R. J. Ramer, M. M. Plum, J. P. Adams, and C. A. Dahl
Idaho National Engineering and Environmental Laboratory
Lockheed Martin Idaho Technology Co
Idaho Falls, Idaho 83415-3135

The National Spent Nuclear Fuel (NSNF) Program conducted by Lockheed Martin Idaho Technology Co. (LMITCO) at the Idaho National Engineering and Environmental Laboratory (INEEL) is evaluating final disposition of spent nuclear fuel (SNF) in the Department of Energy (DOE) complex. Final disposition of SNF may require that the fuel be treated to minimize material concerns. The treatments may range from electrometallurgical treatment (EMT) and chemical dissolution to engineering controls. Treatment options and treatment locations will depend on fuel type and location of the fuel. One of the first steps associated with selecting one or more sites for treating SNF in the DOE complex is to determine the cost of each option. An economic analysis will assist in determining which fuel treatment alternative attains the optimum disposition of SNF at the lowest possible cost to the government and the public.

For this study, a set of questions was developed for the EMT process for fuels at several locations. The set of questions addresses all issues associated with design, construction, and operation of a production facility. A matrix table was developed to determine questions applicable to various fuel treatment options. A work breakdown structure (WBS) was developed to identify a treatment process and costs from initial design to shipment of treatment products to final disposition. Costs can be applied to determine the life-cycle cost of each option. This technique can also be applied to other treatment techniques for treating SNF.

The DOE Environmental Management (EM) SNF Program has the mission of safely, reliably, and efficiently managing DOE-owned SNF and preparing it for disposal. The NSNF Program assists EM in this mission through the active development of disposal strategies, coordination, and integration with other DOE sites, the Repository Program, and management of NSNF issues. It is unlikely that all SNF will be suitable for final direct disposal without treatment.

One treatment option for a portion of the EM-SNF, being evaluated by Argonne National Laboratory – West, is the EMT process.^1,2 For this process, fuel pieces are dissolved in a molten salt electrolyte. The uranium is electrochemically deposited on a cathode. The uranium-loaded cathode is removed from the electrorefiner. The uranium is removed and blended with depleted uranium to produce a low-enriched ingot. Cladding hulls, which may contain a small quantity of the less reactive fission products, are also removed for waste treatment. Most fission products and the transuranic elements accumulate in the salt through repeated electrorefining cycles. The salt can be pumped out of the electrorefiner for treatment.

Because significant quantities and types of SNF may require some type of treatment before final disposal, a comparative cost matrix was developed by the NSNF Program to aid in the evaluation of treatment processes/treatment site for several fuel types. Treatment is assumed to be any production process required to process interim storage SNF for final disposal. This includes storage, pretreatment, treatment, transportation, and disposal costs. NSNF personnel developed a set of questions that incorporate requirements specified in the SNF Program Requirements Documents.³ Then, a cost matrix incorporating an economic analysis was developed.

One of the first steps associated with selecting one or more sites for treating the SNF in the DOE complex is to determine the cost for each option. This is accomplished by:

• The issues associated with fabrication (if applicable) and operation of a production facility are articulated by a list of specific treatment questions intended to ensure that all issues and costs associated with each option are identified.
• A WBS is developed to provide the basis for capturing life cycle cost.
• The costs associated with the questions are estimated and summed through the WBS to determine total costs for each option.

During the evolution of these treatment questions, care was taken to ensure that all issues associated with fabrication and operation of a production facility were included. This was accomplished, in part, by basing the questions on the relevant sections of the Spent Nuclear Fuel Program Requirements Document.³ This document presents top-level requirements for the NSNF Program and is based on the SNF Strategic Plan.⁴ The purpose of the document is to clearly describe the requirements, which if met, will accomplish the goals of the SNF program mission. A systems engineering approach was used to integrate the overall SNF program planning with specific programmatic needs, stakeholder participation, safety, environmental protection, quality, safeguards and security, and facilities design and operation. Thus, it is judged that if the questions associated with the various options adequately address the requirements of the SNF Program Requirements Document, fabrication and operation of the production facility will meet the objectives of the NSNFP. This approach will also maximize the probability that all significant costs associated with fabrication and operation of such a facility will be identified.

The questions have been divided into three generic types to address technical, schedule, and programmatic issues. Technical questions are those that specifically address technical issues such as 1) Will the treatment process require modification in order to treat the specific fuel type?, 2) What will the treatment products be and will they meet final disposal facility criteria?, and 3) Do approved cask designs exist for transportation of the SNF? The schedule questions are those that specifically address whether or not the SNF can be treated in time to meet existing schedules such as the Idaho Agreement.⁵ The programmatic questions are those that address issues such as 1) What plans (transportation plans, safeguard and security plans, QA plans, etc.) are required for the option?, 2) Is the work force adequate to operate the facility?, and 3) What are the D&D and recycling issues?

Dividing the questions into three categories helps in ensuring completeness, though it is somewhat arbitrary and some of the questions could fit in more than one category. This is not a problem since costs associated with each option will be summed and it is the total cost that will be used to determine the best path-forward for each specific fuel type.

