ML20091P279
| ML20091P279 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom, Limerick  |
| Issue date: | 01/24/1992 |
| From: | Beck G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-048, REF-GTECI-049, REF-GTECI-NI, TASK-A-48, TASK-A-49, TASK-OR GL-91-11, NUDOCS 9202030010 | |
| Download: ML20091P279 (8) | |
Text
-- -.-___
... - - - - ~ -. -
_~
10 CI'R 50. ' 4 ( 1 )
s GL 91-11 Pilll> del.I'lil A El.ECTRIC COMi%NY NUCLIIAR GROUP lil!ADQUARTIIRS i
955 65 CllllSTERHROOK lilND, WAYNH, PA 19087 5691 (215) 640 6000 January 24, 1992 NUCLTAR t.NGINtBINu & $LRYlCt.5 DUAR1 MINT Doc h e (,
No8, $Q-277 50-278 50-352 50-353 Licenso Nos. DPR-44 DPR-56 NPF-39 NPF-85 U.S. Nuclear He ilatory Commission Attn Document s>ntrol Dosh Washington, DC 20555
SUBJECT:
Peach Dottom Atomic Power Stat. ion, Units 2 and 3 Limerick Generating Station, Unita 1 and 2 RJaponse to Ganoric !.etter 91-11, "Hosolution of Generic Issues 48, "LCOs for Class 1E Vit.al I ns t.rumen t Buses," and 49, " Interlocks and LCOs for Class 1E Tie Dreakers" Pursuant. to 10 CFR 50. 54 ( f )"
Dear Sir Enclosed are our res,)onses to the recommendeu actions provided in the subject Generic Lottor 91-11, dated July 18, 1991.
Genoric Lottor 91-11 concerns the resolution of GI-40 und GI-49.
G1-48 and GI-49 address vital AC buses and tio bronkers that-connect redundant. safoty-ro. lated buses.
provides t.he responses for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. providos the responses for Limerick Generat.ing Station (LGS), Unit.s 1 and 2.
Philadelphia Elect.ric Company cort.111os
- t. hat LGS, Uni t.s I and 2 and PBAPS, Unita 2 and 3 meet. the guidance provided in this Generic Letter.
If you have any quest.lons, please contact. us.
Very truly gg,ura j ffY G.
J.f lock, Manager Licensing Section Enclosures cc:
T.
T. Martin, Administrator, Region I, USNRC l
J.
J.
Lyash, USNRC Senior Resident. Inspector, PDAPS 40}['
l T.
J. Kenny /, USNRC Senior Resident Inspector, LGS l
3000 0
I 9202030010 920124 PDR ADDCK 05000277 I
i p
o..
i COMMONWEALTil ~ OF PENNSYLVANI A l
8 Ss.
COUNTY OF CHESTER i
1 D. R. llolwig, being first duly sworn, deposos and says:
t l
)
- ths; ho is Vice President of Philadelphia Electric Company, that he has road the response to Gonoric Lotter No. 91-11, and knows the i
contents thoroof; and that the statements and matters not forth thoroin are true and correct to the best of his knowledge, information and beliot.
l t
A e
] h) sr-1
~
s Vice President-Subscribed and sworn to.
before me this JY" day of;&{E9 anusjuf-1992.
+ -
- (!
q M
wm/
/
,s-e +
>w.
wr&d Erica A Sy4% tttvyPec Tr%erv No CreJerCo re M Conrnsaw hn - M 10. y t
t 615
-,-w
,n.,---..,
~,n, r,
-r.~.,e s.w,
..,,.,,..~,+--..-,---v,,..,.-,,
..-w...,,n..-
~+.+-....-.-.~-w-
') Peach Bottom Atomic Power Station Encionuro 1 Units 3 and 3 Page 1 4
PEACH DOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 t
EESPONSE TO GENEHIC LETTER _91-11 EECOMMENDED ACTION 1
" Ensure that your plant has procedures that include timo limitations and curvo111anco requirements for i
- 1. Vital inst.rument buser, (typically 120V pc_bunes),"
i HESPONSE During plant. operat.lon, vit.al AC inst.rumont busos and i
selected Class IC DC instrument, busos are supplied with normal power through a Manual Transfer Switch (MTS).
