotope data was supplemented with other published Pu data for soils collected in the vicinity of the Semipalatinsk nuclear test site and Lop Nor nuclear test site. Results indicate that 239, 240 Pu inventories and 240 Pu/ 239 Pu atomic ratios in soils exhibit large variations with distance from the Semipalatinsk nuclear test site. High deposition and accumulation of Pu, and low 240 Pu/ 239 Pu ratios were observed in close-in fallout and downwind regions of the Semipalatinsk nuclear test site and China's Lop Nor nuclear test site. Graphical abstract: Image 1 Highlights: 239, 240 Pu in Xinjiang, China mainly comes from global fallout. Enhanced Pu pollution mainly occurs nearby and downwind of nuclear weapons test sites. 239, 240 Pu inventories decrease with increasing distance from nuclear weapons test sites. 240 Pu/ 239 Pu atom ratios are comparatively lower close to nuclear weapons test sites.