(1) A licensee authorized to use a remote afterloader unit for medical use shall perform full calibration measurements on each unit:
- (a) Before the first medical use of the unit;
(b) Before medical use under the following conditions:
- (i) Following replacement of the source or following reinstallation of the unit in a new location outside the facility; and
- (ii) Following any repair of the unit that includes removal of the source or major repair of the components associated with the source exposure assembly; and
- (c) At intervals not exceeding one calendar quarter for high dose-rate, medium dose-rate, and pulsed dose-rate remote afterloader units with sources whose half-life exceeds 75 days; and
- (d) At intervals not exceeding one year for low dose-rate remote afterloader units.
(2) To satisfy the requirement of subsection (1) of this section, full calibration measurements must include, as applicable, determination of:
- (a) The output within ± five percent;
- (b) Source positioning accuracy to within ± one millimeter;
- (c) Source retraction with backup battery upon power failure;
- (d) Length of the source transfer tubes;
- (e) Timer accuracy and linearity over the typical range of use;
- (f) Length of the applicators; and
- (g) Function of the source transfer tubes, applicators, and transfer tube-applicator interfaces.
- (3) A licensee shall use the dosimetry system described in WAC 246-240-366(1) to measure the output.
- (4) A licensee shall make full calibration measurements required by subsection (1) of this section in accordance with published protocols accepted by nationally recognized bodies.
- (5) In addition to the requirements for full calibrations for low dose-rate remote afterloader units in subsection (2) of this section, a licensee shall perform an autoradiograph of the sources to verify inventory and sources arrangement at intervals not exceeding one calendar quarter.
- (6) For low dose-rate remote afterloader units, a licensee may use measurements provided by the source manufacturer that are made in accordance with subsections (1) through (5) of this section.
- (7) A licensee shall mathematically correct the outputs determined in subsection (2)(a) of this section for physical decay at intervals consistent with one percent physical decay.
- (8) Full calibration measurements required by subsection (1) of this section and physical decay corrections required by subsection (7) of this section must be performed by the authorized medical physicist.
- (9) A licensee shall retain a record of each calibration in accordance with WAC 246-240-614.
[Statutory Authority: RCW 70A.388.040 and 70A.388.110. WSR 22-19-084, § 246-240-372, filed 9/20/22, effective 10/21/22. Statutory Authority: RCW 70.98.050. WSR 06-05-019, § 246-240-372, filed 2/6/06, effective 3/9/06.]