ML003739328

Draft Regulatory Guide DG-8011, for Comment, Radiation Dose to the Embryo/Fetus

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U.S. NUCLEAR REGULATORY COMMISSION OUAR February 1992

• i* OFFICE OF S-0 NUCLEAR REGULATORY RESEARCH Division 8 STask DG-8011 0 DRAFT REGULATORY GUIDE N.0

Contact:

S. S. Yaniv (301)492-3744 DRAFT REGULATORY GUIDE DG-8011 RADIATION DOSE TO THE EMBRYO/FETUS A. INTRODUCTION Section 20.1208 of 10 CFR Part 20, "Standards for Protection Against Radiation," requires that each licensee ensure that the dose to a mbryo/fetus during the entire pregnancy, from occupational exposure of a declared pregnant woman, does not exceed 0.5 rem (5 mSv). Paragraph 20.1208_, ires the licensee to make efforts to avoid substantial variation above a iunform monthly exposure rate to a declared pregnant woman that would sf the 0.5 rem limit.

The dose to the embryo/fetus is to. be the sum of ( the deep-dose equivalent to the declared pregnant woman (10 CFR 20.1208(c)(1)), ..d 2) the dose to the embryo/fetus from radionuclides 'inthe embry feu'ad radionuclides in the declared pregnant woman (10 CFR 20.1208( )(2)).

This guide is being developed to .... deguidance on calculating the radiation dose to the embryo/fetus .

Any information collection atvities mentioned in this draft regulatory guide are contained as requi ents in 10 CFR Part 20, which provides the regulatory basis for this guide..The information collection requirements in 10 CFR Part 20 have been cleared under OMB Clearance No. 3150-0014.

B. DISCUSSION Revi*ion 2 of Regulatory Guide 8.13, "Instruction Concerning Prenatal Radiation Exposure," provides instructions concerning prenatal radiation exposure.

Its main purpose is to ensure that workers are informed of the increased This regulatory guide is being issued in draft form to involve the public in the early stages of the develop ment of a regulatory position in this area. It has not received complete staff review and does not represent an official NRC staff position.

Public comments are being solicited on the draft guide (including any implementation schedule) and its associ ated regulatory analysis or value/impact statement. Comments should be accompanied by appropriate supporting data. Written comments may be submitted to the Regulatory Publications Branch, DFIPS, Office of Administra tion, U.S. Nuclear Regulatory Commission, Washington, DC 20555. Copies of comments received may be examined at the NRC Public Document Room, 2120 L Street NW., Washington, DC. Comments will be most helpful if received by May 4, 1992.

Requests for single copies of draft guides (which may be reproduced) or for placement on an automatic distri bution list for single copies of future draft guides in specific divisions should be made in writing to the U.S. Nuclear Regulatory Commission, Washington, DC 20555, Attention: Office of Administration, Distribution and Mail Services Section.

radiosensitivity of the embryo/fetus. The mammalian embryo/fetus is more susceptible to radiation injury than is the adult. The stage of gestation at exposure and the rate at which radiation is delivered affect the nature and severity of the induced effects. In the first 8 to 15 weeks of pregnancy, the fetus is most sensitive to radiation. The primary effects from radiation during this period are seen in the central nervous system. This stage includes the time period in which a woman might be unaware of her pregnancy.

The 1987 report by the National Council on Radiation Protection and Measurements (NCRP), "Recommendations on Limits for Exposure to Ionizing Radiation" (Ref. 1), recommends a total dose equivalent limit of 0.5 rem for the embryo/fetus, with a further limitation of 0.05 rem per month once the pregnancy becomes known. The 1987 Federal radiation protection guidance for occupational exposure (Ref. 2) specifies a dose equivalent limit of 0.5 rem to the unborn child during the entire gestation period if the pregnancy has been declared by the mother. The Federal guidance also recommends that substantial variations in the monthly rate of exposure be avoided. The limits in 10 CFR 20.1208 adopt both the recommended dose equivalent limit and the guidance on variations in the monthly rate of exposure.

Calculating the radiation dose to the embryo/fetus from internally deposited radionuclides requires quantitative information about maternal radionuclide intake, placental transfer and kinetics, and resulting embryo/

fetus radionuclide concentrations. Intakes of radioactive material occurring prior to the pregnancy may also be important if these materials remain in the pregnant woman during all or part of the gestation period. Transfer kinetics from the mother to the embryo/fetus are modelled as a function of stage of pregnancy, route of intake by the pregnant woman, and time after intake. The stage of gestation (or fetal development) is an important parameter in esti mating radionuclide concentrations in the embryo/fetus. The geometry of the embryo/fetus (i.e., organ size and weight) affects the radionuclide dosimetry.

It is recognized that calculation of prenatal radiation doses from internally deposited radionuclides has many associated difficulties, including a lack of quantitative information about prenatal radionuclide concentrations and transfer across the placenta. The International Commission on Radiologi cal Protection (ICRP) in Publication 56 (Ref. 3) stated that, for most radio nuclides, preliminary estimates from dosimetric and biokinetic models indicate that the dose to the embryo can be approximated by the dose to the uterus.

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The dose to the fetus is dependent upon the activity present in both fetal and maternal tissues. ICRP Publication 56 (Ref. 3) also states that, for most radionuclides, the dose to fetal tissue will be similar to or less than the dose to the corresponding maternal tissues.

The current methods available for assessing the radiation dose to the human embryo/fetus from internally deposited radioactive materials in the pregnant woman are subject to a number of uncertainties. NUREG/CR-5631, "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose Interim Recommendations" (Ref. 4), provides recommendations and methods for estimating the radiation doses to the embryo/fetus from internal radionu clides. In NUREG/CR-5631, a number of radionuclides were evaluated. To expedite efforts, the initial evaluation was directed to those radionuclides that were expected to be of greatest significance for prenatal exposure in the work environment. The radionuclides that were identified and included were 3H, 14C, 57C0' 58C0, 6°C0 , 89Sr, 90St, 106 Ru 1251, 1311, 1321, 1331, 1341, 1351, 134Cs, 13 7 Cs, 233 u, 23 4 u, 235u, 238u, 238pu, 239pu, and 24 1Am. The methods of NUREG/CR 5631 are considered interim as efforts continue to further develop the bases and calculational methods for estimating prenatal radiation doses. The details of the data and bases for determining the dosimetric features used in NUREG/CR-5631 can be found in Reference 4.

It is expected that the embryo/fetus dose assessment methods will evolve over the next several years as more research is conducted in this area. As additional research is conducted, better estimates of actual embryo/fetus doses resulting from the exposure of the declared pregnant woman will be pos sible. For internal doses, research that categorizes the degree of placental transfer, the resulting embryo/fetus/placenta concentrations, and the poten tial radiation exposures of the embryo/fetus from radionuclides in their more usual chemical forms should simplify assessment of the dose to the embryo/

fetus based on the maternal exposure. The ICRP is considering the formulation of dose assessment methods specific for the embryo/fetus. Because of the developing scientific information, the NRC staff seeks detailed technical comments on the utility or difficulty of the methodologies presented in this guide on determination of the dose to the embryo/fetus.

This regulatory guide provides a means for licensees to determine when the dose to the embryo/fetus needs to be evaluated. For internal exposure, a simplified approach and a more detailed methodology are presented for conduct ing dose evaluation. This guide provides guidance on threshold criteria for 3

when the dose to the embryo/fetus needs to be determined in Regulatory Posi tion 1. Regulatory Position 2 presents a simplified approach for estimating the dose to the embryo/fetus from intakes by the declared pregnant woman.

Regulatory Position 3 provides an alternative, more detailed methodology for a limited number of radionuclides, utilizing the gestation time-dependent dosimetric data from NUREG/CR-5631 (Ref. 4). A graded approach to determining when to evaluate, with both a simple and more detailed dose assessment method ology, is provided. It is recognized that some licensees will only need to demonstrate that the dose to the embryo/fetus is not likely to exceed the monitoring threshold of 10 CFR 20.1502, while other licensees may need to determine an embryo/fetus dose for demonstrating compliance with the dose limit of 10 CFR 20.1208 and the recordkeeping requirements of 10 CFR 20.2106(e).

The total radiation dose to the embryo/fetus is limited by placing more stringent restrictions on the exposure of the declared pregnant woman than on other members of the occupational work force. As specified in 10 CFR 20.1208(a), the dose to the embryo/fetus from occupational exposure of the declared pregnant woman must not exceed 0.5 rem. In addition, the licensee is required to make efforts such that the maximum dose rate does not vary markedly from a uniform monthly rate throughout the period of gestation. If the dose to the embryo/fetus is found to have exceeded 0.5 rem, or is within 0.05 rem of this dose, by the time the woman declares the pregnancy to the licensee, the licensee is required to limit the additional dose to the em bryo/fetus to 0.05 rem during the remainder of the pregnancy.

Guidance on monitoring requirements and methods for summation of internal and external occupational doses needed for demonstrating compliance with the dose limits of 10 CFR 20.1208 is being developed in a separate regulatory guide.

C. REGULATORY POSITION

1. CRITERIA FOR DETERMINING DOSE TO THE EMBRYO/FETUS 1.1 Monitoring The dose equivalent to the embryo/fetus should be determined based on the monitoring of the declared pregnant woman as required by 10 CFR 20.1502. This 4

dose determination is not required when monitoring of the declared pregnant woman is not required.

External monitoring of the declared pregnant woman should be performed for determining the external dose to the embryo/fetus if the declared pregnant woman is likely to receive a deep-dose equivalent in excess of 0.05 rem for the entire gestation period.

Monitoring the intake of radionuclides by the declared pregnant woman should be performed for determining an internal dose to the embryo/fetus if the intakes by the declared pregnant woman are likely to exceed 1% of the stochastic ALIs during the gestation period. According to 10 CFR 20.1502(b)(2), the licensee must monitor the occupational intakes of radio active material for the declared pregnant woman if her intake is likely to exceed, in 1 year, a committed effective dose equivalent in excess of 0.05 rem (0.5 Msv). The position that the dose to the embryo/fetus be determined if the intake exceeds 1% of ALI is based on this same threshold. This threshold will ensure that any potentially significant exposures to the embryo/fetus are evaluated and, as appropriate, doses are determined.

1.2 Evaluation of Dose to the Embryo/Fetus The dose to the embryo/fetus should be evaluated by determining the embryo/fetus dose equivalent for the duration of the pregnancy. An assessment of the 50-year committed dose is not required. Also, it is not appropriate to use effective dose equivalent or committed effective dose equivalent. (Note:

the committed dose equivalent to the uterus may be applied to the embryo/fetus under certain conditions as a simplified approach as specified in Regulatory Position 2.)

