Nuclear Sample Provenance and Age Determination Using Ruthenium Isotopes.

Area of Science:

• Nuclear Chemistry
• Radiochemistry
• Isotope Geochemistry

Background:

• Ruthenium isotopic composition in nuclear samples can indicate production methods, irradiation history, and age.
• Investigating ruthenium isotopes in a 106Ru standard eliminates environmental mixing complexities.

Purpose of the Study:

• To assess the feasibility of using ruthenium isotope measurements to determine the origin and history of nuclear materials.
• To analyze the ruthenium isotopic composition of 106Ru radioactivity standards.

Main Methods:

• Measurement of ruthenium isotope composition in 106Ru standards.
• Comparison of isotopic data with nuclear reactor simulations.
• Application of radiochronometry using 106Ru and its 106Pd daughter.

Main Results:

• Stable ruthenium isotopic compositions consistent with fissiogenic ruthenium were observed.
• Lot 1 106Ru standard showed a different isotopic composition than lots 2 and 3, indicating longer irradiation.
• Radiochronometry determined Lot 1 to be older than lots 2 and 3.
• Nuclear reactor simulations suggested production from low-enriched uranium in a light water reactor.

Conclusions:

• Ruthenium isotope analysis is a powerful tool for discerning the origin and history of nuclear materials.
• Findings have implications for nuclear treaty monitoring and understanding sample provenance.
• The study demonstrates the utility of isotopic analysis in characterizing nuclear materials.