[Ancapistani]

> but given the clear disparity between the necessary level of enrichment for weapons production and 60%

I'm also not an expert here, but I did a bit of research out of curiosity.

First, the core Little Boy was 64kg of 80% enriched uranium. Wikipedia says the theoretical lower limit for an implosion-type nuclear bomb of 20%. This report[1], cited on Wiki's "enriched uranium" page, seems to indicate that the critical mass for 60% HEU is ~100kg (for U233) or ~200kg (for U235).

Based upon that, it's not at all clear to me that 60% HEU isn't a direct step toward acquiring nuclear weapons.

1: https://web.archive.org/web/20131102011417/http://web.ornl.g...