Document Details

PATHWAY: A DYNAMIC FOOD-CHAIN MODEL TO PREDICT RADIONUCLIDE INGESTION AFTER FALLOUT DEPOSITION ( HEALTH PHYSICS, VOL. 52, NO. 6, JUNE 1987, PP. 717-737 )

WHICKER, F W [COLORADO STATE UNIVERSITY]; KIRCHNER, T B [COLORADO STATE UNIVERSITY]

MATHEMATICAL MODELS; FOOD CHAINS; CALCULATION METHODS; RADIONUCLIDE MIGRATION; FALLOUT; RESEARCH PROGRAMS; RADIONUCLIDE KINETICS; HUMAN POPULATIONS

Location - DOE/NNSA NUCLEAR TESTING ARCHIVE Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - NTA@NV.DOE.GOV

JOURNAL ARTICLE

1987 Jun 30

Never classified

0021

NV0067444

HEALTH PHYSICS - JOURNAL

1994 Aug 26

2003 Sep 18

THIS MANUSCTIPT DESCRIBES THE STRUCTURE AND BASIS FOR PARAMETER VALUES OF COMPUTERIZED FOOD-CHAIN TRANSPORT MODEL FOR RADIONUCLIDES. THE MO DEL, CALLED "PATHWAY," ESTIMATES THE TIME-INTEGRATED INGESTION INTAKE BY HUMANS OF 20 RADIONUCLIDES AFTER A SINGLE DEPOSITION FROM THE ATMOS PHERE TO THE LANDSCAPE. THE MODEL SOLVES A SET OF LINEAR, COUPLED DIF FERENTIAL EQUATIONS TO ESTIMATE THE INVENTORIES AND CONCENTRATIONS OF RADIONUCLIDES IN SOIL, VEGETATION, ANIMAL TISSUES AND ANIMAL PRODUCTS AS A FRNCTION OF TIME FOLLOWING DEPOSITION. DYNAMIC PROCESSES IN THE MODEL INCLUDE FOLIAR INTERCEPTION, WEATHERING AND ABSORPTION: PLANT GR OWTH, UPTAKE, HARVEST AND SENESCENCE: SOIL RESUSPENSION, (CONTINUED) (CONTINUED) PERCOLATION, LEACHING AND TILLAGE: RADIOACTIVE DECAY; AND LIVESTOCK INGESTION, ABSORPTION AND EXCRETION. HUMAN DIETARY DATA ARE INCLUDED TO PERMIT CALCULATION OF TIME-DEPENDENT RADIONUCLIDE INGESTI ON RATES, WHICH ARE THEN NUMERICALLY INTEGRATED. THE MODEL CONSIDERS SEASONAL CHANGES IN THE BIOMASS OF VEGATATION AND ANIMAL DIETS, AS WELL AS SPECIFIC PLOWING AND CROP-HARVEST DATES; THUS THE INTEGRATED RADIONUCLIDE INTAKES BY HAUMNS ARE DEPENDENT ON THE SE ASONAL TIMING OF DEPOSITION. THE AGRICULTURAL DATA BASE REPRESENTS TH E ARID AND SEMI-ARID REGIONS OF THE WESTERN UNITED STSTES. THE FOLIAR DEPOSITION PARAMETERS APPLY TO REGIONAL (CONTINUED) (CONTINUED) FALLOUT OUT TO A FEW HUNDRED MILES FROM NUCLEAR DETONATION S AT THE NEVADA TEST SITE. WITH NODIFICATION, THE MODEL COULD BE APPL IED TO CHRONIC OR OTHER ACUTE RELEASES, PROVIDING THE GROUND DEPOSITIO N IN BECQUEREL METER E-2 COULD BE ESTIMATED. THE OUTPUT OF PATHWAY (B ECQUEREL INGESTED PER BECQUEREL METER E-2) MAY BE MULTIPLIED BY THE DE POSITION AND DOSE CONVERSION FACTOR (GRAY BECQUEREL E-1) TO YIELD AN ORGAN-SPECIFIC DOSE ESTIMATE. THE MODEL MAY BE RUN DETERMINISTICALLY TO YIELD SINGLE ESTIMATES OR ST OCHASTICALLY ("MONTE-CARLO" MODE) TO PROVIDE DISTRIBUTIONAL OUTPUT THA T REFLECTS UNCERTAINTY IN THE OUTPUT DUE TO UNCERTAINTY (CONTINUED) (CONTINUED) IN PARAMETERS. TESTS OF THE PREDICTIVE ACCURACY ARE BRIEF LY DESCRIBED AND WORK PUBLISHED TO DATE ON VALIDATION TRIALS IS CITED.