I&C upgrades are often necessary to ensure continued safe and reliable operation. However, a number of unsettled technical and regulatory issues continue to hinder I&C modernization efforts. In some cases existing regulatory guidance is being reassessed, and issues once considered resolved have been reopened. Updates to key sections of the NRC’s Standard Review Plan are now in development, but the specifics are largely unknown. This session will address some of the key technical issues and areas of regulatory uncertainty and risk that affect digital upgrades at operating plants and will affect license approvals for new plants.

Specific topics include safety system actuation setpoints, human factors considerations for new control rooms, new I&C architectures that use advanced technologies, the latest thinking on the software common-mode failure issue and diversity and defense-in-depth requirements, and the applicability of risk-informed approaches to digital equipment. Discussion will emphasize activities that might be undertaken by the various stakeholders (utilities, EPRI, NEI, and NRC) to resolve the open issues sooner and more efficiently, so that they don’t result in crippling delays for future operating plant modernization programs and new plant license approvals.

P054-“Addressing I&C Issues for New Nuclear Plant Deployment”

Layla Sandell, Ray Torok, EPRI

The U.S. nuclear industry is making significant progress toward overcoming financial, regulatory, and technical barriers to deployment of new nuclear power plants. Progress toward overcoming financial barriers is being made by reducing the uncertainties around capital costs for new nuclear plants. The Energy Bill of 2005 offers key financial incentives for new nuclear power plant construction in three forms, including loan guarantees, production tax credits, and standby support—risk insurance to cover cost associated with delays that are beyond the control of plant sponsors. Regulatory barriers are being overcome with efforts to demonstrate the new plant licensing process. Four plant designs have been certified by the NRC, one design application is currently under review, and four other designs have been submitted for pre-application review. The NRC is also reviewing three utility Early Site Permit applications. Several individual utilities and consortia (groups of utility companies and vendors) are planning on submitting Combined Construction & Operating License (COL) applications in 2007-2008, including consortia that have received DOE co-funding to demonstrate the licensing process. Technical barriers are being addressed by industry research including significant work managed by EPRI. Specifically, in the I&C area an industry initiative for new plants was recently started that will identify and prioritize large generic issues, establish resolution paths and schedules, and identify the roles of various stakeholders including utility companies, EPRI, NEI, vendors and the NRC. Through the course of this initiative we will address I&C issues for both existing and new plants. To begin, an industry workshop has been scheduled for March 28-29, 2006. This paper describes key I&C related technical and regulatory issues and their implications for new plants, and provides a status report on the efforts to resolve them.

P044-“Risk-Informed Evaluations of Nuclear Power Plant Digital Upgrades Technical and Regulatory Issues”

David Blanchard, Applied Reliability Engineering

An area of technical and regulatory uncertainty in the implementation of digital upgrades at nuclear power plants is the application of risk-informed techniques to the evaluation of the design of a digital upgrade. All nuclear power plants have plant specific probabilistic risk assessments (PRAs) [1] with which risk-informed analyses are routinely performed in the operation, maintenance and licensing of the plants. Furthermore, NRC policy is to increase the use of PRA in all regulatory matters to the extent supported by the state of the art in order to complement existing deterministic and defense-in-depth approaches as well as reduce unnecessary regulatory burden [2].

However, developed prior the completion of the plant specific PRAs, current regulatory guidance with respect to evaluation and review of digital upgrade design [3] remains largely deterministic and does not yet take advantage of risk insights that can be derived from the PRAs. In this paper, the following questions will be addressed with respect to the use of risk insights in the implementation of a nuclear power plant digital upgrade:

· What technical issues are barriers to the use of PRA in the evaluation of the risks associated with a digital upgrade?

· What kinds of risk insights can be derived from a plant specific PRA using existing techniques that are useful in support of licensing a digital upgrade?

· What do these risk insights say regarding the effectiveness of existing deterministic regulatory guidance in managing safety in the implementation of a digital upgrade?

· How can these risk insights be used to reduce regulatory uncertainties?

