ML18092A652
| ML18092A652 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 06/27/1985 |
| From: | Corbin McNeil Public Service Enterprise Group |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8507150371 | |
| Download: ML18092A652 (8) | |
Text
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Public Service Electric and Gas Company
(
Corbin A. McNeill, Jr.
Vice President -
Public Service Electric and Gas Company P.O. Box236, Han cocks Bridge, NJ 08038 609 339-4800 Nuclear June 27, 1985 Director of Nuclear Reactor Regulation
- u. s. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, MD 20014 Attention:
Mr. Steven Varga, Chief Operating Reactors Branch 1 Division of Licensing
Dear Mr. varg a:
REQUEST FOR ADDITIONAL INFORMATION CONCERNING THE SAFETY PARAMETER DISPLAY SYSTEM SALEM GENERATING STATION DOCKET NOS. 50-272 AND 50-311 PSE&G hereby submits, in the attachment to this letter, its response to your request of December 7, 1984 for additional information concerning the Safety Parameter Display System
( SPDS).
Inasmuch as we had also been requested to respond to questions concerning our Detailed Control Room Design Review, we had requested an extension in providing the information on SPDS.
Your Mr. D. C. Fischer, in a telephone conversation with our Mr. R. s. Patwell on February 27, 1985, granted that extension until July 1, 1985.
Should you have any questions, do not hesitate to contact us.
Attachment c
Mr. Donald C. Fischer Licensing Project Manager Mr. Thomas J. Kenny Senior Resident Inspector Sincerely,
SALEM GENERATING STATION UNITS NO. 1 AND 2 SAFETY PARAMETER DISPLAY SYSTEM RESPONSE TO NRC LETTER DATED DECEMBER 7, 1984
REFERENCE:
PSE&G'S REPORT "SAFETY ANALYSIS FOR SPDS PARAMETERS" DATED JANUARY 30, 1984 Response to NRC concerns are in the order indicated in the enclosure to the letter dated December 7, 1984.
ISOLATION DEVICES The data acquisition system consists of five multiplexer cabinets and one data concentrator per unit and is configured to meet redundancy requirements.
Four of the cabinets are lE which are physically separated and the one dual cabinet is Non-lE.
The data concentrator is Non-lE.
There are 323 class lE field signals per unit which go to the lE cabinets and 220 Non-lE field signals per unit which go to the Non-lE cabinets.
The foregoing indicates that no isolation devices are required prior to the multiplexer cabinets.
The signals from these cabinets however are transmitted to the data concentrator by means of fiber optic cables.
These cables isolate the multiplexer cabinets from data concentrator and the rest of the system.
Fiber optic cables were used for the Non-lE cabinets because of their noise immunity capability. is a one-line block diagram showing the system configuration.
The fiber optic cable specification is as follows:
Fiber Manufacturer:
Corning Corporation or Corning Corporation Licensee Core Diameter:
50 Micron Core and Cladding Diameter:
125 Micron Numerical Aperature (NA):
0.2 Attenuation
4dB/km or better Bandwidth/length:
200MHZ/km Fiber Type:
Glass core and cladding D6/25 1 OF 6
HUMAN FACTORS PROGRAM Display System The display system provides the primary means of information presentation to the operator.
Man-Machine Interface (MMI) consideration will be addressed by utilizing a CRT/keyboard configuration.
Included in this system are CRT copiers for color hard copy of CRT displays and high-speed printers for hard copy of logs, reports and nongraphic CRT displays.
All console CRTs are provided with interactive keyboards.
The primary CRT utilizes a special purpose function keyboard for presentation of SPDS primary displays.
The secondary CRT utilizes a full ASCII keyboard with 60 functional keys for interactive system dialog as well as presentations of both primary and secondary system displays.
Graphics CRT The graphics CRTs in the system are IDT #2250 graphics computer systems.
These devices utilize four (4) microprocessors for graphics processing and I/O handling.
The display is a 19-inch color CRT with 512x512 dot resolution.
Included with each CRT system are:
o Standard keyboard with minimum of 60 functional keys; o
Eight color (plus blink) display capability; o
Two serial ports for host computer communication; o
2MBIT of Bubble Memory for program storage; o
Real-time clock and CMOS RAM for system functions; o
Hardware vector generator for fast display processing; o
Extended plot and complex fill routines for fast display processing.
High-Speed Printer The high-speed printers which will be located in the Control Rooms (CR) are Versatec V-80 Printer Plotter.
D6/25 2 OF 6
CRT Copier A color copier will be located in each control room, TSC and EOF.
Subsystem Operation Static picture information for displays is initially created in an off-line environment using the Interactive Display Editor.
Display information is data compressed utilizing an encoding technique and stored on the system data disks.
Static picture information is kept within each graphic CRT and stored in bubble memory.
When a primary display is requested (either by a primary function key or secondary keyboard keystrokes) the static information is obtained from the local CRT memory and written to the screen.
The current dynamic data for the display is assembled at the host computer and transmitted to the CRT for screen display.
