DOE’s Technical Standard for

Evaluating Radiation Doses to Biota:

Overview of the Graded Approach

DOE’s Technical Standard for

Evaluating Radiation Doses to Biota:

Overview of the Graded ApproachBiota Dose Assessment Committee Meeting

Washington, DC

August 18 - 20, 1999

- Stephen Domotor - Environmental Policy and Assistance

Air, Water and Radiation Division (EH-412)

Presentation OutlinePresentation Outline

Guiding Principles for Methods Development

Biota Dose Assessment Committee

Process Employed in Methods Development

DOE’s Graded Approach for Compliance

Biota Manual, Spreadsheets, and Database

Issues and Opportunities

Path Forward

Guiding Principles for DOE Methods Development

Provide a graded approach for multiple users

Easy to use and technically sound

Utilize existing generic and site-specific data

Applicable to multiple media

Incorporate eco-risk framework

Interdisciplinary team approach

Provide leadership in methods development

Biota Dose Assessment Committee

Formed June 1998 under DOE’s Technical Standards Program

An interdisciplinary team (health physics; radioecology; dose assessment; environmental monitoring)

Broad representation (DOE sites; labs; universities)

DOE focal point for biota dose assessment

Primary role in Biota Manual development

Advisory role to Program and Operations Offices

Web Site http://tis-nt.eh.doe.gov/oepa/public/bdac

BDAC Technical Standard Writing GroupBDAC Technical Standard Writing Group

Ernie Antonio (Pacific Northwest National Lab)

Gordon Bilyard (Pacific Northwest National Lab)

Steve Domotor (Dept. of Energy)

Gary Friday (Westinghouse Savannah River Co.)

Kathy Higley (Oregon State Univ.)

Dan Jones (Oak Ridge National Lab)

Dave Kocher (Oak Ridge National Lab)

Brad Sample (CH2M Hill)

A Process That Involves Users and Developers of the Method A Process That Involves Users and Developers of the Method

A consensus-based process

BDAC Core Team prepared the strawman

Full BDAC review at each phase

Selected outside reviewers

Issues resolved via conference calls & Web Site

ISCORS inter-agency coordination initiated

BDAC workshop to pilot and refine the method

DOE Technical Standards Approval Process

DOE’s Graded ApproachDOE’s Graded Approach

Compare mediaconcentrations with BCGs

1 DataAssembly

2 GeneralScreening

Site-representative parameters

3 AnalysisSite SpecificScreening

Site SpecificAnalysis

Site SpecificBiota DoseAssessment

Kinetic modeling tool

Eco-risk framework

Receptors Used in Deriving the Screening MethodologyReceptors Used in Deriving the Screening Methodology

BCGs

aquatic riparian terrestrial terrestrial

animal animal animal plant

Biota Concentration GuidesBiota Concentration Guides

Biota Manual

USING THE GRADED APPROACH (user-friendly)

– Applications and Exclusions

– Look-up tables and Step-by-Step Guidance

APPENDICES (detailed references and technical basis)

– Time averaging and spatial variability

– Biota sampling methods

– Default parameter values

– Derivation of screening and kinetic model equations

– Radiation weighting factor for alpha particles

User Friendly SpreadsheetsUser Friendly Spreadsheets

Encodes Method– Microsoft Excel®

– Visual Basic®

Automated CalculationsAutomated Calculations

Site-Specific ModificationsSite-Specific Modifications

Helpful Reference NotesHelpful Reference Notes

A Web-Accessible DatabaseA Web-Accessible Database

Supports DOE approach and other methods

Contains parameter data (Kds; Bivs) & references

Users can add, edit and search for data remotely

Users can search by multiple attributes:– nuclide; parameter, taxonomic group, organism type, soil

type, reference

A prototype is available within the BDAC

Issues and OpportunitiesIssues and Opportunities

Technical -

– Radiation weighting factor for alpha-emitters

– Vertical transport of radionuclides by plants: considerations for soil sampling

– Adjustments for size of contaminated zone and organism home range

– Compilation and “benchmarking” of models and methods

– Risk management options following an indication that dose limits are potentially exceeded

Interest and Support -

– Strong interest from the radioecology community, local regulators, private sector, and internationally

Successes and a Path Forward for Continued Progress

Early Work Oct 1996 and Dec 1997 trial approaches

Jun 1998 BDAC Formed

Dec 1998 Draft Biota Manual/new method completed

Jan 1999 IAEA Technical Committee Meeting

Jan - Feb 1999 Biota Manual reviewed within BDAC

Jan - Jul 1999 Refine and pilot (5/99) database

Mar - Apr 1999 Assess and resolve comments

Apr - Jul 1999 Refine spreadsheets and Biota Manual

May 1999 International Symposium (Canada)

Jun 1999 Health Physics Society Annual Mtg.

Aug 1999 BDAC Meeting/Workshop

Sep - Oct 1999 Final Biota Manual to DOE TSP/External