U.S. Nuclear Regulatory Commission

Question 9: A licensee monitors a worker for both external

and internal exposure under §20.1502, but the internal

exposure for the year is less than 10% of the dose limit.

Does the licensee add it to the external exposure?

Answer: If both internal and external doses were required

to be monitored (see 10 CFR 20.1502 for these

requirements), then they must be summed. If only the

internal or external dose required monitoring, then they

don't have to be summed. (References: 10 CFR 20.1202, 10

CFR 20.1502)