[1] Generic Letter 88-20 "Independent Plant Examination for Severe Accident Vulnerabilities", USNRC, November 23, 1988.

[2] "Use of Probabilistic Risk Assessment Methods in Nuclear Regulatory Activities", Federal Register Vol. 60 pg. 42622, August 16, 1995.

[3] Branch Technical Position HICB-19, “Guidance for Evaluation of Defense-in-Depth and Diversity in Digital Computer-Based Instrumentation and Control Systems”.

P045-“The Functionality of Instrument Loops and How That Can Be Determined”

Robert Fredricksen, EXELON Nuclear

The expectations from the regulator as to what is required for compliance with 10CFR50.36 with regard to Limiting Safety System Settings and the surveillance activities that will be required to support these new expectations to ensure compliance will have an impact on the majority of the operating nuclear power reactors in the United States. This paper will address the revised expectations and what are the deviances from the present industry practices. It will address some additional actions that will be required to comply with these new expectations and identify what areas may still be subject to disagreements

P046-“Control Room and Human-System Interface Guidelines for Nuclear Power Plant Modernization Programs”

Joseph Naser, EPRI

Several nuclear power plants are starting instrumentation and control (I&C) modernization programs using digital equipment to address obsolescence issues and the need to improve plant performance, while maintaining high levels of safety. As an integral part of the I&C modernization program, the control room and other human-system interfaces (HSIs) are also being modernized. A project, jointly funded by the Electric Power Research Institute and the U.S. Department of Energy, has developed guidance that will facilitate specification, design, implementation, operations, maintenance, training, and licensing activities for control rooms and HSIs.

This guidance is actually 35 sets of guidelines in five areas. These five areas are guidance for: 1) control room modernization planning, 2) human factors engineering (HFE) design, analysis and tools, 3) HFE guidelines, 4) regulatory and licensing activities, and 5) special topics related to operations and maintenance. The application of these guidelines will help to reduce the likelihood of human errors and licensing risk, to gain maximum benefit of implemented technology, and to increase performance. The guidance is intended for application by utilities, vendors/suppliers, and third party integrators of modernization activities. However, most of the guidance applies to new plant design as well. Many of the guidelines are already being used by several utilities. Several sections of these guidelines have already been used successfully by utilities. This paper provides a description of the guidelines project and the guidelines. It does not specifically discuss the licensing implications of the aspects of the guidance that addresses design and process elements that will receive regulatory scrutiny. Examples of these are the acceptance of the graded approach to HFE, appropriate approach to determine the minimum inventory of fixed position and continuously available indicators and controls, appropriate technical and regulatory requirements for qualified HSIs for accident mitigation, display evaluation, soft controls, computerized procedures, automation, etc., and appropriate criteria to be applied to assure appropriate teamwork between operating crew members and between automation and operators.

P020-”Human-Machine Interface Evaluation”

Rachel Vail, Washington Safety Management Solutions.

It has been approximately 20 years since the majority of human factors engineering evaluations of the commercial nuclear power plant control room were performed. Many technological advances have been made in the look-and-feel, usability and reliability of the nuclear control room human-system interface (HSI) in the past two decades. The U.S. Nuclear Regulatory Commission has updated is design and evaluation process, NUREG-0700, several times to provide a systematic method for evaluating the HSI design for control rooms. NUREG-0700 is required for both HSI design submittals prepared by licensees or applicants for a license or new design certification of commercial nuclear power plants. NUREG-0700 added approximately 600 new requirements to the most recent revision of NUREG-0700 and brings the total requirements to over 2000.

Performing the human factors engineering review manually of an entire control room or even a major modification is a time consuming process. Major changes to NUREG-0700 (Rev. 2) will be highlighted and a method will be discussed to streamline the HSI review process.

Presentation of these papers will be followed by a panel discussion, started with a brief presentation by Allan Howe on the NRC’s Perspective on the Evolving Technical and Regulatory Environment

Allan Howe, I&C Branch Chief, NRR, Nuclear Regulatory Commission