Table 5 -4. Dose Conversion Factors for 238U (a)

DOE-STD-1136-2004

Guide of Good Practices for Occupational Radiological Protection in Uranium Facilities

Table 5 -4. Dose Conversion Factors for 238U (a)

Dose Conversion Factor (rem/nCi)

Solubility

Model

Class

CEDE

Bone Surfaces

Fisher Modified

2.9E-3

5.2E-2

Wrenn-Lipsztein

ICRP

7.1E-3

---

ICRP

1.2E-1

---

(a) Factors calculated using CINDY Version 1.4 (Strenge et al. 1992).

Radiation exposure records programs must also provide for the summation of internal and external

doses, as required by 10 CFR 835.702. While the summation process is not necessarily performed under a

site internal dosimetry program, it is recommended that the program coordinator recognize what is

required. The following summations are identified by 10 CFR 835.702(c)(5):

total effective dose equivalent (TEDE) defined as the summation of effective dose equivalent

(deep dose equivalent) from external exposure and the CEDE,

summation of the effective dose equivalent (deep dose equivalent) from external exposure and

the CDE to organs or tissues of concern,

cumulative TEDE received from external and internal sources while employed at the site or

facility, since January 1, 1989, and

for the embryo/fetus of a declared pregnant worker, the summation of the deep dose equivalent to

the mother from external exposure during the entire gestation period and the gestation period

dose equivalent to the embryo/fetus from intakes by the mother during the entire gestation period.

Doses should be calculated and recorded for any confirmed uranium intake. What constitutes a

confirmed intake is discussed in Section 5.7. Along with the doses, supporting records must be maintained,

including the bioassay data, assumptions, biokinetic models, and calculational methods used to estimate the

doses. These may be included in letter-report dose assessments, databases, technical basis documents, and

similar records, either singly or in combination.

5.1.2 Protection of the Embryo/Fetus, Minors, and Members of the Public

The TEDE limit for the embryo/fetus of a declared pregnant worker is 0.5 rem for the entire gestation

period, defined as the summation of external dose received and internal dose received during the gestation

period (not the 50-year committed internal dose). Internal exposure monitoring is required if an intake is

likely to result in more than 10% of that limit (i.e., 50 mrem for the gestation period). Providing adequate

protection to keep the mother's intakes below the occupational limits will also provide adequate protection

for the embryo/fetus. Thus, special bioassay for uranium during pregnancy

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