ML20207C700
| ML20207C700 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/22/1986 |
| From: | Bailey J GEORGIA POWER CO. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 GN-1256, NUDOCS 8612300212 | |
| Download: ML20207C700 (5) | |
Text
v Georgia Power Company Post Offic; Box 282 Waynesboro, Georgia 30830 Telephone 404 554 9%1 404 724 8114 Southern Company Services, Inc.
Fbst Office Box 2625 R
Birmingham. Alabama 35202 Telephone 205 870-6011 VOgtle Project December 22, 1986 Director of Nuclear Reactor Regulation Files X7BC35 Attention:
Mr. B. J. Youngblood Log GN-1256 PWR Project Directorate #4 Division of PWR Licensing A U. S. Nuclear Regulatory Commission Washington, D.C.
20555 NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMBERS CPPR-108 AND CPPR-109 V0GTLE ELECTRIC GENERATING PIANT - UNITS 1 AND 2 PLANT SAFETY MONITORING SYSTEM VERIFICATION AND VALIDATION
Dear Mr. Denton:
The Plant Vogtle Plant Safety Monitoring System (PSMS) is utilized to process and output many of the Regulatory Guide 1.97 Revision 2 variables to internal plasma displays and external indicators. displays, cabinets and other equipment. The PSMS consists of three types of modular components: the remote processing units (RPUs); the display processing units (DPUs); and the plasma displays (PDs). The system is seismically and environmentally qualified and is configured to meet single failure criteria.
The Category 1 Regulatory Guide 1.97, Revision 2 variables that are displayed on the Plant Vogtle PSMS as specified in Table 7.5.2.1 of the Plant Vogtle FSAR include the followings Reactor coolant pressure (wide range) (4 channels) o o RCS wide range That (1 Per loop)
RCS wide range Tcold (1 Per loop) o o Wide range steam generator water level (1 per steam generator)
Narrow range steam generator water level (4 per steam generator) o o Pressurizer level (3 channels)
Containment pressure (4 channels) o Steamline pressuie (3 per steamline) o Refueling water stor,tge tank level (4 channels) o Containment water level (narrow range) (2 channels) o containment water level (wide range) (2 channels) o Condensate storage tank level (2 per tank) o Auxiliary feedwater flow (2 per loop) o Core exit temperature (50 thermocouples) o RCS subcooling (2 channels) pl o
Neutron flux (extended range) (2 channels) t o
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0612300212 061222 PDR ADOCK 0500 4
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Director of Nuclear Reactor Regulation File X7BC35 December 22, 1986 Log:
GN-1256 Page 2 o Reactor vessel water level (2 channels) o containment pressure (extended range) (2 channels) o Containment hydrogen concentration (2 channels)
The design of the plasma display pages provides an upper level Plant Status Summary and four lower level displays for nuclear power, reactor vessel water level, core exit thermocouples and pressure-temperature limits.
In addition the capability is provided for displaying variable time trend histories and detailed data listings.
Several of the displays are exhibited in the Plant Vogtle submittal on NUREG-0737, item II.F.2.
A verification and validation process is currently underway on the Plant Vogtle PSMS. A comparison has been conducted to determine the software unit commonality between the South Texas Project PSMS subsystem of the QDPS and the Plant Vogtle PSMS. The results of the study indicate that 93 percent of the sof tware contained in the Plant Vogtle has already undergone verification as part of the South Texas Project PSMS subsystem.
In addition, all modifications to the South Texas Project PS"S software as a result of the verification program have been incorporated into the Plant Vogtle PSMS software.
A functional requirement decomposition is currently being performed on the Plant Vogtle PSMS functional requirements. Some of the validation tests performed on the South Texas Project will be applicable to the Plant Vogtle PSMS and will not be required to be rerun. This is due to the similarity of hardware and sof tware between the two systems.
In addition, any hardware and sof tware modifications that are implemented on the South Texas Project PSMS subsystem due to resolution of validation trouble reports will be implemented in the Plant Vogtle PSMS.
A detailed Factory Acceptance Test (FAT) has also been conducted on the Plant Vogtle PSMS.
The following is a general description of the type of test s and sequence of the testing:
- 1. Each RPU (7), DPU (2) and display (2) went through a 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> burn-in period.
- 2. Each RPU sent through a test cevering: Menu Test and Calibration, Data Link Test, and Digital and Analog Input Test.
i Director of Nuclear Reactor Regulation Files X7BC35 December 22, 1986 Lost GN-1256 Page 3 l
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- 4. The DPU test covered NVRAM constants, calibration, and menu operation.
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The ext series of tests (equivalent to system test, tied all units t
together) covered l
l a) Communications Test DPU to Display Link j
RPU to Display Link l
l b) Sof tware Operation Test l
Redundant Sensor Algorithm RVLIS Core Subcooling Core Exit Thermocouples All total of 300 to 350 hours0.00405 days <br />0.0972 hours <br />5.787037e-4 weeks <br />1.33175e-4 months <br /> of testing time was accumulated on the AGE PSMS prior to shipment to the Vogtle Site.
