1 RIC 2009 Perspectives on Digital I&C Licensing in the 10 CFR 52 Environment Thomas R. Fredette, PE NRO/DE/ICE2 March 11, 2009

2 Overview Digital I&C design licensing process through certification, COL issuance, implementation and ITAAC closeout is not proven-- “We don’t know what we don’t know.” Staff is seeking to provide clarity of the process through a new ISG

3 Applicable Regulations 10 CFR requires, in part: - I&C performance and design information of sufficient detail to support inspection and construction/installation specifications, and - Evaluation against the Standard Review Plan (SRP criteria provide the level of detail for meeting regulations)

4 I&C Design Application Issues Staff review of current applications have identified challenges related to: - Level of detail that addresses SRP acceptance criteria - Use of DAC beyond the original intent of SECY

5 Application Issues (Examples) “Communication directly between the four channels is limited to the minimum such as channel trip signals and bypass status signals.” “These I&C systems parameters are appropriately separated from each other...” Minimum instrument inventory submitted as DAC, but should have been part of the application Incomplete IEEE-603 compliance tables submitted in Tier 1 DCD to be closed through DAC; description of how compliance would be accomplished would have enabled a safety conclusion without using DAC

6 Interim Staff Guidance- Objectives New ISG will address: - I&C design level of detail - Use of I&C DAC in conjunction w/ system design attributes - DAC implementation (mechanisms and schedule)

7 Key ISG Features Level of Detail for digital I&C system “attributes” Schedule for DAC implementation (in conjunction w/ I&C system development) DAC implementation

8 I&C Level of Detail DAC was intended for rapidly evolving technology (e.g. digital I&C platforms and ancillary equipment) SRP criteria focuses on I&C architecture, system requirements, and interfaces; NOT the digital platform (the I&C “Black Box”).

9 I&C Level of Detail (“Black Box”) Digital Computer Process Signals Control Signals IndicationsControls Environment Seismic Temperature/Humidity Electromagnetic Radiation System Requirements Functionality Logic & Timing Design Constraints & Planning

10 I&C Level of Detail I&C applications should address SRP criteria, including limiting parameters, values/ranges, drawings, etc. to provide Staff the basis for a reasonable assurance safety finding.

11 DAC Utilization Inner design details of the digital platform (the “black box”) Selected I&C attributes –System Quality –Human Factors Engineering –Diversity & Defense-in-Depth (D3) DAC should not apply elsewhere

12 DAC Implementation Schedule

13 DAC Schedule (cont.) Schedule is conceptual Availability of DAC information is essential for Staff review Key milestone is centered on a complete control room simulator 24 months prior to fuel load

14 DAC Implementation Three (3) options for DAC reconciliation: (1) Amendment to the design certification; Staff would review and issue SER (2) Submittal during COL review; Staff would review for that COL (3) Submittal after COL issuance; Staff would inspect as part ITAAC closeout. Note- enforcement would apply.

15 ISG Path Forward – Spring ‘09 Federal Register Notice Public Workshop Comment Period Final ISG Issued Note - Final resolution will update SRP