GENII 2.10: Environmental Radiation Dosimetry Software System
Pacific Northwest National Laboratory, Richland, Washington. Original funding came from the EPA Office of Radiation and Indoor Air.
Pentium running Windows; Fortran and Basic (C00737PCX8602).
FRAMES 1.7/GENII 2.10 replaces GENII 2.09, which has been distributed by RSICC. The GENII system includes capabilities for calculating radiation doses following chronic and acute releases. Radionuclide transport via air, water, or biological activity may be considered. Air transport options include both puff and plume models, each allowing use of an effective stack height or calculation of plume rise from buoyant or momentum effects (or both). Building wake effects can be included in acute atmospheric release scenarios. The code provides risk estimates for health effects to individuals or populations; these can be obtained using the code by applying appropriate risk factors to the effective dose equivalent or organ dose. In addition, GENII Version 2 uses cancer risk factors from Federal Guidance Report 13 to estimate risk to specific organs or tissues. Although the codes were initially developed at Hanford, they were designed with the flexibility to accommodate input parameters for a wide variety of generic sites.
Data entry is accomplished via interactive, menu-driven user interfaces. Default exposure and consumption parameters are provided for both the average (population) and maximum individual; however, these may be modified by the user. Source term information may be entered as radionuclide release quantities for transport scenarios or as basic radionuclide concentrations in environmental media (air, water, soil). For input of basic or derived concentrations, decay of parent radionuclides and ingrowth of radioactive decay products prior to the start of the exposure scenario may be considered. A single code run can accommodate unlimited numbers of radionuclides including the source term and any radionuclides that accumulate from decay of the parent because the system works sequentially on individual decay chains.
The code package also provides interfaces, through the Framework for Risk Analysis in Multimedia Environmental Systems (FRAMES), for external calculations of atmospheric dispersion, geohydrology, biotic transport, and surface water transport. Target populations are identified by direction and distance (radial or square grids for Version 2) for individuals, populations, and for intruders into contained sources.
A stochastic edition of GENII Version 1, named GENII-S (RSICC package CCC-648), was developed for the Waste Isolation Pilot Plant assessments by Sandia National Laboratory. GENII V.2 is completely stochastic, using the FRAMES SUM driver.
Please note that GENII Version 2.10 differs from GENII 1.485, which is the tool box code version endorsed by DOE in response to DNFSB 2002-1. GENII 2.06 incorporated the ICRP standards 56-72 for radiation protection versus earlier versions for GENII 1.485. The new GENII is consistent with the TRU waste standard; however, the old breathing rate from the earlier ICRP standards was used to be consistent with the RADCON manual and other DOE directives.
GENII Version 2.07 Updates
1. Revision of the plume models to accommodate the problem identified in Droppo, J. G., Jr, and B. A. Napier, “Wind Direction Bias in Generating Wind Roses and Conducting Sector-Based Air-Dispersion Modeling,” Journal of the Air and Waste Management Association, 58(7):913-918. This consists of the addition of a small random component to the reported wind direction to ensure that binning errors are minimized. There will be an ~30% reduction in X/Q for N/E/S/W directions, and smaller increases in the other directions for some meteorological input files.
2. A correction of the definition of the “z” parameter for the GENII Lake Model in the surface water module in the UI input description, help file, and SDD.
3. Correction of the reported start time in the EPF file for the second time period for acute releases for non-atmospheric cases. (It was reported as zero, while it should have been a small positive value.)
4. Elimination of the “NOT FOUND” in the release rate summary of the Report Generator in decay chains (caused by a change in handling of decay chains in FRAMES).
5. Correction of a recent FRAMES-induced connectivity issue between User Defined and the GENII Chronic Exposure modules.
6. Addition of a new 95th percentile atmospheric dispersion module. This is a variant of the older acute plume model. 95% is defined using the air concentration; corresponding values of dry and wet deposition and direct finite plume exposure are maintained. The change includes updates to the SDD, Users Manual, and example problems.
7. A problem of dropping of significant figures for values in the range of 0.001 to 0.0099 in the SUM3 user interface has been resolved. Numbers are no longer converted to exponential notation for very large and very small values.
GENII Version 2.08 Updates
A series of very minor updates and corrections to 2.07, including:
1. correcting a flag in GENII Chronic Exposure module to allow output of aquatic plants; correct logic for attaching more than one User Defined source to the Chronic Exposure Module,
2. correcting a data statement in GENII Acute Exposure module to allow calculation of elemental tritium,
3. elimination of an old 16-bit numeric underflow trap in GENII Surface Water module, near-shore lake model to eliminate reporting instabilities under certain conditions,
4. correction of SDD Equation 5.32 (text change only),
5. correction of SDD Equation 11.11 units (text change only),
6. revision to GENII Acute Exposure Module to put default season change dates into external file SEASON.DAT; complimentary revision to Report Generator to print these dates for acute air cases, and
7. update of all files to 2.08; rerun of all example cases.
GENII Version 2.08a updates
Rev. 19 September 2008
1. Only one significant change, involving FRAMES components only, was made. The SUM3 uncertainty/sensitivity driver was not correctly picking up the effective or organ doses for selections made by pathway (effective dose summed over all pathways was working properly) – reported values were all equal to the initial dose on the organ list, adrenals for the FGR13 option. (Proper effective selected for ICRP-30 option).
2. Updated frames.dll included in GENII v.2.08a install package
3. Item 6 of the 2.08a updates for SEASON.DAT was slightly modified to obtain the file from the default directory rather than explicitly the FRAMES directory (code would not run if installed in other than \FRAMES).
4. Update of all reports to 2.08a, rerun of all example cases.
GENII Version 2.09
Significant new functionality was added under contract to U.S. Nuclear Regulatory Commission.
1. The GENII Surface Water (SW) module was enhanced to add consideration of impoundments for SW releases prior to discharge into rivers or lakes. This involved new Fortran coding as well as additional inputs to the Surface Water UI.
2. A new Biota Dose module was added. This module uses the environmental parameters developed for the human Chronic Exposure module, with much of the same logic for accumulation and loss in the environment. A limited number of reference organisms are provided. This required new Fortran coding, a new Biota Dose UI, and additions to the GENII.mdb database.
3. Significant revisions were made to the Atmospheric Release Report Generator, including the capability to implement a food-distribution network for population doses, reporting by nuclide, by pathway, and user selection of output units. This required new Fortran coding and updates to the Air Report Generator UI.
4. A new Surface Water Report Generator, parallel in function to the Air Release Report Generator, was added. The combination includes a new Surface Water Report Generator UI.
5. These new capabilities are described in updates to the GENII Software Design Document and Users Manual; a new biota example was added.
6. Enhancements were made to the GENII database, so that default solubility classes are now available in the Health Impacts UI.
7. Corrections were made to the FRAMES XLSChart capability, which provides viewers for intermediate data. This module was not handling cases in which non-decay-progeny nuclides had zero release and therefore all zero consequences.
8. The water immersion dose factor in GENII.mdb had a units correction; prior versions were low by a factor of 1000 due to incorrect units.
9. In earlier versions, the factor of 2 difference between swimming and boating was missing—this has been added.
10. The atmospheric Puff model UI interfaces were updated so that intermittent loss of input data upon re-entry was avoided.
11. Incorrect handling of user-selected units in the Health Impacts UI, Method Parameters tab was corrected.
12. Minor updates were made to labels in the DES files for Exposure and Surface Water modules.
13. Corrections were made to handling of the error reporting files; stops due to errors should be more graceful in many instances now.
GENII Version 2.10
Version 2.10 was released on an expedited basis to correct two significant errors found in the water and air report generators. It also includes several less-significant upgrades to version 2.09 functionality. The significant errors are:
1. The user input of population and food production grids in the Atmospheric Pathway Report Generator, introduced in Version 2.09, was found to be mislabeled by one sector. Existing files were imported and functioned correctly if prepared as described in the Users Guide, but the labeling in the User Interface was incorrect. The sectors begin in the first sector clockwise from north (e.g., 22.5 degrees if 16 sectors are used or 10 degrees if 36 sectors are used) and the final sector is north (0/360 degrees). Labels have been corrected to prevent user misinterpretation; additional discussion of the intermediate files has been added to the Users Guide.
2. The summary output of the Surface Water Report Generator was not including Drinking Water because of a difference in labeling between the User Interface (i.e. “Drinking Water,” “ingestion”) and the calculation module (i.e., “Water,” “ingestion”). The calculation module has been revised to accept either or both as equivalent. The population was not correctly used in the estimation of population cancer incidence; this has also been corrected.