1.3 External Dose to the Embryo/Fetus As specified in 10 CFR 20.1208(c)(I), the external dose to the embryo/

fetus is to be taken to be equal to the deep dose equivalent to the declared pregnant woman. The external dose should consider all occupational exposures of the declared pregnant woman since the estimated date of conception. The deep-dose equivalent that should be assigned is that dose that would be most representative of the exposure of the embryo/fetus (e.g., in the lower torso region). If multiple measurements have been made, assignment of the highest 5

deep-dose equivalent for the declared pregnant woman to the embryo/fetus is not required unless that dose is also the most representative deep-dose equivalent for the region of the embryo/fetus.

1.4 Internal Dose to the Embryo/Fetus The internal dose to the embryo/fetus should consider the exposure to the embryo/fetus from radionuclides in the declared pregnant woman and in the embryo/fetus. The intake for the declared pregnant woman should be determined using the air sample data, bioassay data, or a combination of the two. Guid ance on bioassay measurements used to quantify intake is being developed and has been issued for public comment as Draft Regulatory Guide DG-8009, "Inter pretation of Bioassay Measurements." As appropriate, multiple bioassay meas urements should be taken to ensure a better estimate of intake. Air sample data may be used to determine the intake. Specific guidance on workplace air sampling is being developed and has been issued for public comment as DG-8003, "Air Sampling in the Workplace."

1.5 Evaluating Continuous Exposure For continuous or near continuous exposure to radioactive material that may be inhaled or ingested, the cumulative intake should be quantified at least every 30 days. If significant variation in the exposure levels may have occurred, the time interval for quantifying the intake should be reduced. A more frequent evaluation should also be performed if the potential dose to the embryo/fetus exceeds 25 mrem per 30-day period. If continued over a 9-month gestation period, 25 mrem in a 30-day period would approach 1/2 of the total gestation dose limit from internal exposure alone. The methods presented in Regulatory Positions 2 or 3 should be used for evaluating this potential dose.

1.6 Existing Maternal Body Burdens Maternal body burdens resulting from internal exposures prior to concep tion should be included in determining the embryo/fetus dose. The contribu tion to the embryo/fetus dose from a maternal burden existing at the time of conception should be evaluated if the maternal burden at the time of pregnancy exceeds 1% of the radionuclide's stochastic ALl value for the appropriate mode 6

of intake and class (for inhalation intakes). Only body burdens existing at the time of conception need to be considered in evaluating this threshold; radioactive material already eliminated from the body should not be included.

This threshold of 1% ALl provides a simplified approach for determining when pre-existing body burdens should be evaluated. At this threshold, it is unlikely that any resultant dose to the embryo/fetus would be significant (i.e., greater than 10% of the 0.5 rem limit). As an alternative, the dose assessment methods presented in Regulatory Position 3 of this guide may be used for determining whether a pre-existing body burden represents a poten tially significant dose (i.e., greater than 0.05 rem). Any dose greater than 0.05 rem should be included in the determination of the total dose to the embryo/fetus.

2. SIMPLIFIED METHOD FOR DETERMINING EMBRYO/FETUS DOSE FROM MATERNAL INTAKES The determination of the dose to the embryo/fetus from the intake of radioactive material by the pregnant woman should be based on the best avail able scientific data. For most radionuclides, the dose to the fetal tissue will be similar to or less than the dose to the corresponding maternal tissue (Ref. 3). However, the data in NUREG/CR-5631 (Ref. 4) indicate that the embryo/fetus dose may be significantly different for some radionuclides, either greater than or less than the dose to the uterus.

Based on these premises (uterus dose similar to fetal dose and the NUREG/CR-5631 data), a set of dose factors have been developed for use in cal culating an embryo/fetus dose. Except for those radionuclides addressed in NUREG/CR-5631 (Ref. 4), the dose factors presented in Appendix A to this guide represent the committed dose equivalent to the uterus per introduction of unit 1

blood) of the woman.

activity into the first transfer compartment (i.e.,

For the radionuclides in NUREG/CR-5631, the dose factors in Appendix A repre sent the maximum dose equivalent to the embryo/fetus for the gestation period

'The uterus committed dose equivalent factors presented in Appendix A were calculated based on the modeling employed during the development of the ICRP 30 (Ref. 5) data. It is recognized that the metabolism of the pregnant woman may not be adequately represented by the standard metabolic model.

However, partly because of the lack of more definitive data, this modeling has been used for determining the uterine dose commitment factors that may be used for evaluating compliance with the embryo/fetus dose limit.

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from the introduction of unit activity into the first transfer compartment of the woman at any time during the gestation period.

The dose limit for the embryo/fetus is expressed as a 9-month gestation dose equivalent. Particularly for certain radionuclides with both long radio logical half-lives and long-term biological retention, the committed dose equivalent to the uterus may be significantly different than a 9-month ges tation dose equivalent to the embryo/fetus. Several radionuclides of this type have been evaluated in NUREG/CR-5631 (Ref. 4), and data have been devel oped for calculating an embryo/fetus gestation dose instead of using the com mitted dose equivalent to the uterus. The methodology of NUREG/CR-5631 may be used for evaluating other radionuclides with long radiological half-lives and long-term biological retention.

For demonstrating compliance with the dose limits of 10 CFR 20.1208, the dose factors in Appendix A may be used for approximating the embryo/fetus dose equivalent for the entire gestation period.

The steps for determining the embryo/fetus dose, using the simplified method, are as follows.

2.1 The calculation of the embryo/fetus dose should include the intakes by the declared pregnant woman at any time during the gestation period.

2.2 For ingested radionuclides, determine the activity uptake by the first transfer compartment (blood) by multiplying the intake by the appropri ate uptake factor (fl) from Appendix B (adapted from Federal Guidance Report No. 11, Table 3 (Ref. 6)). The uptake factor, fl, is the fraction of an ingested compound of a radionuclide that is transferred into the first trans fer compartment (i.e., blood uptake fraction).

2.3 For inhaled radionuclides, determining the fraction of initial intake that is transferred to the blood involves an evaluation of the deposi tion in the three compartments of the lung and the subsequent time-dependent transfer to the body fluids and to the GI tract. Unless it is known other wise, it should be assumed that the transfer from the lung to body fluids and from lung to GI tract to body fluids follows the ICRP 30 (Ref. 5) modeling (which is the basis for this guide).

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2.4 The total uptake into the blood from the maternal intake is assumed to be instantaneous. For radionuclides with lung clearance class of W (10- to 100-day half-life clearance) or Y (greater than 100-day half-life clearance),

the actual translocation from the lung and uptake in the blood may occur over a time period that exceeds the gestation period. Clearance from the lung may take up to several years. All the initially deposited material is not imme diately available for uptake by the first transfer compartment (blood). For simplicity and conservatism in the modeling, an instantaneous transfer should be assumed for use with the dose factor data in Appendix A. However, an incremental transfer from the lung to the blood may be assessed based on the lung model as described in ICRP Publications 30 and 19 (Refs. 5 and 7).2 The following Table 1, adapted from the data in Figure 5.2 of ICRP 30 (Ref. 5), may be used for determining the total transfer from the lung to the first transfer compartment (i.e., blood).

Table I Fractional Transfer of Inhaled Activity to First Transfer Compartment Class Transfer Fraction D 0.48 + 0.15 f, W 0.12 + 0.51 f, Y 0.05 + 0.58 f, 2.5 For pre-existing body burdens, the total burden determined to exist at time of pregnancy should be assumed to be available for uptake in the blood of the woman. Transfer should be assumed to occur during the first month of pregnancy.

This method provides a simplified approach for evaluating the signifi a

cance of pre-existing conditions. If the embryo/fetus is likely to receive 2As modeled in ICRP Publications 19 and 30, the clearance from the different lung compartments is assumed to follow first-order kinetics. This approach is complex, involving interlinking differential equations, and is considered outside the scope of a routine operational health physics program.

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dose in excess of 25% of the limit from pre-existing burdens (i.e., greater than 125 mrem), more detailed modeling should be considered. 3 2.6 Based on the determination of the maternal intake, the dose to the embryo/fetus for the entire gestation period should be calculated using the following equations:

INGESTION INTAKES DE =

• Ai x f,, i x DF1 Equation 1 INHALATION INTAKES DE= Ai x FTi x DF Equation 2 where:

DE dose equivalent to the embryo/fetus for the entire gestation period from the acute intakes of all radionuclides during the gestation period (rems)

Ai= intake of radionuclide i by the declared pregnant woman at any time during the gestation period (ACi)

DFj = dose factor for use in approximating the dose equivalent to the embryo/fetus for the entire gestation period from the introduc tion of unit activity (I 4Ci) into the maternal blood at any time during the gestation period, from tabular data presented in Ap pendix A to this guide (rem/MCi in maternal blood) fj'= the fraction of radionuclide i reaching the body fluids following ingestion (i.e., the fraction of ingested activity of radionu clide i that enters the blood), from data presented in Appendix B to this guide 3 The inaccuracy of the above simplified approaches for evaluating pre-existing body burdens is recognized. The methods are presented as simplified ap proaches with reasonable assurance that actual dose to the embryo/fetus from existing body burdens will not be significantly underestimated. More de tailed evaluations may be needed for very unusual circumstances where pre existing body burdens may present a significant source of exposure to the embryo/fetus. Such a situation is thought to be unlikely, although not impossible. An evaluation of this nature should be conducted by individuals knowledgeable in the area of internal dosimetry. Such a detailed evaluation could consider the element retention functions as presented in ICRP Publica tions 30 and 54 (Refs. 5 and 8). Also, an application of the modeling pre sented in NUREG/CR-5631 (Ref. 4) could be applied. The details of this type of an evaluation are beyond the types of analyses that are considered rou tinely required and, as such, are outside the scope of this guide.

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FTi = fractional transfer of inhaled activity to the first transfer compartment (i.e., the fraction of inhaled activity of radionu clide i that enters the blood, see Table 1 of this guide).

2.7 Doses from multiple nuclides or multiple intakes should be evaluated on a frequency corresponding to the determination of intake (i.e., at least once every 30 days). Multiple dose determinations should be added to deter mine the total dose. Doses may need to be reevaluated if better estimates of intakes are provided by follow-up bioassay measurements.

3. DETERMINING TIME-DEPENDENT EMBRYO/FETUS DOSE USING NUREG/CR-5631 METHODS As an alternative to the simplified methods presented above, a time dependent dose to the embryo/fetus may be calculated for the radionuclides addressed in NUREG/CR-5631 (Ref. 4). NUREG/CR-5631 presents dosimetric meth ods for calculating the dose to the embryo/fetus following the instantaneous introduction of unit activity into the first transfer compartment (blood) of the pregnant woman at successive stages of gestation. These methods include the contribution to the embryo/fetus dose from the resultant body burdens of the declared pregnant woman and from activity in the embryo/fetus resulting from transfer across the placenta. Refer to NUREG/CR-5631 (Ref. 4) for a detailed description of the modeling.

