[ RadSafe ] Announcement - Catalogue of Radiological Risk Assessment Parameters

[Philip Egidi]

Members of RADSAFE,

Please take a moment to review the following announcement of interest
to risk assessors.

The federal Interagency Steering Committee On Radiation Standards
(ISCORS) has prepared a web-based catalog of information on existing
sources of environmental modeling data, entitled ISCORS Catalog of
References to Parameter Values and Distributions Used in Environmental
Pathway Modeling for Cleanup of Sites Contaminated with Radioactivity. 
It is found at http://web.ead.anl.gov/iscors/.

The catalog is a national repository of information on parameter values
and distributions.  The website contains indexed and searchable
compilation of references and other sources of peer-reviewed information
on parameters used in contaminant transport and exposure modeling. The
website is designed to be easy to use and easily updated. The risk
assessment community is encouraged to utilize this site as a source of
information and to submit additional references for parameters to the
catalog.

The catalog does not contain numerical point values or probabilistic
distributions for any particular input parameter, but rather provides
links or directions to sites or other published materials where such
information can be obtained.  It also provides general information on
the parameters (such as definitions, units, and applicable measurement
methodologies), relationships among similar or identical parameters as
used in different models, code-specific variations in naming or use of a
particular parameter, exposure pathways containing or affected by the
parameter, etc., that may help with their use.  

Very importantly, the contents are vetted before entry, which should
provide some degree of assurance on the quality of the parameter
information contained in the source.  Acceptance criteria include
publication in a peer-reviewed technical journal, appearance in a
formally-issued federal agency report, etc.
	
The catalog offers subject- and text-search capabilities.  It provides
information on parameter definitions, on transport/exposure pathways,
and on standard models and codes, and contains a tutorial and frequently
asked questions (FAQs) page.  The website is intended to be used by
professionals, managers, and others involved or interested in the use of
pathway modeling to determine the doses and risks associated with
contaminated sites.

Initial focus has been on parameters that appear in four specific
models:  DOE's RESRAD  (including ecosystem-exposure parameters of
RESRAD-BIOTA), NRC's DandD, EPA's Radionuclide PRG Calculator, and
DOE/EPA's GENII 2.  Although many variables are common to two or more of
the models/codes, their names or precise definitions may differ
somewhat, so it has been necessary to determine relationships among them
and organize their presentation.  While these models together contain
hundreds of parameters, those selected for initial entry into the
database include at least the 47 for which distributions were developed
in NUREG/CR-6697 and NUREG/CR-5512, Volume 3.  

The system employs a Microsoft Access 2000 relational database with
separate tables for model/parameter information, contaminant
information, source document information, source author information, and
source document/parameter information. Relevant information is presented
to the web site user through an intuitive interface that queries the
database dependent on the options selected by the user.

At present, more than 300 references have been entered into the
catalog.  The entries include references for radionuclide-specific
parameters, such as gamma ray shielding factors, and also
element-specific ones, such as distribution coefficients and transfer
factors. These models together contain more than five hundred
differently-named parameters, but many of them are found to be
equivalent (or nearly so) to a basic set of about one hundred common,
shared parameters (referred to as common parameters).  The
model-specific name is retained as the common name for those parameters
that appear in only one computer code or model.

It is intended, however, that over the long run, the database will be
enlarged on an on-going basis primarily through user submissions by one
of two methods.  One option allows users to provide general
bibliographic information to ISCORS about a reference for consideration
by the web site managers who will then enter the appropriate information
into the catalog.  A second allows users to submit proposed references
to the web site managers via a mechanism that makes possible rapid entry
of the complete reference information into the catalog database. 
Following a QA check and approval, the submitted item is then
automatically placed in the database and made available to the user
community.

Please consider taking a few minutes to visit the catalog and
submitting references to the database.  Keeping the catalog relevant
will depend on all of us.  If you have additional questions about the
catalog, contact Mark Thaggard, (US NRC) at 301-415-6971 or mxt3 at nrc.gov
.

(Member organizations of ISCORS are the EPA, the NRC, the DOE, the DoD,
other Federal Agencies, and for this project, the State of Colorado,
representing the states).

******
Submitted by Phil Egidi
Colorado Department of Public Health and Environment
phil.egidi at state.co.us