adding nuclide in scale6.2

[Nicolas Slosse]

Dear scale community,

I was wondering how to add an extra nuclide (Hf-178n) when performing activation calculation.

This isotope is present in the JEFF 3/0 activation library, but not in the decay library nor in the APMX library.

While running couple, I got error messages such like : 

the reaction  741820 to  721782 is not used because  721782 is not in library 1

Is there a known workaround ?

Kind Regards,

Nicolas Slosse 

Tractebel Engie

[BK Jeon]

Dear Nicolas,

Thank you for your question and for your interest in SCALE and ORIGEN.

At present, SCALE v6.3 (or 6.2) / ORIGEN officially supports metastable nuclides only up to the first metastable state. Therefore, although Hf-178m2 is present in the JEFF-3.0/A activation library, it is not included in the ORIGEN nuclide set. 

This is why COUPLE reports messages such as:

the reaction 741820 to 721782 is not used because 721782 is not in library 1

In this case, the product nuclide is not available in the ORIGEN decay library, so the reaction pathway is excluded during library processing.

For SCALE 6.3, there is no recommended workaround for this limitation. In principle, a user could attempt to manually add the nuclide by providing the corresponding half-life and decay data in the decay library. However, this is not recommended because nuclides beyond the first metastable state are still removed internally by the code and are therefore not reliably supported in ORIGEN calculations.

This user need has been recognized, and support for higher-order metastable nuclides beyond the first metastable state is under development for SCALE 7.0. The intent is to include such nuclides in the ORIGEN nuclide set in a more consistent and supported manner.

We apologize that there is no practical workaround available in SCALE 6.2 and 6.3, and we appreciate your continued interest in SCALE and ORIGEN.

Kind regards,

BK,

2026년 5월 12일 화요일 오전 5시 44분 54초 UTC-4에 Nicolas Slosse님이 작성: