ML20217E451

Summary of 970911 Meeting W/Util in Rockville,Md Re STP 3-train Design & Improved Std TSs Format

ML20217E451
Person / Time
Site:	South Texas
Issue date:	09/22/1997
From:	Kennedy J NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9710070035
Download: ML20217E451 (55)

Text

i s Setember 22, 1997 LICENSEE: HOUSTON LIGHTING & POWER COMPANY FACILITY: SOUTH TEXAS PROJECT

SUMMARY

OF SEPTEMBER ll, 1997 MEETING WITH HOUSTON LIGHTING &

POWER COMPANY REGARDING THE SOUTH TEXAS PROJECT 3-TRAIN DESIGN AND THE IMPROVED STANDARD TECHNICAL SPECIFICATIONS A meeting was held on Thursday, September 11, 1997, for the Nuclear Regulatory Commission (NRC) staff and the licensee to discuss the unique South Texas Project (STP) 3-train design and how it relates to the licensee's request to convert the STP technical specifications into the improved standard technical specifications format. The meeting was held at the request of the staff at NRC headquarters in Rockville, Maryland. A notice of this meeting was issued on September 5, 1997. Attachment 1 is the list of attendees. Attachment 2 is the licensee's handout used during the meeting.

The purpose of the meeting was for the staff and its contractor to gain a better understanding of the STP design features and in particular, the 3-train design which affects the emergency core cooling systems and associated support systems. The licensee is attempting to factor the STP 3-train design into the improved standard tecnnical specification conversion process. As such, the staff needs to better understand the STP design to be able to review the licensee's conversion request. The meeting consisted of the licensee's

)resentation of its unique design features (as shown in Attachment 2) and

)rief questions by the staff during that presentation.

ORIGINAL SIGNED BY:

Janet L. Kennedy, Project Manager Project Directorate IV-1 Division of Reactor Projects Ill/1Y Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499 Attachments: As stated cc w/atts: See next page -

1 DISTRIBUTION:  !

l Hard Copy E-mail Docket File SCollins/FMiraglia (SJC1/FJM) RZimmerman (RPZ)

PUBLIC EAdensam (EGAl) TAlexion (TWA)

PD4-1 r/f JKennedy (JLK2) CHawes (CMH2)

OGC WBeckner (WDB) CSchulten (CSSI)

ACRS MReinhart (FMR) NGilles (NVG)

JClifford (JWC) PGwynn (TPG) MWohl (MLWI) 00CVMENT NAME: STP0911.MTS To receive a copy of this document, indicate in the box: "C" - Copy without l

enclosures "E" - Copy with enclosures "N" - No copy l OFFICE PM/PD4-1 E LA/PD4-1 l i NAME JKennedy/sp JL CHawes(1/H[

l DATE 09/ D /97 09/ D2 /97 _ _ , , ,

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'**** September 22, 1997 LICENSEE: HOUSTON LIGHTING & POWER COMPANY FACILITY: SOUTH TEXAS PROJECT

SUMMARY

OF SEPTEMBER ll, 1997. HEETING WITH HOUSTON LIGHTING &

POWER COMPANY REGARDING THE SOUTH TEXAS PROJECT 3-TRAIN DESIGN AND THE IMPROVED STANDARD TECHNICAL SPECIFICATIONS A meeting was held on Thursday, September ll,1997, for the Nuclear Regulatory i

Commission (NRC) staff and the licensee to discuss the unique South Texas Project (STP) 3-train design and how it relates to the licensee's request to convert the STP technical specifications into the improved standard technical specifications format. The meeting was held at the request of the staff at NRC headquarters in Rockville, Maryland. A notice of this meeting was issued on September 5, 1997. Attachment 1 is the list of attendees. Attachment 2 is the licensee's handout used during the meeting.

8 The purpose of the meeting was for the staff and its contractor to gain a better understanding of the STP design features and in particular the 3-train designwhichaffectstheemergencycorecoolingsystemsandassocIatedsupport systems. The licensee is attempting to factor the STP 3-train design into the improved standard technical specification conversion process. As such, the staff needs to better understand the STP design to be able to review the licensee's conversion request. The meeting consisted of the licensee's presentation of its unique design features (as shown in Attachment 2) and brief questions by the staff during that presentation.

