What is ISO 15646 — Re-sintering test for UO2, (U, Gd)O2 and (U, Pu)O2 pellets about?
ISO 15646 is an international standard that covers specifications for nuclear fuel pellets.
ISO 15646 describes a procedure for measuring the densification of UO2, (U, Gd)O2, and (U, Pu)O2 pellets, achieved by heat treatment under defined conditions.
ISO 15646 gives a brief description of the test procedure, notifies about the incidents, and specifies technicalities such as apparatus used, sampling of the specimen, reagents required, test methods, evaluation, the precision of the procedure, and concluding the test report.
Who is ISO 15646 — Re-sintering test for UO2, (U, Gd)O2 and (U, Pu)O2 pellets for?
ISO 15646 on Re-sintering test for UO2, (U, Gd)O2 and (U, Pu)O2 pellets is useful for:
- Nuclear power stations
- Nuclear fuel technology providers
- Fissile material manufacturers
- Military and Defense authorities
- Atomic research organizations
- Regulatory bodies
Why should you use ISO 15646 — Re-sintering test for UO2, (U, Gd)O2 and (U, Pu)O2 pellets?
The densification of fuel in power operation is an important design feature. Essentially, it depends on structural parameters such as pore size, spatial pore distribution, grain size, and in the case of (U, Gd) O2 and ( U, Pu)O2, oxide phase structure.
ISO 15646 lays out the specifications for a thermal re-sintering test, that can be used for characterizing the dimensional behavior of the pellets under high temperatures. The results of this test help the users like the fuel designer, to predict dimensional behavior in the reactor, as thermal densification in the reactor is also dependent on these structural parameters, albeit in a differing manner in terms of quantity.
ISO 15646 informs to correlate the results of this test by some correlation rules, as the results of this test vastly depend on the re-sintering conditions such as heat treatment temperature, treatment time, gas content, and partial oxygen pressure.
Overall, ISO 15646 helps the users to perform the re-sintering test for UO2, (U, Gd)O2, and (U, Pu)O2 pellets, in order to evaluate densification of the nuclear fuel pellets under different conditions.
