Abstract: The radiation dose survey of a radiotherapy facility at a hospital, aimed at radiation protection assessment, indicates the machine-room shielding in accordance with the approved scheme upon pre-assessment does not conform to the standard requirements. The assessment agency requested the hospital have it rectified. The shielding thickness is increased asa result. Re-survey of radiation dose confirms that the health and safety of therapists and the public is able to be guaranteed under normal operation condition of the accelerator.

Key words: Assessment, Pre-assessment, Occupational hazard, Radiation protection, Radiation source