JOJMS l. 16.LCkLY Janet L. Kennedy, Project Manager Project Directorate IV-1 Division of Reactor Projects !!!/IV Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499 Attachments: As stated cc w/atts: See next page

_ _ _ _ _ . - _ _ ~ _ - - - - - - _ - - - . _

Houston Lighting & Power Company South Texas, Units 1 & 2 Cc:

Mr. David P. Loveless Jack R. Newman, Esq.

Senior Resident Inspector Morgan, Lewis & Bockius U.S. Nuclear Regulatory Commission 1800 M Street, N.W.

P. O. Box 910 Washington, DC 20036-5869 Bay City, TX 77414 Mr. Lawrence E. Martin Mr. J. C. Lanter/M. B. Lee General Manager, Nuclear Assurance Licensing City of Austin Houston Lighting and Power Company Electric Utility Department P. O. Box 289 721 Barton Springs Road Wadsworth, TX 77483 Austin, TX 78704 Rufus S. Scott Mr. M. T. Hardt Associate General Counsel Mr. W. C. Gunst Houston Lighting and Power Company

, City Public Service Board P. O. Box 61867 P. O. Box 1771 Houston, TX 77208 4

' San Antonio. TX 78296 Joseph R. Egan, Esq.

Mr. G. E. Vaughn/C. A. Johnson Egan & Associates, P.C.

Central Power and Light Company 2300 N Street, N.W.

P. O. Box 289 Washington, DC 20037 Mail Coder N5012 Wadsworth, TX 74483 Office of the Governor ATTN: Andy Barrett, Director INPO Environmental Policy Records Center P. O. Box 12428 700 Galleria Parkway Austin, TX 78711 Atlanta, GA 30339-3064 Arthur C. Tate, Director Regional Administrator, Region IV Division of Compliance & Inspection U.S. Nuclear Regulatory Connission Bureau of Radiation Control 611 Ryan Plaza Drive, Suite 400 Texas Department of Health Arlington, TX 76011 1100 West 49th Street Austin, TX 78756 Dr. Bertram Wolfe 154b3 Via Vaquero Texas Public Utility Commission Monte Sereno, CA 95030 ATTN: Mr. Glenn W. Dishong 7800 Shoal Creek Blvd.

Judge, Mata 'a County Suite 400N Matagorda Ct ;y Courthouse Austin, TX 78757-1024 1700 Seventh treet Bay City, TX 77414 Mr. William T. Cottle Executive VP & General Manager Nuclear Houston Lighting & Power Company South Texas Project Electric Generating Station P. D. Box 289 Wadsworth, TX 77483

- - . - - . .= - - _.

ATTENDEES AT MEETING OF SEFTEMfIER 11. 1997 ON THE SOUTH TEXAS PROJECT 3-TRAIN DESIGN HAME AFFILIA110!i

, J. Kennedy NRC/IlRR/DRPW/PD4-1 N. Gilles NRC/t4PR/TSB C. Morton NRC Contractor - PQP M. Wohl NRC/NRR/SPSB

W. Beckner NRC/NRR/TSB M. Reinhart NRC/NRR/TSB

2. Schulten NRC/NRR/TSB J. Self HL&P/ Excel D. Stillwell HL&P/ Risk & Reliability W. Harrison llL&P/ Licensing J. Page HL&P/ Operator Training T. Alexion NRC/NRR/DRPW/PD4-1 I

ATTACHMENT 1

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SOUTH TEXAS PROJECT ELECTRIC GENERATING STATION 9 ,

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DESIRED OUTCOME

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• Basic understanding of:

l

• 3-train arrangement l

• additional capabilities of the 3-train arrangement i

• how ITS was adapted to the 3-train arrangement

• Significant STP design differences w ,,

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GENERAL PLANT DESCRIPTION-

. WESTINGHOUSE 4 LOOP PWR 3800 MW(t}

. UNIT ONE COMMERCIAL - 1988 ,

l . UNIT TWO COMMERCIAL - 1989 L . IDENTICAL (SLIDE ALONE}

l . ESSENTIAL COOLING POND THE ONLY SHARED FUNCTION i

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GENERAL DESIGN BASIS FOR THREE TRAINS -

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3 e 1ST TRAIN FAILS

. e 2ND TRAIN INJECTS INTO BROKEN LOOP (INEFFECTIVE) e 3RD TRAIN EFFECTIVELY MITIGATES THE EVENT t

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ESF DIST.dIRUIIO.N TYPICAI (3) .- ..

