The IFFY yields do not yet take into account the absorption of neutrons by fission products (FP). The Barns_FP table has data for 241 isotopes (no isomers), some of which are not fission fragments but might be useful someday. There are 165 isotopes in the FullSnaps table that might be relevant neutron absorbers. We can ignore many of these for three reasons:
- 65 change from a Stable/Primordial isotope directly to another stable/primordial isotope of the same element,
- 39 have a yield less than 2, which is 1 ppm at Snap20 (for 235-U/Slow),
- 32 have a cross-section less than 1.0, which take at least 1200 years to transmute
This leaves 29 isotopes that might be relevant with respect to neutron absorptions that significantly change the composition of the waste. These are listed in the Absorbers table with a Relevant value of 1. In my copious free time…
A form of neutron absorption has now been incorporated into the model.