[JoeAltmaier]

Use for heavy lifting? Depends on efficiency. If it 'burned' its fuel completely, then maybe not as dirty as imagined.

Further the oceans already contain dissolved uranium salts. Returning them to the ocean is 'net neutral' in a sense. Especially if we harvested them from there to begin with!

[philipkglass]

The dirty part is the fission products, not the unspent uranium. You wouldn't want to launch a nuclear salt water rocket from the surface even if it achieved 100% fuel burnup.

https://en.wikipedia.org/wiki/Nuclear_fission_product