Emergency Response Data System (Generic Letter 89-15)
August 21, 1989
TO: ALL HOLDERS OF OPERATING LICENSES OR CONSTRUCTION PERMITS FOR
NUCLEAR POWER PLANTS*
SUBJECT: EMERGENCY RESPONSE DATA SYSTEM - GENERIC LETTER 89-15
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
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
.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
RCS Charging/Makeup Flow
Reactor Vessel Level (When Available)
Reactor Coolant Flow
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 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
. Enclosure 2
BWR Parameter List
Primary Coolant System Reactor Pressure
Reactor Vessel Level
Safety Injection RCIC Flow
Core Spray Flow
Condensate Storage Tank Level
Containment Drywell Pressure
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
. 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
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
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
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
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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