U.S. Nuclear Regulatory Commission
Question 406: Regulatory Guide 8.36, "Radiation Dose to the Embryo / Fetus," (Section C.1.3) states that "the determination of external dose should include all occupational exposures of the declared pregnant worker since the estimated date of conception."
(a) If declared pregnant worker has received occupational dose during this pregnancy while working for a previous licensee, is it intended that the dose from the previous licensee be obtained and included in estimating and limiting the embryo / fetus dose for the gestation period?
(b) If this is the intention, what should be done if applicable dose records are not available because the worker had not declared pregnancy or was not monitored (i.e., was not likely to exceed 10% of a limit) at her previous workplace?
(c) In the absence of other data, should the previous dose be assumed to be zero?
(b) The licensee should make an effort to make a reasonable estimate of the dose using other information that the worker and her previous employer have concerning her exposure. Even when the worker was not monitored, a well-trained worker and her employer should be able to provide some information concerning her exposure.
(c) No. Neither should it be assumed to be the maximum possible dose. See answer to question (b).
(Reference: Regulatory Guide 8.36).