POLICY ISSUE 

INFORMATION 

October 30, 2008 SECY-08-0166

FOR: The Commissioners 

FROM: Eric J. Leeds, Director 

 Office of Nuclear Regulatory Regulation 

SUBJECT: TRAINING AND INFRASTRUCTURE NEEDS DUE TO DIGITAL 

MODIFICATIONS ON OPERATING REACTORS TO SUPPORT 

REACTOR INSPECTIONS AND OPERATOR LICENSING 

PURPOSE: 

This paper discusses the staff’s actions to ensure that the U.S. Nuclear Regulatory Commission 

(NRC) operator license examiners (examiners) and inspectors maintain the necessary expertise 

as the existing reactors convert from analog to digital systems. The Commission requested this 

information paper in Staff Requirements Memorandum M080407A, “Staff Requirements—

Briefing on Digital Instrumentation and Controls,” dated May 1, 2008. The Commission has 

received similar information on training and infrastructure needs for new reactors presented in 

SECY-08-0096, “Training and Infrastructure Needs to Accomplish New Reactor Inspections and 

Operator Licensing,” dated July 3, 2008. This paper does not address any new commitments or 

resource implications. 

BACKGROUND: 

At an increasing rate, the original analog electronic equipment used at nuclear plants is no 

longer available because of technology changes. To maintain operations, utilities are replacing 

obsolete analog equipment with digital components using site-specific approaches. The 

replacement of analog with digital equipment is not unique to nuclear power plants. The 

chemical processing and other industries have been replacing analog equipment at their 

facilities for many years. Additionally, nuclear fuel cycle facilities are in the process of installing 

digital systems in their existing and new facilities. 

CONTACT: William B. Cartwright, NRR/DIRS 

 301-415-8345 
The Commissioners 2 

To date, most analog equipment replacements at operating power plants have been non-safety 

related components. Digital replacements of safety related equipment have typically been 

equivalent component replacements with a similar appearance. 

DISCUSSION: 

Categories of Planned Digital Modifications at Operating Nuclear Power Plants 

Digital modifications can take several approaches. The simplest and most common category of 

modification is the replacement of an analog device with an equivalent digital device. Many of 

these modifications have been made at operating reactors under licensee design controls, often 

as resolutions to obsolescence issues. Examples are gauge and chart recorder replacements 

with equivalent digital components. The NRC examiners and inspectors have been successfully 

dealing with these changes for a number of years. Special training or infrastructure is not 

needed for examiners and inspectors to support this category of change. 

Functional modifications constitute the second category of digital changes. Other than changes 

to display appearance, they are usually transparent to the plant operators, NRC inspectors, and 

NRC examiners. This category can include combining the analog functions of several 

components into a digital architecture or reengineering the logic of the new circuits to take 

advantage of digital capabilities. Functional changes to safety related systems usually require 

NRC approval (because of license changes). The most extensive functional modification 

proposal submitted to the NRC to date (from Oconee) converts several safety related systems 

from analog to digital architecture. The digital architecture offers enhanced capabilities such as 

error checking, signal validation, fault-tolerance features, trending, and testing improvements. 

This is a first-of-a-kind project that will establish a model for the industry license amendments of 

this type. If the proposed Oconee changes are approved by the NRC, similar major digital 

modification proposals are expected from other operating nuclear power stations. 

For this second category of digital modification inspectors and examiners require a basic 

understanding of the technology and failure modes, similar to all types of modifications. 

Experience indicates that additional NRC infrastructure or special training is not required to 

support this category of digital modifications at this time. 

From the perspective of an inspector and examiner, the third and most complex category of 

digital modifications involves changes to the human-machine interface (HMI). New reactor 

applicants have proposed substantial changes over previous control room designs by replacing 

individual components with flat screens and computer interfaces. While some licensees of 

operating reactors have discussed conceptual designs for extensive flat-screen style HMI 

modifications, they have not yet been formally proposed. 

As HMI modifications are developed, and if they are economically feasible, they may be 

proposed for existing reactors. For the operating reactor fleet, the timing and scope of all digital 

modifications are expected to vary depending on site-specific needs and resources. The staff 

has no indication from industry that it should anticipate major HMI modifications in the near term 

(several years). 
The Commissioners 3 

Extensive digital modifications to operating reactors (that require license amendments) will 

require prior NRC approval. This will provide the staff with advance notification of the scope 

and details associated with future digital modifications at operating reactors. 

Staff Actions to Date Regarding Digital Modifications 

Inspection procedures for digital modifications have been available since 1995. For NRC 

inspectors or examiners, the process for evaluating digital modifications is the same as for other 

plant modifications—the inspector validates that the design requirements have been 

implemented properly, and the examiner ensures that license applicants have an appropriate 

understanding of the site-specific procedures and operator requirements. 