13.8 KV STDY BUS 13.8 KV EMERG. BUS 1L  :

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N.C.) N.O. )

l l N.C. ---

• > - - - - - - - - - - - - - - - - N.O.

l 13.8 KV/4.16 KV l

________________________________T___AU X ES F T R A N __________________________________,

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i l Bus  : l l l N.C.) N.O. ) l)N.C. j

4.16 KV/480V 4.16 KVl480V  ;

l TRANSFORMER 5500 KW TRANSFORMER ;

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. l . es ESF DIESEL rn  ;  ;

l GENERATOR l l N.C. N.C. j i

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MCC i

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Electrical Pow r Distribution .

i i PREFERRED POWER - NORMALLY SUPPLIED FROM ..

SWITCHYARD THROUGH STANDBY TRANSFORMER VIA STANDBY BUSSES TO 3 SEPARATE, REDUNDANT ESF POWER TRAINS.

STANDBY POWER - STANDBY DIESELS I'3'i START AND TIE TO THE ENGINEERED SAFETY FEATURES BlJsES AND i SEQUENTIALLY LOAD THE APPROPRIATE EQUIPMENT FOR THE CONDITION ON A LOSS OF LOSS OF OFF - SITE POWER (LOOP)

DC POWER IS SUPPLIED FROM FOUR I'4'l INDEPENDANT i CHANNELS WHICH ARE BACKED BY A sATTERY BANK FOR EACH CHANNEL EMERGENCY POWER - EMERGENCY TRANSFORMER CAPABLE OF PROVIDING. POWER TO ONE ESF BUS ON EITHER UNIT. USED WHEN NO OTHER POWER IS AVAILABLE.

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South Texas Plant AFW, PORV, and ECCS Arrangement  !

Pumped St Train A Pumped St Train B s O

HHSI O HHSI ACC A ACCB LHSI LHtil

. PORV A PORVB

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i SGB AFWTrain A AFWTrain B r 7 j

] t Pressurizer -

PORV RV C p

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i SGC-1 1 AFWTrain D AFW Train C LHSI ACC C HHS:

O Pumped SiTrain C

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EMERGENCY CORE COOLING SYSTEM (ECCS) &"

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TYPICAL (3) WST

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i RESIDUAL HEAT REMOVAL SYSTEM (RHR) -

PRIMARY FUNCTION OF THE RHR SYSTEM IS TO REMOVE CORE DECAY HEAT DURING COLD SHUTDOWN AND REFUELING OPERATIONS.

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! THE RHR IS PLACED IN SERVICE AT A PRESSURE OF 350 PSIG AN '

A TEMPERATURE OF 350 F THE THREE (3 RHR HEAT EXCHANGERS AND ASSOCIATED PIPING!

l ARE SHARED ) COMPONENTS WITH THE LOW HEAD SA INJECTION SYSTEM.

THE RHR SYSTEM IS LOCATED ENTIRELY INSIDE CONTAINMENT THE RHR PUMPS ARE NOT PART OF THE SAFETY INJECTION SYSTEM. THEY ARE SAFETY RELATED PUMPS FOR THE SAFE SHUTDOWN OF THE PLANT.

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ECCS SUPPORY SYSTEMS .

• Standby Diesel Generators - Provide backup emergency power ,

to the Emergency Core Cooling system and components.

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• Component Cooling Water - Provide a heat sink for the Residual!

, Heat Removal system and Low Head Safety injection System during a LOCA condition.

• Essential Cooling Water - Provide a heat sink for the ComponentCooling Water system and cooling to the Standby

Diesels.

• Essential Cooling Pond - Located inside the owner controlled area is the Ultimate Heat Sink

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D.G.B. ECW INTK STRUCTURE  !