The issues involved with siting a production facility are:

These issues were captured in five generic siting options. In addition, an option is listed to capture untreated disposal costs as a baseline.

The siting options are:

The specific questions are listed in Table I. Each question was examined to determine whether or not it is applicable for each of the siting options. For example, for Treatment Option D, none of the questions regarding fabrication and operation of a production facility were applicable. Transportation of the fuel to the production facility is not applicable for Options B1 and B2, since they involve onsite treatment of the SNF.

Table II is an example of an options table, which was set up to provide a visual representation of the questions for treating various fuels. This specific table is based on some of the sodium-bonded SNF currently stored at the INEEL and the EMT process. The questions in this table refer to the questions in Table I. The distribution of the questions among the three categories (technical, schedule, and programmatic) is the same in both tables.

In Table II, the questions, as they apply to the treatment options for the specific fuel type, are either: Applicable, Not Applicable, or Applicable and Addressed. For example, any questions regarding treatment of the SNF type are "Not Applicable" for Option D since this option involves shipping the SNF, untreated, to the repository. Obviously, the only questions that are "Applicable and Addressed" are some of those associated with treatment of SNF in the existing ANL-W facility as part of the demonstration project. This category is included for tracking purposes after a decision is made regarding application of the EMT process for specific SNF types.

Two economic tests are available to determine the economic viability of an investment, program, or project.

The first and most common economic test is cost-effectiveness. Cost-effectiveness has the primary objective of ensuring all requirements are met at the lowest possible cost. The cost-effectiveness test is simple because only total costs are evaluated, not benefits. This test assumes the minimum standard of performance has been met. Because only cost information must be determined, this test is less expensive to perform. For most businesses and the government, cost-effectiveness is the preferred test since the minimum goal and performance requirements are agreed to and well established. Cost-effectiveness has been determined to be the preferred economic test for promoting the efficient allocation of limited federal government funding.⁶

The second economic test is cost efficiency. Cost efficiency has the primary objective of maximizing return on investments. This test is used less often because significantly more information requiring both cost and benefit analysis is used to maximize return on investment. Additionally, performance standards tend to modulate more and are compromised more often, thus making it much more difficult to optimize return on investment. Typically, only business uses this economic test.

Because environmental laws and regulations often prescribe minimum standards of performance, cost-effectiveness and its accompanying cost minimization is the desired test of economic viability. For this reason, the objective of this economic analysis is to determine which siting option attains the program goals for the SNF disposition at the lowest possible cost to the government and public.

Although many modeling techniques are available to test for cost-effectiveness, the most common and acceptable technique is life-cycle analysis (LCA). Also known as cradle-to-grave analysis, LCA accounts for all of the economic activities necessary for the project, program, or investment beginning with the preoperational activities of planning, permitting, and conceptual design through the postoperational activities of project close-out, decommissioning, and long-term monitoring. Costs that are not included are any costs previously spent, also known as sunk costs. By definition, the LCA method will evaluate all competing alternatives expressed in present value or discounted terms. As defined by the selected evaluation methodology, the alternative with the lowest LCA is the preferred option.

From the questions discussed earlier, a WBS was developed for a generic fuel type. A WBS is a tree of product-oriented components that organize individual work activities of a project using a hierarchical process. Almost always, the WBS is determined by decomposing work elements from the highest level to a lower, more manageable work element level. By definition, an integrated WBS will identify all work activities that must be performed to complete the project. Thus, the summation of all WBS activities at any given level is the total project costs.

WBS components may be products or services. Components can be broken into smaller subcomponents, depending on the complexity and the level of detail required to properly manage the project. The WBS sodium-bonded SNF disposal with the EMT is shown in Figure 1. This WBS was constructed solely for this evaluation and is not intended to replace any program WBS currently in existence. The WBS dictionary describes each WBS element. Using a WBS leverages process information into an easily identifiable cost analysis of a project. This parallel cost effort is often referred to as a cost breakdown structure.

After the treatment questions were clarified and the WBS developed, an economic analysis can be performed. From the analysis of each fuel type, costs will be applied to the WBS matrix to determine the cost/kg to process fuel from current to final storage. A computerized cost model has been developed as a generic modeling tool. This generic format was established as a modeling requirement. The generic format permits broad and flexible analysis of the anticipated and any unforeseen treatment options. Additionally, the model was developed to accommodate the analysis requirement that many possible treatment solutions exist (depending on the fuel type). The treatment solutions may be combined to evaluate the whole SNF Program's effort. Results from the model are not yet available, pending application of the methodology described in this report.

For each fuel type, cost data can be inserted into the WBS matrix to derive a per unit cost (i.e., cost/kg of HM or cost/kg total fuel mass) for each treatment step. Treatment options will also be evaluated according to facility location. For example, if a fuel is transported to an offsite location for treatment at an existing facility, building costs are minimized. However, transportation costs are increased. Thus, tradeoffs in treatment activities are captured in the economic analysis.

The cost matrix analysis tool will allow an economic analysis to aid in determining which siting alternative attains the disposition of SNF at the lowest possible cost to the government and the public. The model can be used to evaluate optimal treatment options for disposition of SNF.