HEU age determination

Technical Report · Tue Jul 01 00:00:00 EDT 1997

DOI:https://doi.org/10.2172/534522· OSTI ID:534522

Moorthy, A R; Kato, W Y

A new technique has been developed to determine the age of highly enriched uranium (HEU) in solids. Uranium age is defined as the time since the uranium-containing material was last subjected to a process capable of separating uranium from its radioactive-decay daughters. [Most chemical processing, uranium enrichment, volatilization processes, and phase transformations (especially relevant for uranium hexafluoride) can result in separation of the uranium parent material from the decay-product daughters.] Determination of the uranium age, as defined here, may be relevant in verifying arms-control agreements involving uranium-containing nuclear weapons. The HEU age is determined from the ratios of relevant uranium daughter isotopes and their parents, viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gamma rays and their daughters by alpha spectroscopy. In some of the samples, where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the samples. In this report the methodology and the data for determining the age of two HEU samples are presented.

• Research Organization: Brookhaven National Lab., Upton, NY (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 534522
• Report Number(s): BNL--52535; SSN--97-23; ON: DE98000152
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
AGE ESTIMATION
ALPHA SPECTROSCOPY
GAMMA SPECTRA
HIGHLY ENRICHED URANIUM
ION EXCHANGE
ISOTOPE RATIO
NUCLEAR MATERIALS MANAGEMENT
NUCLEAR WEAPONS DISMANTLEMENT
PROCESSING
PROTACTINIUM 231
QUANTITATIVE CHEMICAL ANALYSIS
SAFEGUARDS
SEPARATION PROCESSES
THORIUM 230
URANIUM 234
URANIUM 235
URANIUM HEXAFLUORIDE
URANIUM ISOTOPES