Design and Licensing
The independent review of proposed fuel and component design changes is critical to ensure that the components will meet the supplier’s performance goals and the utility’s expectations without introducing new performance issues. ANATECH’s fuel design reviews ensure that the fuel supplier has considered the full range of performance characteristics that may be impacted by the design change. These review activities include an independent review of the supplier’s design calculations, test reports, and performance database along with direct discussions with the supplier’s engineering staff.
The experience base of our staff is unparalleled in the industry and consists of design reviews of BWR, PWR, VVER and test reactor fuel for utilities in the US, Europe and Asia. Selected design review activities have included:
- Review and evaluation of advanced BWR, PWR, and VVER fuel designs
- Structural design of advanced components
- Material evaluations of advanced cladding alloys and structural components
- Design and analysis of fuel assembly and core components in support of advanced reactor concepts.
Design Review
The transition to a new fuel design, or the implementation of advanced features offered by a fuel vendor, necessitates a detailed review to ensure that the advanced features a) meet the vendor’s design and licensing requirements, b) are compatible with the utility’s co-resident designs and plant interfaces, and c) will meet the vendor’s performance goals without introducing new performance and reliability issues. As such, a full-scope review performed by ANATECH would likely include:
- Review of the scope and completeness of the vendor’s evaluations,
- Review analysis results against the Standard Review Plan (NUREG-0800) Chapter 4.2 fuel system design acceptance criteria and the vendor’s design criteria and licensed methods,
- Review of the vendor’s test program and results, including lead assembly irradiation programs, applicable to the particular design changes to be implemented,
- Review of the new design features against the current experience base for similar features,
- Review of the vendor’s and utility’s programs for ensuring compatibility with the co-resident fuel and plant interfaces, and
- Review of manufacturing and inspection-related changes (may include a fabrication audit to review process, procedural and other changes implemented for the new features/design as well as a qualification audit to ensure the new processes necessary for the implementation of the new features/design have been adequately qualified).
ANATECH’s staff has performed numerous design reviews for clients around the world including:
- Review of an advanced, next generation, 10×10 BWR fuel design,
- Review of material and design changes to increase discharge burnup,
- Review of advanced PWR and BWR cladding alloys,
- Evaluations of competing advanced VVER designs for a European reactor (US and Russian designs),
- Evaluation of fuel performance and reliability impacts of fabrication-induced damage in an advanced fuel design,
- Design review of advanced Lead Fuel Assemblies and their implementation in-core,
- Design and evaluation of an advanced LWR fuel design and core components.
Seismic Qualification
Standard Review Plan (NUREG-0800) Chapter 4.2 requires that the fuel system response be evaluated for various loading conditions including seismic events. As such, the analysis must begin with the evaluation of the nuclear plant’s structural response to the site seismic event. Through an evaluation of the plant structural response, the forcing functions on the reactor vessel can be evaluated.
The seismic qualification review typically performed by ANATECH then considers the vendor’s seismic methodology for determining the fuel system loads and deflections based on the input forcing functions. This is accomplished through a review of the vendor’s topical reports that define the licensed methodology and the design calculations that implement the approved methodology and document the fuel system response. Specific models, inputs and calculated component stresses and impact loads are reviewed – stresses, deformations and impact loads are compared against vendor-specified limits and Standard Review Plan acceptance criteria.
Licensing Support
The continued evolution of fuel designs, plant operating strategies, and performance goals in today’s competitive power generation market demands that licensing and safety analysis of nuclear reactors be flexible and responsive. ANATECH continually works with the nuclear industry to develop and advance fuel and component regulatory acceptance criteria for use in the licensing and safety analyses of advanced fuel designs. This has included the development of advanced methodologies for use in fuel design and safety analysis support. Through these activities, our staff interacts closely on behalf of our utility clients with regulatory agencies and international research organizations in the design, conduct and interpretation of experiments and hot-cell examination results.
- Support of Fuel Design Licensing Requirements in Conformance With Chapter 4 of the Standard Review Plan, NUREG-0800
- Accident Analyses in FSAR Chapter 15
- LOCA, RIA, REA
Vendor Transition Support
The review necessitated by the transition to a new fuel vendor will likely include the scope noted above for Design Reviews with additional review areas as the new vendor will have a different Quality Assurance program, will implement the program differently, may implement different fabrication processes and procedures, and may have different sub-suppliers. As such, the review may include:
- Detailed process reviews,
- A review of fabrication process qualifications as the vendor may implement processes and materials that are a) different from those implemented by the utility’s current fuel vendor, or b) may be necessitated by the implementation of the new features/design,
- A review of the supply chain for materials and components,
- A review of design-related activities to ensure that they meet the vendor’s Quality Assurance requirements, and
- A review to ensure that utility-specific requirements are implemented.
The scope of the transition reviews is tailored to best meet the needs of the utility.
Spent Fuel Storage and Transportation
Spent fuel storage and transportation involves the analysis of storage and transportation hypothetical cask drops and impacts with hard targets, airplanes and trains with the purpose of demonstrating the integrity of the casks. ANATECH has nearly 20 years of experience performing such analysis of commercial casks, dry storage facilities and the Yucca Mountain Project.
ANATECH has been involved with the structural performance of high-burnup spent fuel cladding during dry storage and transportation for several years. The major issues include:
- Characterization and development of predictive models for damage mechanisms perceived to be potentially active during dry storage
- Modeling and analysis of deformation processes during long-term dry storage
- Development of cladding failure models and failure criteria considering cladding material and physical conditions during dry storage and transportation, and
- Failure analysis, considering end-of-dry-storage conditions, of spent fuel systems subjected to the normal and the accident conditions of transport prescribed in Part 71 of Title 10 of the Code of Federal Regulations, (10 CFR 71).
In addition to the above, ANATECH works with utilities in supporting the licensing of Dry Fuel Storage facilities.
