I didn’t say it was anywhere close to critical mass. People were suggesting Alvin’s sample would be worst (likely because of how U-235 is notoriously used in nukes) but I reminded them that only a big chunk of sufficiently pure U-235 would be catastrophic, otherwise the radiation is surprisingly mild.

And Theodore’s sample will also contain a varying amount of U-235 but it will take tens of thousands of years to get pure enough.