Following delivery of the Plant Vogtle PSMS hardware and sof tware to the site, l
many pre-operational tests were conducted on the system to demonstrate acceptable system performance.
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A review of the Category 1 Regulatory Guide 1.97 Revision 2 variables that are l
displayed on the PSMS reveals that only six of the variables are not displayed on the control board via diverse indications. These aret Core exit temperature (50 thermocouples) o o RCS subcooling (2 channels) o Reactor vessel water level (2 channels) o Neutron flux (extended range) (2 channels) o Containment water level (narrow range) (2 channels) o Containment pressure (extended range) (2 channels)
The algorithms utilized in computing the core exit temperature and RCS I
subcooling on the South Texas Project PSMS subsystem and the Plant Vogtle PSMS l
are identical; hence all software modules used in the calculations have been verified.
In the interin until the Plant Vogtle PSMS V&V program is completed, procedures will be written and implemented by the Plant Operations staf f providing instructions to the operators on how to determine the information by l
a means independent of the PSMS should the PSMS displayed information be i
unavailable for the above variables. These procedures will be implemented prior to the plant exceeding 5 percent power. A brief overview of the procedures are given below for the applicable variables.
The alternate method of obtaining core exit temperature will be to measure the voltage output of the thermocouples at the terminal screw inputs to the PSMS cabinets using a portable meter.
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o Director of Nuclear Reactor Regulation Files X7BC35 December 22, 1986 Log GN-1256 Page 4 The alternate method of obtaining RCS subcooling will be to utilize reactor coolant pressure (wide range) control board analog indications that are independent of the PSMS and RCS wide range That control board analog indications and manually compute RCS subcooling utilizing steam tables.
A current Plant Vogtle license condition is that the reactor vessel water level instrument need not be operational prior to June 1,1987 or commercial operation whichever occura first. The Plant Vogtle PSMS V&V process is scheduled to be completed prior to that time.
The Plant Vogtle neutron flux (extended range) instrument has a local panel analog meter readout outside the control room. This indication will be used should the information not be available on the PSMS.
Plant Vogtle has not only implemented Regulatory Guide 1.97 Revision 2, Category 1 containneat water level (narrow range) instruments but also wide range instruments. Should the indications in the plasma display be unavailable, the containment water level (wide range) instruments have analog meter indications on the control board.
Finally, containment pressure is also considered a Category 1 variable on Plant Vogtle. Should the containment pressure (extended range) not be available on the PSMS, the containment pressure channels have analog meter indications on the control board.
For those variables for which an analog meter indication is available on the control board, diverse from the PSMS, Plant Vogtle has committed to perform a weekly check between the plasma display indicated value and the analog meter indicated value. The purpose of this independent check is to demonstrate the acceptability of the PSMS displayed values. This checking will be conducted until the PSMS V&V process is completed.
The Plant Vogtle PSMS V&V program is currently underway. A comparison of software commonality has already been conducted and the functional decompositions are scheduled to be completed by the end of January 1987.
Verification of the seven percent of software not common to the South Texas Project PSMS subsystem is scheduled to begin in early February 1987. The validation effort is to begin by early March 1987. Af ter completing the V&V process, a final report, referencing the South Texas Project QDPS final V&V report submittal in December 1986, presenting the results of the Plant Vogtle V5V program will be issued to the NRC staff by June 1,1987 with information similar to that provided on the South Texas Project.
Until Plant Vogtle personnel develop an in-house capability to implement PSMS software modifications and/or upgrades, Westinghouse will be responsible for maintaining the configuration control of the PSMS software.
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t Director of Nuclear Reactor Regulation Files X7BC35 December 22, 1986 Lost CN-1256 Page 5 l
The identical process is followed for burning-in the Plant Vogtle PSMS PROMS as was described in the South Texas Project QDPS staff audits. Similarly, the same internal safeguards exist on the Plant Vogtle PSM3 as those that were demonstrated in the South Texas Project QDPS concerning insertion of PROMS in wrong positions due to technician error or malicious mischief. As demonstrated on the South Texas Project, the systes either didn't initialise properly (processor halt) or indicated a diagnostic error (check sum) for all situations in which a PROM was installed incorrectly. The teste conducted are defined in the South Texas Project QDPS final V4V report.
If your staff requires any additional information, please do not hesitate to contact me.
Sincerely, f
9 &.L'-
y J. A. Bailey Project Licensing Manager JAB /nm xc:
R. E. Conway NRC Regional Administrator l
R. A. Thomas NRC Resident Inspector J. E. Joiner Esquire D. Fein B. W. Churchill, Esquire R. W. McManus M. A. Miller (2)
L. T. Gucwa B. Jones, Esquire Vogtle Project File
- 0. Bockhold, Jr.
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