ML20003F912
| ML20003F912 | |
| Person / Time | |
|---|---|
| Issue date: | 08/01/1980 |
| From: | Murley T NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RIL-099, RIL-99, NUDOCS 8104230874 | |
| Download: ML20003F912 (2) | |
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NUCLEAR REGULATORY COMMisslON o
WASHINGTON, D. C. 20555 2
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AUG 1 1910
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x MEMORANDUM FOR: Harold R. Denton, Director Office of Nuclear Reactor Regulation FROM:
Thomas E. Murley, Acting Director Office of Nuclear Regulatory Research
SUBJECT:
RESEARCH INFORMATION LETTER # 99 - DOSE-RATE CONVERSION FACTORS FOR EXTERNAL EXPOSURE TO PHOTON AND ELECTRON RADIATION C
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This memorandum transmits a compilation of dose-rate conversion factors for use in calculating external exposure to photon and electron radiation for 240 radio-nuclides of potential importance in routine releases from nuclear fuel cycle facilities. 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 of the Office of Nuclear Regulatory Research (RES).
Research Request NRR-78-5, " Confirmatory isesearch Programs in Radiation Dose Estimation," stated that NRR staff estimations of radiation exposure to man required a broadly applicable, documented, state-of-the-art dose estimation methodology. The computer code DOSFACTER was written to calculate dose-rate conversion factors for photon and electron radiation for immersion in con-taminated air, imersion in contaminated water, and exposure to a contaminated ground surface. For a given radionuclide the code calculates body-surface dose-rate factors for photons and electrons and organ dose-rate factors for photons for 22 body organs. The dose-rate factors are calculated in units of mrem /yr per microcurie /cm3 for imersion in contaminated air and water, and in units of mrem /yr per microcurie /cm2 for exposure to a cantaminated ground surface.
The models and assumptions used to obtain the dose-rate factors are described in detail in the report entitled " Dose-Rate Conversion Factors for External Exposure to Photon and Electron Radiation from Radionuclides Occurring in Routine Releases from Nuclear Fuel Cycle Facilities," (NUREG/CR-0494). The calculations assume that the contaminated air, water, and ground surface are infinite in extent and that the radionuclide concentration is uniform throughout the exposure medium.
For immersion in contaminated air and water, the calculations are based.on the requirement that all of the energy of the photons and electrons emitted in the radioactive decay process is absorbed in the infinite medium itself in the absence of an exposed individual. For ground-surface exposure, the dose-rate factors are calculated for a refe.renca position located one meter above a smcoth, infinite plane using the point-kernel integration method and known specific absorbed fractions for photo.
r ' electrons in air.
' - ~ ate conversion factors presented in NUREG/CR-0494 We recomend thi be used by fr-
.ilating doses to man resulting from external 8104280 77Y-
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2-Harold R. Denten. Director ex;;csure to radienuclides.
If you have any questions with regard to this report, please centact Dr. Judith D. Foulke (427-4358).
i Ah Thoras E. Murley ing Director Office of Nuclear Regulatory Research D
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