The manual
~
transfer switch (MTS) is: located on the lino sido of each-vital-t AC instrument bus and select.ed battery chargers which supply 10 DC instrument buses.
One category-of MTS's aro Inst.alled such that a1tornato power sourcos can be used to supply the vital AC Inst.rument buses and battery chargers while performing i
maintenanco during plant shutdown.
A second category of MTS's aro installed such that the battery charaer can be supplied by_an alternato source during an Appendix R 11ro.
The MTS is designed such that the normal and a1tornato sources cannot. be connected in parallel.
The MTS is the only method provided by the Peach l
Bottom Atomic Power St.ation (PHAPS) design which would allow the supplying of a1tornato power to tho vital AC instrument buses or battery chargers.
3 The MT3's installed for maintenanco purposes rocoivo normal supply _during-all modos of plant. operation.
The maint.onanco MTSs' alternato supply, which can be used while performing maintenanco during plant shutdown, is derivod;from the samo channel but from the ot.her unit.
Since the emergency diosol generators - (EDG) are common to both units, and each EDG-supplies
. j tho - aamo channel in. bot.h - units, tho single f ailuro critorion and i'
other plant design critoria are sat.inflod when tho MTS's are used.
~
Some MTS's-have boon installed for fire protect.lon (Appendix R)-circuits.
Tho_MTS's installed _for firo protection (Appendix l
R)' circuits recolvo normal supply during all modos of plant operation.- In~the event of an Appendix R fire, the alternato supply-for-some, but'not all, MTS's in fire protect. ion (Appendix R) circuits -is derived f rom dif forent channels in the ot.her unit.
The-postulatod' single fallure fur circuits associated with Appendix R requirements is an Appendix R fire.
Thoroforo, tho alt.ornato power supply for those circuits need not. comply wit.h -
the single falluro-requirements.
a v
9 s er%y-g-eg
,-c ypw--
p r *W+=.y-y-,-yw-yv w.,w, c y-,wer y y-g c p'9w, wa-e ey,, y -. w g.. w =r yr.,w,ar v i - e-N v-t*w'-'re.-
ww suwv womew 'iw-tm eret wnewe-* musW e
- w we a r
- r +* a oravr rwr we w 4ew-
- Y Poach Bottom Atomic-Power Station-Enclosuro 1 o,,
Units 3.and 3 Pago 2 Ono MTS, associated with the 2DD003 battery chargor, sorvos as both a maintenanco and fire protection (Appondix R) food.
The MTS normal supply is utilized during all modos of plant operation.
In the event of an Appondix R firo or maintenanco, the alternato supply is dorived from the samo channel but from the other unit.
Startup proceduro GP-2 reguires a visual verification of each MTS (via proceduro RT-0-56-300-2(3) ontitled " Required Switch and Breaker Positions Prior to Unit 2(3) startup"),
including those MTS's associated with Appendix R circultu, prior to' plant startup to ensure tho.MTS is in the normal supply
-position.
The PBAPS vital AC instrument busos are discussed in Section 8.6 of the PBAPS Updated Final Safety Analysis Report (UPSAR).
The PBAPS class IE DC buses are discunned in Section 8.7 of the PBAPS UFSAR.
RECOMMENDED ACTION _2 i
" Ensure that ),ar plant has procedures that includo Limo limitotions and surveillanco ror11romonts for 2.
Inverters or other onsito power sources to the vital instrument buses, and" HESPONSE The vital AC instrument power supply system and Class 1E DC power supply system at PBAPS does not-roly on invorters-for continuous powoc supply to vital AC instrument buses.
