e-CFR Navigation Aids


Simple Search

Advanced Search

 — Boolean

 — Proximity


Search History

Search Tips


Latest Updates

User Info


Agency List

Incorporation By Reference

eCFR logo

Related Resources

Electronic Code of Federal Regulations

We invite you to try out our new beta eCFR site at https://ecfr.federalregister.gov. We have made big changes to make the eCFR easier to use. Be sure to leave feedback using the Help button on the bottom right of each page!

e-CFR data is current as of October 22, 2020

Title 10Chapter IPart 110Subpart K → Appendix

Title 10: Energy
Subpart K—Rulemaking

Appendix M to Part 110—Categorization of Nuclear Materiald

[From IAEA INFCIRC/225, Rev. 1]

1. PlutoniumaUnirradiatedb2 kg or moreLess than 2 kg but more than 500 g500 g or less.
2. Uranium-235cUnirradiated:b
      Uranium enriched to 20 pct U235 or more5 kg or moreLess than 5 kg but more than 1 kg1 kg or less.
      Uranium enriched to 10 pct U235 but less than 20 pct10 kg or moreLess than 10 kg.
      Uranium enriched above natural, but less than 10 pct U23510 kg or more.
3. Uranium-233Unirradiatedb2 kg or moreLess than 2 kg but more than 500 g500 g or less.

aAll plutonium except that with isotopic concentration exceeding 80 pct in plutonium-238.

bMaterial not irradiated in a reactor or material irradiated in a reactor but with a radiation level equal to or less than 100 rd/h at 1 m unshielded.

cNatural uranium, depleted uranium, thorium and quantities of uranium enriched to less than 10% not falling into Category III should be protected in accordance with prudent management practice.

dIrradiated fuel should be protected as category I, II, or III nuclear material depending on the category of the fresh fuel. However, fuel which by virtue of its original fissile material content is included as category I or II before irradiation should only be reduced one category level, while the radiation level from the fuel exceeds 100 rd/h at 1 m unshielded.

ePhysical security determinations will not be required for 15 g or less of plutonium, uranium-233 or high-enriched uranium, or for 1 kg or less of uranium with an enrichment between 10 and 20 pct in uranium-235.

(Sec. 161, as amended, Pub. L. 83-703, 68 Stat. 948 (42 U.S.C. 2201); sec. 201, as amended, Pub. L. 93-438, 88 Stat. 1243 (42 U.S.C. 5841))

[43 FR 21641, May 19, 1978. Redesignated and amended at 49 FR 47204, Dec. 3, 1984. Further redesignated at 55 FR 30450, July 26, 1990; 58 FR 13005, Mar. 9, 1993; 61 FR 35603, July 8, 1996]

Need assistance?