Skip to content

December 2009

It’s been a busy 2009 for the SCAPA.  Updated versions of the Protective Action Criteria/ Temporary Emergency Exposure Limits (PAC/TEEL) data set (“Revision 25”) and the Chemical Mixture Methodology (CMM) data set (also called “Revision 25” to emphasize its compatibility with PAC/TEEL Revision 25) have been released.

PAC/TEEL Revision 25 provides protective action information for 3,373 chemicals.  See the PAC/TEEL webpage for a link to the PAC/TEEL data set and associated documentation.   The data set is still provided in three different formats: an Excel workbook, formatted data tables, and a searchable database.

The first comprehensive review and update of all the chemical data used in deriving PAC/TEEL data began in 2008, continued in 2009, and should be completed in 2010 or 2011.   This process began with the review of all chemicals whose PAC/TEEL values are based on regulatory limits.  Updates to these chemicals are incorporated in PAC/TEEL Revision 25.  The review team has also completed the update of an initial group of 760 chemicals that use toxicity-based exposure limits.   These 760 chemicals include all chemicals on the TEEL list prior to 1997.  Additional chemicals will be accessed in 2010.  PAC/TEEL Revision 26 will likely be released sometime in the first half of 2010.  Revision 26 will incorporate all those chemical updates that have been completed and quality assured prior to a designated cutoff date.

In addition to updating existing chemical data, an external review of the PAC/TEEL development methodology was conducted in 2009.  Recommendations from the external review committee have been provided to NA-41 and the TEEL Advisory Group (TAG).   A path forward is being plotted and some modifications in the TEEL methodology for deriving PAC/TEEL values will likely be instituted.  However, don’t look for a change in the PAC/TEEL development methodology to show up in the PAC/TEEL data set until Revision 27.

CMM Revision 25 represents the culmination of a two year effort to make the CMM and PAC/TEEL data sets compatible.  In the past, the CMM has lagged one or more revisions behind the PAC/TEEL data set.   Now the two products are moving forward in lock-step, with Health Code Numbers (HCNs) available in the CMM for all the chemicals in the PAC/TEEL data set.   See the CMM webpage for a link to the CMM Revision 25 data set and user’s guide.

A multi-year year effort to review and update all the HCN data in the CMM database continued this year.   In 2009, the HCNs for about 1,000 chemicals were reviewed and updated.  This review began with the first batch of chemicals ever entered into the CMM and includes the chemicals most often used in CMM analyses.   Research interns Phil Bouslaugh and Donna Trott, working under the direction of Xiao-Ying Yu and Rocky Petrocchi, performed the HCN review.  Quality assurance work on the updated HCN data for the 1,000 chemicals is scheduled to be completed in early 2010 and these updates should be included in CMM Revision 26.  Review work on the next batch of 1,000 chemicals will begin in the spring of 2010.

A journal article on the CMM and the HCN development methodology was drafted in 2009 and will be submitted for publication in early 2010.

In the consequence assessment arena, 2009 saw the drafting of a SCAPA Software Quality Assurance (SQA) guidance document for safety-related and other non-safety consequence assessment models.  This guidance will provide an important supplement to the existing DOE order and guide for safety software.   As 2009 draws to a close, the SCAPA SQA document is undergoing final technical editing and should be posted for use in early 2010.  Once that occurs, DOE consequence assessment model developers will conduct a gap analysis on their SQA programs and will work to close any identified gaps before the end of FY10.   A revised SCAPA modeling toolbox will be released in early 2010.  The toolbox will provide a list of models that currently adhere to the SCAPA SQA guidance or are working to close any remaining SQA gaps.

In the biosafety arena, the SCAPA Biosafety Working Group has been addressing a number of issues related to emergency preparedness and response.   Some of their accomplishments in this arena include the publication of a white paper on the transport and dispersion of biological agents and toxins for emergency preparedness applications, the formation of an alliance with the American Biological Safety Association (ABSA), and participation in the work of the Federal Biosecurity Working Group.

The revitalized Source Term Working Group was quite active in 2009.  Under the leadership of Michele Wolgram, this group is tackling a series of technical issues important to the DOE emergency preparedness community.   This includes an assessment of potential transuranic (TRU) source terms, source terms for ball-milled Pu-238, and the appropriate use of dose equivalent curies for source term characterization.

The 2010 annual EMI SIG and SCAPA meetings will be held May 3-8, 2010 in Las Vegas, NV at the Renaissance Las Vegas Hotel.  The Renaissance is a non-gaming, smoke-free hotel and is located just two blocks away from the legendary Las Vegas Strip. The Hotel has 548 spacious guest rooms and suites, a steakhouse and lounge, pool, a 24-hour business center, and workout facilities. 

This year’s SCAPA annual meeting will move from its traditional all-day Thursday time slot to an extended Monday afternoon time slot.  There are a number of advantages and disadvantages to this move, and we will assess the net impact of this change after this year’s meeting.   On the plus side the shortened meeting week will save resources (one less day on travel).  Also some presentations that would normally have been presented at the SCAPA meeting will now be presented during the main EMI SIG meeting.  On the down side, the shortened week will mean that a few working groups will be meeting in the early morning before the start of the daily EMI SIG session and we will need to find a way to report the results of the working group sessions back to all SCAPA members.