Soveral vital loads are supplied from the_ vital AC instrument buses and Class IE DC buses through dedicated power supplies.- The
' dedicated power supplies recolvo power from only one channel of AC and/or DC power.
In addition, the PBAPS design does not have provisions for cross connecting channels of on-sito power sources supplying the vital AC instrument busos or Class 1E DC busos.
Vital loads for the vital AC instrument power supply system are supplied by EDG's during loss of off-sito power.
A discussion of the PBAPS vital'AC instrument on-sito power sources is provided in Section 8.5 of the PBAPS UPSAR.
The class 1E DC power supply system relics on battery chargers for continucus power supply to ossential loads.
When AC power input to tho battery chargers is availablo, the battery
- chargers provide rectified AC power to the essential loads.
When AC power input to the battery chargers is unavailablo, the 125V Datteries provido DC power to the ossential loads.
The change between rectiflod-AC power and DC power occurs automatically.
The PDAPS Class IE.DC on-site power sources are discussed in Section 8.7 of the PBAPS UFSAR.
- $ poach Bottom Atomic Power Station Enclosuro 1 Units 3 and 3-Pago 3 f
RECOMMENDED ACTION 3
" Ensure that your plant has proceduros that include timo limitations and surveillanco requirements for 3.
Tio breakers that can connect redundant Class 1E buses (ac or j
de) at one unit or that can connect Class 1E busos betwoon units at the same sito."
RESPONSE
i The Class 1E busos (AC and DC) are configured such that each channel is supplied with an independent, fully rated, on-sito power sourco.
Thereforo, tio breakers do not exist and i
the nood for-proceduros addressing timo limitations and survoillanco requirements for tio breakers that can connect redundant Class 1E buses (AC or DC) at ono unit or that can t
connect Class IE buses betwoon units are not applicablo.
The PHAPS Class IE buses (AC and DC) are documented in Sections 0.5 &
During-plant shutdown only, selected Class 1E load contors/
i motor control contors have provisions for supplying power to loads normally supplied from difforont channel _ load contors/
motor control-contors.
Thoso provisions are designed au a convenience to maintenanco personnel and are enacted by operating procedures which place affected equipment in a-limiting condition for operation when maintenanco is required on tho normal supply.
^
SUMMARY
-PBAPS is designed for'a loss of off-sito power (LOOP) concurrent.with a worst-caso single failuro of one EDG as documented in PBAPS UFSAR Soction 8.5.2.
Additionally, the PBAPS circuitry is designed to withstand a timo deley without creating 1
unacceptablo' failure modos during EDG starting.
f T
k l
l
Limerick Gonorating Station Eiclonuro 3 Units 1 and 3 Pago 1 l
i LIMERICK GENERATING S_TATION, UNITS 1 AND 2 13ESPONSE TO_GENEHIC LETTER 91-11 i
RECOMMENDED ACTION 1
" Ensure that your plant has procedures that include timo limitations and survoillanco requirements for
- 1. Vital instrument buses (typically 120V ac buses),"
RESPONSE
l l
The Limerick Generating Station (LGS), Units 1 and 2, Technical Specifications (TS) are based on the Standard Technical
. Specifications (STS) for General Electric (GE) Bolling Wator Reactors (BWRs).
The LGS, Units 1 and 2 TS specify timo limitations for the inoperability of the vital AC instrument buses and Class 1E DC buses in the limiting conditions for operation-in Section 3/4.8.3.
This LGS TS section also speciflos associated sur"o111anco requirements.
Additionally, the LGS, Units 1 and 2 doulgn doos not include provisions for cross connecting channels supplying the vital AC Instrument busos or the Class 1E DC busos without modification to the plant.
The vital AC instrument buses are supplied exclusively.by their respectivo AC power-supply system channel.
l The LGS Class 1E DC buses are supplied by battery-chargers which 1
are supplied exclusively by their respectivo AC powor supply l
system channel.
