Conclusions

Superfund sites such as RFETS are environmental problems of national significance. As such, we in the scientific community hope that our best science is brought to bear on decision making to improve its technical basis and to make it more transparent, repeatable, and thus, scientifically defensible. This came about at RFETS because of several factors, including the willingness of the integrating contractor to seek outside scientific advice and guidance; the acceptance through time, down to the project level, of the value of scientific advice in avoiding pitfalls and improving operations; and the gradual acceptance of the independence and veracity of the AME scientific advisors by the stakeholders. This willingness and acceptance allowed DOE, the integrating contractor, the regulators, and other stakeholders to focus on specified goals and objectives.

Making the case for particle-transport mechanisms, rather than aqueous sorptiondesorption processes, as the cause of plutonium and americium mobility established a successful scientific basis for the dominance of physical transport processes by wind and water. The scientific basis was successful because it was in agreement with general theory on insolubility of PuO2 in oxidation state IV; results of ultrafiltration analyses of field water and sediment samples; and XAFS analyses of soil, sediment, and concrete samples. It was also in general agreement with on-site monitoring data.

This understanding in turn allowed Site contractors to rapidly move to adopt soilerosion and sediment-transport models as the means of predicting plutonium and americium transport, which led to design and application of sitewide soil erosion control technology to help control downstream concentrations of plutonium and americium in streamflow.

Finally, good scientific understanding in the public interest helped bring clarity and focus to real issues of actinide migration at RFETS. This in turn helped to develop a more defined scope with a clearer endpoint that allowed the most extensive cleanup in the history of Superfund legislation to finish one year ahead of schedule, ultimately resulting in billions of dollars in taxpayer savings and removing a $600 million-plus annual liability from the DOE budget forever.

Next article ... "Rocky Flats National Wildlife Refuge"