Emergency Response Data System (Generic Letter 89-15)

     August 21, 1989



The Commission is in the process of implementing an Emergency Response Data 
System (ERDS).  The ERDS will provide direct electronic transmission of a 
limited set of parameters from a licensee computer to the NRC during an 
emergency at a licensed nuclear power facility.  Implementation is proceeding 
on a voluntary basis and efforts are being taken to minimize the burden on the 
participating facilities.  We believe that the implementation of this system 
will be beneficial to both the NRC and licensees for the reasons explained 

The Commission has defined the NRC's primary role in an emergency at a 
licensed nuclear facility as one of monitoring the licensee to assure that 
appropriate recommendations are made with respect to offsite protective 
actions.  Other aspects of our role include supporting the licensee with 
technical analysis and logistic support, supporting offsite authorities, 
including confirming the licensee's recommendations to offsite authorities, 
keeping other Federal agencies and entities informed of the status of the 
incident, and keeping the media informed of the NRC's knowledge of the status 
of the incident.

To fulfill the NRC's role, the NRC requires accurate, timely data on four 
types of parameters:  (1) core and coolant system conditions must be known 
well enough to assess the extent or likelihood of core damage; (2) conditions 
inside the containment building must be known well enough to assess its 
status; (3) radioactivity release rates must be available promptly to assess 
the immediacy and degree of public danger by these pathways; and (4) the data 
from the plant's meteorological tower is necessary to provide insight into the 
potential distribution of a release.

Experience with the voice-only emergency communications link, currently 
utilized for data transmission, has demonstrated that excessive amounts of 
time are needed for the routine transmission of data and for verification or 
correction of data that appear questionable.  Error rates have been excessive 
and the frequency of updates has been unreliable.

The ERDS concept is a direct electronic transmission of selected parameters 
(Enclosures 1 and 2) from existing facility electronic data systems which have 
been established by the licensees.  The ERDS would be for use only during 
emergencies at the facilities and would be activated by the licensees upon 
declaration of an ALERT or higher emergency classification to begin 
transmission to the NRC Operations Center.  The ERDS would be supplemented 
with voice transmission over the existing Emergency Notification System (ENS) 
of essential data not available on licensees' systems, rather than requiring 
modifications to existing systems.

*See page 3 for special instructions for certain plants.

.Generic Letter 89-15                - 2 -              August 21, 1989

The utility is expected to provide an output port on the appropriate data 
system and the necessary software to assemble the data to be transmitted.  No 
personnel action should be required for the acquisition or transmission of 
data after activation of the system.

Accuracy and reliability are expected to be excellent because there are no 
human interfaces and many data systems, such as the Safety Parameter Display 
System (SPDS), will incorporate automatic data validation.  Timeliness should 
be excellent because the system would be immediately available and capable of 
rapid transmission with frequent updating.  Parametric coverage is expected to 
be excellent because the primary objective of the SPDS requirement is to 
provide the licensee with a tool for quickly assessing the overall status of 
the plant, i.e., the same need that the NRC faces.  Therefore, voice 
communications would be directed toward plant conditions and plant response 
rather than individual instrument readings.

Tests of the ERDS concept have been conducted with Duke Power Company 
(McGuire) and with Commonwealth Edison (LaSalle and Zion).  These tests have 
demonstrated that there is great value in using electronic data transmission 
for obtaining a limited set of reliable, time tagged data.  The NRC response 
teams functioned more efficiently and their assessments were more timely.  
Major improvements in the ability to focus on significant factors and to 
predict the course of events were noted.  The questions that were asked of the 
licensee were focused on the overall status and corrective actions being 
considered rather than simple data requests, thereby reducing the volume of 
voice communications.

Actual work on the ERDS project began in 1985 with an initial feasibility 
survey conducted at approximately 80 percent of the licensed nuclear 
facilities in the United States.

An ERDS implementation contractor began work in January 1988.  The initial 
activities of the contractor have focused on an indepth review of the survey 
results, the production of final NRC hardware and software designs and the 
procurement of the necessary hardware and software.  We are currently working 
with an initial set of utilities that have agreed to participate and we expect 
to establish initial plant connections in 1989.  The lessons learned in 
implementation with this initial group will be fed back to the subsequent 
participants.  Extensive interactions were held with NUMARC.  Additionally, 
the ERDS program was discussed at the NRC Regulatory Conference with industry 
in April, 1989.  We hope to complete all plant connections by early 1992.  
Enclosed is a list of frequently asked questions and our answers to assist you 
in a better understanding of the ERDS program.

