I. PURPOSE AND SCOPE

The environmental qualification (EQ) rule (10CFR50.49) imposes replacement equipment requirements in paragraph L of the rule. In that paragraph, the EQ rule requires use of upgraded components when it becomes necessary to replace electrical equipment important to safety. To address this upgrade provision, BNP committed to a programmatic replacement with Category I electrical equipment qualified per NUREG-0588, unless sound reasons to the contrary exist which would preclude its replacement. This program will evaluate approximately 50 percent of the plant EQ-related electrical equipment.

This project includes gradual but coordinated replacement of multiple similar components (where feasible) rather than replacement of individual components during isolated corrective maintenance activities or at the end of the individual component’s qualified life. Where replacement of groups of components is not feasible or efficient, each affected component is upgraded based on the most efficient approach relative to the entire project and relative to the individual application. This approach results in significant flexibility and efficiencies in the actual replacement work, in updating plant design configuration documentation, and in maintenance and test programs. Future audits and inspections should conclude that management of environmentally qualified equipment is adequate. Unqualified or expired electrical components should not be found in the plant.

II. EVALUATION

Schedule Index: 22 - With the exception of HVAC cooling of important components, the nuclear safety probabilistic risk assessment (PRA) does not explicitly address the survivability of equipment during accident conditions. It is assumed that the equipment is designed to perform its function under accident conditions. Electrical equipment is required to be operational and capable of performing design safety functions over the life of the plant, including during the adverse plant environmental conditions (e.g., temperature, pressure, and humidity) that are anticipated to occur in the event of an accident. Therefore, since nuclear safety is the basis for the EQ program, this project is judged to have a moderate impact on important systems in the PRA (0.5 x 32). The replacement equipment is expected to be inherently more reliable during normal operations, thus potentially increasing plant operational availability (0.2 x 12). In addition, new components with increased reliability will reduce overall maintenance requirements. Similarly, since the approach being taken is to replace the equipment in an efficient, comprehensive manner rather than piecemeal, worker productivity and error avoidance will be enhanced, thus resulting in general operational and maintenance enhancements (0.5 x 8).

Economic Aspects: The upgraded equipment is generally more expensive, but this is somewhat offset by increased reliability and availability of current vendors. Replacement of some multiple components can be optimized in a manner that minimizes project cost. This has been recognized and is part of the planning process for this project. Although this replacement program has a regulatory-driven purpose, it will also relieve equipment obsolescence problems and will support BNP plant life extension and maintenance programs.

Related Standards: This project is related to the Work Management Policy for material condition.

Other Considerations: Component and inventory replacements will be accomplished as needed to avoid expiration of design life of installed equipment. The work will be accomplished first for equipment with less than a 40 year design plant life, then for equipment having a 40 year design plant life. This project is currently planned to continue until the year 2005. In some cases where advanced change-out is not prudent, the needed quantities of upgraded replacement equipment will be purchased and retained in stock. Thereafter, the affected components will be replaced with the stocked replacement components when it is actually required for corrective or preventive maintenance. This approach will also remove older stock replacement components and thus minimize the possibility of using non-upgraded components from stock. Due to the range of equipment and systems affected by this project, much of this work will have to be accomplished during unit outages. A separate but closely related project (PID 00912D) addresses Rosemount transmitters.

This project implements the plant response to important equipment environmental qualification requirements contained in 10CFR50.49. The project will continue in a systematic, coordinated manner until all plant electrical equipment conforms to 10CFR50.49. This will allow a controlled, cost effective resolution of this issue.