Other changes include:
3. increasing the allowable volume of an impoundment in the Surface Water User Interface to 1E10 (independent of units),
4. revising the Surface Water module so that the time integration of the source is performed using the times input in the Source Term module rather than the “Duration of the Release” input parameter,
5. revising the label of the surface contamination in the Acute Puff module to “Total Deposition” (This has no user impact; it makes future conversion from FRAMES 1.7 to FRAMES 2.x possible.),
6. revising the Chronic and Acute Exposure modules to include drinking water consumption by farm animals in the tritium/carbon-14 model from surface water sources even if irrigation is not turned on,
7. a small addition to the Users Guide, Appendix B, indicating to meteorologists that in the absence of all precipitation data a value of “0” rather than “>6” be used for the precipitation code (If all precipitation data are indicated as being missing, the code would cycle through all hours without producing an answer.),
8. a related change in all GENII atmospheric dispersion modules to trap errors where the precipitation code input is set to zero but a non-zero precipitation rate is entered (The precipitation code is assumed to be dominant; if it is zero then precipitation rates and types are also assumed to be zero.),
9. a revision to FRAMES and the Contaminant Database module to allow users to add references while in standard use mode, rather than only in stand-alone mode,
10. the Surface Water viewer address/location fields were expanded, and the food production summary table was cleaned up to eliminate unneeded zeros, and
11. corrected FRAMES and DoAll to eliminate occasional annoyance closings of the code,
12. revised incorrect labels in the database for ICRP-30 ingestion dose factors; soluble and insoluble labels were interchanged (This has no calculation effect because the code currently selects the larger of these regardless of label.).
Available release scenarios include chronic and acute releases to water or to air (ground level or elevated sources), and initial contamination of soil or surfaces. GENII implements the NRC models in LADTAP for surface water doses. GENII does not explicitly include modules for performing groundwater transport calculations; however, the FRAMES system allows addition of other computer modules to the GENII system. Exposure pathways include direct exposure via water (swimming, boating, and fishing), soil (surface and buried sources), air (semi-infinite cloud and finite cloud geometries), and inhalation and ingestion pathways. The tritium model includes consideration of both gas and vapor, conversion of gas into vapor, and biological conversion of both into organically-bound tritium.
GENII Version 1 implemented dosimetry models recommended by the ICRP in Publications 26, 30, and 48, and approved for use by DOE Order 5400.5. GENII V.2 implements these models plus those of ICRP Publications 56 through 72 and the related risk factors published in Federal Guidance Report 13. Risk factors in the form of EPA developed “slope factors” are also included (these are a special subset of the FGR-13 values). These dosimetry and risk models are considered to be “state of the art” by the international radiation protection community and have been adopted by most national and international organizations as their standard dosimetry methodology.
Various structural limitations on data input are described in the users’ manual. Of note: the atmospheric dispersion modules are limited in output format; the chronic or acute plume models use either 16 or 36 compass directions and 1 to 10 distances, and the chronic and acute puff models have a maximum grid array of 21x21 nodes. Population distribution input files MUST match the geometry of the atmospheric dispersion output (ATO) file based on the choice of plume/puff and selection of number of radii/distances or grid nodes.
Running times vary.
GENII V.2 runs on Pentium computers under Windows and requires a minimum of 80 MB on-line disk storage. The codes will generally run fastest on machines with 256 Mbytes of memory or more.
Executables included in this package were tested under Windows XP and Windows 7. The GENII developer created these executables under Windows using Visual Basic 6 for the interfaces and Digital Visual Fortran for GENII modules. Source codes are not included in this distribution.
“Getting Started With GENII Version 2, Full Edition.”
B. A. Napier, GENII Version 2 Users’ Guide, PNNL-14583, Rev. 3a (June 2010).
B. A. Napier, et al. GENII Version 2 Software Design Document, PNNL-14584, Rev. 3 (December 2009).
Enclosed are the references listed above and the executable programs, sample cases and data files on a CD in a Windows installer (InstallShield Wizard) file.
April 2007, February 2010, September 2010.
KEYWORDS: ENVIRONMENTAL DOSE; FISSION PRODUCT INVENTORY; INTERNAL DOSE; LIQUID PATHWAY; MICROCOMPUTER; RADIOACTIVITY RELEASE; RADIOLOGICAL SAFETY; RADIONUCLIDES