# Does anyone care about uranium, anymore?

**URL:** <https://boards.straightdope.com/t/does-anyone-care-about-uranium-anymore/151780>\
**Category:** Factual Questions\
**Created:** [January 31, 2003, 1:50am UTC](https://boards.straightdope.com/t/does-anyone-care-about-uranium-anymore/151780 "2003-01-31T01:50:17Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\
**Post date:** [January 31, 2003, 7:54pm UTC](https://boards.straightdope.com/t/does-anyone-care-about-uranium-anymore/151780/21 "2003-01-31T19:54:47Z")

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Okay, one quick question. Why isn’t neptunium used? I’ve always assumed that it either has no fissile isotopes or that it must have too short a half-life to be of any use.

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**Author:** ![Akatsukami](https://avatars.discourse-cdn.com/v4/letter/a/ea666f/32.png) [@Akatsukami](https://boards.straightdope.com/u/Akatsukami)\
**Post date:** [January 31, 2003, 8:24pm UTC](https://boards.straightdope.com/t/does-anyone-care-about-uranium-anymore/151780/22 "2003-01-31T20:24:18Z")

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Six of one, half-dozen of the other, **asterion**. [sup]228[/sup]Np is fissile, but its half-life is about 62 seconds. [sup]237[/sup]Np is fissile (and has a half-life of 2,114,000 years, long enough to be useful), but the fraction of spontaneous fissions is less than 2x10[sup]-10[/sup] (by constant, [sup]235[/sup]U has an SF fraction of 7x10[sup]-9[/sup], and [sup]239[/sup] of 3x10[sup]-10[/sup]). I suppose it could be bred, but why bother? Uranium or plutonium are better choices as a “fuel” element.

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