Just what is a uranium stockpile anyway? I imagined ...

[reACTIONary]

.... Iran's "stockpile" to be something like a 900 lb stack of silver bars, maybe in wooden crates. But that does not seem to be the case.

From what I read, the uranium stockpile is in the form of a gas - uranium hexafluoride, aka UF6. This is the input and the output of the gas centrifuges that purify the uranium. It is stored in this form, probably in pressurized cylinders, and converted to metallic form just prior to actual use. This is done at a conversion facility. One such facility was a target of the recent attack.

According to one report, the Iranians stored the UF6 in containers that could be transported in the trunk of a typical car. So they must have had a lot of fairly small cylinders.

[Diraven]

1. UF6 is a solid

At room temperature so it's easy to store, but it turns into a gas with with only a little heat so it's very convenient for enrichment.

[reACTIONary]

2. Thanks! None of this is very well explained...

... in the general reporting. I appreciate the details you provided!

[canetoad]

4. Thank you

For the info. Appreciated.

[Disaffected]

3. I believe the small cylinders are required as

when storing a fissile material (i.e. material will undergo fission), this including enriched uranium, the amount stored in a single batch must not be above a certain mass or a fission chain reactor will occur (i.e. it goes "prompt critical" ) with dire radiation poisoning consequences for anyone nearby.

The small cylinders must furthermore not be stored together which is probably why a lot of vehicles were apparently used to transport the stuff.

The UF6 itself is nasty stuff as it breaks down in contact with water forming hydrofluoric acid which also has grave consequences if inhaled or in skin contact.