Design Criteria for Fire Protection Systems Used in Safety Significant and Safety Class Applications

1. James O�Brien and James Bisker DOE/HSS James Landmesser DOE/EM EFCOG Engineering Practices Working Group Workshop April 2010 Design Criteria for Fire Protection Systems Used in Safety Significant and Safety Class Applications

2. 2 Presentation Overview Background Design Criteria Development Process Design Criteria Issues/Lessons Learned Summary

3. 3 Background Defense Nuclear Facilities Safety Board Recommendation 2008-1, Safety Classification of Fire Protection System Concern: No DOE criteria supporting the design and operation of fire protection systems used in safety significant/class applications. Each new project had to develop this criteria on its own and that this was inefficient. Recommendation: Develop specific criteria applicable to the design and operation of fire protection systems being relied upon as a primary means of protecting the public and workers from radiological hazards at the DOE�s defense nuclear facilities.

4. 4 Development Process System Survey Collected data on types of fire protection systems used in safety class and safety significant application complex-wide. Current Facilities and New Projects As expected, wet pipe sprinkler systems were by far the predominant fire protection system utilized in safety significant and safety class applications. Interim Guidance Development for Sprinkler Systems Working group of fire protection and safety analysis experts from throughout the complex to support the development of the guidance. Framework based upon DOE Order 420.1B, Facility Safety, Design and Safety Basis Requirements.

5. 5 Development Process(continued) DOE Order Requirements Addressed System Functions: Safety analyses must be used to establish the identity and functions of safety class and safety significant SSCs. Design Margins: Defense in depth must include applying conservative design margins and quality assurance (QA). � Reliability: Safety SSCs and safety software must be designed, commensurate with the importance of the safety functions performed, to perform their safety functions when called upon. Safety class electrical systems must be designed to preclude single-point failure.

6. 6 Interim Guidance Organized consistent with DOE Guide 420.1-1 topical areas. Function System Boundary Support Systems Interfacing Systems Reliability/Redundancy/Single Failure Resistance Conservative Design Margins Quality Assurance

7. 7 Interim Guidance(continued) Function: Information to be included in the Documented Safety Analysis includes: Information regarding the size and type of fires that the system is designed for. Specific considerations that may be required for the system to perform its intended function in the Documented Safety Analysis. For example, automatic water-based fire suppression systems are generally intended to limit fire spread, but not necessarily extinguish it (unless special hazards are considered).

8. 8 Interim Guidance(continued) System Boundary: The boundary of the safety class or safety significant Wet Pipe Sprinkler system should be defined such that it is clear which components are to be classified within the system. A boundary for sprinklers is typically determined at the system control valve or at the underground lead-in post indicator valve. All piping should either be designed for the maximum pressure and design basis accident conditions, or the design must show that failure of the piping or component not credited to be safety class or safety significant will not negatively impact the credited portions of the system.

9. 9 Interim Guidance(continued) Support Systems: Interim Guide reiterates key aspect of Guide 420.1-1. Provides specific guidance for several support systems including the water supply systems (provided in a separate interim guide due to the significance and complexity associated with it), freeze protection system, alarm devices and associated trim, and pressure monitoring systems.

10. 10 Interim Guidance(continued) Reliability/Redundancy/Single Failure Resistance: Safety Class Systems Wet Pipe Sprinkler systems should be designed to prevent a single-point failure for active components. Active components in sprinkler systems include the sprinklers, and any valves that must open or close during the performance of its nuclear safety function. Normally locked and/or electronically monitored are considered passiv.e Safety Significant Systems Safety significant components meeting these National Fire Protection Administration (NFPA) and Highly Protected Risk requirements are adequate to ensure the appropriate level of reliability. No additional consideration of redundancy or single failure resistance is necessary.

11. 11 Interim Guidance(continued) Conservative Design Margins: DOE relies on NFPA for conservatively designed fire protection systems. Design margin is less for some types of components allowed by NFPA (therefore, the guide recommends not utilizing these types of components). Several good practices are recommended.

12. 12 Summary DOE has developed design and operations criteria and guidance for wet pipe sprinkler guidance utilized in safety significant and safety class application. The criteria and guidance were developed by a team of fire protection and safety analysis experts and utilize DOE�s facility safety order (DOE Order 420.1B) and associated guide (DOE Guide 420.1-1) to support the development. The resulting guide should result in more efficiency (and consistency) in performing sprinkler system designs for safety significant and safety class Some tough issues related to implementation of the Order requirements have been addressed utilizing the collective knowledge and experience of the experts involved in two fields (fire protection and safety analysis). Developed criteria was completed and submitted to stakeholders on an interim basis until it could be incorporated into a revision to DOE-STD-1066, Fire Protection Design Criteria, that is planned for the latter part of 2010.

13. Contacts James O�Brien, Director james.o�brien@hq.doe.gov James Bisker jim.bisker@hq.doe.gov James Landmesser james.landmessersr@em.doe.gov 13