National Nuclear Security Administration; Notice of Floodplain/Wetlands Involvement for the Disposition of the Omega West Reactor Vessel and Ancillary Structures at Los Alamos National Laboratory, Los Alamos, New Mexico

AGENCY:

National Nuclear Security Administration, Office of Los Alamos Site Operation, Department of Energy.

ACTION:

Notice of Floodplain Involvement.

SUMMARY:

The Department of Energy's National Nuclear Security Administration, Office of Los Alamos Site Operations hereby provides notice for its proposal to decontaminate and demolish the Omega West Reactor vessel along with the remaining structures associated with the Omega Facility, and to remove the resulting waste from the Los Alamos canyon floodplain and out of the canyon bottom. The Omega Facility, located in Los Alamos Canyon at LANL in New Mexico, housed an old research reactor known as the Omega West Reactor (OWR). The OWR was shut down in 1992 and the fuel removed in 1994. The Facility, originally constructed in 1944, and its associated structures are of advanced age and not in a condition suitable for renovation or reapplication. Further, they are located within a potential flood pathway. There is no foreseeable future use for the Facility, which is eligible for inclusion in the National Register of Historic Places.

DATES:

Written comments are due to the address below no later than March 7, 2002.

ADDRESSES:

Written comments should be addressed to Jeff Robbins, U.S. Department of Energy, National Nuclear Security Administration, Albuquerque Operations Office, P.O. Box 5400, Albuquerque, New Mexico, 87185 or transmitted by E-mail via Internet to jfrobbins@doeal.gov, or by facsimile to (505) 284-7101.

FOR FURTHER INFORMATION CONTACT:

Rich Nevarez, Document Manager, U.S. Department of Energy, Albuquerque Operations Office, ERD SC-1, PO Box 5400, Albuquerque, New Mexico 87185, Telephone (505) 845-5804, or transmitted by E-mail via Internet to rnevarez@doeal.gov, or by facsimile (505) 845-4239.

For Further Information on General DOE Floodplain Environmental Review Requirements, Contact: Carol M. Borgstrom, Director, office of NEPA Policy and Compliance (EH-42), U.S. Department of Energy, 1000 Independence Avenue, SW, Washington, DC 20585-0119, Telephone (202) 586-4600 or (800) 472-2756, facsimile (202) 586-7031.

SUPPLEMENTARY INFORMATION:

In May 2000, the Cerro Grande Fire burned across the upper and mid-elevation zones of several watersheds, including the Los Alamos Canyon watershed. Several of the Omega Facility's small support buildings and structures were demolished and disposed of during the first 6 months post Cerro Grande Fire. The remaining buildings, including Building 2-1 that houses the OWR vessel, and the associated structures and utilities and infrastructure, continue to be vulnerable to damage from flooding and mudflows as a result of the fire and the changed environmental conditions upstream from the Facility. While all buildings are vulnerable, the support buildings and structures are especially at risk due to their construction characteristics. An assessment of the floodplain is being included in the Disposition of the Omega West Vessel and Ancillary Structures Environmental Assessment (EA).

According to the requirements of E.O. 11988—Floodplain Management and 10 CFR part 1022—Compliance with Floodplain Environmental Review Requirements, notice is given that NNSA is planning to decontaminate and demolish (D&D) the OWR vessel and the remaining Omega Facility structures located within Los Alamos Canyon at Los Alamos National Laboratory, Los Alamos, New Mexico.

The D&D activities would consist of characterization and removal of radiological and other potential contamination in all the structures and subsequent demolition of the structures; dismantlement of the reactor vessel; segregation, size reduction, packaging, transportation, and disposal of wastes; and removal of several feet of potentially contaminated soil from beneath the reactor vessel. The D&D of the entire Omega Facility is proposed to be conducted using a phased approach. For each individual structure, the initial phase would include the characterization and planning of the work, followed by the decontamination effort, and lastly the demolition of the structure and disposal of resulting debris. Decontamination of the Omega Facility would include the removal of nonradiological and radiological contamination from building and structure surfaces throughout the Omega Facility. The extent of decontamination performed would be limited to those activities required to minimize radiological and hazardous material exposure to workers, the public, and the environment. This would involve mostly decontamination of the Omega Facility, its components and spot contamination of surrounding areas, buildings and structure components.

Once the Omega Facility has been decontaminated, the buildings, structures, foundations, and other facility components would be demolished. All building and structural materials would be removed from the canyon and sent to appropriate disposal sites. The buildings are not expected to be technically difficult to demolish and the resultant wastes can be handled, transported, and disposed of in accordance with standard LANL D&D procedures. The demolition of the OWR vessel and its concrete radiation shielding would generate high exposure rates in the room as the vessel is dismantled. Therefore, a safe method of demolition would be employed that would assure the involved workers could maintain their exposure limits below one rem per year. The OWR vessel and radiation shielding would be horizontally sectioned using diamond wire saws or other similar equipment for cutting the structure. The result cut sections would be packaged as appropriate, transported out of the canyon for eventual disposal.

An assessment of the floodplain effects is being included in the draft EA for the proposed disposition of the OWR vessel and associated structures, which is under preparation. After NNSA issues the assessment, a floodplain statement of findings will be published in the Federal Register.