As a result of the digital modification proposed for Oconee that is being reviewed, the staff has 

developed the new Inspection Procedure 52003, “Digital Instrumentation and Control 

Modification Inspection.” This new inspection procedure provides guidance for the installation, 

testing, and operational phases of large digital modifications. Training on the requirements of 

this procedure is being conducted. Contractor support for digital modification inspections has 

been budgeted in 2009 and 2010 to supplement NRC inspector expertise. The staff will use the 

inspection feedback process to identify any lessons learned, future digital inspection 

improvements, and any additional inspector training needs. 

The staff is also following industry initiatives on major HMI modifications for both new and 

existing reactors. As the industry develops the details for proposed HMI changes, the staff will 

recommend future NRC training needs. 

To deal with obsolescence issues similar to those faced by the industry, the NRC has converted 

about five percent of its simulator indicators and controllers to equivalent digital components. 

This provides some training exposure for the NRC inspectors and examiners. In terms of formal 

courses, a digital instrumentation and control course for technical design reviewers has been 

developed and held several times. The training organization anticipates future requests for 

additional digital technology courses for inspectors and examiners as the industry develops 

specific modification proposals. 

NRC inspectors and examiners are now exposed to site-specific combinations of analog and 

digital equipment in use for both safety and non-safety related applications (hybrid control 

room). Although there are site-specific differences, general digital training topics for inspectors 

are being defined, and external training opportunities have been identified, and are being used. 

Currently, NRC examiners validate the license exams at the sites before administering them. 

This ensures that the examiners are familiar with the site-specific systems, controls, and 

procedures being tested before the exam, which provides them with learning opportunities. It is 

important for inspectors and examiners to maintain expertise in both the analog and digital 

equipment at operating reactors as both are in use. 

An Inspection Manual Chapter 1245 “Qualification Program for the Office of Nuclear Reactor 

Regulation Programs” working group has existed for several years and is used as a forum for 

discussing inspector and examiner qualification requirements. This working group is developing 

advanced electrical training qualifications that include digital instrumentation. The working 

group members are drawn from the training organization, each regional office, and 

Headquarters, making it well suited to make training recommendations for inspectors and 
The Commissioners 4 

examiners. Part of this working group’s charter is to review inspector requests for training 

communicated by both the inspection feedback process and a biennial internal survey. 

Communications between the working group and the design technical branches reviewing 

proposed digital changes also ensure that future inspector and examiner needs are considered 

based on the proposed modifications under review. 

Conclusions 

For digital modifications at existing reactors, the NRC inspectors and examiners are 

successfully meeting their responsibilities. Inspector and examiner skills will be enhanced by 

training developed using the existing inspection feedback processes, monitoring future 

proposed changes, utilizing contractor expertise, and learning from the large proposed digital 

modification now under review. These enhanced skills will support future site-specific digital 

modifications. 

The staff expects the implementation of large-scale digital modifications will occur at existing 

reactors during the same time period that the new reactors are being built. This will result in 

opportunities to develop the infrastructure that meet the needs of both, resulting in cost and 

resource efficiencies. The Office of Nuclear Reactor Regulation, the Office of Human 

Resources, and the Office of New Reactors will continue close communications to coordinate 

their resources in this area. 

COORDINATION: 

The Office of the General Counsel reviewed this paper and has no legal objection. 

 /RA/ (James T. Wiggins acting for) 

 

 Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 
The Commissioners 4 

examiners. Part of this working group’s charter is to review inspector requests for training 

communicated by both the inspection feedback process and a biennial internal survey. 

Communications between the working group and the design technical branches reviewing 

proposed digital changes also ensure that future inspector and examiner needs are considered 

based on the proposed modifications under review. 

Conclusions 

For digital modifications at existing reactors, the NRC inspectors and examiners are 

successfully meeting their responsibilities. Inspector and examiner skills will be enhanced by 

training developed using the existing inspection feedback processes, monitoring future 

proposed changes, utilizing contractor expertise, and learning from the large proposed digital 

modification now under review. These enhanced skills will support future site-specific digital 

modifications. 

The staff expects the implementation of large-scale digital modifications will occur at existing 

reactors during the same time period that the new reactors are being built. This will result in 

opportunities to develop the infrastructure that meet the needs of both, resulting in cost and 

resource efficiencies. The Office of Nuclear Reactor Regulation, the Office of Human 

Resources, and the Office of New Reactors will continue close communications to coordinate 

their resources in this area. 

COORDINATION: 

The Office of the General Counsel reviewed this paper and has no legal objection. 

 /RA/ (James T. Wiggins acting for) 

 Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 

* via e-mail 

Accession Number: ML082890070 WITS 200800249/EDATS: SECY-2008-0322 

OFFICE DIRS/NRR D/DIRS/NRR D/DE/NRR HR/ADHRTD D/DCIP/NRO 

NAME WBCartwright:cct FDBrown PLHiland KHGibson* GMTracy* 

(JMunday for)

DATE 10/28/08 10/28/08 10/23/08 10/23/08 10/24/08 

OFFICE OGC Tech Editor OD/NRR 

NAME 

EWilliamson KAzariah-Kribbs* EJLeeds 

(JWiggins for) 

 

DATE 10/28/08 10/24/08 10/30/08 

 OFFICIAL RECORD COPY