The methods and data of NUREG/CR-5631 (Ref. 4) may be used for determin ing the dose to the embryo/fetus from maternal intakes at successive stages of gestation for the radionuclides 3 H, 14 C, 57 Co, 5 8 Co, 6 0Co, 89 Sr, 9 0 Sr, 106 Ru, 1251, 4 23 5 239 1311, 1321, 1331, 1341, 135i, 34 1 Cs, 137 Cs, 233U, 23 U, U, 238u, 238pu, pu, and 24 1 Am.

The steps for determining the embryo/fetus dose using NUREG/CR-5631 (Ref. 4) methods are as follows.

3.1 The methods presented in Regulatory Positions 2.1 through 2.5 should be used for determining the uptake in the first transfer compartment (blood) of the declared pregnant woman.

3.2 Equations 1 and 2 of Regulatory Position 2.6 may be used for deter mining the embryo/fetus dose with the following clarifications:

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3.2.1 For Equations 1 and 2, the dose factor parameter, DF 1 , should be taken from Appendix C of this guide for the time period representing the time of intake relative to stage of gestation. For using the tabular dose data in calculating the embryo/fetus dose, it may be assumed that all intakes occur ring within any of the 30-day periods of gestation occur at the beginning of that period. 4 The cumulated dose column should be used in order to determine the total dose for the remainder of the gestation period.

3.2.2 The dose factor data in Appendix C of this guide are for an ab sorbed dose (in rads) from introduction of 1 MCi of the radionuclide into the first transfer compartment (blood) of the woman at the beginning of the specified month of gestation. To convert from an absorbed dose (rad) to a dose equivalent (rem), the data in Appendix C should be multiplied by the appropriate quality factor from Table 1004(b).1 of 10 CFR Part 20. For 3 H, 14C, 57C°' 58C°' 60C°' 89Sr, 90Sr, 106Ru, 1251, 1311, 1321, 1331, 1341, 1351, 134Cs and 137Cs, a quality factor of 1 should be applied.

For 233U, 234 U, 235 U, 238 U, 238pu, 239Pu, and 241Am, a quality factor of 20 should be applied, recognizing that most of the embryo/fetus dose results from the alpha activity.

3.2.3 For existing body burdens, the uptake in the blood should be considered to occur during the first month of pregnancy for the purpose of evaluating the dose to the embryo/fetus. Alternatively, time-dependent release kinetics may be used for calculating that fraction of the body burden that is translocated to the blood through the duration of the pregnancy. The time-dependent release is described in ICRP Publications 30 and 54 (Refs. 5 and 8). This approach is complex, involving interlinking differential equa tions, and is considered outside the scope of a routine health physics pro gram.

3.3 Doses from multiple nuclides and multiple intakes should be evaluat ed with a frequency corresponding to the intake (i.e., at least once every 30 days). Multiple dose determinations should be added to determine the total 4The correlation of intake to actual stage of gestation can only be roughly estimated. For this reason, it is believed that the correlation should be limited to the best estimate of the month of gestation.

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dose. Doses may need to be reevaluated if better estimates of intakes are provided by follow-up bioassay measurements.

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

This draft guide has been released to encourage public participation in its development. Except in those cases in which the applicant or licensee proposes an acceptable alternative method of complying with specified portions of the Commission's regulations, the method to be described in the active guide reflecting public comments will be used in the evaluation of applica tions for new licenses or license renewals and for evaluating compliance with 10 CFR §§20.1001-20.2401.

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REFERENCES

1. National Council on Radiation Protection and Measurements, "Recommenda tions on Limits for Exposure to Ionizing Radiation," Report No. 91, 1987.

2. "Radiation Protection Guidance to Federal Agencies for Occupational Expo sure," Federal Register, page 2822 (52 FR 2822), January 27, 1987.

3. International Commission on Radiological Protection, "Age-Dependent Doses to Members of the Public from Intake of Radionuclides: Part I," ICRP No.

56, Pergamon Press Inc., 1989.

4. M. R. Sikov, R. J. Traub, and H. K. Meznarich, "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose-Interim Recommendations,"

NUREG/CR-5631 (PNL-7445), U.S. Nuclear Regulatory Commission, (in press).

5. International Commission on Radiological Protection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts I through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc.,

1979.

6. K. F. Eckerman, A. B. Wolbarst, and A. C. B. Richardson, "Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion," Environmental Protection Agency, Federal Guidance Report No. 11 (EPA-520/1-88-020), Septem ber 1988.

7. International Commission on Radiological Protection, "The Metabolism of Compounds of Plutonium and other Actinides," ICRP No. 19, Pergamon Press Inc., May 1972.

8. International Commission on Radiological Protection, "Individual Monitor ing for Intake of Radionuclides by Workers: Design and Interpretation,"

ICRP No. 54, Annals of the ICRP, Volume 19, No.1-3, Pergamon Press Inc.,

1988.

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APPENDIX A DOSE EQUIVALENT FACTORS FOR USE IN APPROXIMATING THE EMBRYO/FETUS DOSE FROM RADIONUCLIDES IN MATERNAL BLOOD Except as noted, the dose factors (DFi) presented in Table A-1 represent the committed dose equivalent to the uterus per introduction of unit activity into the first transfer compartment (i.e., blood) of the woman. These entries were calculated from tabulated values of uterine committed dose equivalent per unit intake and fractional absorption (fl) from the gastrointestinal tract using ICRP-30 (Ref. Al) methodology. The DF, dose factors were derived by dividing the committed dose equivalent per unit intake by the fractional absorption factor (fl). These dose factors are based on unit activity in the blood. The most conservative f, (i.e., largest fraction) for each radionu clide has been used for deriving the data in Table A-I.

57Co, 58Co, 6 0Co, 89 Sr, 9 0 Sr, 1 06 Ru, For the radionuclides 3H, 14C, 1251, 34 134 13 7 4 235 239 1311, 1321, 1331, 1 1, 1351, Cs, Cs, 233U, 23 U, U, 238U, 238pu, pu, and 241Am, the dose factors in Table A-i represent the maximum dose equivalent to the embryo/ fetus for the gestation period from the introduction of unit activity into the first transfer compartment of the woman at any time during the gestation period. These entries are based on the modeling of NUREG/CR 5631 (Ref. A2) and are derived from the data tables presented in Appendix C to this guide. The maximum calculated embryo/fetus dose (as presented in the Appendix C tables) from intake by the declared pregnant woman during the gestation period has been used for inclusion in Table A-i.

The dose factor data presented in NUREG/CR-5631 (Ref. A2) are for an absorbed dose expressed in units of rads. To adapt this data as presented in Appendix C of this guide for inclusion in Table A-i, appropriate quality factors have been applied to convert from rads to dose equivalent, expressed in units of rems. For beta and gamma emitting radionuclides, a quality factor of I has been applied. For 2 3 3 U, 2 3 4 U, 2 3 5 U, 23 8 U,

23 8 Pu, 239pu, and 2 4 1Am, a quality factor of 20 has been applied, recognizing that most of the embryo/fetus dose results from the alpha activity.

A-i

TABLE A-1 DOSE EQUIVALENT FACTORS FOR USE IN APPROXIMATING THE EMBRYO/FETUS DOSE FROM RADIONUCLIDES IN MATERNAL BLOOD DFi DFi DFi Nucl ide (rem/pCi) Nucl ide (rem/ACi) Nucl ide (rem/pCi)

H-3 5.87E-05" Cr-51 6.96E-04 Ga-68 5.66E-02 Be-7 1.67E-02 Mn-51 3.65E-04 Ga-70 8.99E-05 Be-l0 1.79E-02 Mn-52 4.70E-02 Ga-72 1.53E+00 C-11 1.21 E-05 Mn-52M 2.80E-04 Ga-73 9.36E-02 C- 14 1.29E-03* Mn-53 5.77E-05 Ge-66 1.42E-04 F-18 1.32E-05 Mn-54 1.86E-02 Ge-67 1.11E-05 Na-22 1.06E-02 Mn-56 2.18E-03 Ge-68 8.81E-04 Na-24 1.21 E-03 Fe-52 1.30E-02 Ge-69 3.02E-04 Mg-28 3.83E-03 Fe-55 3.88E-03 Ge-71 6.99E-06 Al-26 5.33E-01 Fe-59 4.63E-02 Ge-75 1.61E-05 Si-31 3.85E-05 Fe-60 1.47E+00 Ge-77 3.40E-04 Si-32 4.33E-02 Co-55 4.01E-03 Ge-78 1.08E-04 P-32 3.03E-03 Co-56 3.43E-02 As-69 2.46E-05 P-33 4.33E-04 Co-57 2.12E-03* As-70 2.90E-04 S-35 3.53E-04 Co-58 9.17E-03" As-71 1.21E-03 Cl-36 2.96E-03 Co-58M 5.17E-05 As-72 2.70E-03 Cl-38 3.17E-05 Co-60 3.80E-02* As-73 3.02E-04 Cl-39 3.89E-05 Co-60M 4. 12E-07 As-74 2.90E-03 K-40 1.84E-02 Co-61 4.50E-05 As-76 1.11E-03 K-42 7.73E-04 Co-62M 5.33E-05 As-77 1.88E-04 K-43 7.1OE-04 Ni-56 5.39E-02 As-78 1.85E-04 K-44 1.94E-05 Ni-57 3.60E-02 Se-70 1.61E-04 K-45 1.21E-05 Ni-59 2.71E-03 Se-73 3.66E-04 Ca-41 3.21E-05 Ni-63 6.29E-03 Se-73M 3.21E-05 Ca-45 6.61E-04 Ni-65 1.43E-03 Se-75 8.79E-03 Ca-47 5.18E-03 Ni-66 2.81E-03 Se-79 4.19E-03 Sc-43 2.48E+00 Cu-60 9.32E-05 Se-81 1.OOE-06 Sc-44 4.59E+00 Cu-61 2.69E-04 Se-81M 1.46E-05 Sc-44M 2.56E+01 Cu-64 2.09E-04 Se-83 3.62E-05 Sc-46 3.15E+01 Cu-67 6.50E-04 Br-74 3.33E-05 Sc-47 1.86E+00 Zn-62 1.38E-03 Br-74M 6.18E-05 Sc-48 3.52E+01 Zn-63 5.92E-05 Br-75 6.07E-05 Sc-49 4.18E-04 Zn-65 3.49E-02 Br-76 1.20E-03 Ti-44 1.36E+00 Zn-69 3.09E-06 Br-77 3.27E-04 Ti-45 1.54E-02 Zn-69M 5.54E-04 Br-80 3.01E-06 V-47 2.29E-03 Zn-TiM 5.75E-04 Br-80M 1.46E-04 V-48 4.37E-01 Zn-72 5.28E-03 Br-82 1.87E-03 V-49 8.36E-05 Ga-65 9.18E-03 Br-83 2.72E-05 Cr-48 5.77E-03 Ga-66 9.95E-01 Br-84 2.56E-05 Cr-49 3.51E-04 Ga-67 2.50E-01 Rb-79 1.15E-05

