United States Nuclear Regulatory Commission - Protecting People and the Environment

U.S. Nuclear Regulatory Commission

Question 205: (a) 10 CFR 20.1301 (a) (2) requires that

the dose in any unrestricted area from external sources

does not exceed 2 millirem "in any one hour." Since this

is not an instantaneous limit, can the licensee operate at

levels much higher than 2 millirem per hour for a very

short period of time (e.g., 90 millirem /hr for 1 minute,

then no dose for the rest of the hour)? (b) If so, how is

the 2 mrem in any one hour inspectable?

Answer: General response: This requirement in 10 CFR

20.1301 (a) (2) is not new. It is essentially the same as

the requirement in 10 CFR 20.105 (b) (1). Specific

response: (a) Yes.

(b) The licensee must be able to demonstrate compliance

with the dose limits of 10 CFR 20.1301 and the survey

requirements of 10 CFR 20.1501. If an inspector identifies

areas where the radiation levels may be in excess of 2 mrem

in any one hour and the licensee is unable to demonstrate

compliance with the dose limits for an unrestricted area

and with the survey requirements, the licensee may be

cited. (Reference: 10 CFR 20.1301, 10 CFR 20.1501)

Page Last Reviewed/Updated Thursday, March 29, 2012