Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

Journal Article · Sat Jun 11 04:00:00 EDT 2005 · Spectrochemica Acta Part B, vol. 61, no. 8, August 1, 2006, pp. 971-979

OSTI ID:898018

Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 898018
• Report Number(s): UCRL-JRNL-217812
• Journal Information: Spectrochemica Acta Part B, vol. 61, no. 8, August 1, 2006, pp. 971-979, Journal Name: Spectrochemica Acta Part B, vol. 61, no. 8, August 1, 2006, pp. 971-979
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
43 PARTICLE ACCELERATORS
54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
61 RADIATION PROTECTION AND DOSIMETRY
CHEMICAL COMPOSITION
ELECTRON MICROSCOPES
FLUORESCENCE
MARSHALL ISLANDS
MASS SPECTROMETERS
PARTICLE SIZE
PARTICULATES
PLUTONIUM
RADIOACTIVITY
RADIOISOTOPES
SAFETY
SOILS
SOURCE TERMS
SPECTROSCOPY
SYNCHROTRON RADIATION
WEAPONS