ML20245G489
| ML20245G489 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/10/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-89537, NUDOCS 8908160023 | |
| Download: ML20245G489 (11) | |
Text
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E
-Log # TXX-89537 Fi1e # 10010 r
908.3 1UELECTRIC William J. Cahill, Jr.
Executive Vice President U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
C0HANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 ADVANCE FSAR SUBMITTAL EMERGENCY DIESEL GENERATOR START DEMAND DURING C0ASTDOWN, FOLLOWING TESTING Gentlemen:
This letter provides an advance copy of changes to be included in a future FSAR amendment regarding an Emergency Diesel Generator (EDG) start demand during coastdown, following testing. These changes are provided to add the operator's function to ensure the reset of the static exciter voltage regulation (SEVR) circuit if an EDG start demand is received, when engine speed is between 450 and 425 rpm during coastdown, following testing. This is consistert with TXX-89272 of May 25, 1989, concerning SDAR CP-88-033.
In order to facilitate NRC staff review of these changes, the enclosure is organized as follows:
1.
Draft revised FSAR pages, with changed portions indicated by a bar in the margin, as they are to appear in a future amendment (additional pages immediately precoding and/or following the revised pages are provided if needed to understand the change).
2.
A line-by-line description / justification of each item revised.
3.
A copy of related SER/SSER sections.
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An index page containing the title of " bullets" which consolidates I
and categorizes similar individual changes by subject and related SER section.
5.
The bold / overstrike version of the revised FSAR pages referenced by the description / justification for each item identified above.
The bold / overstrike version facilitates review of the new text in bold type font and overstriking with a slash (/) the portion of the text that is deleted.
UU@
8908160023 890810 n
PDR ADOCK 05000445 A
PDC I\\
400 North Olive Street LB 81 Dallas, Texas 75201
TXX-89537 August 10, 1989 Page 2 of 2 TU Electric requests that the'NRC perform an expedited review of the above FSAR changes and inform us.as to their acceptability.
If you have any questions regarding this submittal please contact' Joe Narnden:
at'(214) 812-8226.
Sincerely,
/t 1
hm William J. Cahill, Jr.
WJH/vid l'
l c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3) i.-
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Enclosure to TXX-89537 August 10, 1989 Advance FSAR Change Regarding Emergency Diesel Generator Start Demand during Coastdown Following Testing Item 1 Draft Revised FSAR Page pg. 2 thru 3 Item 2 Description / Justification for FSAR Change pg. 4 Item 3 Related SER/SSER Pages pg. 5 thru 6 Item 4 Index Page Containing the pg. 7 Title of " Bullets" Item 5 Markup of Existing FSAR Pages pg. 8 thru 9 pg.1 of 9
Enclosure to TXX-89537
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jAugust 10, 1989 CPSES/FSAR L Page 2 of 9' f.-
Electrical' tests
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Subsystem tests The objectives er.d requirements of the preceding tests are established in IEEE 387-1977 [32].
Periodic testing of the diesel generators will be performed as specified in the Technical Specifications to verify their continued capability and availability to perform their design function after commercial operation of the plant. Typical tests consist of availability and operational tests as outlined in IEEE 387-1977 and as discussed in the following paragraphs:
a.
One Diesel Generator System at a time is tested for starting and loading capabilities to demonstrate continued availability for operation. These tests are performed at intervals less than a month apart.
0040.121 0040.57-During testing, the diesel generator is paralleled with the 30 offsite source. Should there be a DBA during these j
periods, separation of the two sources is established by 11 automatic tripping of the diesel generator breaker by an "S" signal. The diesel generator returns to standby status and continues to operate at rated voltage and frequency with no load.
However, if an automatic DRAFT initiation signal is received with engine speed between approximately 450 and 425 rps during the coastdown period when the diesel generator is being stopped after testing, the operator will have to reset the exciter.
This action is ensured by an operator stationed at the EDG local control panel as required by the system operating procedure.
8.3-25 Draft Version
' Enclosure to'TXX-89537 :
l August 10 1989-l L Page 3 of:9' CPSES/FSAR l
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The capability of the diesel' generators to start, be synchronized, and deliver power up to nameplate rating can.
i be demonstrated manually.
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During unit shutdown for refueling or schedultd maintenance, the diesel generator operational tests, such as. starting, load acceptance, rated load, lead te.jec' ion, and subsystem, are performed.