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-2

TABLE A-1 (Con't)

DFi DFi DFi Nucli de (rem/pCi) Nucl ide (rem/ACi) Nucl ide (rem/pCi)

Rb-81 8.18E-05 Nb-90 2.39E-01 Rh- 105 1.93E-03 Rb-81M 1.08E-05 Nb-93M 9.29E-04 Rh- 106M 6.86E-03 Rb-82M 3.49E-04 Nb-94 3.04E-01 Rh-107 8.51E-05 Rb-83 7.07E-03 Nb-95 1.24E-01 Pd-100 3.94E-01 Rb-84 1.05E-02 Nb-95M 1.27E-02 Pd-101 3.33E-02 Rb-86 8.14E-03 Nb-96 2.03E-01 Pd-103 1.39E-03 Rb-87 4.22E-03 Nb-97 4.11E-03 Pd-107 7.33E-06 Rb-88 1.02E-05 Nb-98 9.66E-03 Pd- 109 1.27E-03 Rb-89 1.20E-05 Mo-90 7.77E-04 Ag- 102 3.76E-04 Sr-80 3.96E-04 Mo-93 4.36E-04 Ag- 103 8.58E-04 Sr-81 1.22E-04 Mo-93M 4.76E-04 Ag-104 3.05E-03 Sr-82 1.25E-02 Mo-99 9.39E-04 Ag-104M 1.09E-03 Sr-83 2.31E-03 Mo-101 1.48E-05 Ag-105 1.94E-02 Sr-85 4.03E-03 Tc-93 1.33E-04 Ag-106 2.12E-04 Sr-85M 4.81E-05 Tc-93M 4.67E-05 Ag-106M 8.2 1E-02 Sr-87M I.62E-04 Tc-94 4.56E-04 Ag-108M 6.59E-02 Sr-89 1.84E-02" Tc-94M 7.08E-05 Ag-IiOM 1.04E-01 Sr-90 5.22E-02" Tc-95 3.86E-04 Ag-111 1.41E-03 Sr-91 1.49E-03 Tc-95M 1.23E-03 Ag-112 2.18E-03 Sr-92 7.79E-04 Tc-96 2.62E-03 Ag-115 1.98E-04 Y-86 2.18E+01 Tc-96M 2.29E-05 Cd-104 3.30E-03 Y-86M 1.26E+00 Tc-97 4.67E-05 Cd-107 1.95E-04 Y-87 1.01E+01 Tc-97M 2.42E-04 Cd-109 2.12E-02 Y-88 3.96E+01 Tc-98 2.97E-03 Cd-113 2.77E-01 Y-90 4.66E-04 Tc-99 2.79E-04 Cd-i13M 2.55E-01 Y-90M 1.21 E+00 Tc-99M 3.32E-05 Cd-115 9.47E-03 Y-91 6.03E-02 Tc-101 2.96E-06 Cd-115M 1.27E-02 Y-91M 2.13E-01 Tc- 104 2.07E-05 Cd-117 4.23E-03 Y-92 4.81E-01 Ru-94 2.32E-03 Cd-1I7M 9.62E-03 Y-93 4.18E-01 Ru-97 6.89E-03 In-109 7.95E-03 Y-94 1.IOE-01 Ru- 103 1.97E-02 In-i10 4.01E-02 Y-95 3.56E-02 Ru-105 4.09E-03 In-1t0 4.50E-03 Zr-86 8.62E-01 Ru- 106 1.12E-01 In-Ill 3.05E-02 Zr-88 3.87E-01 Rh-99 2.19E-02 In-112 9.47E-05 Zr-89 7.31E-01 Rh-99M 3.51E-03 In-113M 1.24E-03 Zr-93 8.79E-05 Rh-100 3.86E-02 In-114M 3.05E-02 Zr-95 6.16E-01 Rh-101 3.33E-02 In-115 8.99E-01 Zr-97 5.24E-01 Rh-lOIM 9.40E-03 In-115M 2.16E-03 Nb-88 1.17E-03 Rh-102 1.93E-01 In-116M 4.92E-03 Nb-89 1.83E-02 Rh-102M 3.48E-02 In-117 1.22E-03 Nb-89 1 .30E-02 Rh-103M 1.18E-06 In-117M 2.61E-03

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-3

TABLE A-i (Con't)

DFi DFi DFi Nucl ide (rem//iCi) Nuclide (rem/ACi) Nuclide (rem/MCi)

In-119M 1.39E-05 Te-127M 1.82E-03 Ba-131M 1.32E-05 Sn-110 2.11E-02 Te-129 2.35E-05 Ba-133 1 .27E-02 Sn-111 8.81E-04 Te-129M 3.39E-03 Ba- 133M 8.77E-04 Sn-113 2.63E-02 Te- 131 2.18E-04 Ba-135M 7.03E-04 Sn-11TM 1.57E-02 Te-131M 6.64E-03 Ba-139 4.55E-05 Sn-119M 2.29E-03 Te-132 8.57E-03 Ba- 140 1.54E-02 Sn- 121 3.70E-05 Te- 133 3.26E-05 Ba-141 9.47E-05 Sn-121M 5.70E-03 Te-133M 5.48E-04 Ba-142 2.74E-04 Sn-123 6.35E-03 Te-134 3.98E-04 La-131 3.77E-02 Sn-123M 2.48E-04 1-120 9.36E-05 La-132 5.07E-01 Sn-125 2.37E-02 I-120M 8.73E-05 La-135 3.43E-02 Sn-126 2.35E-01 1-121 1.79E-05 La-137 7.55E-02 Sn-127 1.14E-02 1-123 2.27E-05 La- 138 2.84E+00 Sn-128 7.14E-03 1-124 2.16E-04 La- 140 2.32E+00 Sb-115 2.OOE-04 1-125 1. 38E-03" La-141 9.43E-03 Sb-116 1.59E-04 1-126 2.23E-04 La-142 1.91E-01 Sb-116M 1.49E-03 1-128 5.25E-06 La-143 2.85E-03 Sb-117 3.34E-04 1-129 5.11E-04 Ce-134 3.13E+00 Sb-118M 6.59E-03 1-130 2.29E-04 Ce-135 4.44E+00 Sb-119 2.08E-04 1-131 3.64E-03" Ce-137 7.13E-02 Sb-120 3.70E-05 1-132 1. 56E-04* Ce-137M 3.31E-01 Sb-120 3.42E-02 I-132M 6.14E-05 Ce-139 1.15E+00 Sb-122 5.85E-03 1-133 9.04E-04" Ce- 141 5.56E-01 Sb-124 2.98E-02 1-134 4.83E-05* Ce-143 1.05E+00 Sb-124M 4.88E-05 1-135 3.72E-04" Ce-144 3.79E-01 Sb-125 8.51E-03 Cs-125 1.33E-05 Pr-136 4.12E-02 Sb-126 4.37E-02 Cs-127 5.96E-05 Pr-137 1.26E-01 Sb-126M 1.69E-04 Cs-129 2.13E-04 Pr- 138M 9.61E-01 Sb-127 9.66E-03 Cs-130 6.99E-06 Pr-139 1.16E-01 Sb- 128 1.33E-04 Cs-131 2.27E-04 Pr-142 1.36E-01 Sb-128 8.73E-03 Cs-132 2.10E-03 Pr-142M 1. 73E-03 Sb-129 3.36E-03 Cs-134 1.11E-01* Pr-143 4.53E-08 Sb-130 9.40E-04 Cs-134M 2.66E-05 Pr- 144 8.44E-04 Sb-131 3.36E-04 Cs-135 7.07E-03 Pr- 145 1.41E-02 Te-116 1.45E-03 Cs-135M 2.42E-05 Pr-147 1.95E-02 Te-121 4.87E-03 Cs-136 1.42E-02 Nd- 136 3.59E-01 Te-121M 7.90E-03 Cs-137 5.94E-02" Nd-138 8.26E-01 Te-123 3.09E-05 Cs- 138 2.95E-05 Nd-139 4. 11E-02 Te-123M 2.94E-03 Ba- 126 1.14E-03 Nd-139M 1.74E+00 Te-125M 9.75E-04 Ba- 128 1.17E-02 Nd- 141 4.33E-02 Te-127 6.31E-05 Ba- 131 7.40E-03 Nd-147 8.45E-01

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-4

TABLE A-1 (Con't)

DFi DFi DFi Nucl ide (rem/ACi) Nucli de (rem/pCi) Nucli de (rem/#Ci)

Nd-149 1.37E-01 Gd-149 2.47E+00 Tm-166 2.37E+00 Nd-151 2.53E-02 Gd- 151 4.99E-01 Tm-167 1.03E+O0 Pm- 141 3.63E-02 Gd-152 O.OOE-01 Tm-170 5.38E-02 Pm- 143 1.79E+00 Gd-153 8.92E-01 Tm-171 8.13E-03 Pm- 144 8.68E+00 Gd-159 1.52E-01 Tm-172 1.89E+00 Pm- 145 2.58E-01 Tb-147 6.76E-01 Tm-173 5.88E-01 Pm- 146 4.34E+00 Tb-149 1.27E+00 Tm-175 2.70E-02 Pm-147 3.49E-05 Tb-150 1.01E+00 Yb-162 8.97E-02 Pm- 148 2.60E+00 Tb-151 2.33E+00 Yb-166 6.08E+00 Pm-I 48M 1.08E+01 Tb- 153 1.16E+00 Yb-167 1.23E-02 Pm- 149 4.70E-02 Tb-154 5.65E+00 Yb-169 2.47E+00 Pm-150 6.86E-01 Tb- 155 9.52E-01 Yb-175 2. lOE-01 Pm- 151 1.11E+00 Tb-156 8.65E+00 Yb-177 6.98E-02 Sm-141 4. 11E-02 Tb-156M 9.32E-01 Yb- 178 4.11E-02 Sm-141M 1.42E-01 Tb-156M 2.89E-01 Lu-169 3.60E+00 Sm-142 2.11E-01 Tb-157 2.39E-02 Lu-170 8.42E+00 Sm- 145 5.56E-01 Tb-158 4.79E+00 Lu-171 3.72E+00 Sm- 146 O.OOE-01 Tb-160 6.08E+00 Lu-172 9. 20E+00 Sm- 147 O.OOE-01 Tb-161 2.64E-01 Lu-173 1.10E+00 Sm- 151 1.26E-05 Dy-155 1.08E+00 Lu-174 8.93E-01 Sm- 153 3.54E-01 Dy-157 5.81E-01 Lu-174M 5.54E-01 Sm-155 5.65E-03 Dy-159 4.19E-01 Lu-176 3.45E+00 Sm- 156 3.55E-01 Dy-165 1.38E-02 Lu-176M 1.53E-02 Eu-145 2.OOE+O0 Dy-166 3.56E-01 Lu-177 2.24E-01 Eu-146 3.38E+00 Ho-155 1.41E-01 Lu-177M 6.80E+00 Eu-147 8.51E-01 Ho-157 2.57E-02 Lu- 178 8.18E-03 Eu-148 3.53E+00 Ho-159 3.47E-02 Lu-178M 5.54E-02 Eu-149 1.40E-01 Ho-161 4.70E-02 Lu-179 3.03E-02 Eu-150 2.92E-02 Ho-162 4.66E-03 Hf- 170 4.74E-01 Eu-150 3.02E+00 Ho-162M 1.43E-01 Hf-172 4.63E-01 Eu-152 2.20E+00 Ho-164 3.lOE-03 Hf- 173 2.26E-01 Eu-152M 1.38E-01 Ho-164M 1.32E-02 Hf-175 3.70E-01 Eu-154 2.28E+00 Ho-166 1.04E-01 Hf-177M 5.22E-02 Eu-155 1.60E-01 Ho-166M 1.07E+01 Hf- 178M 2.94E+00 Eu-156 1.90E+00 Ho-167 2.38E-01 Hf-179M 8.51E-01 Eu- 157 2.01E-01 Er-161 6.29E-01 Hf- 180M 1.71E-01 Eu-158 3.56E-02 Er-165 1.12E-01 Hf- 181 4.96E-01 Gd- 145 1.09E-01 Er-169 1.34E-04 Hf- 182 1.16E+00 Gd-146 4.11E+00 Er-171 5.88E-01 Hf- 182M 2.61E-02 Gd- 147 4.91E+00 Er-172 2.59E+00 Hf-183 2.33E-02 Gd- 148 O.OOE-01 Tm- 162 6.87E-02 Hf-184 1.94E-01