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ESSENTIAL COOLING WATER SYSTEM (ECW) -

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. THREE REDUNDANT ECW TRAINS PROVIDE COOLING TO VARIOUS PRIMARY PLANT COMPONENTS DURING NORMAL

AND ACCIDENT CONDITIONS.

l I MAJOR LOADS ARE:

l 1) STANDBY DIESEL GENERATOR COOLING

2) COMPONENT COOLING WATER HEAT EXCHANGER

3) ESSENTIAL CHILLER CONDENSERS

4) COMPONENT COOLING WATER PUMP SUPPLEMENTARY ,

COOLERS i l

ECW SUPPLY SOURCE IS THE ESSENTIAL COOLING POND ,

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CCW ESF LOOP (3) 8 3 ORC 'IRC IRC 8ORC l 2 m l l RHR HX , ' ' l COMMON r 3 VENT l 8

SUPPLY

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"  : HEADER E l,E H M M !i E u, TO NON DE5AIN. ] [y ri iri RHR PUMP r, r ESF WATER k)[ l l I I l I l l 6

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COMMON SUPPLY MEADER i,

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l COMPONENT COOLING WATER (CCW) .

THREE REDUNDANT CCW TRAINS PROVIDE COOLING TO VARIOUS PRIMARY PLANT COMPONENTS DURING NORMAL AND l ACCIDENT CONDITIONS.

'i l ACTS AS AN INTERMEDIATE FLUID BARRIER BETWEEN THE RADIOACTIVE SYSTEMS AND THE ESSENTIAL COOLING WATER SYSTEM (ECW) WHICH USES THE ESSENTIAL COOLING WATER POND FOR COOLING ALL THREE TRAINS WILL AUTO START ON A SAFETY INJECTION SIGNAL OR A LOSS OF OFFSITE POWER SIGNAL AND AUTOMATICALLY ALIGN TO RCFC COOLERS.

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SIMPLf6 CONTAINMENT SPRAY SYSTEM DRAWING d TYPICAL (3)

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SPRA ADD TANKS PCV O N V "

ABANDONED IN PLACE i

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\ BYPASS RETURN ,g, RA h A A A A k b- E _,b A A A A AA 1A A A

, , A A Z-i j n t.C.  :: 1 SPRAY L.O.

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TRAINS .m 1 1C 2 I CS/ SIS 7 ~~ - -

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$Ech TSP CS PUMP 1A T.C. g (HHS1 PUMP J BAS;(ETS, L.C. ),,

(LHS1 PUMP..l I "  !

SUMP CS/ SIS PUMP SUMP 1A

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RCFC's (3 TRAINS OF 2) ~

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IN CORE INSTRUMENT i

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TRAIN C ll t TRAIN B C k51,500 CFM

' o CONTAINMENT E' RAY SYSTEM AND REACTOR CONTAINMENT FAN COOLERS .

REACTOR CONTAINMENT FAN COOLERS AND CONTAINMENT SPRAY SYSTEM WORK TOGETHER TO REDUCE PRESSURE WITHIN THE REACTOR CONTAINMENT BUILDING DURING POST

LOCA CONDITIONS REACTOR CONTAINMENT FAN COOLER HEAT EXCHANGER IS COOLED BY CHILLED WATER SYSTEM DURING NORMAL CONDITIONS AND BY COMPONENT COOLING WATER DURING ACCIDENT CONDITIONS CONTAINMENT SPRAY ALSO WORKS IN CONJUNCTION WITH THE TSP BASKETS INSIDE CONTAINMENT TO MAINTAIN pH OF THE CONTAINMENT EMERGENCY SUMP

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FUEL HANDLING BUILDING HVAC - BASIC .

SUPPLY AIR TO BUILDING '

EMERGENCY OPERATION ONLY aL REUEFSUPPLY DAMPER

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% FHB HVAC N OUTSIDE l SUPPLY SUBSYSTEM AIR ,

INTAKE 1. SUPPLY FILTERS (3) '

2. HC/CC(3)

3. SUPPLY FANS (3)

.; TO PLANT i 3r STACK r r ak  !

1 1 1 r 1r 3r i ECCSTRAIN SPENT FUEL MAIN AREA PUMP CUBICLES POOLAREA CASK N  !

A B C NEW FUEL AREA 1r 1r 1r HANDUNG AREA '

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EXHAUST BOOSTER FAN W@ FAN OF E9 - gg --

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- -->C -> --> C ' l MAB FHB FHB s

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FbEL HANDLING BUILDING (FHB) HVAC .

i FHB HVAC SUPPLY SYSTEM AUTOMATICALLY SECURES ON A HIGH RADIATION SIGNAL OR SAFETY INJECTION SIGNAL. THE SUPPLY AIR IS SUPPLIED VIA RELIEF DAMPERS INSIDE THE BUILDING.

