Unshielded Installations

T.O. 33B-1-1 6.9.7.2.4 In evaluating the results of the survey, consideration shall be given to actual operating conditions, including workload, use factor, occupancy factor and attenuation of the useful beam provided by objects permanently in the path of the useful beam. NOTE Use of engineering design controls such as addition of shielding will take precedence over operational (administrative) controls. 6.9.7.2.5 Whenever, in the opinion of the RSO or the radiographer, there is a reasonable probability that a person in an uncontrolled area adjacent to any type of radiation installation may receive more than 2 mrem (20 mSv) in any one hour or 100 mrem (1 mSv) in any calendar year, then one or more of the following courses of action (whichever may be appropriate) shall he taken to ensure that no person will receive exposure in excess of the basic radiation protection standard: a. Use personnel or area monitoring devices to estimate the exposure received by occupants of the area, applying appropriate occupancy factors for each assessed location (Air Force personnel must coordi- nate with AL/OEBD, Brooks AFB TX, 78235-5114, DSN 240-3486) b. Add supplementary shielding to the protective barriers to insure conformity with protective barrier recommendations contained in this publication. c. Restrict use of the equipment (workload (on-time), kVp or use factor). d. Restrict occupancy of the area. 6.9.7.2.6 Radiation hazards found in the course of a survey of any type installation shall be eliminated before the installation is used routinely. If the design and/or approved use of a shielded installation depend upon restrictions on the use factor of any primary barrier, it must be verified that these restrictions are actually observed. 6.9.7.2.7 All interlocks, ‘‘ON-OFF’’ beam control mechanisms, safety and warning devices, remote monitoring systems, etc. shall be inspected for proper operation prior to initial operation on each shift when x-ray equipment will be used and subjected to detailed testing to assure proper operation at intervals not to exceed six months. A log initialed by the person making the inspection shall be maintained. Any malfunctioning devices shall be appropriately serviced prior to use and reinspected to verify proper operation. 6.9.7.3 Unshielded Installations. A detailed radiation protection survey of all unshielded installations upon initial use or use with new equipment shall be made by a fully qualified health physicist, Bioenvironmental Engineer, Nuclear Medicine Science Officer or qualified radiological health technician. Unshielded installations shall be surveyed by radiographers during each subsequent operation. In addition, a radiation assessment shall be made by the RSO as an integral part of the annual quality assurance audit of the Radiation Protection Program. Assessments shall verify the adequacy of operating procedures, the presence and proper use of radiation warning signs and signals and other necessary equipment. Initial surveys must include radiation exposure measurements to establish or verify safe operating conditions as established by the applicable standard operating procedures. 6.9.7.4 Portable Equipment Set-Ups. The radiographer shall assure that a comprehensive radiation protection survey is performed each time portable equipment is used in an unshielded area to insure that exposures are adequately controlled. He shall also survey radiation levels prior to re-entry into the radiation area to assure that the radiation source has ceased to function or has returned to its shielded position, as applicable. Change 2 6-121