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-5

TABLE A-1 (Con't)

DFi DFi DFi Nucl ide (remlACi) Nucl ide (rem/ACi) Nucl ide (rem/gCi)

Ta-172 4.07E-02 Os-189M 5. 11E-06 Hg-193M 3.23E-04 Ta-173 1.94E-01 Os-191 1.99E-02 Hg-194 1.81E-01 Ta- 174 4.25E-02 Os-191M 1.12E-03 Hg-195 7.47E-05 Ta-175 4.96E-01 Os-193 8.55E-03 Hg-195M 5.48E-04 Ta-176 8.25E-01 Os-194 8.69E-02 Hg- 197 2.38E-04 Ta-177 1.30E-01 Ir-182 2.23E-03 Hg- 197M 2.97E-04 Ta-178 1.47E-01 Ir-184 3.24E-02 Hg- 199M 7.55E-06 Ta-179 9.40E-02 Ir-185 3.85E-02 Hg-203 5.33E-03 Ta- 180 1.16E+00 Ir-186 1.12E-01 TI-194 6.44E-06 Ta- 180M 3.47E-02 Ir-187 2.08E-02 T1-194M 2.16E-05 Ta- 182 2.15E+00 Ir-188 1.60E-O1 TI-195 3.49E-05 Ta- 182M 2.65E-03 Ir-189 1.96E-02 Tl-197 3.85E-05 Ta- 183 5.44E-01 Ir-190 2.52E-01 TI-198 1.94E-04 Ta- 184 7.40E-01 Ir-190M 1.O1E-03 Tl-198M 8.36E-05 Ta-185 9.25E-03 Ir-192 1.63E-01 Tl-199 5.55E-05 Ta- 186 7.03E-03 Ir-192M 8.99E-02 T1-200 6.55E-04 W-176 6.55E-04 Ir-194 7.55E-03 TI -201 2.48E-04 W-177 3.66E-04 Ir-194M 4.55E-01 Ti -202 1.38E-03 W-178 6.43E-04 Ir-195 1.24E-03 TI -204 2.43E-03 W-179 8.12E-06 Ir-195M 1.03E-02 Pb-195M 1.65E-04 W-181 2.80E-04 Pt-186 2.06E-02 Pb-198 3.92E-04 W-185 3.51E-07 Pt- 188 1.21E-01 Pb- 199 6.51E-04 W-187 1.04E-03 Pt-189 2.08E-02 Pb-200 3.37E-03 W-188 1.68E-04 Pt- 191 4.88E-02 Pb-201 1.78E-03 Re-177 1.49E-05 Pt- 193 1.07E-04' Pb-202 6.77E-02 Re-178 8.37E-06 Pt- 193M 2.71E-03 Pb-202M 1.91E-03 Re-181 4.61E-04 Pt-195M 1.58E-02 Pb-203 2.02E-03 Re- 182 4.56E-04 Pt-197 2.64E-03 Pb-205 3.63E-04 Re- 182 1.92E-03 Pt-197M 1.12E-03 Pb-209 9.93E-06 Re-184 1.64E-03 Pt-199 5.40E-04 Pb-210 2.31E+00 Re-184M 1.31 E-03 Pt-200 2.04E-02 Pb-211 3.63E-04 Re- 186 4.53E-04 Au- 193 1.63E-03 Pb-212 3.29E-02 Re- 186M 9.43E-04 Au-194 1.1OE-02 Pb-214 5.64E-04 Re- 187 1.82E-06 Au-195 2.35E-03 Bi-200 1.66E-03 Re-188 3.73E-04 Au-198 5.66E-03 Bi-201 4.07E-03 Re-188M 8.19E-06 Au-198M I.05E-02 Bi-202 4.83E-03 Re-189' 2.46E-04 Au-199 1.68E-03 Bi-203 2.54E-02 Os-180 1.78E-03 Au-200 1.01E-04 Bi-205 4.82E-02 Os-181 1.75E-02 Au-200M 1.61E-02 Bi-206 9.03E-02 Os-182 1.07E-01 Au-201 1.15E-05 Bi-207 4.88E-02 Os-185 1.33E-01 Hg- 193 4.88E-05 Bi-210 1.46E-03

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-6

TABLE A-1 (Con't)

DFi DFi DFi Nuclide (rem/ACi) Nuclide (rem/ACi) Nuclide (rem/14Ci)

Bi-210M 8.66E-02 U-233 2.92E-02* Am-245 2.68E-04 Bi-212 1.70E-03 U-234 2.92E-02* Am-246M 1.51E-02 Bi-213 4.36E-04 U-235 2.67E-02* Am-246 2.03E-02 Bi-214 3.52E-04 U-236 1.81E-01 Cm-238 1.31E-01 Po-203 1.07E-03 U-237 5.42E-03 Cm-240 3.50E-02 Po-205 1.64E-03 U-238 2.55E-02* Cm-241 8.69E-01 Po-207 4.03E-03 U-239 5.52E-05 Cm-242 3.30E-02 Po-210 3.05E+00 U-240 4.17E-03 Cm-243 3.74E-01 At-207 8.32E-04 Np-232 8.69E-03 Cm-244 3.19E-02 At-211 3.92E-02 Np-233 2.85E-03 Cm-245 3.11E-01 Fr-222 2.13E-03 Np-234 1.45E+00 Cm-246 1.27E-01 Fr-223 8.58E-03 Np-235 2.99E-03 Cm-247 9.51E-01 Ra-223 7.84E-01 Np-236 4.29E-01 Cm-248 3.49E+01 Ra-224 3.85E-01 Np-236 5.25E-02 Cm-249 1.07E-03 Ra-225 6.23E-01 Np-237 3.59E-01 Cm-250 2.76E+02 Ra-226 1.69E+00 Np-238 6.07E-01 Bk-245 4.11E-01 Ra-227 6.10E-05 Np-239 2.55E-01 Bk-246 1.04E+00 Ra-228 2.90E+00 Np-240 7.07E-02 Bk-247 2.83E-01 Ac-224 9.47E-02 Pu-234 1.24E-01 Bk-249 8.40E-04 Ac-225 3.68E-01 Pu-235 1.72E-03 Bk-250 1. 54E-01 Ac-226 1.66E-01 Pu-236 6.81E-02 Cf-244 9.25E-05 Ac-227 2.60E-01 Pu-237 1.07E-01 Cf-246 2.88E-02 Ac-228 3.12E-01 Pu-238 5.56E-02" Cf-248 4.18E-02 Th-226 3.02E-03 Pu-239 5.22E-02" Cf-249 9.80E-01 Th-227 3.52E+00 Pu-240 2.80E-02 Cf-250 3.30E-01 Th-228 4.40E+01 Pu-241 2.96E-04 Cf-251 4.26E-01 Th-229 8.51E+01 Pu-242 2.81E-02 Cf-252 1. 15E+01 Th-230 1.26E+01 Pu-243 9.62E-03 Cf-253 8.55E-04 Th-231 8.97E-02 Pu-244 1.07E+00 Cf-254 3.70E+02 Th-232 2.26E+01 Pu-245 2.22E-01 Es-250 4.77E-02 Th-234 2.33E-01 Pu-246 1.34E+00 Es-251 1.24E-01 Pa-227 2.42E-03 Am-237 2.60E-02 Es-253 3.58E-02 Pa-228 9.58E-01 Am-238 7.81E-02 Es-254M 5.22E-01 Pa-230 1.04E+00 Am-239 1.63E-01 Es-254 1.33E+00 Pa-231 2.25E-01 Am-240 1.16E+00 Fm-252 2.61E-02 Pa-232 8.95E-01 Am-241 1. 11E-02" Fm-253 1.38E-01 Pa-233 3.81E-01 Am-242M 3.64E-02 Fm-254 6.11E-03 Pa-234 6.77E-01 Am-242 1.32E-02 Fm-255 2.85E-02 U-230 6.13E-01 Am-243 4.74E-01 Fm-257 2.60E-01 U-231 2.63E-03 Am-244M 1.05E-05 Md-257 3.69E-02 U-232 6.02E-01 Am-244 3.92E-01 Md-258 5.96E-02

• Dose equivalent factor based on data presented in NUREG/CR-5631 (Ref. A2). All other factors represent the committed dose equivalent to the uterus.

A-7

REFERENCES Al. International Commission on Radiological Protection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts I through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc., 1979.

A2. M. R. Sikov, R. J. Traub, and H. K. Meznarich, "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose-Interim Recommendations," NUREG/CR-5631 (PNL-7445), U.S. Nuclear Regulatory Commission, (in press).

