ML19289E422
| ML19289E422 | |
| Person / Time | |
|---|---|
| Issue date: | 03/23/1979 |
| From: | Foulke J NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Swanberg F NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| NUDOCS 7904170532 | |
| Download: ML19289E422 (4) | |
Text
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NUCLEAR REGULATORY COMMISslON g
g WASHINGTON, D. C. 20555 o
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MAfi L L 1979 MEMORANDUM FOR:
F. Swanberg, Jr., Chief Environmental Effects Branch Division of Safeguards Fuel Cycle and Environmental Research FROM:
Judith foulke Environmental Effects Branch Division of Safeguards, Fuel Cycle and Environmental Research
SUBJECT:
RESEARCH REVIEW GROUP MEETING:
INHALATION T0XICOLOGY RESEARCH INSTITUTE'S EARLY MORBIDITY AND MORTALITY ESTIMATES FOR DIFFERENT NUCLEAR ACCIDENTS (A1203)
On March 16, 1979 staff members of the Inhalation Toxicology Research Institute (ITRI) met with NRC staff in Silver Spring, Maryland to discuss their activities during Phase I of the project entitled, "Early Morbidity and Mortality Estimates for Different Nuclear Accidents." Individuals in attendance and their affiliations are listed in Enclosure 1.
F. Hahn, ITRI, presented an overview of the project, which had the ob-jective of developing a computer-based simulation model to predict early mortality and morbidity in a population exposed to radionuclides released during a postulated accident.
During Phase I ITRI, in a joint effort with Battelle Pacific Northwest Laboratories, (PNL), examined the esisting data on early health effects of inhaled radioactive materials and acute whole body external exposure. He noted that ITRI has developed a model to predict early deaths but has not yet initiated the morbidity model.
Following discussion of some questions concerning metabolic models used in calculating internal doses and the usefulness of extrapolating animal data to man, he sunmarized the research needs which must be filled to refine estimates of early mortality.
M. Parsont, OSD, stated that there appeared to be some overlap in the research proposed for Phase II.
F. Hahn explained that in one case the whole body exposure would be given externally before the inhalation exposure.
In the other case, the whole body dose would result from inhalation of soluble radionuclides.
G. N. Kelly, NRPB, asked if human models were being applied to calculate doses to dogs.
R. Cuddihy explained that doses were determined from measure-ments of retention of radionuclides in dogs and on whole body counting and tissue analyses at death or scheduled sacrifices.
G. N. Kelly also questioned what is included in the lung dose.
R. Cuddihy answered that it includes everything below the trachea.
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F. Swanberg, Jr. %.
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B. Scott presented the hazard-function method of resolving radiation dose-response relationships. Since the binomial estimate of number affected divided by number exposed is incorrect, it is necessary to correct for wasted dose.
J. Foulke asked for a specific exampic to illustrate the dettonination of Rsc, the subcritical dose rate, and Dco, the cutoff dose.
B. Scott discussed the empirical dose-response models developed for lung, bone, and the gastro-intestinal tract. He noted that radiation-induced pulmonary injury sufficient to cause death from early effects depends on the temporal distribution of the absorbed dose for beta emitters, but not for alpha emitters. There did appear to be an effect due to specific activity for alpha emitters. He pointed out that bone marrow response is species-dependent.
In order to extrapolate animal data to man, a scaling r' cedure is used. This is done by assuming that,the ratio of the D50 to tne D10 is the same for man and dog.
S. Yaniv asked if ITRI had considered inter-organ synergism.
B. Boecker stated that it was premature to say if it was necessary, ITRI will see if the model, as developed, gives the correct answers when experimental data are available.
S. Yaniv also asked if nasal effects were considered.
R. Cuddihy answered that this would come under morbidity rather than mortality.
R. Cuddihy next described the two computer programs DOSE and EFFECT. These will be provided to NRC as modules.
J. Foulke asked R. Blond if he would be able to run them and he indicated agreement.
Modifications to INREM II, such as elimination of the quality factor, were described. A table giving rads per microcurie calculated by ORNL and by ITRI showed excellent agree-ment.
R. Cuddihy presented a comparison of the predictions of early mortality for exposure to various radionuclides for a range of lung and bone doses ob-tained using the Reactor Safety Study Model, the Wells Model, the Goldman Model, and the ITRI Model.
R. Cuddihy emphasized that these models were designed for different purposes so that it is not possible to go beyond showing their relative capabilities for reproducing the data that were originally used to build the models. When the lung is the critical organ, all models predict that animals receiving over 30,000 rads in the first year will die and that those receiving less than 10,000 rads will live. The predictions differ for doses between these limits.
The final subject of discussion was Phase II.
F. Swanberg asked what coordination there w~s with PNL in arriving at the proposed research.
F. Hahn stated that there was no conflict or duplication between what the two laboratories were proposing to do.
F. Swanberg directed ITRI to submit a
nan
, 19,y F. Swanberg 189 referencing the work proposed by PNL.
B. Boecker stated that ITRI had 20,000 - $25,000 remaining.
'M uO'A dith D. Foulke Environmental Effects Branch Division of Safeguards, Fuel Cycle and Environmental Research
Enclosure:
List of Attendees
List of Attendees Nuclear Regulatory Commission S. Acharya, NRR M. Au, NMSS R. Blond, RES E. Branagan, NMSS J. Foulke, RES B. Immennan, RES M. Parsont, SD P. Psomas, NMSS F. Swanberg, Jr., RES S. Yaniv, RES Inhalation Toxicology Research Institute B. Boecker R. Cuddihy F. Hahn B. Scott National Radiological Protection Board (U.K.)
G. N. Kelly