Hello and welcome – Radiation safety recommendations can actually vary from state to state and facility to facility! I would check with the clinic where your RAI was done for more specific information, but the American Thyroid Association released some general safety guidelines a couple of years ago (link included below). That guidance says that a standard washing for sheets is sufficient, and bleach is not needed, nor additional rinse cycles. Again, check with your clinic, but I believe that once you get past the isolation period, the concern is more with radiation being passed on via bodily fluids (sweat, urine, etc.), so I wouldn’t imagine the walls would be an issue.
With that said, though, since your guest is pregnant, it wouldn’t hurt to be extra cautious and switch rooms so that you have the isolation room and she has a different room for her stay.
(Note on links: if you click directly on the following link, you will need to use your browser’s “back” button to return to the boards after viewing, or you will have to log back in to the forum. As an alternative, you can right-click the link and open it in a new tab or new window).
http://www.thyroid.org/wp-content/uploads/publications/guidelines/thy.2010.0403.pdf
Take care!