thanks for the info google AI - dirty bomb info

how much uranium is required to make a dirty bomb?

Uranium is generally considered a
poor candidate for a "dirty bomb" (radiological dispersal device)
because its natural radioactivity is relatively low. While there is no
fixed amount required to create one, using common commercial-grade
uranium for such a device would theoretically require up to 1,000 tons
to achieve significant radioactive dispersal, making it impractical
for this purpose.
Wikipedia +1

Uranium vs. Other Radioactive Materials

A dirty bomb combines conventional explosives with radioactive
material to contaminate a localized area. Because uranium has a long
half-life and low activity, other isotopes are far more likely to be
used:
Nuclear Regulatory Commission (.gov) +2

Cesium-137: Approximately 41 grams would be more effective than tons of uranium.
Iridium-192: As little as 0.4 grams could be used to create a
detectable and disruptive device.
Other Common Sources: Materials like Cobalt-60, Strontium-90, and
Americium- ....

wmd nuke etc