The SNL/NM Classified Waste Landfill Excavation: Lessons Learned Moving from Planning to Implementation
The Sandia National Laboratories/New Mexico (SNL/NM) Environmental Restoration Project is halfway through excavating the Classified Waste Landfill in Technical Area II, a disposal area for weapon components for approximately 40 years. While the planning phase of any project is important, it is only a means of getting to the field implementation phase where reality quickly sinks in. Documents outlining the general processes are developed, heavy equipment, supply needs, requisite skills, and staffing levels are anticipated, and contingencies for waste management are put in place. However, the nature of landfill excavation dictates that even the most detailed plans will probably change. This project is proving that trying to account for undefined variables and predicting the total cost of landfill remediation is very difficult if the contents are not well known. In landfill excavation, contingency cannot be minimized. During development of the waste management plan, it was recognized that even the best forecasting could not formulate the perfect cradle-to-grave processes because waste streams are rarely definable before excavation begins. Typically, as excavation progresses and waste streams are generated, new characterization information allows further definition of disposal options which, in turn, modify the generation/management process. A general plan combined with close involvement of waste management personnel to resolve characterization and packaging questions during generation has worked very well. And, as expected, each new pit excavated creates new waste management challenges. The material excavated consists primarily of classified weapon assemblies and related components, so disposition must include demilitarization and sanitization. The demilitarization task at the start of the project was provided by an SNL/NM group that has since lost their funding and operational capability. This project is having to take on the task of disassembly, destruction, and recycling of classified components, along with the associated costs and infrastmcture. Very stringent radiological controls were imposed on site operations during the planning phase. Radiological controls that are not justified significantly impact the efficiency and cost of operations. If the initial approach is too conservative, there should be well-defined provisions for scaling down the protective measures to reflect the actual risks. Once the effectiveness of early detection, monitoring, and surveys is proven, radiological controls and postings should be re-evaluated to verify that they are appropriate. High levels of heavy metals dust were not anticipated during the planning phase but were suspected, then confirmed, during material handling. Respiratory protection and monitoring were upgraded accordingly and the costs added to the baseline. In contrast to radiological constraints, industrial hygiene guidelines were worked into the process with a minimum of adverse impact. While a lot of unforeseen expenses occur, some expected costs can be reduced. During the planning phase, the anticipated need to adequately characterize a variety of radionuclides in soil led to using Large Area Gamma Spectroscopy (LAGS) to survey all the soil excavated. About a quarter of the way through the project, it was obvious that very little radioactive material was present in the excavated soils. Since all the soil is processed through a screen plant, producing a fairly homogeneous mix, a more common method of sampling soil piles was implemented to replace the LAGS unit, increase productivity, and reduce costs. In summary, the most important lesson is to expect and be ready to change. Excavating a landfill requires the flexibility to quickly adjust processes to handle the unknown variables, and close attention to detail so all the different facets of the project are kept under control.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 6459308
- Report Number(s):
- SAND99-1234J; ON: DE00007052
- Resource Relation:
- Other Information: Preprint; Related Information: TIE Quarterly
- Country of Publication:
- United States
- Language:
- English
Similar Records
Clean-up progress at the SNL/NM Classified Waste Landfill
Successful Waste Treatment Methods at Sandia National Laboratories