monthly equivalent dose limit of 0.05 rem (0.5 mSv)tothe embryo/fetus once the pregnancyisknown (Ref. 2). In view of theNCRPrecommendation,any monthlydoseofless than 0.1 rem(1mSv)maybeconsideredasnotasubstantialvariation aboveauniform monthly dose rate andassuchwill not require licensee justification. However, a monthly dose greater than 0.1 rem (1 mSv) should be justified by the licensee.

########## IMPLEMENTATION The purpose of this section is to provide information to licensees and applicants regarding the NRCstaff's plans for using this regulatory guide.

Unless a licensee or an applicant proposes an acceptable alternative methodforcomplyingwiththespecified portions of the NRC's regulations, the methods described in this guide will be used by the NRC staff in the evaluation of instructions to workers on the radiation exposure of pregnant women.

########## REFERENCES USNRC, 'Instructio n Concerning Risks fromOccupational Radiation Exposure, ' Regulatory Guide 8.29, Revision 1, February 1996. National Council on Radiation Protection and Measurements, Limitation of Exposure to Ionizing Radiation , NCRP Report No. 116, Bethesda, MD, 1993.

########## APPENDIX QUESTIONS AND ANSWERS CONCERNING PRENATAL RADIATION EXPOSURE Why amI receiving this information?

The NRC's regulations (in 10CFR 19.12, 'Instruction s to Workers' ) require that licensees instruct individuals workingwith licensed radioactivematerialsin radiationprotectionasappropriateforthesituation. The instruction below describes information that occupational workers and their supervisors should knowabout the radiation exposure of the embryo/fetus of pregnant women. The regulations allow a pregnant woman to decide whether she wants to formally declare her pregnancyto take advantage of lower dose limits for the embryo/fetus. This instruction provides information tohelp women make an informed decision whether to declare a pregnancy.

########## If I become pregnant, amI required to declare my pregnancy?

No. Thechoicewhethertodeclareyourpregnancyiscompletelyvoluntary.Ifyouchoosetodeclareyour pregnancy,you mustdosoinwritingandalowerradiation doselimit will apply toyour embryo/fetus. If youchoosenottodeclareyour pregnancy,youandyourembryo/fetuswillcontinuetobesubjecttothesameradiationdose limits that apply to other occupational workers.

########## If I declare my pregnancy in writing, what happens?

If you choose to declare your pregnancyinwriting, thelicensee musttake measurestolimit thedoseto your embryo/fetus to 0.5 rem (5 millisievert) during the entire pregnancy. This is one-tenth of the dose that anoccupational worker may receive in a year. If you have already received a dose exceeding 0.5 rem (5 mSv) in the period betweenconceptionandthe declaration ofyourpregnancy,anadditionaldoseof 0.05 rem(0.5 mSv) i s allowed during the remainder of the pregnancy. In addition, 10 CFR 20.1208, 'Dos e to an Embryo/Fetus,' requires licensees to make efforts to avoid substantial variation above auniform monthly dose rate so that all the 0.5 rem (5 mSv) allowed dose does not occur in a short period during the pregnancy. This may mean that, if you declare your pregnancy, the licensee may not permit you to do some ofyour normal job