Is there guideline for portable X-ray photographier in hospital?

[ijsun@VghTpe.Gov.TW (Ing-Jou Sun)]

Please do me a favor, dear list members!

X-ray machine to take chest x-ray film(CXR) for patients in the ICU in our
hospital. We want to setup a guideline to protect other patients or hospital
staff from radiation of portable x-ray machine.

I need guideline or regulation or law of US, about this topic. Please tell me 
where I can get these information in Internet. If your hospital has such a
guideline, please let me know. I'll contact with you for getting a copy by
FAX, mail, or email. Thank you very very much!!

Ying-Chou Sun, 
email:  ijsun@vghtpe.gov.tw