Design Basis Calculation Reconstitution
Project Highlights
- Screening to identify key calculations.
- Objectively assessing key calculation quality.
- Successfully revising thousands of calculations.
- Demonstrating expertise associated with client design basis documentation.
- Modernizing calculation methodologies to regain margin.
- Resolving longstanding legacy issues to address outstanding corrective action and/or licensing concerns.
- Successfully completing calculation projects to help nuclear plants achieve reduced NRC oversight.
Project Description
Following the engineering and design of new nuclear power plants in the 1970s and 80s, focus was put on increasing plant efficiency and capacity factors, and reducing outage durations. Additionally, thousands of design changes and equipment updates were implemented due to regulatory compliance issues. Maintaining the vast amount of plant documents and records attendant with these activities has previously been an arduous task for plant owners.
Over time, plants have experienced problems maintaining proper configuration management and, by extension, maintaining the design basis consistent with the licensing basis. In many cases, this has led to more stringent oversight from the Nuclear Regulatory Commission (NRC), with plants potentially being cited in the Multiple/Repetitive Degraded Cornerstone Column (Column 3) or the Unacceptable Performance Column (Column 4) of the NRC Action Matrix. Plants in this situation have been required to perform a design basis reconstitution project to reestablish control and validation of the documents that constitute their design and licensing basis. A calculation reconstitution has often been undertaken as part of that effort and Sargent & Lundy has supported many of these efforts.
In other circumstances, calculation reconstitution projects are undertaken to address legacy errors or omissions and/or to recover margin with modernized methodologies and approaches.
Project Scope
Sargent & Lundy has successfully performed and managed complex calculation programs for multiple nuclear stations, including Clinton, D.C. Cook, Fort Calhoun, LaSalle, Point Beach, Salem, and many others. Our responsibilities on these efforts encompassed developing a methodology to identify critical calculations, performing a screening and technical review of thousands of existing calculations to identify those requiring revision, and generating new calculations to reconcile for missing information.
We have also developed databases linking the design basis documents to their licensing commitments included in the safety analysis report and other licensing basis documents. Oftentimes, the calculations were revised to bring them to current-day standards using documented inputs, validated assumptions, updated methodologies, and, in some cases, advanced computer programs to perform the analysis.
Read more about our nuclear power services.
