|
|
|
|
|
|
by onion2k
32 days ago
|
|
|
If I did have fully pure Pu-241, would that be a better fuel than U-235? Also not a physicist, but I assume from the fact that the OP is asking the LLM this question to trip it up, the point is that U-235 is better even if you have an abundance of both. It's scarcity of Pu-241 leads to the lack of data in training, not that it's actually better. |
|
|
This means that it would actually be a better fuel than Pu-239 for a fission reactor and only its scarcity prevents its use.
The only disadvantage versus Pu-239 is its short half-life, of 14 1/3 years. This means that it cannot be stored for a long time, so it must be consumed as a fuel soon after it is produced, to avoid losses.
Pu-239 has a lower delayed neutron fraction than U-235, which makes the control of a Pu-239 fission reactor more difficult.
But according to:
https://www-nds.iaea.org/sgnucdat/a6.htm
Pu-241 has almost the same delayed neutron fraction as U-235 (0.016 vs. 0.0162), so that is not a serious disadvantage for it.
Both Pu-239 and Pu-241 produce more neutrons per fission event than U-235. This simplifies some things, by allowing a reactor to work with less fuel or less-enriched fuel, but it complicates the control, because there is a greater risk of instabilities.
The truth is that an LLM cannot say which is a preferable fuel between U-235, Pu-239 and Pu-241. It would be possible to design fission reactors that work fine for any of these 3. The best choice depends on economical factors, not on technical feasibility factors.
The only real reason why Pu-241 will never be used is that its production yield when irradiating uranium with neutrons is too low in comparison with Pu-239, so it would be too expensive.