Physics support for brachytherapy with 252Cf at M.D. Anderson consists of patient dosage calculations, source preparation and inventory, facility design and construction, and radiation safety for physician and nursing personnel. Recently, a shielded facility for storage and handling of up to 300 mu g of 252Cf afterloading cells (for interstitial work) and tubes (for intracavitary work) was designed and constructed for the Department of Radiotherapy. The main shield consists of a centrally located lead pot surrounded by borated water-extended polyester. A built-in, curved personnel barrier with sliding Lucite eye shields enables safe and rapid handling of sources during calibration, inventory, cleaning operations and movement to and from the source storage rods. The design radiation levels for the mixed neutron-gamma field from 252Cf were 3 mrem h-1 at the surface of the shield in the working area, less than 2 mrem h-1 in the corridor and adjacent radiotherapy patient room and less than 0.2 mrem h-1 in the nursing office below. The radiation survey of the completed facility and its environs confirmed the calculations.