The total display call-up time for primary displays (time from keyboard entry to complete static and dynamic screen display) is typically one second.
Once a display has been called up on a CRT, only the dynamic portions need to be periodically updated.
This is done by the primary host computer every two seconds for all displays that are dynamic.
Note that since only dynamic data is regularly assembled and distributed by the host computer, system loading is dependent only on the number of display CRTs and is not a function (except for static picture storage) of the total number of displays in the data base.
Communication between the host and the CRTs is accomplished via 19.2KB RS-232 serial links to the data highway.
Future addition of secondary displays can be readily accommodated.
Based on an average compressed size of 5000 bytes per static display, bubble memory capacity exceeds 70 mimic type displays and additional bubble memory can be added as an option.
Hard copy of a screen image is initiated directly by the operator at the CRT keyboard.
Upon initiation of the copy command, the screen image is transferred through a high-speed parallel interface to the video copier.
Printing takes between one and a half and three minutes, depending on D6/25 3 OF 6
display complexity.
Upon completion, the hard copy may be used immediately because no drying time is required.
During the print cycle, the copier input buffer is disabled.
If a new copy command is issued, the copier will issue a "busy" to the requesting CRT.
Hard copy of logs, reports and nongraphic screen images are initiated at the secondary display keyboards for printing on the line printers in the control room.
The display system is presently being designed.
A contract was awarded to General Physics Corporation to conduct a human factors review.
The results of the review will be evaluated and incorporated into the design as appropriate.
This review is expected to be completed by October 30, 1985.
At that time the report will be available for your review.
DATA VALIDATION The ERF Computer System addresses sensor validation at two distinct modes, the Computer Products Inc. (CPI) data concentrator and the PACE alarm processor.
PACE is the name of the software package which will be used for the system.
The data concentrator will detect the following hardware channel failures as the first mode of sensor validation:
o Current loop less than 4ma and greater than 20ma.
o Thermocouple open circuit.
o Thermocouple out of range.
o RTD out of defined bridge range.
o Multiplexer unable to scan sensor.
PACE produces several sensor qualities or flags that will be used to validate a sensor's value, e.g. alarm, offscan, and hardware channel failure.
PACE supports four levels of alarms; Hi, Hi-Hi, Lo, and Lo-Lo.
Except as discussed below, the Hi and Lo alarms will be used in the conventional sense to warn of approach to operating limits while Hi-Hi and Lo-Lo will be used to indicate nonsense readings such as a negative tank level.
Offscan is a validation indicator because it means that at the second consecutive instrument limit violation, the point is taken offscan.
This means that the sensor's value is invalid.
Instrument violation can also be set at nonsense instrument process readings.
D6/25 4 OF 6
Invalid data being displayed can be detected by the operator using the following techniques:
o A foreground color blink of the value when it is Hi-Hi or Lo-Lo with the symbol 'NV' placed on the right of the value.
For those parameters which have an actual Lo-Lo or Hi-Hi alarm (e.g. containment pressure and steam generator level) the offscan technique will be used.
o A foreground color blink of the value when the point is offscan with the symbol 'OS' placed on the right of the value.
If the value disappears off the screen when the point is offscan, then there will be an 'OS' in place of the value.
o Graphic represented data, e.g. a pump or valve, will have its color and blink changed based on the above flags.
PARAMETER SELECTION Please refer to PSE&G's submittal dated January 30, 1984 for the rationale which justifies parameter selection.
This is under the section entitled "Parameter Selection" and Attachment No. 3.
Attachment No. 4 "Critical Safety Function Status Trees" shows the relationship between the parameters selected for display on the Safety Parameter Display System and the Critical Safety Functions.
Radioactivity Control and Containment Conditions indicated on page 8 of Supplement 1 to NUREG 0737 is addressed by the Critical Safety Function "Containment Environment."
Radioactivity Control is monitored by Containment Area Radiation, Containment Effluent Radioactivity and Main Steam Radiation monitors and these parameters are available on the Safety Parameter Display System.
Other parameters not used for the Critical Safety Functions can be accessed at the terminal by using a track ball and one or two keystrokes.
UNREVIEWED SAFETY QUESTIONS The signals for all parameters used for the Safety Parameter Display System will be acquired from existing instrument loops.
During the design of the data acquisition system interface with the plant instruments, the possibility of D6/25 5 OF 6
failure or malfunction due to circuit overload and the effects on existing systems were addressed.
The function of the existing systems will not be altered and the safe shut down of the reactor will not be affected.
The SPDS interfaces were also designed taking into consideration electrical separation and isolation.
This will ensure that failure of the SPDS or any associated equipment will not increase the probability or consequences of accidents analyzed in the FSAR.
The margin of safety has not been diminished due to the addition of the SPDS.
Because of the foregoing, an unreviewed safety question is not involved.
There will be no new systems or instruments added as a result of the installation of the data acquisition system.
Since the functions of the existng systems will not be changed, the technical specifications associated with any system or instrument in that system will not be affected.
MHA:ljs 6/24/85 D6/25 6 OF 6
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