ML19057A209

U.S. Nuclear Regulatory Commission (NRC) Experience: Oversight of the First Two Integrated System Validation Tests of New Reactor Control Rooms

ML19057A209
Person / Time
Issue date:	02/26/2019
From:	Brian Green NRC/NRR/DIRS/IRAB
To:
Green B, NRR/DIRS, 301-415-6728
References
Download: ML19057A209 (5)

Text

U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Reactor Regulation Experience: Oversight of the First Two Integrated System Validation Tests of New Reactor Control Rooms What Is Integrated System Validation?

Integrated system validation (ISV) is an important part of human factors verification and validation activities as described in NUREG-0711. ISV is performed to provide performance-based evidence that the integrated system design can safely be used to operate the plant. This includes using a variety of performance measures to assess how well the operators interact with the hardware, software, and procedures in the main control room.

Human engineering discrepancies (HEDs) are identified if performance criteria are not met. HEDs are analyzed and tracked to ensure that any HEDs that could impede safe operation are addressed with changes to the design, procedures, or operator training before operation.

Recent NRC Experience ISV testing can be particularly complex, requiring a sophisticated testbed and test participants who are trained to a level roughly equivalent to a licensed operator. The NRC considers these and other factors when adjusting its oversight to balance the need for adequate validation while considering the associated costs.

The NRC recently conducted a series of inspections of the AP1000 ISV and a series of audits of the NuScale ISV. These were the first implementations of Inspection Procedure (IP) 65001.23. In addition, the staff used IP 43002 when conducting vendor inspections.

This presentation summarizes NRC experience with oversight of the ISV process.

Key ISV Criteria from NUREG-0711 Conditions Performance Plant Personnel Data Analysis

• Realistic and challenging Measures

• Representative of

• Variety of analyses operating scenarios

• Objective measures people who will one used to draw

• Wide variety of operational (time, accuracy, errors, day operate the plant conclusions about the conditions (normal etc.)

• Training and safe operation of the operations, design-basis

• Subjective measures qualifications plant and to identify accidents, startup, etc.) (workload, situation issues that must be

• Realistic secondary tasks awareness, etc.) resolved in order to assure safe operation Validation Validation Test Design Testbed Personnel

• Scenario sequencing

• High-fidelity simulator

• Independence from the

• Test procedures (usually the same one design team

• Test personnel training used for operator

• Specially qualified for

• Participant training licensing) conducting ISV

• Pilot testing

Recent NRC Experience with ISV LICENSING APPROACHES WITH AND WITHOUT DESIGN ACCEPTANCE CRITERIA LEAD TO DIFFERENCES IN OVERSIGHT The Commission allows the use of design acceptance criteria (DAC) for licensing the human factors aspects of main control room (MCR) designs. When DAC are used, inspections, tests, analyses, and acceptance criteria are used to verify completion of the DAC.

Alternatively, applicants may choose to complete the control room design before design certification and not use DAC. This can lead to alternate strategies for the timing and conduct of the ISV. As such, the AP1000 (with DAC) NRC has taken different approaches to overseeing the ISV process. NuScale (without DAC)

• The NRC reviewed and approved AP1000: Used the DAC approach by submitting implementation plans

• The NRC reviewed and commented on the ISV implementation plan. that the staff reviewed and approved during the design certification the ISV implementation plan.

• Vendor inspections were used to review.

• An audit of the ISV test was used to ensure ISV was conducted in ensure that it was conducted in accordance with the implementation NuScale: Did not use DAC as other applicants have done in the past. accordance with NUREG-0711.

plan and to review ISV analyses and Instead, NuScale had a nearly complete MCR design when it submitted

• An audit will be used to review the ISV conclusions. the design certification application. ISV is being conducted concurrently results and analyses concurrent with the with the design certification review. Phase 4 safety evaluation.

Key Points of Interest during Inspections/Audits Planning Analyses

• Implementation plan should be

• Review the conclusions drawn about consistent with NUREG-0711 pass/fail criteria and diagnostic

• Principles described in NUREG-0711 analyses are used to ensure credible ISV results

• Confirm appropriate identification and

• Applicants should discuss the timing of prioritization of HEDs the ISV during preapplication

• Determine whether design changes are interactions needed Execution Retesting

• ISV should be conducted consistent

• Determine whether design changes with an NRC-approved implementation warrant retestingis the change likely plan or NUREG-0711 if a results to invalidate conclusions drawn by the summary report is submitted in lieu of ISV?

an implementation plan

• Verify that appropriate retesting methods were used

• Verify that design changes cause no new human performance issues

References NRC Guidance Documents

• NUREG-0711, Revision 3, Human Factors Engineering Program Review Model, November 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12324A013)

• IP 65001.23, Inspection of Human Factors Engineering Verification and Validation ITAAC, December 22, 2014 (ADAMS Accession No. ML14279A071)

• IP43002, Routine Inspections of Nuclear Vendors, July 15, 2013 (ADAMS Accession No. ML13148A361)

AP1000 Inspection Reports

• NRC Inspection of Westinghouse Electric Company Report No. 99900404/2015-201, April 5, 2016 (ADAMS Accession Contact Information No. ML16091A462)

• NRC Inspection of Westinghouse Electric Company Report No. 99900404/2016-206, December 9, 2016 (ADAMS Accession U.S. Nuclear Regulatory Commission

• No. ML16336A244)

NRC Inspection of Westinghouse Electric Company Report Office of Nuclear Reactor Regulation No. 99900404/2017-202, July 30, 2018 (ADAMS Accession No. ML18207A243) 11555 Rockville Pike Rockville, MD 20852 NuScale Audit Reports

• July 25, 2017-February 14, 2018, NuScale Human Factors Engineering (HFE) Audit Report (ADAMS Accession No. ML18135A049)

Brian.Green@nrc.gov

• June 26-28, 2018, NuScale HFE Audit Summary Report (ADAMS Accession No. ML18208A370) www.nrc.gov

• July-August 2018, NuScale ISV Audit Summary Report (ADAMS Accession No. ML18298A190)