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WASHINGTON, DC - The Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM) today released a report confirming the technical soundness of infiltration modeling work performed by U.S. Geological Survey (USGS) employees. 

"The report makes clear that the technical basis developed by the USGS has a strong conceptual foundation and is corroborated by independently-derived scientific conclusions, and provides a solid underpinning for the 2002 site recommendation," said OCRWM's Acting Director Paul Golan.  "We are committed to opening Yucca Mountain based only on sound science.  The work that we do must be without question or qualification, and this report confirms that we are on the right path forward."

Last March, DOE disclosed e-mails between USGS employees that appeared to suggest that these employees had failed to follow certain quality assurance procedures during their work.  This report was developed to assess how issues raised by the e-mails may have impacted some of the scientific conclusions contributing to the Yucca Mountain Site Recommendation of 2002 and the Key Technical Agreements between DOE and NRC.  The report found no impact on those conclusions.

The 144-page final report, entitled Evaluation of Technical Impact on the Yucca Mountain Project Technical Basis Resulting From Issues Raised by E-mails of Former Project Participants, examined work products developed by the USGS employees-mainly the infiltration contributing to the evaluation of the long-term performance modeling of the underground repository.  The report concludes that the net infiltration ranges, as determined by the USGS employees, were consistent with ground water recharge rates determined by other scientists studying other arid and semi-arid regions in the United States and provides reasonable inputs to models used for the 2002 site recommendation.

Although the report's findings indicate that the infiltration rate estimates are corroborated and consistent with other independently derived work, OCRWM will replace or supplement the infiltration modeling work, as needed, and will review or verify the supporting documentation.

As part of OCRWM's comprehensive review process, preliminary drafts of the report were supplied to three, non-DOE affiliated experts in hydrology and computer modeling in October 2005.  The independent experts studied the drafts and associated references, and their feedback is reflected in the final report.

The technical report is available at

Media contact(s):

Craig Stevens, 202/586-4940