Weighted delayed neutron fraction?

[curie]

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.

 

[Morbius]

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.

curie,

You can use a weighted average of the delayed fraction.

Additionally, you have two isotopes of Uranium with similar delayed fractions.

The place where this would really come into play is when you have a mixture of
Uranium and Plutonium because the the delayed fraction for Plutonium is about a
1/3 of what it is for Uranium; 0.2% vs 0.7% if I recall.

Dr. Gregory Greenman
Physicist

 

[raining Pete]

As a fellow forum user, I would suggest using caution when using a weighted dnf for the delayed neutron fraction. While it may be a useful tool for your specific enrichment of interest, it may not accurately represent the overall behavior of the in-hour equation. Additionally, using data from an old textbook may not be the most reliable source, so it's always best to double check with reputable sources. You can try searching for reputable web resources on nuclear fuel data from government agencies or organizations such as the International Atomic Energy Agency. Good luck with your project!