FHB EXHAUST SYSTEM CONTAINS:

I

1) THREE 50% CAPACITY MAIN EXHAUST FANS

2) TWO 100% CAPACITY EXHAUST FILTER UNITS

3) THREE 50% CAPACITY EXHAUST BOOSTER FANS KEEPS THE FHB UNDER NEGATIVE PRESSURE TO PREVENT OUT LEAKAGE OF CONTAMINATED AIR MITIGATES THE CONSEQUENCES OF A FUEL-HANDLING ACCIDENT RAD RELEASE BY ROUTING EXHAUST AIR FROM THE SPENT FUEL POOL AND MAIN AREAS THROUGH FILTER UNITS.

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CONTROL ROOM ENVELCPE (CRE) VENTILATONl THREE INDEPENDENT TRAINS (50% CAPACITY) CONSISTING OF:

1) SUPPLY FAN AND FILTERS

2) EXHAUST FAN

3) CLEAN UP UNIT

4) MAKEUP UNIT CRE HVAC MAINTAINS CONTROL ROOM HABITABILITY FOR

SAFE SHUTDOWN OF THE PLANT UNDER ALL CONDITIONS AND l DURING ANY POSTULATED DBA 11

!' CRE HVAC AUTOMATICALLY TRANSFERS TO THE RECIRCULATION AND MAKE UP FILTRATION MODE OF OPERATION ON:

l HIGH SMOKE HIGH RADIATION SIGNAL l SAFETY INJECTION AND/OR LOSS OF OFFSITE POWER SIGNAL TWO TRAINS OF CRE HVAC REQUIRED TO MAINTAIN 1/8" POSITIVE PRESSURE IN THE CONTROL ROOM ENVELOPE l ONE TRAIN WILL MAINTAIN A SLIGHT POSITIVE PRESSURE IN THE ,

i CONTROL ROOM ENVELOPE i

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AUXILIARY FEEDWATER SYSTEM AFW l.V.C. R.C.B.

STORAGE 1 X S/G RECIRC .

TK ATMOS PUMP 1D 1 MAIN ST AM) l S/G D AFW ll ;9 l

RECIRC TO PUMP 14 LO*

AFW STOR < - -> -

l S/G RECIRC

9 PUMP 1A <

ST AGE 1 X X '

X >4 .W S/G A AFW 2L RECIRC TO PUMP 11 L* 0*

AFW STOR < 'm -

S/G RECIRC PUMP 1B 4 l AFW , ,

X X h y STORAGE ? X J  ? m r4 l W S/G B AFW ^ B RECIRC TO PUMP 12 LO* '- l AFW STOR 1 -- -

S/G RECIRC l 9 PUMP IC <

l AFW I ,

a X X h y' STORAGE ; X jJ n -

l .W S/G C AFW ll l

RECIRC TO PUMP 13 AFW STOR 4 4 LO* 's TK [d, l

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l AUXILIARY FEEDWATER SYSTEM _

i CONSIST OF 4 INDEPENDENT TRAINS

'A' S/G - MOTOR DRIVEN PUMP - ESF 'A' TRAIN

'B' S/G - MOTOR DRIVEN PUMP - ESF 'B' TRAIN

'C' S/G - MOTOR DRIVEN PUMP - ESF 'C' TRAIN

'D' S/G - TURBINE DRIVEN PUNIP 'D' STEAM GENERATOR EACH TRAIN CAN BE CROSS-CONNECTED TO SUPPLY ANY OF THE FOUR STEAM GENERATORS.

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CONCLUSION .

l = CONSERVATIVE DESIGN i

l l = DEFENSE IN DEPTH i = REDUNDANCY

= ACCIDENT MITIGATION CAPABILITY

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Improved Technical Specifications for" .

Three-train Plant Allowed Outage Times Three Primary Concepts:

- Action statements to cover the progression from j three trains available to no trains available l

- Allowed outage time for one train inoperable are increased from two train design because three train design has substantially more capability

- Short allowed outage times are appropriate instead of immediate shutdown for conditions with two trains inoperable since three train plant has not suffered a complete loss of function w-

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Gonsral Cace for Allowsd Outage ~

Times Standard Two Train Current STP Proposed STP 2 Train Comments 3 Train CominEnts (Typical) Specification Specification (Typical) (Typical)

AII trains operable unlimited unlimited unlimited Meets design basis Meets design basis l

1 Train inoperable 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 7 days 7 days No loss of safety No loss of safety l function, but does function and MEETS not meet single single failure in most

' failure cases 2 Trains inoperable TS 3.0.3 TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Complete loss of Safety function safety function and maintained under non-accident safe most accident shutdown capability conditions.

