ML19218A349

August 1, 2019 BTP 7-19 Public Teleconference Summary

ML19218A349
Person / Time
Issue date:	08/14/2019
From:	Tekia Govan NRC/NRR/DIRS/IRGB
To:	Rossnyev Alvarado, Ronaldo Jenkins, Nancy Salgado Division of Engineering
Govan T, 415-6197, NRR/DIRS
References
Download: ML19218A349 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 14, 2019 MEMORANDUM TO: Nancy L. Salgado, Chief Instrumentation and Controls Branch (A)

Division of Engineering Office of Nuclear Reactor Regulation Rossnyev D. Alvarado, Acting Chief Instrumentation and Controls Branch (B)

Division of Engineering Office of Nuclear Reactor Regulation Ronaldo V. Jenkins, Chief Instrumentation, Controls and Electrical Engineering Branch Division of Engineering Office of Nuclear Regulatory Research FROM: Tekia V. Govan, Project Manager /RA/

ROP Support and Generic Communication Branch Division of Inspection and Regional Support Office of Nuclear Reactor Regulation

SUMMARY

OF THE PUBLIC TELECONFERENCE ON THE INTEGRATED ACTION PLAN TO MODERNIZE INSTRUMENTATION AND CONTROLS REGULATORY INFRASTRUCTURE:

MODERNIZATION PLAN #1D, REVISION TO BRANCH TECHNICAL POSITION 7-19 HELD ON AUGUST 1, 2019 On August 1, 2019, the U.S. Nuclear Regulatory Commission (NRC) staff held a Category 2 public teleconference with the Nuclear Energy Institute (NEI) to discuss Modernization Plan (MP) #1D, to revise Branch Technical Position (BTP) 7-19, Guidance for Evaluation of Diversity and Defense-In-Depth in Digital Computer-Based Instrumentation and Control Systems, Revision 7, issued August 2016. This topic was discussed in the NRCs Integrated Action Plan to Modernize Digital Instrumentation and Controls Regulatory Infrastructure, updated January 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19025A312).

CONTACT: Tekia V. Govan, NRR/DIRS (301) 415-6197

N. Salgado, et al. Prior to this meeting, NEI provided the NRC staff with recommended language for consideration in the revision of Section 1.8, Potential Effects of [Common Cause Failure] CCF: Failure to Actuate and Spurious Actuation, of BTP 7-19 (ADAMS Accession No. ML19211B057). The staff reviewed this information and developed questions regarding the document to be discussed during the meeting. NRC staff made no decisions or took any agency positions during this meeting.

Meeting Summary NRC and industry management made brief opening remarks, and all attendees introduced themselves.

NEI provided an overview of their proposed language submitted for Section 1.8 of BTP 7-19 (referenced above). The NRC staff requested that NEI clarify the use of Clauses 4 and 5.5 of Institute of Electrical and Electronics Engineers (IEEE) Standard 379, IEEE Standard Application of the Single-Failure Criterion to Nuclear Power Generating Station Safety Systems, as guidance criteria in their proposed language for Section 1.8 of BTP 7-19. After some discussion NEI agreed to submit a revised proposal for the NRC staffs consideration in this section of the BTP to address the reference to Clauses 4 and 5.5 of the IEEE standard.

The NRC staff then presented their plan to address the topic of spurious actuations (ADAMS Accession No. ML19212A112). The staff noted a change in terminology in the draft BTP 7-19, where spurious actuations would now be referred to as spurious operations, in part, to convey the notion that not only false safety systems (e.g., engineered safety feature actuations) can result in undesirable plant conditions, but also that mis-operation of control systems (i.e.,

erroneous control actions) could result in such adverse plant conditions. NEI agreed with the staff that the use of the term, spurious operations, was an appropriate term to use as part of the revision to BTP 7-19. The staff also pointed out that digital instrumentation and control defensive design measures can be used to limit or prevent spurious operations, so that the consequences of those spurious operations may also be limited or prevented. The staff reiterated that effects of spurious operations resulting from single random hardware failures should be evaluated using design basis analysis methods, but the effects of spurious operations resulting from design defects considered to be beyond design basis, such as software errors, may be analyzed using best estimate methods.

The NRC staff also presented several examples where proposed approaches for the use of defensive design measures were found to be acceptable by the staff for addressing spurious safety and control system operations. These examples included: 1) design measures applied to the design of the Watts Bar Nuclear Plant, Unit 2 distributed control system to improve plant reliability and availability; 2) the Westinghouse Advance Passive 1000, pressurized-water reactor, proposal to remove certain safety related functions from the non-safety related operator workstation where a control failure was deemed too onerous to prevent or mitigate spurious operation and the use of an accelerated driven system blocking device that was independent of process management system failure modes; and 3) the use of control function segmentation, network traffic monitoring, and additional thermal-hydraulic analysis of postulated spurious operation of a single safety function for the Advanced Power Reactor 1400 design certification effort.

N. Salgado, et al. Conclusion At the end of the meeting, NRC and industry management gave closing remarks. NEI expressed appreciation for the open dialogue and willingness of the NRC staff to hear industry views. Following the meeting, NEI provided the NRC staff with a revised recommendation of language for consideration in the revision of Section 1.8 of BTP 7-19 (ADAMS Accession No. ML19218A073). The NRC staff has committed to make the draft revision to BTP 7-19 publicly available by August 15, 2019. The next public meeting on the revision to BTP 7-19 is scheduled for August 29, 2019.

The enclosure provides the attendance list for this meeting.

Enclosure:

As stated

ML19218A349 *Concurrence via e-mail OFFICE NRR/DIRS/IRGB NRR/DE/EICA/TR* NRR/DIRS/IRGB/OLA* NRR/DE/EICB/TR*

NAME TGovan WMorton IBetts RAlvarado DATE 08/07/2019 08/14/2019 08/07/2019 08/14/2019 LIST OF ATTENDEES INTEGRATED ACTION PLAN TO MODERNIZE INSTRUMENTATION AND CONTROLS REGULATORY INFRASTRUCTURE: MODERNIZATION PLAN #1D, REVISION TO BRANCH TECHNICAL POSITION 7-19 August 1, 2019, 10:00 AM to 12:00 PM Teleconference ATTENDEE ORGANIZATION

1. Paul Rebstock NRC

2. Deanna Zhang NRC

3. Nancy Salgado NRC

4. Paul Kallan NRC

5. Bob Weisman NRC

6. David Desaulniers NRC

7. Robert Beaton NRC

8. Eric Benner NRC

9. Wendell Morton NRC

10. Tekia Govan NRC

11. Maxine Segarnick NRC

12. Ismael Garcia NRC Participated via conference line

13. Rossnyev Alvarado NRC

14. David Rahn NRC

15. John Schrage Entergy

16. David Herrell MPR Associates

17. Steve Vaughn NEI

18. Warren Odess-Gillett Westinghouse

19. Raymond Herb Southern Nuclear

20. Mark Burzynski New Clear Day Inc.

21. Don Chase Curtiss-Wright

22. Neil Archambo Duke Energy

23. Gordon Clefton Idaho National Laboratory

24. Mike Wiwel PSEG

25. Bill Catullo Westinghouse

26. Thomas Thorton Entergy Enclosure