Code of Federal Regulations (alpha)

CFR /  Title 10  /  Part 140  /  Sec. 140.84 Criterion I--Substantial discharge of radioactive material

The Commission 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) The Commission 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)------------------------------------------------------------------------Thyroid.................................................... 30Whole body................................................. 20Bone marrow................................................ 20Skin....................................................... 60Other organs or tissues.................................... 30------------------------------------------------------------------------ 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) The Commission 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 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\------------------------------------------------------------------------

Column 1 Offsite

property,

contiguous to

site, owned or

Type of emitter leased by person Column 2 Other

with whom an offsite property

indemnity

agreement is

executed------------------------------------------------------------------------Alpha emission from transuranic 3.5 microcuries 0.35 microcuries

isotopes. per square meter. per square meter.Alpha emission from isotopes 35 microcuries per 3.5 microcuries

other than transuranic isotopes. square meter. per square meter.Beta or gamma mission........... 40 millirads/hour 4 millirads/hour @

@ 1 cm.\2\. 1 cm.\2\------------------------------------------------------------------------\1\ The maximum levels (above background), observed or projected, 8 or

more hours after initial deposition.\2\ Measured through not more than 7 milligrams per square centimeter of

total absorber. [33 FR 15999, Oct. 31, 1968, as amended at 40 FR 8794, Mar. 3, 1975]