10 CFR § 36.21 - Performance criteria for sealed sources.
---
identifier: "/us/cfr/t10/s36.21"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "10 CFR § 36.21 - Performance criteria for sealed sources."
title_number: 10
title_name: "Energy"
section_number: "36.21"
section_name: "Performance criteria for sealed sources."
chapter_name: "NUCLEAR REGULATORY COMMISSION"
part_number: "36"
part_name: "LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
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, 2112, 2201, 2231, 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: "58 FR 7728, Feb. 9, 1993, unless otherwise noted."
cfr_part: "36"
---
# 36.21 Performance criteria for sealed sources.
(a) *Requirements.* Sealed sources installed after July 1, 1993:
(1) Must have a certificate of registration issued under 10 CFR 32.210;
(2) Must be doubly encapsulated;
(3) Must use radioactive material that is as nondispersible as practical and that is as insoluble as practical if the source is used in a wet-source-storage or wet-source-change irradiator;
(4) Must be encapsulated in a material resistant to general corrosion and to localized corrosion, such as 316L stainless steel or other material with equivalent resistance if the sources are for use in irradiator pools; and
(5) In prototype testing of the sealed source, must have been leak tested and found leak-free after each of the tests described in paragraphs (b) through (g) of this section.
(b) *Temperature.* The test source must be held at −40 °C for 20 minutes, 600 °C for 1 hour, and then be subjected to a thermal shock test with a temperature drop from 600 °C to 20 °C within 15 seconds.
(c) *Pressure.* The test source must be twice subjected for at least 5 minutes to an external pressure (absolute) of 2 million newtons per square meter.
(d) *Impact.* A 2-kilogram steel weight, 2.5 centimeters in diameter, must be dropped from a height of 1 meter onto the test source.
(e) *Vibration.* The test source must be subjected 3 times for 10 minutes each to vibrations sweeping from 25 hertz to 500 hertz with a peak amplitude of 5 times the acceleration of gravity. In addition, each test source must be vibrated for 30 minutes at each resonant frequency found.
(f) *Puncture.* A 50-gram weight and pin, 0.3-centimeter pin diameter, must be dropped from a height of 1 meter onto the test source.
(g) *Bend.* If the length of the source is more than 15 times larger than the minimum cross-sectional dimension, the test source must be subjected to a force of 2000 newtons at its center equidistant from two support cylinders, the distance between which is 10 times the minimum cross-sectional dimension of the source.