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Draft Version 8.3-26
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f, f Enclosure to' TXX-8953F 7
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- August 10 1989 CPSES FSAR--
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- Page 4 ;of 9-DETAILED DESCRIPT!ON FS/A Page (as amended).
Groun agarrintien
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- 8.3-25 2.
Adds the operator's function to "etsure the reset of SEVR f f.EDS is required.durthy coastdown following testing.
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Addition:
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The. system operating procedure.has been revised to
' i require that during EDG chutdown..an ~perator will be present at the EDG local contr%1 panel. The operator's function is to manually activate the exciter reset 4
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pushbutton if the EDG. starting tight comes on and the' j
engine speed is approximately bt Ween 450 and 425 rpt during the shutdown before the stat"ic exciter voltage reguletion (SEVR) circuit autometictlly resets.
This is consistent with T7.K-89272 oV Nay 25, 1989, l
concerning SDAR CP-88-033, h*
FSAR Change Request Number: 89-480 Commitment Register Number: NL-3488 Related SER Section:'8.3.1 SER/SSER Tapacti Yes SER discussion does not cover 25 rpm window during EDG L'
shutdown where, in the unlikely event of a concurrent DBA,'the operator would reset the SEVR.
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Enclosure to TXX-89537-August }0, 1989 Page 5 of 9 8.3 Onsite Eneroeng gowr Syytyis 8.3.1-AC Power System The ac onsite power :ystce is a Cla:s 1E system which serves as a standby to the offsite power tystem.
Thrscfety function of the ac onsita ener provide suffi(assuring the offsitt power system is not functioning) genc power system is to cient capacity and capability to ensure that the structures, systems, and componwnts inocrtmA to safety perfom as intended.
The objec-tives of the staff rey'few em to detemine if the ac onsite emergency power system har the Nautred redendancy, meets the single-failure crir. orion, is tesi;able, and has the capscityi capability, and reliability to supply power to all required safety loads in accordance with the. requirements of GDC 5,17, and 18.
. pw The onsite ac power systes consistr, of various Nxiliary electrical systems
' designed to provide electrfc power to Class If and non-Class 1E station loads.
The stan6y ac power systess is an independent, onsita systas designed to automatically start and provide adequate power for Class 1E loads to ensure safe plant shutdown when ptsferr9d and alternate power sources are not ava!1able.
The Class 1E portion of the onsite power system is comprised of two redundant and independent U.9-kV distribution systems with their 400-V load centers and motor control centers, 1 & V ac power system, 125-V de system, and the standby power supplies (diesel gerarator units).
Onsite emergency power fu each unit is supplied by two diesel generators.
Each diesel generator is automatically started by either a safe <;y injection
-actuation signal or an emergency bus undervoltage signal on its respective emergency bus. 'Esch diesel generator is capable of attaining rated voltage and fisquency within 10 see after receiving a starting signa. After obtaining rated voltage and frequency, the their respective emergency buses. generators are connected automatically tc Under accident conditions the safety loads will be connected in a predetermined sequence to their respec,tive diesel nonerator.
There is one diesel generator per bus.
Each diesel generator and
'ts associated equipment is located in a separate seismic Catepory I structure and is rated at '7000 W for continuous operation, and has a 2-Tr rating of 7700 W.
The continucus rating exceeds the maximum predicted operating loads.
The applicant has documented that tests will be performed to demonstrate that i
l during the loading sequence, the frequency and voltage are saintained above a l
1evel which would degrade the performance of any load below mininum requirements.
The design and continuous rating are consistent with Regulatory Guide 1.9 and IEEE 387-1977 and, therefore, are acceptable.
l Branch Technical Position ICS8 2 (PSB) (in Appendix 8A of the Standard Review Plan) requires that new and previously untried diesel generator designs to be used in nuclear testing program. power plant service undergo a prototype reliability verification The staff review indicates that the diesel generators have successfully passed a prototype reliability verification program of 300 valid start and load tests with no more than three allowed failures.
This is in confomance with the staff position and is acceptable.
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.Enslosure tb TXX-8953T
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- August 10 1989 i
0 Page 6Nof 9' During t.he periodic testing of a diesel generator, if a safety-injection by an "S" signal. actuation signal occurs, the generator breaker will be tripped a y
with the system and enables the diesel generator to attain'th
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j standby mode.