A-8

APPENDIX B BLOOD UPTAKE FRACTIONS FOR INGESTED ACTIVITY Element fl Element fl Actinium 1E-3 Cerium 3E-4 (Ac) (Ce)

Al umi num 1E-2 Cesium lEO (Al) (Cs)

Americium 1E-3 Chlorine IEO (Am) (Cl)

Antimony 1E-I Chromium IE-1 (Sb) (Cr)

Arsenic 5E-1 Cobalt 3E-01 (As) (Co)

Astatine IEO Copper 5E-i (At) (Cu)

Barium 1E-1 Curium 1E-3 (Ba) (Cm)

Berkelium IE-3 Dysprosium 3E-4 (Bk) (Dy)

Beryllium 5E-3 Einsteinium 1E-3 (Be) (Es)

Bismuth 5E-2 Erbium 3E-4 (Bi) (Er)

Bromine 1EO Europium 1E-3 (Br) (Eu)

Cadmi um 5E-2 Fermium I E-3 (Cd) (Fm)

Calcium 3E-1 Fluorine 1EO (Ca) (F)

Californium IE-3 Francium 1EO (Cf) (Fr)

Carbon 1EO Gadolinium 3E-4 (C) (Gd)

B-i

Blood Uptake Fractions for Ingested Activity (con't)

El ement fl Element fl Gallium 1E-3 (Md)

(Ga)

Mercury IEO Germanium IEO (Hg)

(Ge)

Molybdenum 8E-1 Gold IE-1 (Mo)

(Au)

Neodymium 3E-4 Hafnium 2E-3 (Nd)

(Hf)

Neptunium IE-3 Holmium 3E-4 (Np)

(Ho)

Nickel 5E-2 Hydrogen IEO (Ni)

(H)

Niobium IE-2 Indium 2E-2 (Nb)

(In)

Osmium IE-2 Iodine lEO (Os)

(I)

Palladium 5E-3 Iridium 1E-2 (Pd)

(Ir)

Phosphorus 8E-1 Iron IE-I (P)

(Fe)

Platinum 1E-2 Lanthanum 1E-3 (Pt)

(La)

Plutonium IE-3 Lead 2E-1 (Pu)

(Pb)

Polonium 1E-1 Lutetium 3E-4 (Po)

(Lu)

Potassium lEO Magnesium 5E-1 (K)

(Mg)

Praseodymium 3E-4 Manganese 1E-1 (Pr)

(Mn)

Mendelevium I E-3 B-2

Blood Uptake Fractions for Ingested Activity (con't)

El ement fl Element fl Promethium 3E-4 Technetium 8E-i (Pm) (Tc)

Protactinium 1E-3 Tellurium 2E-I (Pa) (Te)

Radium 2E-1 Terbium 3E-4 (Ra) (Tb)

Rheni um 8E-I Thallium HEO (Re) (Tl)

Rhodium 5E-2 Thorium 2E-4 (Rh) (Th)

Rubidium 1EO Thulium 3E-4 (Rb) (Tm)

Ruthenium 5E-2 Tin 2E-2 (Ru) (Sn)

Samarium 3E-4 Titanium 1E-2 (Sm) (Ti)

Scandium IE-4 Tungsten 3E-1 (Sc) (W)

Sel eni um 8E-i Uranium 5E-2 (Se) (U)

Silicon 1E-2 Vanadium 1E-2 (Si) (v)

Silver 5E-2 Ytterbium 3E-4 (Ag) (Yb)

Sodium lEO Yttrium 1E-4 (Na) (Y)

Strontium 3E-1 Zinc 5E-1 (Sr) (Zn)

Sulfur 8E-i Zirconium 2E-3 (S) (Zr)

Tantalum IE-3 (Ta)

B-3

APPENDIX C RADIATION ABSORBED DOSE TO THE EMBRYO/FETUS FOLLOWING INTRODUCTION OF SPECIFIED RADIONUCLIDES AND CHEMICAL FORMS INTO THE MATERNAL TRANSFER COMPARTMENT (BLOOD)

The entries for selected radionuclides and chemical forms in the tables in this appendix have been calculated from the modeling presented in NUREG/CR 5631 (Ref. CI). It has been assumed that 1 pCi of activity is introduced into the maternal transfer compartment (blood). Pregnancy is assumed to begin at the time of fertilization, roughly 2 weeks after menses, and gestation is considered to consist of nine 30-day months.

Radiation dose rates were calculated from the initial fraction that was present after a single administration at the start of each of these months or on the assumed final day (day 270) of gestation. Monthly doses were deter mined by integrating under the curve relating the fraction of the activity in the embryo/fetus at the start of each month after administration and the frac tion at the beginning of the subsequent month of gestation. Monthly doses are shown for the inclusive periods, expressed in days. Doses to the embryo/fetus from radionuclides in maternal organs were calculated; when appropriate, these are included to provide total radiation absorbed doses. The tabulated values of cumulated doses were determined as the sum of the monthly doses.

As was noted in NUREG/CR-5631 (Ref. Cl), ICRP Publication 30 (Ref. C2) employs a metabolic model in which a fraction of activity in the first trans fer compartment (blood) often is assumed to go immediately to excretion.

Because of the minuscule mass of the embryo/fetus immediately following fertilization, for some materials the biokinetic model thus predicts that there would be negligible initial activity in the embryo after administration at that time, and that there would be minimal activity at later times. As a consequence, the dose rate and doses also would be negligible, which is indicated by N in the table. For these nuclides, an approximation of the cumulative dose for an intake occurring during the first 30 days should be made based on a time-weighted average of the 30-day intake data. The cumula tive dose from an intake in the first 30 days of pregnancy may be estimated by multiplying the ratio of remaining days at time of intake to the 30-day period by the cumulative dose for an intake occurring at day 30. For example, assuming a maternal intake of 14 C resulting in a 1 ACi blood uptake on the 20th day of the pregnancy, the gestation dose should be determined by multi plying the cumulative dose from an intake at day 30 (i.e., Table C3, Cumulated Dose column, 1.89E-04 rads) by the ratio of 20 days to 30 days.

C-1

Table C1. Radiation Doses to the Embryo/Fetus from I ACi of 3 H, as Tritiated Water, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 9.03E-06 3.96E-11 7.67E-14 2.OOE-15 5.31E-17 2.63E-18 1.72E-19 1.34E-20 1.18E-21 9.03E-06 30 1.77E-05 2.64E-08 7.50E-10 1.94E-11 9.70E-13 6.30E-14 4.94E-15 4.33E-16 1.77E-05 60 3.93E-05 8.96E-07 2.47E-08 1.21E-09 7.91E-11 6.17E-12 5.41E-13 4.02E-05 90 3.82E-05 1.06E-06 5.19E-08 3.39E-09 2.64E-10 2.32E-11 3.93E-05 120 4.50E-05 2.14E-06 1.41E-07 1.1OE-08 9.63E-10 4.73E-05 150 4.98E-05 3.22E-06 2.53E-07 2.21E-08 5.33E-05 180 5.28E-05 4.08E-06 3.57E-07 5.72E-05 210 5.40E-05 4.70E-06 5.87E-05 240 5.28E-05 5.28E-05 n-,

Table C2. Radiation Doses to the Embryo/Fetus from 1 ,ICi of 3H, as a Hexose or Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N N N. N N N N N N 30 2.21E-05 2.14E-07 4.68E-08 1.04E-08 4.37E-09 2.35E-09 1.50E-09 1.06E-09 2.24E-05 60 6.OOE-05 7.27E-06 1.67E-06 6.81E-07 3.68E-07 2.34E-07 1.66E-07 7.04E-05 90 5.82E-05 9.25E-06 3.69E-06 1.97E-06 1.26E-06 8.92E-07 7.53E-05 120 7.24E-05 1.97E-05 1.03E-05 6.50E-06 4.62E-06 1.14E-04 150 8.29E-05 3.05E-05 1.89E-05 1.33E-05 1.46E-04 180 8.96E-05 3.93E-05 2.72E-05 1.56E-04 210 9.31E-05 4.58E-05 1.39E-04 240 1.05E-04 1.05E-04

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-i.

(. ( (

Table C3. Radiation Doses to the Embryo/Fetus from 1 ACi of 14 C, as a Bicarbonate, Hexose, Amino Acid, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) I Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N* N N N N N N N N N 30 1.87E-04 1.72E-06 4.12E-07 9.18E-08 3.88E-08 2.09E-08 1.34E-08 9.56E-09 1.89E-04 60 4.96E-04 5.83E-05 1.46E-05 6.02E-06 3.26E-06 2.09E-06 1.49E-06 5.82E-04 90 4.81E-04 7.48E-05 3.24E-05 1.74E-05 1. 11E-05 7.95E-06 6.25E-04 120 5.96E-04 1.59E-04 9.09E-05 5.74E-05 4. 11E-05 9.44E-04 150 6.80E-04 2.47E-04 1.66E-04 1.17E-04 1.21E-03 180 7.33E-04 3.19E-04 2.39E-04 1.29E-03 210 7.61E-04 3.70E-04 1.13E-03 240 8.88E-04 8.88E-04

(-,

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-i.

57Co, Introduced into the Maternal Table C4. Radiation Doses to the Embryo/Fetus from 1 JLCi of Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 7.30E-04 2.76E-04 2.36E-04 1.97E-04 1.75E-04 1.56E-04 1.39E-04 1.23E-04 1.09E-04 2.14E-03 30 8.66E-04 2.74E-04 2.45E-04 2.07E-04 1.82E-04 1.60E-04 1.41E-04 1.24E-04 2.20E-03 60 8.71E-04 2.82E-04 2.56E-04 2.15E-04 1.88E-04 1.63E-04 1.42E-04 2.12E-03 90 8.96E-04 2.96E-04 2.67E-04 2.22E-04 1.91E-04 1.64E-04 2.04E-03 120 9.37E-04 3.08E-04 2.75E-04 2.25E-04 1.92E-04 1.94E-03 150 9.78E-04 3.18E-04 2.79E-04 2.27E-04 1.80E-03 180 1.01E-03 3.22E-04 2.83E-04 1.61E-03 210 1.03E-03 3.19E-04 1.35E-03 240 1.04E-03 1.04E-03

Table C5. Radiation Doses to the Embryo/Fetus from 1 ILCi of 58Co, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods,(days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 4.81E-03 1.27E-03 9.03E-04 6.03E-04 4.25E-04 3.OOE-04 2. 13E-04 1.52E-04 1.09E-04 8.79E-03 30 5.12E-03 1.30E-03 9.30E-04 6.24E-04 4.37E-04 3.06E-04 2. 15E-04 1.53E-04 9.08E-03 60 5.26E-03 1.34E-03 9.62E-04 6.41E-04 4.45E-04 3.09E-04 2.17E-04 9.17E-03 90 5.39E-03 1.38E-03 9.88E-04 6.54E-04 4.49E-04 3.11E-04 9.17E-03 120 5.59E-03 1.42E-03 1.01E-03 6.59E-04 4.53E-04 9.13E-03 150 5.75E-03 1.45E-03 1.02E-03 6.64E-04 8.88E-03 180 5.87E-03 1.46E-03 1.03E-03 8.36E-03 210 5.95E-03 1.45E-03 7.40E-03 240 6.OOE-03 6.OOE-03 Table C6. Radiation Doses to the Embryo/Fetus from 1 MCi of 6 0Co, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 1.28E-02 4.73E-03 4.37E-03 3.79E-03 3.60E-03 3.40E-03 3.22E-03 3.05E-03 2.88E-03 4.18E-02 30 1.38E-02 4.73E-03 4.40E-03 3.98E-03 3.73E-03 3.48E-03 3.26E-03 3.06E-03 4.04E-02 60 1.39E-02 4.76E-03 4.62E-03 4. 12E-03 3.81E-03 3.52E-03 3.27E-03 3.80E-02 90 1.40E-02 4.99E-03 4.79E-03 4.22E-03 3.86E-03 3.54E-03 3.54E-02 120 1.46E-02 5. 17E-03 4.90E-03 4.27E-03 3.88E-03 3.28E-02 150 1.52E-02 5.29E-03 4.96E-03 4.29E-03 2.97E-02 180 1.56E-02 5.35E-03 5.01E-03 2.60E-02 210 1.59E-02 5.29E-03 2.12E-02 240 1.60E-02 1.60E-02

