Work Item
ASTM WK46601

New Test Method for The Determination of the Oxygen to Metal (O/M) Ratio in Sintered Mixed Oxides ((U, Pu)O2) Pellets by Gravimetry

1. Scope

This practice is an alternative method to test method C698 for the determination of the oxygen-to-metal atom ratio (O/M) in sintered mixed oxide fuel (MOX) pellets. The method presented in test method C698 is a one-step thermogravimetric method for determining O/M ratio in sintered MOX powders and pellets. As stated in ASTM C 698, thermogravimetric methods using a two-step heating cycle are also satisfactory. The method presented in this test method is a two-step heating cycle method. This practice is applicable to sintered MOX pellets containing up to 10 weight percent PuO2.


plutonium; thermal analysis; gravimetry; uranium; MOX; oxygen to metal (O/M) ratio


This standard is needed because it is a method used in large scale MOX fuel fabrication facilities. It will be used to measure O/M ratio in MOX fuel fabricated in the MOX fuel fabrication facility on the Savannah River Site.

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: C26.05

Committee: C26

Staff Manager: Stephen Mawn

Work Item Status

Date Initiated: 06-30-2014

Technical Contact: Ben Karmiol

Item: 002

Ballot: C26.05 (14-03)

Status: Negative Votes Need Resolution

Item: 015

Ballot: C26 (15-01)

Status: Ballot Item Approved