ML18163A390

June 13-14, 2018, Meeting Slide Regarding NRC-Industry Mps ISG-06 R2 Tabletop D.2.2 New System Architecture

ML18163A390
Person / Time
Site:	Nuclear Energy Institute
Issue date:	06/13/2018
From:	Nuclear Energy Institute
To:	Office of Nuclear Reactor Regulation
Golla J A
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Download: ML18163A390 (4)

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NRC-Industry MP4 ISG-06 R2 Tabletop D.2.2 New System ArchitectureNRC-Industry MP4 ISG-06 R2 Tabletop D.2.2 New System Architecture June 13-14, 2018Industry MP4 Team June 13-14, 2018Industry MP4 Team 2 2DCPP LAR Differences for AR Process

• When reviewing the DCPP LAR for architecture content, the following "gaps" were identified that would be expected to be available as part of the LARDemonstrate how the design detects malfunctions:

• How the application interfaces and uses the self-test and self-diagnostic features defined in the approved topical report and evaluated in the SE.

• The LAR does not explicitly describe how the application program utilizes the results of the self-diagnostics. They are only described in a general way with reference to the ATRs

.

3 3 Gaps (continued)

Gaps (continued)

• Treatment and detection of malfunctions in the system inputs including sensors and transmitters, in the system logic including internal voters within the safety system or voters external to the safety system, and malfunctions in the system outputs include discrete output switches, analog modulating outputs, and the actuated devices as well as feedback of actual position or condition where employed. This should include the expected failure state(s) of each input and the response of the system to each failure, and the expected failure state(s) of each output and the response of the plant to each failure. These should be based on the platform FMEA and considering the FMEA for the plant

application. The level of detail on how the diagnostics affect the resulting bistableresult is not discussed

.

4 4 Gaps (continued)

Gaps (continued)*The following items are indicated as ISG-06 Phase 2 items. These would be included in an AR LARSeparate I/O power supplies are provided and qualified by PG&E during detailed design for the Triconexand ALS subsystems.Operating voltage will be selected during detailed design to power instrument loops without exceeding voltage limitations of instrument

loop sensors (transmitters).The system-level PPS replacement Failure Modes and Effects Analysis (FMEA) will be completed during Phase 2.