(, I (

Table C7. Radiation Doses to the Embryo/Fetus from 1 ACi of 57 Co, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus Durinn Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 1.47E-03 1.11E-03 7.18E-04 4.88E-04 3.34E-04 2.28E-04 1.54E-04 1.02E-04 6.74E-05 4.67E-03 30 1.67E-03 1.1OE-03 7.44E-04 5.1OE-04 3.48E-04 2.35E-04 1.56E-04 1.03E-04 4.87E-03 60 1.68E-03 1.14E-03 7.80E-04 5.31E-04 3.59E-04 2.38E-04 1.57E-04 4.89E-03 90 1.74E-03 1.19E-03 8.13E-04 5.49E-04 3.64E-04 2.40E-04 4.90E-03 120 1.82E-03 1.24E-03 8.38E-04 5.56E-04 3.67E-04 4.82E-03 150 1.89E-03 1.28E-03 8.48E-04 5.60E-04 4.58E-03 180 1.95E-03 1.30E-03 8.55E-04 4.10E-03 210 1.98E-03 1.31E-03 3.29E-03 240 1.99E-03 1.99E-03 CI Table C8. Radiation Doses to the Embryo/Fetus from 1 jCi of 60 Co, as Vitamin B-12, Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus Durinq Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 2.54E-02 1.90E-02 1.33E-02 9.38E-03 6.88E-03 4.98E-03 3.56E-03 2.52E-03 1.77E-( 03 8.68E-02 30 2.71E-02 1.90E-02 1.34E-02 9.82E-03 7.1OE-03 5.09E-03 3.61E-03 2.53E-( 03 8.76E-02 60 2.70E-02 1.91E-02 1.40E-02 1.02E-02 7.28E-03 5.16E-03 3.62E-( 03 8.64E-02 120 2.74E-02 2.OOE-02 1.45E-02 1.04E-02 7.38E-03 5.18E-( 03 8.49E-02 150 2.86E-02 2.08E-02 1.49E-02 1.05E-02 7.41E-403 8.22E-02 180 2.97E-02 2.13E-02 1.51E-02 1.06E-( 02 7.67E-02 210 3.04E-02 2.15E-02 1.51E-I 02 6.70E-02 240 3.08E-02 2.16E-I 02 5.24E-02 270 3.10E-l 02 3.10E-02

89 Sr Introduced into the Table C9. Radiation Doses to the Embryo/Fetus from 1 uCi of Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 4.09E-03 5.66E-04 2.92E-04 1.37E-04 6.64E-05 3.59E-05 2.1OE-05 1.23E-05 7.01E-06 5.23E-03 30 5.35E-03 5.74E-04 2.95E-04 1.36E-04 6.57E-05 3.53E-05 2.05E-05 1.20E-05 6.49E-03 60 9.01E-03 1.20E-03 3.84E-04 1.63E-04 7.45E-05 3.86E-05 2.18E-05 1.09E-02 90 9.09E-03 1.36E-03 5.06E-04 2.12E-04 9.67E-05 4.93E-05 1.13E-02 120 1.07E-02 2.24E-03 8.99E-04 3.90E-04 1.84E-04 1.44E-02 150 1.19E-02 3.15E-03 1.40E-03 6.55E-04 1.71E-02 180 1.26E-02 3.87E-03 1.89E-03 1.84E-02 210 1.29E-02 4.38E-03 1.73E-02 240 1.31E-02 1.31E-02 C1 Radiation Doses to the Embryo/Fetus from 1 MCi of 90Sr (in Equilibrium with 90 Y)

Table C10.

Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 9.07E-03 2.01E-03 1.57E-03 1.1OE-03 8.07E-04 6.58E-04 5.81E-04 5.15E-04 4.43E-04 1.68E-02 30 1.13E-02 2.04E-03 1.57E-03 1.09E-03 7.99E-04 6.49E-04 5.69E-04 5.OOE-04 1.85E-02 60 2.03E-02 3.60E-03 1.72E-03 1.33E-03 8.94E-04 7.1OE-04 6.04E-04 2.92E-02 90 1.50E-02 3.31E-03 2.80E-03 1.67E-03 1.17E-03 8.98E-04 2.48E-02 120 1.90E-02 7.93E-03 4.71E-03 3.11E-03 2.22E-03 3.70E-02 150 2.69E-02 1.1OE-02 7.41E-03 5.23E-03 5.05E-02 180 2.86E-02 1.36E-02 1.OOE-02 5.22E-02 210 2.95E-02 1.54E-02 4.49E-02 240 2.93E-02 2.93E-02

K I (

Table C11. Radiation Doses to the Embryo/Fetus from I IiCi of 106Ru (in Equilibrium with 106 Rh) Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 1.56E-03 1.OOE-03 9.36E-04 7.68E-04 6.67E-04 5.94E-04 5.35E-04 4.85E-04 4.41E-04 6.99E-03 30 2.02E-03 1.21E-03 9.48E-04 7.77E-04 6.72E-04 5.94E-04 5.32E-04 4.80E-04 7.23E-03 60 2.42E-03 1.23E-03 9.56E-04 7.80E-04 6.70E-04 5.90E-04 5.27E-04 7.17E-03 90 2.50E-03 1.24E-03 9.68E-04 7.84E-04 6.68E-04 5.85E-04 6.74E-03 120 2.53E-03 1.25E-03 9.63E-04 7.77E-04 6.62E-04 6.18E-03 150 2.55E-03 1.26E-03 9.59E-04 7.69E-04 5.54E-03 180 2.55E-03 1.25E-03 9.55E-04 4.75E-03 210 2.54E-03 1.23E-03 3.77E-03 240 2.53E-03 2.53E-03 C)

Table C12. Radiation Doses to the Embryo/Fetus from 1 aCi of 125I Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 2.08E-05 1.12E-05 7.34E-06 1.34E-05 1.46E-05 6.07E-06 4.65E-06 3.01E-06 2.07E-06 8.31E-05 30 2.72E-05 1.05E-05 1.27E-05 1.40E-05 1.04E-05 7.27E-06 4.83E-06 3.31E-06 9.02E-05 60 2.74E-05 1.70E-05 2.23E-05 1.63E-05 1.15E-05 7.66E-06 5.28E-06 1.07E-04 90 1.64E-04 5.21E-05 3.23E-05 2.05E-05 1.31E-05 8.84E-06 2.91E-04 120 8.79E-04 2.88E-04 1.22E-04 5.70E-05 3.05E-05 1.38E-03 150 7.81E-04 3.12E-04 1.40E-04 7.08E-05 1.30E-03 180 6.78E-04 2.99E-04 1.48E-04 1.12E-03 210 5.97E-04 2.98E-04 8.95E-04 240 5.33E-04 5.33E-04

Table C13. Radiation Doses to the Embryo/Fetus from 1 gCi of 1311 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 5.93E-05 2.58E-06 1.88E-07 2.20E-08 3.39E-09 2.1OE-10 2.29E-11 1.32E-12 6.35E-14 6.21E-05 30 9.73E-05 2.31E-06 3.38E-07 5.05E-08 3.22E-09 3.47E-10 2.01E-11 9.66E-13 1.OOE-04 60 9.44E-05 4.14E-06 7.60E-07 4.75E-08 5.23E-09 3.02E-10 1.46E-11 9.94E-05 90 6.52E-04 2. 11E-05 9.30E-07 9.12E-08 5.01E-09 2.33E-10 6.74E-04 120 3.54E-03 8.90E-05 6.03E-06 2.33E-07 7.82E-09 3.64E-03 150 2.35E-03 1.49E-04 5.56E-06 1.75E-07 2.50E-03 180 2.88E-03 1.15E-04 3.48E-06 3.OOE-03 210 1.98E-03 6.80E-05 2.05E-03 240 1.OOE-03 1.00E-03 C-)

Table C14. Radiation Doses to the Embryo/Fetus from 1 ACi of 1321 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 8.43E-05 0 0 0 0 0 0 0 0 8.43E-05 30 1.06E-04 0 0 0 0 0 0 0 1.06E-04 60 1.27E-04 0 0 0 0 0 0 1.27E-04 90 1.30E-04 0 0 0 0 0 1.30E-04 120 1.51E-04 0 0 0 0 1.51E-04 150 1.53E-04 0 0 0 1.53E-04 180 1.56E-04 0 0 1.56E-04 210 1.56E-04 0 1.56E-04 240 1.56E-04 1.56E-04

! (

Table C15. Radiation Doses to the Embryo/Fetus from 1 IiCi of 1331 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 2.81E-04 0 0 0 0 0 0 0 0 2.81E-04 30 5.32E-04 0 0 0 0 0 0 0 5.32E-04 60 6.85E-04 0 0 0 0 0 0 6.85E-04 90 7.04E-04 0 0 0 0 0 7.04E-04 120 9.04E-04 0 0 0 0 9.04E-04 150 8.59E-04 0 0 0 8.59E-04 180 8.49E-04 0 0 8.49E-04 210 8.27E-04 0 8.27E-04 240 8.11E-04 8.11E-04 Table C16. Radiation Doses to the Embryo/Fetus from 1 gCi of 1341 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 2.22E-05 0 0 0 0 0 0 0 0 2.22E-05 30 2.79E-05 0 0 0 0 0 0 0 2.79E-05 60 3.44E-05 0 0 0 0 0 0 3.44E-05 90 3.50E-05 0 0 0 0 0 3.50E-05 120 3.81E-05 0 0 0 0 3.81E-05 150 3.91E-05 0 0 0 3.91E-05 180 4.03E-05 0 0 4.03E-05 210 4.83E-05 0 4.83E-05 240 4.06E-05 4.06E-05

Table C17. Radiation Doses to the Embryo/Fetus from 1 gCi of 1351 Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 1.95E-04 0 0 0 0 0 0 0 0 1.95E-04 30 2.63E-04 0 0 0 0 0 0 0 2.63E-04 60 3.07E-04 0 0 0 0 0 0 3.07E-04 90 3.04E-04 0 0 0 0 0 3.04E-04 120 3.65E-04 0 0 0 0 3.65E-04 150 3.66E-04 0 0 0 3.66E-04 180 3.72E-04 0 0 3.72E-04 210 3.69E-04 0 3.69E-04 240 3.70E-04 3.70E-04 0

