I am plotting the in-hour equation. For the delayed neutron fraction, I was thinking of using a weighted dnf for the particular U fuel enrichment of interest, ie combination of U235 & U238 dnfs, as I cannot look one up for this particular enrichment. Any comment on the “validity” or otherwise of this approach? Btw, this is just for playing around with data & equations, not any kind of serious or real application. I am using dnf values from an old textbook which is adequate for my purposes but if you are aware of a reputable web resource for this kind of data I’d be grateful for a link. Thanks for any input.