In this mode of operation, the diesel governor control changes automatically to the isochronous mode which maintains the engine running at a
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synchronous speed corresponding to 60 Hz at the generator terminals.
noncritical protective trips except engine overspeed and generator differential All are bypassed.
mode maintaining the generator at a preset constant voltage of j
j diesel generator unit is now ready to accept load in the event of-a loss-of-The voltage signal (LOVS).
LOVS should occur, the diesel generator breaker is tripped on ove creating an LOVS on the bus.
The offsite power feed breaker is tripped and droop to isochronous mode and the voltage regulator to aut diesel generator breaker is closed, connecting the diesel generator to the The bus.
Branch Technical Position ICS8 17 (PS8) (in Appendix 8A of the Standard Review Plan) requires that diesel generator protective trips be bypassed wher, the diesel generator is required for a design-basis event.
All protective trips are allowed during periodic testing.
The allowed exceptions to the above requirement for bypassing are diesel engine overspeed and generator differential current.
Any other trips retained must utilize coincident logic in order to avoid spurious trips.
In case of a design-basis accident, the applicant is byptssing all the protective trips except engine overspeed and generator differential.
This is in full conformance with the staff position and is
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acceptable.
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Diesel generator. instrumentation and alarm annunciators are located on the i
diesel room control panel.
i One " diesel trouble" signal is sent to the control room when any local alarm is received on the local diesel generator panel.
separate signal is sent to the safety system inoperable indication (SSII)
A panel whenever the diesel generator is not ready for automatic starting.
diesel generator starting mode selector switch has " remote / local / maintenance" The positions and is normall only time it is in the "y in the " remote" mode of operation position.
The local" position is for local manual starting in the event of control room evacuation and nonroutine testing.
If the switch is not returned to the " remote" position from the " local" or ' maintenance" position, an alarm in the control room persists until the switch is returned to the
" remote" mode.
Other manual controls of the auxiliary system of the diesel generator are also alarmed at the SSII panel if failure to return to their auto start position would inhibit automatic operation of the diesel generators.
In response to staff questions, the applicant has presented a list of condi-tions that would render the diesel generator units incapable of responding to an automatic emergency start signal.
The staff has reviewed this information of responding to an automatic emergency start signal is al The alars system display of " bypassed and inoperable status" of the room.
diesel generaturs fulfills the requirements of Regulatory Guide 1.47 and is acceptable.
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, fit;Ebbhe toLTXX-89537:
.yg August.10L1989:
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,8.3.1 JAC' Power System-
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The.FSAR has been clarified regarding en~ Emergency S
Diesel >6enerator (EDG)' start demand.during coastdown,L following testing.
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Enclosure to TXX-89537-August'1.0, 1989 CPSES/FSAR
.Page 8 of 9 f.
Electrical tests g.
Subsystem tests i
The Mdectives and requirements of the preceding tests are established in IEEE 387-1977 [32].
Periodic sesting of the diesel generators will be performed as specified in the Technical Specifications to verify their conti. vied capability and availability to perform their design function after commercial operation of the plant. Ty.pical tests consist of availability and operational tests as outlined in ICEE 387-1977 and as discussed in the following paragraphs:
a.
One Diesel Generator System at a time is tested for starting and loadiog capabilities to demonstrate continued availability for operation. These tests are performed at intervels less than a month apart.
0040.121 0040.57 During testing, the diesel generator is paralleled with the 30 offrite source. Should there be a DBA during these periods, separation of the two sources is established by 11 automatic tripping of the diesel generator breaker by an "S" signal. The diesel generator returns to standby status and continues to operate at rated voltage and frequency with no load.
Newever, if en automatic initiation signal is received with engine speed betwasn approximately 450 and 425 rps during the coastdown period when the diesel generator is being stopped after testing, the operator wi?1 have to reset the exciter. This action is ensured by an operator stationed at the EDG local control panel as required by the system operating procedure.
8.3-25 Bold /0verstrike Version a.a
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Enclosure to'TXX-89537 August 10;'1989 1; ' Page.9;,oV 9
1 CPSES/F$AR
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The capability of the diesel generators to start, be synchronized, and deliver power up to nameplate rating can be demonstrated manually.
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During unit shutdown for refueling or scheduled maintenance, the diesel genert, tor operational tests, such 4s starting, load acceptance, rated load, load rejection, and subsystem, are perfor: feed.
4 Bold /0verstrike 8.3-26 I
Version a