A-description of the LGS vital AC instrument buses and the Class IE DC buses is provided in Section 8.3 of the LGS Updated Final Safety Analysis Report (UFSAR).
HECOMMENDED ACTION-2 1
" Ensure that your plant has procedures that include (;mo-11mitat.ans and surveillance requirements for 2.-
Inverters or other onsita power sources to the vital instrument buses, and" RESPONSE-The vital AC11nstrument power supply system at LGS does not
~rolyfon inverters for continuous power-supply to vital AC Instrument buses.
Several vital loads are supplied from the vital AC instrument busos and-Class 1E DC busos through dodicated power-supplies.
The dedicated power' supplies receive power from only one channo1~of AC and/or DC power. -Additionally, the vital
-loads are supplied by Emergency Diosol Generators (EDGs) during loss of off-site power.
,er.%,we--m wt.rr,,ae,--,e e
y i. -
--wn,m_e-wa
w=
e
-. ~ _ - - - _.
: Limerick Generating Station Enclosuro 2 s,,
Units 1 and 2 Page 2 The Class 1E DC power supply syntom rollos on battury chargers for cont.inuous power supply to ossential loads.
When AC power input to the batt ery chargers is available, the battery charget s provido rnct.ified AC power to the essant.lal loads.
When AC power input to the battery chargers is unavailable, the 125V batteries provido DC power to the ossential loads.
The chango 1
betwoon rectiflod AC power and DC power occurs automatically.
A discussion of the LGS vital AC instrument and Class 1E DC on-site power sources is provided in Section 8.3 of the LGS UFSAR.
Tho LGS, Units 1 and 2 TS are based on the STS for GE DWRs.
The LGS, Units 1 and 2 TS specify timo limitations for the inoperability of the on-sito power sources supplying the vital AC instrument. buses and Class IE DC buses in the limiting conditions for operation in Soetions 3/4.8.1 and 3/4.8.2.
These LGS TS sections also specify associated surveillance requirements.
The LGS TS were rcviewed and approved by the NRC through the licensing el LGS, Units 1 and 2.
The Roactor Protection System (RPS) power supply system at.
LGS, Units 1 and 2 utilinos an inverter as the proforred power source to the RPS bus; however, the RPS bus is a non-safeguard bus and the inverter is non-Class 1E.
Power monitor channels, which monitor the power supply to the RPS bus, are subject to survoillance requirements and timo limitations as defined in LCS, Units 1 and 2 TS Section 3/4.8.4.
HECOMMENDED ACTION 3
" Ensure that your plant has proceduros that include timo limitations and survoillanco requirements for 3.
Tio breahors that can connect redundant Class 1E busos (ac or dc) at one unit or that can connect Class IE buses betwoon units at the same site."
RESPONSE
The LGS, Units 1 and 2 Class 1E buses (AC and DC) are configured such that each channel is supplied with an L
independent, fully rated, on-site power source.
Therefore, tio breakors do not exist.
The LGS Class 1E buses (AC and DC) are discussed in Section 8.3 of the LGS UFSAR.
SUMMARY
LGS is designed in compliance with 10 CFR 50, Appendix A as documented in LGS UFSAR Section 3.1.
This includes compliance w).th the appropriate General Design Critoria which ensures that no single failure would disable AC vital instrument busos or the Class 1E DC buses.
LGS is also designed for a loss of off-site power (LOOP) concurrent with n worst-caso single failure as i
l discussed in LGS UFSAR Section 8.3.1.1.3.
The LGS vital loads l
i
't Limorick Gonorat.ing Station Encionuro 2 s
c.,*
Units 1 and 2 pago 3 are designed to withstand a timo delay without creat.ing unacceptable failure modos during EDG starting.
The LGS design has boon reviewod and approved by the NRC as document.ed in NUREG-0991, "Saioty Evaluation Iteport. Italated to the Operat. ion of Limorick Generating Station, Units 1 and 2," dat.ed August. 1983, and applicable supplements.
0
- k qll i
.