Spent Fuel Management

Overview

The safe, long-term storage of spent nuclear fuel is an industry-wide problem. While the industry awaits a government solution, spent fuel bundles continue to amass in spent fuel pools at plant sites. The interim solution today is dry cask storage. Several products have emerged in this area, but the process of determining which design to use and which fuel bundles can and should be loaded into the casks can be an overwhelming task.

Loading fuel casks requires a detailed evaluation of every fuel bundle in the pool, often numbering in the thousands. Bundles must undergo classification, where they are divided into groups based on mechanical attributes, decay heat, and integrity properties. Limits are placed on what types of bundles may be loaded together into dry storage casks, and those requirements vary based on the model of the cask and the supplier.

To have a successful fuel loading campaign, a vendor experienced with the broad range of fuel designs utilized over the last 50+ years as well as the cask models to be loaded is essential. TransWare has been serving the nuclear industry for more than 30 years, supporting plants in all aspects of core management. This has provided us with valuable experience with the full range of BWR and PWR fuel assembly designs.

We can assist you with all aspects of your spent fuel management program including spent fuel movement planning (e.g. B5B), spent fuel pool cleanout, spent fuel pool gamma heating analysis, fuel characterization, fuel integrity assessment, cask loading plans, best estimate decay heat analysis, dose rate estimates and reduction strategies, cask vendor and system selection, ISFSI design, engineering evaluations, third-party reviews of vendor analysis and training.

TransWare has helped classify more than 65,000 fuel assemblies, many with histories going back as much as 50 years. We’ve assisted several plants including decommissioned sites with updating their fuel selection process and helped select fuel for more than 450 casks from vendors such as Holtec, TransNuclear and NAC, loading more than 22,000 fuel bundles. Since we have worked with the three major vendor cask designs, we have developed a detailed understanding of each of the cask vendor's hardware, operation, and design and licensing basis.

TransWare has performed its work either under the utility QA program, or under the TransWare QA program, which is a NUPIC-approved quality assurance program that meets the requirements of 10CFR50, Appendix B and 10CFR21.

To learn more about TransWare and what we can do to help you with your spent fuel management needs, contact us and we’ll create a proposal geared toward your issue for your plant.

The TransWare Advantage - Spent Fuel Management

Program Initialization

We can review your loading procedures or provide a customized set of procedures to get your program started.
Initialization of your plant-specific fuel database including complete characterization of your existing fuel inventory.
Assistance with cask vendor selection based on site-specific considerations.
Assistance with determining the best licensing approach for your plant, either through the use of cask vendor licensing agreements or through the implementation of a site-specific license.

Cask Load Optimization

We offer a variety of consulting services at TransWare Enterprises Inc., including marketing, strategy, operations, and more. Our team is made up of experts in each of these areas, and Without an appropriate, long-term view of your fuel loading plan, you can find yourself in a corner, limited by the available fuel and unable to cost-effectively utilize your casks and pad. TransWare can improve the functional and cost performance qualities of your program by making sure that the optimal fuel is loaded in each cask at the right time. Effective fuel loads rely on considerations of available fuel in the pool, cask licensing requirements, and site dose restrictions, among others. By incorporating a holistic approach to our program, we can help you achieve the optimal plan for your plant’s current and future loadings. we work together to provide our clients with comprehensive solutions that meet their unique needs.

Spent Fuel Pool

TransWare has experience performing spent fuel pool dose and flux evaluations to determine the impact of those components on the concrete walls, steel liner and poison plates within the spent fuel pool. We can utilize industry standard tools (MCNP, ORIGEN) as well as our in-house, advanced transport solvers to generate accurate flux and dose maps of your pool. Additional tools have been developed to support concrete heating analyses that account for environmental and pool conditions to support the determination of the long-term health of the concrete walls and liner of the pool. Our methods have assisted with fuel placement within the pool and the determination of areas of interest for in-situ poison rack measurement campaigns.

Dose Evaluations

Off-site and occupational dose evaluations based on as-loaded fuel design parameters and pad arrangements.
Gamma and neutron dose contributions included.
High-fidelity models support precise surface dose calculations around the entire cask.
Support for industry-accepted and site-licensed MCNP methods. Additional methods developed in-house provide additional code verification resources.