DEVELOPMENT OF A SITE-WIDE SYSTEM ASSESSMENT CAPABILITY

The Hanford Site has initiated an effort to assess the cumulative long-term effects of Hanford-derived contaminants to the Columbia River and the region after the site closes. The assessment will include impacts to human and ecological health as well as the region’s economy and cultures. To conduct this assessment, the site is in the process of developing the necessary tools and supporting data. The computational capability for performing an initial assessment is known as the System Assessment Capability (SAC Rev. 0). SAC Rev. 0 is being applied during fiscal year 2001 to produce an initial assessment that is essentially a “proof-of-principle ” that a probabilistic analysis of this scope and scale can be performed in a reasonable period of time and for a reasonable commitment of resources. However, initial results will also provide insight for the design of an improved capability, (e.g., SAC Rev 1) that can be used to support cleanup decisions that must be made in a regulatory environment. They should also provide an appreciation of sources of uncertainty and needed investment to first quantify and then reduce the uncertainty of results. At this time, aspects of history matching the SAC Rev. 0 models to uncertain Hanford Site events from 1944 to present are being studied. Initial indications are that a site-wide assessment of this scope and scale, when conducted in a time frame of interest to decision makers, is possible but will fully utilize computational resources available