This request is covered by Office of Management and Budget Clearance Number 
3150-0011 which expires December 31, 1989.  The estimated average burden hours 
is 150 person hours per licensee response, including staff and management 
review, formulation of licensees' position, and preparation of the requested 
response.  These estimated average burden hours pertain only to these 
identified response-related matters and do not include the time for any follow 
on implementation.
.Generic Letter 89-15                - 3 -              August 21, 1989

Send comments regarding this burden estimate or any other aspect of this 
collection of information, including suggestions for reducing this burden, to 
the Records and Reports Management Branch, Division of Information Support 
Services, Office of Information Resources Management, U.S. Nuclear Regulatory 
Commission, Washington, D.C.  20555; and to the Paperwork Reduction Project 
(3150-0011), Office of Management and Budget, Washington, D.C.  20503.

We believe the benefits to the overall incident response capability are 
substantial and the costs to each utility are small.  We would like to 
continue implementation on a voluntary basis.  The purpose of this generic 
letter is to solicit the participation of those utilities which have not yet 
volunteered* in the ERDS program.  Since we also plan to contact each utility 
individually, please provide an appropriate contact in your organization for 
followup discussion.  Should you have any questions, please feel free to call 
Gary Zech, Chief, Incident Response Branch at (301) 492-4193 or have your 
staff call John Jolicoeur, ERDS Project Manager at (301) 492-4155.  


                                   James G. Partlow 
                                   Associate Director for Projects 
                                   Office of Nuclear Reactor Regulation

1.  PWR Parameter List
2.  BWR Parameter List
3.  Questions and Answers List
4.  List of Most Recently Issued Generic Letters

*This generic letter is for information only for Zion, Dresden, Quad Cities, 
Byron, LaSalle, Braidwood, Palisades, Three Mile Island, Oyster Creek, 
Fitzpatrick, Ft. St. Vrain, LaCrosse, Big Rock Point, Rancho Seco, Davis 
Besse, Oconee, McGuire and Catawaba because these facilities are exempt from 
providing a response since they fall into one of the following categories:

          1. Licensee has already volunteered
          2. Reactor facility is inactive
          3. Reactor facility has been deemed
             inappropriate for connection to 
.                                                            Enclosure 1

                               PWR Parameter List

Primary Coolant System             Pressure
                                   Temperatures - Hot Leg
                                   Temperatures - Cold Leg
                                   Temperatures - Core Exit Thermocouples
                                   Subcooling Margin
                                   Pressurizer Level
                                   RCS Charging/Makeup Flow
                                   Reactor Vessel Level (When Available)
                                   Reactor Coolant Flow
                                   Reactor Power

Secondary Coolant System           Steam Generator Levels
                                   Steam Generator Pressures
                                   Main Feedwater Flows
                                   Auxiliary/Emergency Feedwater Flows

Safety Injection                   High Pressure Safety Injection Flows
                                   Low Pressure Safety Injection Flows
                                   Safety Injection Flows (Westinghouse)
                                   Borated Water Storage Tank Level

Containment                        Containment Pressure
                                   Containment Temperatures
                                   Hydrogen Concentration
                                   Containment Sump Levels

Radiation Monitoring System        Reactor Coolant Radioactivity
                                   Containment Radiation Level
                                   Condenser Air Removal Radiation Level
                                   Effluent Radiation Monitors
                                   Process Radiation Monitor Levels

Meteorological                     Wind Speed
                                   Wind Director
                                   Atmospheric Stability
.                                                            Enclosure 2

                               BWR Parameter List

Primary Coolant System             Reactor Pressure
                                   Reactor Vessel Level
                                   Feedwater Flow
                                   Reactor Power

Safety Injection                   RCIC Flow
                                   HPCI/HPCS Flow
                                   Core Spray Flow
                                   LCPI Flow
                                   Condensate Storage Tank Level

Containment                        Drywell Pressure
                                   Drywell Temperatures
                                   Hydrogen and Oxygen Concentration
                                   Drywell Sump Levels
                                   Suppression Pool Temperature
                                   Suppression Pool Level

Radiation Monitoring System        Reactor Coolant Radioactivity Level
                                   Primary Containment Radiation Level
                                   Condenser Off-Gas Radiation Level
                                   Effluent Radiation Monitor
                                   Process Radiation Levels

Meteorological                     Wind Speed
                                   Wind Director
                                   Atmospheric Stability
.                                                            Enclosure 3 

                           ERDS QUESTIONS AND ANSWERS

 1.  Will the implementation of the ERDS affect the NRC response role or the

     way that role is fulfilled?  

