ML20126J241
| ML20126J241 | |
| Person / Time | |
|---|---|
| Issue date: | 03/02/1981 |
| From: | Minogue R NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Jennifer Davis, Harold Denton, Rich Smith NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS), Office of Nuclear Reactor Regulation, NRC OFFICE OF STANDARDS DEVELOPMENT |
| References | |
| RIL-116, RIL-116-01, RIL-116-1, NUDOCS 8104230811 | |
| Download: ML20126J241 (2) | |
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.Y,.* MAR 2 IS81 MEMORANDUM FOR: John G. Davis, Director Office of Nuclear Material Safety and Safeguards Harold R. Denton, Director Office of Nuclear Reactor Regulation ,
Ray G. Smith, Acting Director ,
Office of Standards Development FROM: Robert B. Minogue, Director Office of Nuclear Regulatory Research
SUBJECT:
RESEARCH INFORMATION LETTER # 116 -
MATHEMATICAL PHANTOMS REPRESENTING CHILDREN OF VARIOUS AGES FOR USE IN ESTIMATES OF INTERNAL DOSE This memorandum describes briefly the mathematical phantoms developed to represent children of ages 0,1, 5,10, and 15 years for use in calculating organ doses from internal and external emitters. This work was performed by the Health and Safety Research Division of the Oak Ridge National Laboratory under the direction of the Environmental Effects Research Branch, ,
Office of Nuclear Regulatory Research (RES). The complete description is given in NUREG/CR-ll59, " Mathematical Phantoms Representing Children of Various Ages for Use in Estimates of Internal Dose."
Research Request NRR-78-5, " Confirmatory Research programs in Radiation Dose i Estimation," stated that NRR staff estimations of radiation exposure to man required a broadly applicable, documented, state-of-the-art dose estimation methodology. One of the most pressing needs has been the lack of anatomical data for organ shapes and locations in children. To fulfill this need, a series of distinct phantoms representing children of ages 0 (newborn),1, 5, 10, and 15 years has been developed. The report gives the explicit equations for locating organ boundaries and detailed drawings showing organ locations by age. In addition, the distributions of hematopoietically active bone marrow and inactive fatty marrow are defined.
Each phantom consists of three major sections: (1) an elliptical cylinder representing the trunk and arms; (2) two truncated circular cones representing .
the legs and feet; and (3) an elliptical cylinder capped by nalf an ellipsoid j-representing the neck and head. Attached to the legs section is a small .
I' region with a plane front surface to represent the testes. Attached to the I
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j MAR 2 1981 Multiple Addressees I trunk are portions of two ellipsoids representing the female breasts. Each i phantom is composed of skeletal, lung, and other soft tissue. The skeletal l system represents the total content of the intact skeleton and thus includes l both bone and bone marrow, which is considered to be homogeneously distributed .!
in the skeleton. The three tissue ' types are composed principally of hydrogen, i carbon, nitrogen, and oxygen. In the skeleton, additional elements, primarily l calcium and phosphorus, amount to about 18 percent of. the total mass. The i
. composition of the lungs is somewhat different from other soft tissues because the lungs contain almost no fat but a larger fraction of blood than other organs. l t
We recommend that your staff use the data presented in NUREG/CR-1159 in calculating doses to children from exposure to radionuclides as it provides much more realistic estimates than use of scaling factors from adult data.
For further information on.this method, please contact Dr. Judith D. Foulke (427-4358).
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Robert B. Minogue, Dir ctor l Office of Nuclear Regulatory Research j i
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