Regulations last checked for updates: May 16, 2024

Title 10 - Energy last revised: May 07, 2024
§ 840.4 - Criterion I—Substantial discharge of radioactive material or substantial radiation levels offsite.

DOE will determine that there has been a substantial discharge or dispersal of radioactive material offsite, or that there have been substantial levels of radiation offsite, when as a result of an event comprised of one or more related happenings, radioactive material is released from its intended place of confinement or radiation levels occur offsite and either of the following findings are also made:

(a) DOE finds that one or more persons offsite were, could have been, or might be exposed to radiation or to radioactive material, resulting in a dose or in a projected dose in excess of one of the levels in the following table:

Total Projected Radiation Doses

Critical organ Dose (rems)
Thyroid30
Whole Body20
Bone Marrow20
Skin60
Other organs or tissues30

Exposures from the following types of sources of radiation shall be included:

(1) Radiation from sources external to the body;

(2) Radioactive material that may be taken into the body from its occurrence in air or water; and

(3) Radioactive material that may be taken into the body from its occurrence in food or on terrestrial surfaces.

(b) DOE finds that—

(1) Surface contamination of at least a total of any 100 square meters of offsite property has occurred as the result of a release of radioactive material from a production or utilization facility or device and such contamination is characterized by levels of radiation in excess of one of the values listed in column 1 or column 2 of the following table, or

(2) Surface contamination of any offsite property has occurred as the result of a release of radioactive material in the course of transportation and such contamination is characterized by levels of radiation in excess of one of the values listed in column 2 of the following table:

Total Surface Contamination Levels 1

Type of emitter Column 1—Offsite property 2 Column 2—Other offsite property
Alpha emission from transuranic isotopes3.5 microcuries per square meter0.35 microcuries per square meter.
Alpha emission from isotopes other than transuranic isotopes35 microcuries per square meter3.5 microcuries per square meter.
Beta or gamma emission40 millirads/hour 1 cm (measured through not more than 7 milligrams per square centimeter of total absorber)4 millirads/hour 1 cm (measured through not more than 7 milligrams per square centimeter of total absorber).

1 The maximum levels (above background), observed or projected, 8 or more hours after initial deposition.

2 Contiguous to site, owned or leased by person with whom an indemnity agreement is executed.

[49 FR 21473, May 21, 1984; 49 FR 24374, June 13, 1984]
authority: Sec. 161 of the Atomic Energy Act of 1954, Pub. L. 83-703, 68 Stat. 919 (42 U.S.C. 2201); sec. 170 of the Atomic Energy Act of 1954, Pub. L. 85-256, 71 Stat. 576, as amended by Pub. L. 89-645, 80 Stat. 891 (42 U.S.C. 2210); Department of Energy Organization Act, Pub. L. 95-91, 91 Stat. 565-613 (42 U.S.C. 7101-7352)
source: 49 FR 21473, May 21, 1984, unless otherwise noted.
cite as: 10 CFR 840.4