[ RadSafe ] Query on frequency of inspections by regulatory agencies

[parthasarathy k s]

Friends,

This query is on the frequency of inspections of installations using byproduct materials by regulatory agencies. 

I am under the impression that in USA there is some mandatory requirement that NRC inspectors must visit radiation installations with some frequency depending on the type of installations. Is there such a requirement? If yes can you e-mail me a soft copy of the relevant rules or provide a link to that rule

Is there any such requirement for unannounced inspections?

I understand that the first version of the " Code of conduct on safety and security of radioactive substances" published by the International Atomic Energy Agency (IAEA) contained some recommendations on the frequency but the final version published in January 2004 did not.

I shall appreciate receiving information on the practices followed in USA and other countries.

Regards
K S parthasarathy