be very low. The magnitude of risk of childhood cancer following in utero exposure is uncertain in that bothnegative and positive studies have been reported. The data from these studies 'ar e consistent with a lifetime cancer risk resulting from exposureduring gestation which is twotothreetimesthat for theadult ' (NCRPReport No. 116, Ref. 2). The NRC has reviewed the available scientific literature and has concluded that the 0.5 rem(5mSv)limitspecified in 10CFR20.1208 provides anadequatemarginofprotection for theembryo/fetus. This dose limit reflects the desire to limit the total lifetime risk of leukemia and other cancers associated with radiation exposure during pregnancy. In order for a pregnant worker to take advantage of the lower exposure limit and dose monitoring provisions specified in 10 CFRPart20,thewomanmustdeclareherpregnancyinwritingtothelicensee.Aformletter for declaring pregnancy is provided in this guide or the licensee may use its own form letter for declaring pregnancy. A separate written declaration should be submitted for each pregnancy.

########## 9. REGULATORY POSITION WhoShould Receive Instruction

Female workers who require training under 10CFR 19.12 should be provided with the information containedinthisguide. InadditiontotheinformationcontainedinRegulatoryGuide8.29(Ref.1),thisinformation may be included as part of the training required under 10 CFR 19.12.

########## Providing Instruction

The occupational worker maybegiven a copy ofthis guide withits Appendix, anexplanation ofthecontents of the guide, andanopportunity to ask questions and request additional information. The information in this guide and Appendix should also be provided to any worker or supervisor who may be affected by a declaration of pregnancy or whomay have to take some action in response to such a declaration.

Classroom instruction may supplement the written information. If the licensee provides classroominstruction, the instructor should have some knowledge of the biological effects of radiation to be able to answerquestions that maygo beyond the information provided in this guide. Videotaped presentations may be used for classroom instruction. Regardless of whether the licensee provides classroom training, the licensee should give workerstheopportunitytoaskquestions aboutinformationcontainedinthisRegulatoryGuide 8.13. Thelicensee maytake credit for instruction that the worker has received within the past year at other licensed facilities or in other courses or training.

########## Licensee's Policy on Declared Pregnant Women

The instruction provided should describe thelicensee's specific policy ondeclaredpregnant women,including how those policies may affect a woman's work situation. In particular, the instruction should include a description of the licensee's policies, if any, that may affect the declared pregnant woman's work situation after she has filed a written declaration of pregnancy consistent with 10 CFR 20.1208. The instruction should also identify whoto contact for additional information as well asidentifywhoshould receive the written declaration of pregnancy. The recipient of the woman's declaration may be identified byname(e.g.,JohnSmith), position (e.g., immediatesupervisor,theradiationsafetyofficer), ordepartment(e.g., the personnel department).

########## Duration of Lower Dose Limits for the Embryo/Fetus

The lower dose limit for the embryo/fetus should remain in effect until the woman withdraws the declaration in writing or the womanis no longer pregnant. If a declaration of pregnancy is withdrawn, the doselimit for the embryo/fetus would apply only to the time from the estimated date of conception until the time thedeclarationis withdrawn. If the declaration is not withdrawn, the written declaration may be considered expired one year after submission.

########## Substantial Variations Above a Uniform Monthly Dose Rate

According to 10 CFR 20.1208(b), 'Th e licensee shall make efforts to avoid substantial variation above a uniform monthly exposure rate to a declared pregnant woman so as to satisfy the limit in paragraph (a) of this section, ' that is, 0.5 rem (5 mSv) to the embryo/fetus. The National Council on Radiation Protection andMeasurements(NCRP) recommendsa