Section 35.643 - Periodic spot-checks for remote afterloader units(a) A licensee authorized to use a remote afterloader unit for medical use shall perform spot-checks of each remote afterloader facility and on each unit- (1) Before the first use of a high dose-rate, medium dose-rate, or pulsed dose-rate remote afterloader unit on a given day;(2) Before each patient treatment with a low dose-rate remote afterloader unit; and(3) After each source installation.(b) A licensee shall perform the measurements required by paragraph (a) of this section in accordance with written procedures established by the authorized medical physicist. That individual need not actually perform the spot check measurements.(c) A licensee shall have the authorized medical physicist review the results of each spot-check within 15 days. The authorized medical physicist shall notify the licensee as soon as possible in writing of the results of each spot-check.(d) To satisfy the requirements of paragraph (a) of this section, spot-checks must, at a minimum, assure proper operation of-(1) Electrical interlocks at each remote afterloader unit room entrance;(2) Source exposure indicator lights on the remote afterloader unit, on the control console, and in the facility;(3) Viewing and intercom systems in each high dose-rate, medium dose-rate, and pulsed dose-rate remote afterloader facility;(4) Emergency response equipment;(5) Radiation monitors used to indicate the source position;(7) Clock (date and time) in the unit's computer; and(8) Decayed source(s) activity in the unit's computer.(e) If the results of the checks required in paragraph (d) of this section indicate the malfunction of any system, a licensee shall lock the control console in the off position and not use the unit except as may be necessary to repair, replace, or check the malfunctioning system.(f) A licensee shall retain a record of each check required by paragraph (d) of this section and a copy of the procedures required by paragraph (b) of this section in accordance with § 35.2643 .