     No.  The NRC response role was defined and approved by the Commission and 

     would not change due to the ERDS.  Current response activities, including 

     discussions with the licensee, will be done more quickly and efficiently 

     due to ERDS implementation but would not materially change.

 2.  What communication protocol will be set up to accomplish the ERDS 


     A generic letter providing information about the ERDS and plans for its 

     implementation will be promulgated to all licensees requesting their 

     participation in the program.

     Once a utility has committed to participate in the ERDS project, it will 

     be contacted by telephone by the AEOD ERDS project manager and the NRC 

     contractor to make arrangements for a site specific implementation 


     The NRC will send a questionnaire to the licensee to obtain necessary 

     preliminary information about the licensee's computer system and the ERDS 

     parameters.  For many licensees this questionnaire will also serve to 

.                                    - 2 -

     confirm data obtained during the ERDS feasibility study conducted in 

     1987.  Response to this questionnaire should be forwarded to the NRC and 

     its contractor.  Any questions or problems concerning the questionnaire 

     should be referred to John R. Jolicoeur, AEOD ERDS Project Manager at 

     (301) 492-4155 or Tony LaRosa, ERDS Project Manager, EI International at 

     (208) 529-1000.

     After this information has been reviewed, we will proceed with the system 

     implementation process as described in the response to the following 


3.   How will the plant specific design and implementation aspects of ERDS be

     finalized with a facility?  

     Once a utility has committed to participate in the ERDS project, an 

     initial meeting will be held at the licensee's facilities with the NRC 

     and our implementation contractor.  The topics to be discussed include:

          The data points available on the licensee's computer to be 

          transmitted that best satisfy the NRC parameter list.

          The computer or computers that will be sending the data stream and 

          their operating characteristics.

          The data stream characteristics and communications method (ASCII, 

          EBCDIC) to be used to transmit the data.

.                                    - 3 -

          Any hardware and software required for the ERDS implementation.  The

          plant specific implementation schedule based on plant capabilities, 

          the need for hardware additions or modifications, and software 

          development requirements.

     Subsequent ERDS development and initial testing will be done based on the 

     agreed upon schedule.

 4.  What is the current program schedule?

     Software is being developed by the NRC's contractor and should be 

     completed by late summer 1989.  The first utility on line to the NRC 

     Operations Center in Bethesda is scheduled for early 1990 with subsequent 

     connections scheduled over a 2 to 3 year period.

 5.  Will the implementation of the ERDS require significant equipment 

     modification or addition by licensees?

     The only equipment requirements are for the hardware that is needed to 

     provide the data stream from the current licensee equipment that 

     processes the requested data.  Should the computer system not be capable 

     of producing the data stream for transmittal, then the ERDS will be 

     implemented as site equipment modifications permit.  Approximately 5 to 

     10 percent of the licensee's systems are running at close to 100 percent 

     processing capacity in the post trip or incident environment, and 

     approximately 10 to 

.                                    - 4 -

     15 percent of the licensee systems are hardware limited (e.g. no 

     available output port for an ERDS connection).  The ERDS will follow, not

     drive, licensee equipment modifications.  For those licensees where no 

     new hardware is required, the costs per reactor unit are estimated in the 

     range of $20K to $50K.  This estimate includes labor costs associated 

     with software development, design change notice documentation, testing, 

     and procedure development.  At the upper end of the cost spectrum, the 

     survey revealed that two plant sites would require additional computer 

     equipment to provide the necessary ERDS feed.  The hardware costs were 

     estimated at $150K plus licensee staff time required to set up a custom 

     system development effort with the appropriate contractor.  

 6.  Will the ERDS be considered safety grade or require redundant equipment?

     No.  The ERDS feed will be as reliable as the current licensee equipment 

     providing data to the licensee's own TSC and EOF.  The addition of new 

     plant instrumentation or computer data points to provide ERDS data will 

     not be required.

