---
kind: "section"
citation: "10 C.F.R. § 35.643"
title: "10"
number: "35.643"
heading: "Periodic spot-checks for remote afterloader units."
url: "https://uscodex.org/cfr/10/35.643"
---

# §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)](#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)](#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;
  - (6) Timer accuracy;
  - (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)](#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)](#d) of this section and a copy of the procedures required by [paragraph (b)](#b) of this section in accordance with [§ 35.2643](/cfr/10/35.2643.md).

## Notes

### Authority

Authority: Atomic Energy Act of 1954, secs. 81, 161, 181, 182, 183, 223, 234, 274 (42 U.S.C. 2111, 2201, 2231, 2232, 2233, 2273, 2282, 2021); Energy Reorganization Act of 1974, secs. 201, 206 (42 U.S.C. 5841, 5846); 44 U.S.C. 3504 note.

### Source

Source: 67 FR 20370, Apr. 24, 2002, unless otherwise noted.