(1) A licensee shall retain a copy of each letter that permits the use of radioactive material at a client's address, as required by WAC 246-240-125. Each letter must clearly delineate the authority and responsibility of the licensee and the client and must be retained for three years after the last provision of service.

(2) A licensee shall retain the record of each survey required by WAC 246-240-125 (1)(d) for three years. The record must include the date of the survey, the results of the survey, the instrument used to make the survey, and the name of the individual who performed the survey.