July 19, 2009 ~ Radioactive leak is feared – The Buffalo News, By Aaron Besecker

Statement:

"For more than a year, the advisory board has called on regulators to dig into the cell as part of their study."

Fact:

The Corps has received comments from the community asking that we dig into the Interim Waste Containment Structure (IWCS) at the Niagara Falls Storage Site (NFSS). Our understanding of contamination inside the IWCS and the effectiveness of the IWCS in containing this contamination is outlined in the Remedial Investigation Report for the entire Niagara Falls Storage Site (NFSS). This information was developed through a number of methods, including remote sensing technologies, routine environmental monitoring surrounding the IWCS, groundwater and contaminant transport modeling, and historical document review and interviews on the IWCS construction, but did not include collecting soil or water samples inside the IWCS. During the investigation the Corps concluded that:

• it is possible to develop an understanding of contaminant conditions inside the IWCS and address areas of uncertainty by conducting historical research, by using remote technologies, and by applying very protective assumptions to our engineering evaluations.
• collection of soil and water samples within the IWCS would require drilling through the protective clay cap which is one of the primary protective structures containing the wastes. The IWCS cap was designed and is maintained to ensure that it properly retards radon emissions and inhibits infiltration of water (in the form of precipitation and snow melt) that would result in leaching of contaminants into groundwater.
• drilling through the IWCS clay cap would greatly increase the chances of exposure to contaminants for the workers and the public, although protective measures could be taken, and breach the integrity of the cap that would require increased maintenance and monitoring of the compromised area of the cap to ensure protectiveness to the site workers and local community.
• the value of the information to be gained from these samples and measurements, at this stage of the project, was not worth the potential risks to the health and safety of our workforce and the public and the potential increase in the migration of contaminants. The Corps has sufficient data to evaluate alternatives in the Feasibility Study. However, should a removal option be the selected remedy identified in the Record of Decision, the Corps is open to collection of samples from the IWCS, if needed, for the Remedial Design phase.

Statement:

"That is the only way to know if groundwater has infiltrated the structure, the board contends……Gardella said corps’ analysis-- and resulting determination that there is no leak -- is based more on computer simulations than actual data. He also said he is not diminishing the challenges that exist if the radioactive storage cell is penetrated; corps officials have not provided a list of pros and cons on the issue, he said. Performing the intrusive action is necessary if anyone ultimately wants to know about conditions at the site,” Gardella said…… ”If you’re minimizing the potential for leaks,” he continued, “that starts to factor into the argument about the stability of the temporary storage site. And the stability of the storage site is going to be critical in arguing whether the radioactive material stays here or not.”

Fact:

The IWCS was specifically constructed by the US Department of Energy to house these materials. The IWCS cap is constructed from three feet of compact clay overlaid by eighteen inches of topsoil. The purpose of this design was to minimize the amount of precipitation and snow melt that could penetrate into the structure and radon gas emitted from the IWCS contents into the atmosphere. In addition, a clay cutoff wall and dike surrounds the IWCS to minimize the potential for the transport of materials from the IWCS into groundwater.

The environmental surveillance that is routinely conducted at NFSS indicates that there is no increase in uranium levels measured in groundwater that would indicate that the IWCS is leaking. Environmental Surveillance Technical Memorandums are published yearly, explaining the findings of this monitoring. The groundwater monitoring program also was recently enhanced to further ensure the protectiveness of the IWCS by increasing the frequency of groundwater sampling from annually to biannually, increasing the number of groundwater sampling locations, and expanding the number of groundwater wells monitored to include a lower water-bearing zone (deeper) well immediately down gradient of the IWCS. More information about the environmental surveillance program may be found at: http://www.lrb.usace.army.mil/fusrap/nfss/index.htm#Documents.

During the remedial investigation the Corps sampled ninety one on-site wells, fifty of which surround the IWCS, and numerous other groundwater samples from temporary wells on-site during the remedial investigation.

Also, two technologies were used in the Remedial Investigation Report:

• an extensive multi-technology geophysical survey, which used non-intrusive imaging techniques to infer the conditions below the cap, and
• a site-specific groundwater model was created to evaluate the potential, under both present and conservative conditions, for the radioactivity in the residues to leach to on-site groundwater and then also evaluate whether or not any radioactivity would ever migrate off site in the groundwater.

Findings indicate the IWCS life, or time when the cell is predicted to begin leaking into groundwater, to be 160 years. The Corps is committed to ensuring the protectiveness of the IWCS by means of maintenance and monitoring until a final decision regarding the long-term remedy is selected.