U.S. Nuclear Regulatory Commission

Question 130: 10 CFR 20.1603 (a), Footnote 2, exempts a

nuclear power plant from the requirements of �.1603

unless a non-self-shielded irradiator is used at the

reactor. (a) If the source used for the calibration of

high-radiation instruments is non-self-shielded, and the

absorbed dose at 1 meter distance could exceed 500 rads in

1 hour, is the source an irradiator? b) Do the provisions

of �.1603 (a) apply?

Answer: (a) No. An "irradiator," as the term is used in

10 CFR 20.1603, uses gamma radiation to irradiate products

to change their characteristics in some way (55 FR 50008,

12/4/90, Licenses and Radiation Safety Requirements for

Large Irradiators, proposed 10 CFR Part 36). A radioactive

source used for calibrating radiation survey instruments is

not an "irradiator."

b) No. However, the provisions of 10 CFR 20.1602 would

apply. (Reference: 10 CFR 20.1603).