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Source Term Information

STWG Products and Papers

The following items have been developed by the STWG:

  • Source Term Factors: This presentation was developed for individuals that are new to hazards analysis to provide familiarization with source term terminology and concepts. The training tool describes each of the components of the source term and discusses factors that may influence the final results. Basic examples are also included to illustrate the concepts.

  • Applicability of DOE-STD-5506 to EPHA Analysis: This document was developed to highlight the key areas of the U.S. Department of Energy (DOE) Standard Preparation of Safety Basis Documents for Transuranic (TRU) Waste Facilities (DOE-STD-5506) and provide a recommendation regarding the possible use of the data in Emergency Planning Hazards Assessments (EPHA) analyses. The DOE-STD-5506-2007 (referred to as the “TRU Standard”) provides analytical assumptions and methods, as well as hazard controls to be used when developing Safety Basis documents for TRU waste facilities in the DOE Complex. The main focus of this paper is on the Identification and Evaluation of TRU Waste Events and TRU Waste Source Term Analysis sections of the TRU Standard and the potential applicability of the data to EPHA analyses.

Radiological Source Term Information

  • A key reference on radiological source terms is DOE Handbook--Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities (DOE-HDBK-3010-94).  The handbook is available online at http://energy.gov/hss/downloads/doe-hdbk-3010-94-0.

The handbook provides a compendium and analysis of experimental data from which airborne release fractions (ARFs) and respirable fractions (RFs) may be derived.  These values are used to estimate quantities of radioactive material that may become airborne in a release event.  This information is used to estimate the scope of the potential release spectrum and potential downwind consequences from a given facility or activity. The information provided in this handbook aids in making such estimates.  The data in the handbook can be used in a variety of applications, such as safety and environmental analyses, and to provide information relevant to system and experiment design.   The handbook cautions that the data and analyses it provides need to be critically evaluated for applicability in each situation in which they are used. 

  • In May 2006, the Chairman (A.J. Eggenberger) of the Defense Nuclear Facility Safety Board, reported as part of their comments on the DOE Nuclear Material Packaging Manual  (see http://www.dnfsb.gov/sites/default/files/Board%20Activities/Letters/2006/ltr_200651_4821.pdf ) that “for calculating consequences impacting safety to workers in the immediate vicinity of a radioactive material release from a package,” “the methodology derived from DOE‑HDBK-3010 contrasts with the technical simplicity and regulatory precedence associated with the more conservative methodology based on net intake factor used to calculate the “A2 values specified in 49 CFR 173.435, Shippers―General Requirements for Shipments and Packagings”(see http://edocket.access.gpo.gov/cfr_2009/octqtr/pdf/
    49cfr173.435.pdf
    )

The letter further reports that the “A2 values have long been accepted as adequately conservative by numerous regulatory bodies, including the U.S. Department of Transportation, the U.S. Nuclear Regulatory Commission, and the International Atomic Energy Agency.  The A2 methodology, as applied in the manual, offers a simple, defensible way to determine material thresholds for facility workers by adjusting dose consequences to account for the receptor differences between a nuclear facility worker and a member of the public.”  These comments and the A2 methodology mentioned were discussed in reference to transportation-type accidents and specifically regarding calculating material thresholds for packaging purposes; therefore, the information should be interpreted appropriately, considering these circumstances.

Chemical Source Term Information

There are a number of places to access useful information on chemical source terms.  These include:

Biological Source Term Information

Biological Source Term Information will be added as it is identified by our working group members and made available.