Implementation of Advanced Safety Methodologies

January 19, 2021 by Westinghouse Electric Company
Categories: Safety

Robust safety analyses maximize analytical margin and support long-term operation.


The Challenge

A U.S. pressurized water reactor (PWR) utility was looking to gain operational margin in their Loss of Coolant Accident (LOCA) analysis while also being proactive in addressing recent regulatory changes. They commissioned Westinghouse to implement advanced safety methodology in their plant's design basis.

Our Solution

For U.S. PWR Westinghouse-fueled plants, our PAD5 safety analysis solution includes the latest fuel performance data and supports both LOCA and non-LOCA design bases. This unique solution addresses:

  1. Evolving regulatory requirements
  2. Enables implementation of advanced fuel products that improve fuel economics
  3. Unlocks operational margin providing more resourceful plant operation and viable life extension

Our state-of-the-industry FULL SPECTRUMTM LOCA (FSLOCATM) evaluation methodology was developed in conjunction with PAD5 and provides additional margin and flexibility over previous approaches.

These advanced analyses, coupled with the operational margin gained from implementation, help plants offset margin losses associated with increased plant age and support installation of new components. PAD5 and FSLOCA also support advancements in fuel designs and plant upgrades, particularly as utilities look to enable higher core enrichments and fuel burnup.

The Impact

By implementing the Westinghouse FSLOCA methodology, the utility increased their acceptable steam generator tube plugging (SGTP) limit to fifteen percent, enabling future flexibility for aging plant management. They were also able to reduce the required safety injection (SI) flow, which can add protection for flow degradation due to pump aging.

Key Statistics

  • SGTP limit increased from 5-15%
  • Reduction to SI flow
  • Methodology implemented with no impact to customer schedule
  • NRC approval achieved with no requests for additional information (RAIs)

Learn more about our fuel safety analysis methodologies