Non-accident safe-shutdown ability retained.

3 Trains inoperable NA TS 3.0.3 TS 3.0.3 NA Loss of function

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System Specific Allowed Outage Times .

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! Current Technical Proposed Technical Comments i Specification Specification

,i Emergency Core Cooling 7 days 7 days 7 days unchanged. 24 ITS 3.5.2 TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> hours provides TS 3.0.3 TS 3.0.3 reasonable time for corrective action i

i Essential Cooling Water 7 days 7 days 7 days unchanged. 24 1

ITS 3.7.8 TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> hours provides i TS 3.0.3 TS 3.0.3 reasonable time for i corrective action Essential Chilled Wcter 7 days 7 days 7 days unchanged. 24 ITS 3.7.14 TS 3.0.3 24 hcurs hours provides TS 3.0.3 TS 3.0.3 reasonable time for corrective action Control Room Envelope 7 days -

7 days 7 days unchanged 24 HVAC (Modes 1-4) 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> hours reduces time ITS 3.7.10 TS 3.0.3 TS 3.0.3 based on risk insights

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System Specific Allowed Outage Times -

l Current Technical Proposed Technical Comments Specification Specification

! Component Cooling 7 days 14 days Only one train of CCW

! Water TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is necessary to fulfill ITS 3.7.7 TS 3.0.3 TS 3.0.3 the safety function Residual Heat 7 days 14 days 3 trains of RHR and Removal 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> functional redundancy ITS 3.5.2 Immediate action to immediate action to of LHSI. Not an ECCS, restore restore long term heat removal only.

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1 System Specific Allowed Outage Times

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A i Current Technical Proposed Technical Comments t

Specification Specification l Reactor Containment 7 days 28 days - 28 days is justified by Fan Coolers TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> capability and redundancy ITS 3.6.6 TS 3.0.3 TS 3.0.3 of system. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonable for corrective action Containment Spray 7 days 28 days 28 days justified by ITS 3.6.6 TS 3.0.3 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> analysis that shows TS 3.0.3 TS 3.0.3 substantial margin in system capability. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonable for corrective action

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l System Specific Allowed Outage Times Auxiliary Feed Water Current Technical ed Technical Comments Specification Propecification

-p ITS 3.7.5 4

i Train inoperable 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 28 days Accounts for the " extra" (7 days if steam supply to train turbine) a 2 Trains Inoperable 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Consistent with Standard (72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if the ITS with one train combination inoperable includesTrain A) 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Consistent with Standard ITS with two;aperable '

3 Trains inoperable trains 4 Trains inoperable immediate action to immediate action to Function is lost restore restore

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7.---.----_-

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Ost@rministic Basis for Allowsd .

! Outage Times L = C'ne train inoperable:

L - Retain full accident mitigation capability with no L single failure L - Can mitigate all but most severe accident with j single failure considered l - Can achieve safe shutdown (non-accident} with j single failure considered l = Two trains inoperable:

i - Can mitigate all but most severe accident with no l single failure l -Can achieve safe shutdown assuming no single

! failure l  %., o* __

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6eterministic Bas s for Allowed .!

Outage Times

= Deterministic basis reviewed by NRC for extended allowed outage time for Standby

'l Diesel Generators is applicable to the ITS j = There are some degraded capabilities if only  !

H one train of a system is available for accident l mitigation l - Accident mitigation ability is retained except in

one event

! . Operator action may be required in some cases l . Action is covered by Procedures l

l

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Deterministic Limitations for Single -

l Train Mitigation Effectiveness Alternative Action Comments System Function Affected Safety injection with 2 Cannot mitigate LBLOCA None Event probability ~2E-10 trains unavailable (LHSI if only operable train is and HHSI) injecting in broken loop

! Safety injection (HHSI) Steam Line Break None necessary DNB not expected to l with 2 trains unavailable mitigation degraded occur ,

i ,

Safety injection with 2 SBLOCA with operable Operator action per Operator action is trains unavailable (LHSI train injecting in broken Emergency Procedures to expected to be effective and HHSI) loop depressurize Residual Heat Removal Long-term cooling with Coolwith LHSI until RHR ESF power expected to be only one ESF bus -

is restored recovered before RHR is energized orifinjecting in required broken loop

