Clark University Critiques Cerro Grande Fire Risk Assessment

* Clark University has released a report that indicates that there are flaws with the risk assessment performed following the Cerro Grande fire. The report finds that modeling methods used by the Risk Assessment Corporation (RAC), which was contracted to perform the assessment, used computer modeling techniques that might not have adequately gauged the risk posed by the fire as a result of its burning of Los Alamos National Laboratory (LANL) property.

The Cerro Grande fire began on May 4, 2000 and burned approximately 47,000 acres in northern New Mexico, including 7,300 acres of LANL property. The fire spread over hundreds of waste disposal sites and potentially contaminated areas, which prompted a risk assessment. The assessment was completed in June 2002 and found that the estimated risk of cancer from breathing any radioactive or chemical material directly from LANL found in the smoke plume is less than one in ten million.

Although Abel Russ, a research associate at Clark University who performed a review of the assessment, agrees that cancer risk from the fire is relatively low, he finds that the method used by RAC may not have adequately estimated emissions resulting from the fire. Russ finds that both the monitoring data collected during the fire and the computer model used to estimate risk are unreliable. Russ finds that both characterization of the LANL site and the air monitoring system surrounding LANL must be improved in order for LANL to be considered a credible risk manager by surrounding communities.

Russ also finds that some communities that were affected by the fire, particularly Taos, were not included in the initial modeling of the risk posed by the fire. According to the report, risk to these communities was assessed using an alternate method that was less accurate.

Russ also finds that much of the data used for the assessment was highly uncertain. As Concerned Citizens for Nuclear Safety pointed out in December 2003, much of the data collected for potential release sites around LANL were believed to have underestimated the level of contamination in soil at the site. Also, the methods employed by LANL to collect these samples were not consistent at every site. Therefore, much of this data is questionable. Hence, Russ concludes, "[These] data are insufficient for the purposes of estimating off-site contamination...."

Russ suggests that a more accurate assessment of background radiation is necessary to produce more reliable emergency monitoring data. He also recommends an improved emergency and routine monitoring system, and that the raw data from that system be collected and made readily accessible to surrounding communities.

Russ said, "RAC ... possesses very sophisticated capabilities and yet their assessment was unable to generate any useful results, mainly due to insufficient monitoring and site characterization data. These data should be created. Furthermore, since transparency is critical in establishing community trust, these data should be publicly available."

Community members believe that this may help to make risk assessments of LANL emissions more credible, which is important given that RAC is currently undertaking a risk assessment of the entire LANL complex.

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