10 CFR § 35.432 - Calibration measurements of brachytherapy sources.

---
identifier: "/us/cfr/t10/s35.432"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "10 CFR § 35.432 - Calibration measurements of brachytherapy sources."
title_number: 10
title_name: "Energy"
section_number: "35.432"
section_name: "Calibration measurements of brachytherapy sources."
chapter_name: "NUCLEAR REGULATORY COMMISSION"
part_number: "35"
part_name: "MEDICAL USE OF BYPRODUCT MATERIAL"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "67 FR 20370, Apr. 24, 2002, unless otherwise noted."
cfr_part: "35"
---


# 35.432 Calibration measurements of brachytherapy sources.

(a) Before the first medical use of a brachytherapy source on or after October 24, 2002, a licensee shall have—

(1) Determined the source output or activity using a dosimetry system that meets the requirements of § 35.630(a);

(2) Determined source positioning accuracy within applicators; and

(3) Used published protocols currently accepted by nationally recognized bodies to meet the requirements of paragraphs (a)(1) and (a)(2) of this section.

(b) Instead of a licensee making its own measurements as required in paragraph (a) of this section, the licensee may use measurements provided by the source manufacturer or by a calibration laboratory accredited by the American Association of Physicists in Medicine that are made in accordance with paragraph (a) of this section.

(c) A licensee shall mathematically correct the outputs or activities determined in paragraph (a) of this section for physical decay at intervals consistent with 1 percent physical decay.

(d) A licensee shall retain a record of each calibration in accordance with § 35.2432.

[67 FR 20370, Apr. 24, 2002, as amended at 68 FR 19325, Apr. 21, 2003]