%../ ./

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Datorminiatic Limitations fer Singlo ~

Train Mitigation Effectiveness I

3ystem Function Affected Attemative Action Comments "

Containment S xay with degraded iodine removal MonitorTSC doses and $

only one opera ale train . during LOCA affects TSC relocate to lower dose area doses if required Control Room Envelope Cannot maintain 1/8" None required Positive pressure is l

! HVAC with only one positive pressure expectccl to be maintained operable train so system is functional 5,

Component Cooling Water Degraded flow to RCFCs Manually isolate non-safety Effect of reduced flow is with only one operable train and RHR heat exchangers header slight even without manual action I

Piobabilistic Bas @s for Allowed"

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1 Outage Times ~

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j o PSA Supplement submitted with the application and L

is referenced in the STP ITS Bases a Proposed allowed outage times based on time l required for CDF to cross risk thresholds from EPRI u PSA Applications Guide

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- One train inoperable: time to cross non-risk significant threshold (1E-C6) l -Two trains inoperable: time to cross potentially risk j significant threshold (1E-C5}

l . Not a voluntary configuration  ;

L = Risk Managed by Comprehensive Risk Management l Program f

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PLANT SPECIFIC

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DESIGN CONSIDERATIONS l SOUTH TEXAS PROJECT y

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Rapid Refueling Head 1

1 Package l

= Control Rods are withdrawn into head package for refueling

- Rods not considered " capable of withdrawal" when withdrawn and locked

- Position of reactor trip breakers is irrelevant with the rods latched out

Reactor Coolant .

i System

= ITS 3.4.6 and 3.4.7 (Required RCS Loops in Modes 4 and 5}

- Required operable loops changed to account for 3 RHR trains

- Clarified required action to allow injection of water from idle RHR loop or the RWST

. This allowance appears in various places in the specifications ,

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ITS Section 3.4 Reactor Coolant System (cont.)

= ITS 3.4.12 and 3.4.13 { Low Temperature Overpressure Protection)

! - Divided into two specifications to reflect STP current design

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l = ITS 3.4.15 (RCS Pressure Isolation Valve l Leakage) 1 - Revised to reflect that STP RHR is inside containment (no l penetrations) i

! - STP RHR design does not include " auto-closure interlock" I %s W

l O O n -

I j ITS Section 3.5 o

Emergency Core Cooling

= ITS 3.5.2 (ECCS - C>perating}

! - Required operable trains changed to account il for 3 ECCS trains

-Conditions and Required Actions changed to

account for l . three SI trains l . RHR components that are part of ECCS i

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ITS Section 3.5 -

Emergency Core Cooling (cont.)

ITS 3.5.3 (ECCS - Shutdown)

- Required operable trains changed to account for 3 ECCS trains

-SR Note deleted to reflect RHR design that does not require manual alignment to initiate ECCS

= ITS 3.5.4 (Refueling Water Storage Tank}

-Water temperature requirements not required v

^. ,8, -i L ITS Section 3.6  :

j Containment Systems i

= ITS 3.6.6 (Containment Spray and 1 Cooling Systems}

- Revised to account for increased

redundance in STP systems i

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Plant Systems i

= ITS 3.7.5 (Auxiliary Feedwater) l - Revised allowed outage times to account for redundancy provided by 3 motor-driven AFW trains and 1 steam driven AFW train

= ITS 3.7.7 (Component Cooling Water}

- Revised allowed outage times based on three train philosophy

7TS Section 3.7 oi j Plant Systems (cont.)

j o ITS 3.7.8 (Essential Cooling Water)

- Revised allowed outage times based on three train ij philosophy ,

l o ITS 3.7.10 (Essential Chilled Water) l - Revised allowed outage times based on three train l philosophy l

o ITS 3.7.11 (Control Room Envelope HVAC)

- Revised allowed outage times based on three train philoso

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ITS Section 3.7 -l

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Plant Systems (conts) '

f T = ITS 3.7.12 and 3.7.13 (Fuel Handling _

Building HVAC}

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l j l Separated into two specifications for i' clarity  ;

l

! . Modes 1, 2, 3, and 4 - governed by LOCA l . During fuel movement - governed by j fuel handling accident l \

i

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