Data Category Parameter Names
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Job Control IFTODO, IRTYPE, JC
Source Terms FRADON, IPACT, NSORCE, PACT, QAJUST, SORCE,
IPSOL, PTSZ, PTSZFC, FAS, SRNS, HDP
Meteorology DMM, DMA, FREQ
Food Pathway Parameters FFORI, FFORP, FHAYI, FHAYP, FPR
Population Distribution IPOP, PAJUST
Individual Receptors IADD, XRECEP
Time History NSTEP, TSTART, TSTEP
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- Job Control Parameters
The array IFTODO is used in conjunction with the time history data to control calculation and printing of doses for each time step. The array IRTYPE requests output reports for each individual receptor location. The array JC controls selection of calculational options and report selections.
- Source Term Parameters
Multiple release points may be defined as input to the MILDOS-AREA program. The number defined for a run is specified by the parameter NSORCE. The location, rate of release, and characteristics of each release are defined in the array SORCE. Additional data are defined for area sources, such as tailings piles, where wind suspension is the main driving force for entry to the atmosphere. The sample area source isotopic composition mixes (specific activity in pCi/gm) are defined in array PACT. Three composition mixes may be defined to represent different ore mixes. The array IPACT then assigns these composition mixes to represent each area source as appropriate. For characterizing fixed particulate release rates for area sources (corresponding to the three isotopic composition mixes) array FAS is used. The code would generate the wind-erosion source term for particulate releases if FAS < 0.0. Similarly array SRNS defines the radon release rates.
The population dose to persons beyond the 80-km radius is estimated from radon releases characterized by the nearest of the following four sites: Casper, Wyoming, Falls City, Texas, Grants, New Mexico, Wellpinit, Washington.
The array FRADON is used to select the radon release characteristics for one of these sites or as a geographic weighted average of the four sites. The release rate during each time period is defined by the array QAJUST, and this array is used to adjust the release data in the SORCE array. This flexibility in source term specification is necessary over the lifetime of a uranium mill to account for transitions in operations.
Particle size distribution data is used in the atmospheric transport calculation by MILDOS-AREA. Three particle size distribution sets are available as internal data in MILDOS-AREA. The element SORCE(11,I) selects one of these sets to represent each source I.
- Meteorological Parameters
Average meteorological data characteristics at the mill center are required as input to MILDOS-AREA. The data array FREQ is used to provide the annual average fractional frequency of occurrence of wind speed, wind direction and atmospheric stability. Data are supplied for 16 wind directions in the order N, NNE, NE, ENE, E, ESE, SE, SSE, S, SSW, SW, WSW, W, WNW, NW, NNW; 6 wind speed classifications in the order 0-3, 4-7, 8-12, 13-18, 19-24, >24 mph; and 6 Pasquill atmospheric stability categories in the order A - extremely unstable, B - moderately unstable, C - slightly unstable, D - neutral, E - moderately stable, F - very stable. (The wind direction is the direction the wind is blowing from.) In addition to the joint frequency array, the annual average morning (DMM) and afternoon (DMA) mixing heights are provided.
- Food Pathway Parameters
Several parameters used in the food pathway model must be supplied by the user. Four parameters are required for the animal product pathway describing the feeding habits of livestock near the mill site. The parameters FFORI and FFORP give the fraction of total annual feed requirements that are provided as pasture grass for the individual doses and population doses respectively. The parameters FHAYI and FHAYP give the fraction of total annual feed requirements that are provided as locally grown stored hay for the individual doses and the population doses, respectively. These numbers are fractions that must be entered as nonnegative real numbers between 0 and 1. A default value of 0.5 is used for any of the above parameters that are not supplied in the input set. Further restrictions on the parameters are: FFORI + FHAYI < or = 1.0, and FFORP + FHAYP < or = 1.0. The array parameter FPR gives the food production rate for the region for three food types: vegetables, meat, and milk.
- Population Distribution Parameters
The population distribution within 80 km of the mill center is provided by the integer array IPOP. This array gives the number of people living in each of 12 distance intervals in 16 downwind directions. The distance intervals are (km): 1-2, 2-3, 3-4, 4-5, 5-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80. The direction representations are the same as for the meteorological parameter FREQ.
The population dose calculations beyond 80 km are based on total U.S. population growth relative to the year 1978. The array PAJUST gives the relative population during each time step compared with 1978 population.
- Receptor Location Parameters
The parameter IADD gives the number of individual receptor locations to be considered, and the array XRECEP gives coordinates defining the locations.
- Time History Parameters
This data set describes the time history of the mill operation. The year of initial release is given by parameter TSTART. The mill lifetime is divided into timesteps based on transition points in the mill life and tailings management plans, such as changing from dry grinding to a semi-autogenous grinding. Up to 10 timesteps can be defined. The number of timesteps is specified by NSTEP, and length of each timestep is given in array TSTEP.