 7.  Will the current data list be expanded?

     No.  The issue has been well studied since the Nuclear Data Link was 

     originally proposed after TMI.  The development of the data list followed 

     our determination of our role in an emergency and provides the 

     information we need to perform that role.  Needed data not transmitted 

     over ERDS will still be passed over the ENS.

.                                    - 5 -

 8.  Must the ERDS be used to transmit drill data?  

     That is not a design requirement.  For those system configurations which 

     only allow the transmission of real data, no modification will be 

     expected.  However, if the licensee system is used for drills and can 

     provide the transmission of the drill data, we would like to use the 

     capability for our drill participation.  

 9.  Will the ERDS be an LCO or Tech Spec item?


10.  How soon does the NRC expect the system to be initiated after an Alert 


     The ERDS should be initiated when the licensee notifies the NRC of the 

     declaration of an Alert or higher emergency classification.  

11.  Will the transmission of data point values for times prior to the time of

     the ERDS activation be required?  

     No.  Only the data values from the time of the transmission initiation 

     will be required over the ERDS.  Information on initiating conditions and 

     plant status will be provided over the verbal communication line as 

     necessary.  Specifically, earlier parameter values will not be required.

.                                    - 6 -

     If a licensee system has the capability to transmit earlier data point 

     values the NRC would like to utilize that feature but it clearly is not a

     design requirement.  

12.  Once the ERDS is implemented, will continuous manning of the ENS 

     (Red Phone) still be required?

     Yes.  The ERDS will not eliminate the need for verbal transmission of 

     information such as licensee actions, recommended protective actions, and 

     supplemental event-specific data not provided by ERDS.  Emphasis will be 

     given to producing no new impact on Control Room personnel due to the 

     transmission of data over the ERDS.

13.  What procedures and system controls will be required for the ERDS?  

     A procedure will be required for activation of the system during 

     emergencies, probably an emergency plan implementing procedure, and for 

     conducting system tests with the NRC.  Any procedures or controls for 

     system verification and validation or configuration control should be 

     done in conformance with existing plant procedures as modified to require

     prompt notification of the NRC for any change which affects ERDS 

     parameters or the ERDS data stream.

.                                    - 7 -

14.  Will the ERDS data be provided to State authorities?  

     Although the NRC is not soliciting or recommending State participation in 

     the ERDS program, one provision of the systems design is user ports for 

     States within the 10 mile plume exposure EPZ.  This provision was made to 

     reduce the likelihood of different data being provided to the NRC and a 

     State because of differing data sets where the State has decided to 

     collect data.  This provision is not expected to affect States that 

     already have a data collection system.  If a State expresses a desire to 

     participate in the ERDS program, the NRC will provide ERDS data to that 

     State under a specific Memorandum of Understanding.  The purpose of this 

     Memorandum of Understanding would be to specify communication protocols 

     for clarification of ERDS data and data security requirements.  The NRC 

     would provide those States with contractor developed software and make 

     one output port available to the State from the NRC Operations Center.  

     The States would have to obtain compatible PC hardware and licensed 

     software used in the ERDS system to receive the data.  This will ensure 

     that all parties involved are using the same data base for their 

     analysis.  Any request made by a State to set up the capability to 

     receive the data will be discussed with the utility.

15.  Will the NRC require a periodic test of the ERDS, and if so how


     The NRC does expect that periodic testing will be required to ensure 

     system operability.  Currently we expect that testing will be done 

     quarterly.  Should system reliability permit, the frequency of testing 

.                                    - 8 -

     be reduced.  Testing of a State link portion of the system will be done 

     with the NRC.  Therefore, no licensee participation will be required for 

     this test.

16.  Will participation in the ERDS program remain voluntary?

     The NRC is reviewing the need for rulemaking to require the 

     implementation of ERDS at all nuclear power plants in the event the 

     voluntary program is not achievable.  It is anticipated that the 

     provisions of a proposed rule would be the same as those of the voluntary 

     implementation program currently in effect.

17.  What will be the boundary of system maintenance responsibility?

     The NRC will be responsible for maintenance of all parts of the ERDS 

     system installed starting at the input port of the first ERDS-specific 

     piece of hardware (e.g. modem for single feeder plants and multiplexer 

     for multi-feeder plants).

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