Table C18. Radiation Doses to the Embryo/Fetus from 1 pCi of 134 Cs Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 2.55E-02 2.15E-02 1.69E-02 1.33E-02 1.05E-02 8.29E-03 6.35E-03 4.37E-03 2.81E-03 1.1.OE-01 30 2.82E-02 2.23E-02 1.75E-02 1.38E-02 1.09E-02 8.38E-03 5.75E-03 3.71E-03 1.11E-01 60 2.92E-02 2.30E-02 1.82E-02 1.44E-02 1.1OE-02 7.59E-03 4.88E-03 1.08E-01 90 3.03E-02 2.40E-02 1.89E-02 1.45E-02 9.98E-03 6.43E-03 1.04E-01 120 3.16E-02 2.49E-02 1.91E-02 1.31E-02 8.46E-03 9.72E-02 150 3.28E-02 2.51E-02 1.73E-02 1.12E-02 8.64E-02 180 3.30E-02 2.28E-02 1.46E-02 7.04E-02 210 3.14E-02 2.03E-02 5. 17E-02 240 3.24E-02 3.24E-02

(

Table C19. Radiation Doses to the Embryo/Fetus from 1 ACi of 137Cs Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 1.18E-02 1.13E-02 9. 13E-03 7.36E-03 5.91E-03 4.74E-03 S1.43E-02 3.70E-03 2.60E-03 1.71E-03 5.83E-02 30 1.17E-02 9.43E-03 7.59E-03 6.08E-03 4.74E-03 3.33E-03 2.19E-03 5.94E-02

.60 1.50E-02 1.21E-02 9.72E-03 7.80E-03 6.09E-03 4.27E-03 2.81E-03 5.78E-02 90 1.55E-02 1.25E-02 1.OOE-02 7.79E-03 5.48E-03 3.60E-03 5.49E-02 120 1.60E-02 1.29E-02 1.OOE-02 7.02E-03 4.63E-03 5.05E-02 150 1.65E-02 1.29E-02 9.05E-03 5.96E-03 4.44E-02 180 1.65E-02 1.16E-02 7.60E-03 3.57E-02 210 1.56E-02 1.03E-02 2.59E-02 240 1.60E-02 1.60E-02 Table C20. Radiation Doses to the Embryo/Fetus from I /iCi of 233 U Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N N N N N N N N N 30 1.41E-03 2.31E-05 5.30E-06 1.19E-06 5.01E-07 2.71E-07 1.74E-07 1.24E-07 1.44E-03 60 4.30E-03 7.86E-04 1.89E-04 7.84E-05 4.25E-05 2.72E-05 1.94E-05 5.44E-03 90 6.29E-03 1.52E-03 6.29E-04 3.42E-04 2.19E-04 1.56E-04 9.16E-03 120 8. 1OE-03 3.25E-03 1.78E-03 1.13E-03 8.09E-04 1.51E-02 150 9.51E-03 5.11E-03 3.28E-03 2.34E-03 2.02E-02 180 1.40E-02 8.88E-03 6.36E-03 2.92E-02 210 1.49E-02 1.06E-02 2.55E-02 240 2.38E-02 2.38E-02

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-i.

Table C21. Radiation Doses to the Embryo/Fetus from 1 pCi of 23 4 U Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N N N N N N N N N 30 1.40E-03 2.30E-05 5.26E-06 1.18E-06 5.OOE-07 2.70E-07 1.73E-07 1.23E-07 1.43E-03 60 4.27E-03 7.82E-04 1.87E-04 7.79E-05 4.22E-05 2.70E-05 1.93E-05 5.41E-03 90 6.25E-03 1.51E-03 6.28E-04 3.39E-04 2.17E-04 1.55E-04 9.10E-03 120 8.05E-03 3.23E-03 1.77E-03 1.13E-03 8.07E-04 1.50E-02 150 9.46E-03 5.07E-03 3.26E-03 2.32E-03 2.01E-02 180 1.40E-02 8.88E-03 6.34E-03 2.92E-02 210 1.48E-02 1.05E-02 2.53E-02 240 2.36E-02 2.36E-02 C-.

235 U Introduced into the Table C22. Radiation Doses to the Embryo/Fetus from I pCi of Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N N N N N N N N N 30 1.29E-03 2.11E-05 4.84E-06 1.09E-06 4.60E-07 2.48E-07 1.59E-07 1.13E-07 1.32E-03 60 3.93E-03 7.19E-04 1.73E-04 7.18E-05 3.88E-05 2.49E-05 1.77E-05 4.98E-03 90 5.75E-03 1.39E-03 5.78E-04 3.12E-04 2.OOE-04 1.43E-04 8.37E-03 120 7.40E-03 2.97E-03 1.62E-03 1.04E-03 7.41E-04 1.38E-02 150 8.70E-03 4.67E-03 3.OOE-03 2.14E-03 1.85E-02 180 1.28E-02 8.12E-03 5.82E-03 2.67E-02 210 1.36E-02 9.69E-03 2.33E-02 240 2.17E-02 2.17E-02

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-i.

I C ((.

Table C23. Radiation Doses to the Embryo/Fetus from 1 MCi of 238 U Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N* N N N N N N N N N 30 1.23E-03 2.01E-05 4.59E-06 1.04E-06 4.38E-07 2.36E-07 1.51E-07 1.08E-07 1.26E-03 60 3.75E-03 6.86E-04 1.64E-04 6.83E-05 3.70E-05 2.37E-05 1.69E-05 4.75E-03 90 5.49E-03 1.32E-03 5.49E-04 2.98E-04 1.90E-04 1.36E-04 7.98E-03 120 7.06E-03 2.83E-03 1.55E-03 9.91E-04 7.08E-04 1.31E-02 150 8.30E-03 4.45E-03 2.86E-03 2.04E-03 1.77E-02 180 1.22E-02 7.76E-03 5.54E-03 2.55E-02 210 1.30E-02 9.23E-03 2.22E-02 240 2.07E-02 2.07E-02 C-)

I.

Table C24. Radiation Doses to the Embryo/Fetus from 1 ACi of 23 8pu Introduced into the Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N* N N N N N N N N N 30 2.68E-03 4.38E-05 1.OOE-05 2.26E-06 9.55E-07 5.14E-07 3.30E-07 2.35E-07 2.74E-03 60 8.19E-03 1.50E-03 3.58E-04 1.49E-04 8.05E-05 5. 16E-05 3.67E-05 1.04E-02 90 1.20E-02 2.89E-03 1.20E-03 6.50E-04 4. 15E-04 2.96E-04 1.75E-02 120 1.54E-02 6.18E-03 3.37E-03 2.15E-03 1.54E-03 2.86E-02 150 1.81E-02 9.70E-03 6.24E-03 4.43E-03 3.85E-02 180 2.66E-02 1.69E-02 1.21E-02 5.56E-02 210 2.84E-02 2.01E-02 4.85E-02 240 4.51E-02 4.51E-02

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-i.

239 Pu Introduced into the Table C25. Radiation Doses to the Embryo/Fetus from 1 gCi of Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N* N N N N N N N N N 30 2.52E-03 4.12E-05 9.40E-06 2.12E-06 8.97E-07 4.83E-07 3.1OE-07 2.21E-07 2.57E-03 60 7.68E-03 1.40E-03 3.36E-04 1.40E-04 7.56E-05 4.85E-05 3.46E-05 9.71E-03 90 1.12E-02 2.71E-03 1.12E-03 6.07E-04 3.90E-04 2.78E-04 1.63E-02 120 1.45E-02 5.80E-03 3.17E-03 2.02E-03 1.44E-03 2.69E-02 150 1.70E-02 9.09E-03 5.85E-03 4. 17E-03 3.61E-02 180 2.50E-02 1.59E-02 1.13E-02 5.22E-02 210 2.66E-02 1.88E-02 4.54E-02 240 4.23E-02 4.23E-02 I- 24 1Am Introduced into the Table C26. Radiation Doses to the Embryo/Fetus from 1 jiCi of Maternal Transfer Compartment (Blood)

Days of Cumulated Gestation at Dose (rad) to Embryo/Fetus During Indicated Gestation Periods (days) Dose Introduction 0-30 30-60 60-90 90-120 120-150 150-180 180-210 210-240 240-270 0-270 0 N* N N N N N N N N N 30 5.36E-04 8.76E-06 2.OOE-06 4.52E-07 1.91E-07 1.03E-07 6.60E-08 4.71E-08 5.48E-04 60 1.64E-03 2.99E-04 7.16E-05 2.97E-05 1.61E-05 1.03E-05 7.35E-06 2.07E-03 90 2.39E-03 5.76E-04 2.39E-04 1.30E-04 8.30E-05 5.92E-05 3.48E-03 120 3.08E-03 1.23E-03 6.75E-04 4.31E-04 3.08E-04 5.72E-03 150 3.61E-03 1.94E-03 1.24E-03 8.89E-04 7.68E-03 180 5.32E-03 3.38E-03 2.41E-03 1.11E-02 210 5.67E-03 4.02E-03 9.69E-03 240 9.04E-03 9.04E-03

• N indicates that the metabolic pattern is such that the dose rates and doses would be negligible throughout gestation when activity is administered immediately after fertilization. Approximations of doses resulting from administration during the first month are described on page C-1.

REFERENCES IC. M. R. Sikov, R. J. Traub, and H. K. Meznarich, "Contribution of Maternal Radionuclide Burdens to Prenatal Radiation Dose-Interim Recommendations," NUREG/CR-5631 (PNL-7445), U.S. Nuclear Regulatory Commission, (in press).

2C. International Commission on Radiological Protection, "Limits for Intakes of Radionuclides by Workers," ICRP No. 30, Parts 1 through 4, including supplements, Annals of the ICRP, Volume 2, No. 3/4, Pergamon Press Inc., 1979.

C-15

REGULATORY ANALYSIS A separate regulatory analysis was not prepared for this regulatory guide. The regulatory analysis prepared for 10 CFR Part 20, "Standards for Protection Against Radiation" (56 FR 23360), provides the regulatory basis for this guide and examines the costs and benefits of the rule as imple mented by the guide. A copy of the "Regulatory Analysis for the Revision of 10 CFR Part 20" (PNL-6712, November 1988), is available for inspection and copying for a fee at the NRC Public Document Room, 2120 L Street NW.,

Washington, DC, as an enclosure to Part 20.

RA- 1

UNITED STATES FIRST CLASS MAIL POSTAGE E' FEES PAID NUCLEAR REGULATORY COMMISSION USNRC WASHINGTON, D.C. 20555 PERMIT No. G-67 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 THIS DOCUMENT WAS PRINTED USING RECYCLED PAPER