ML20066J411

Application for Amend to License NPF-3,changing TS 3/4.7.1.3 Re Plant Sys,Condensate Storage Tank & TS Bases 3/4.7.1.3 Re Plant Sys,Condensate Storage Facilities to Delete Ref to Deaerator Storage Tanks

ML20066J411
Person / Time
Site:	Davis Besse
Issue date:	02/15/1991
From:	Myer T, Shelton D CENTERIOR ENERGY
To:
Shared Package
ML20066J406	List: ML20066J404 ML20066J411 ML20066J413
References
NUDOCS 9102260118
Download: ML20066J411 (11)

Text

.. Dockot Husb:r 50-346 Lie:nsa Numb 2r NPF-3 S: riel Husbar 1806

. Enclosure

. Page 1 APPLICATION FOR AMENDHENT TO FACILITY OPERATING LICENSE NUMBER NPF-3 FOR DAVIS-BESSE NUCLEAR POVER STATION UNIT NUMBER 1 Attached is the requested change to the Davis-Besse Nuclear Power Station, Unit NumFar 1 Facility Operating License Number NPF-3. Also included are the Safety Evaluation and Significant Hazards Consideration.

The proposed changes submitted under cover letter Serial Number 1886 concern:

Appendix A, Technical Specifications Section 3/4.7.1.3, Plant Systems, Condensate Storage Tank Appendix A, Technical Specifications Bases Section 3/4.7.1.3, Plant Systems, Condensate Storage Facilities Fort D. C. Shelton, Vice President - Nuclear W/

Dy: / /he T. J. Ay rs, Director - Technical Services Sworn and subscribed before me this 15th day of February, 1991, s

bu&lNY~ 194 Notary Public, State of Ohio EVED?ltrm23 NOTA m & , gu:9 My Com!=,;eggy 23, gg 9102260118 910215 PDR ADOCK0500gj6 P

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Dockst Nuabar 50-346f

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Licensa:Nunbar-NPF-3 i Ssrial Husbar 1886-tEnclosute Page 2-The followingfinformation is provided to support. issuance of the requested changes"to the Davis-Besse Nuclear Pover Station Unit Number _1 Operating License Number NPF-3, Appendix A, Technical Specification-(TS) 3/4.7.1.3,

' Condensate Storage Tank, and TS Bases 3/4.7.1.3, Condensate Storage Facilities.-

A. Time Required'is Implement: This change'is to be implemented within 45

• days after Nuclear Regulatory Commission issuance of the License '

Amendment. <

B. Reason for Change ~(Facility Change Request Number 86-0018): ,

This_ change vill delete.the reference to:the Deaerator Storage Tanks (DSTs) as condensate-storage facilities for the Auxiliary Feedvater ,

System _and make: editorial. corrections.in nomenclature. The reeson for- -

this deletion-of the DSTs from the TS is that alignment of the OSTs to

.the Auxiliary Feedvater Pumps' suction is not_ allowed because the high-temperature water can damage the AFPs'-bearings, and.the ATPs' discharge: lines-vould be considered high energy lines. The editorial

-changes in nomenclature vould serve to clarify and correctly denote

.that the only condensate storace facilities are the condensate storage tanks.-

C. -Safety Evaluation 1- 5=c -ttached. Safety Evaluation (Attacnment 1).

D.- Significant Hazards Consideration: -See-attached Significant flazards Consideration-(Attachment 2).

E. . Markup of TS Pages 1 LSee; attached-marked-up TS pages (Attachment 3).

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. Dockat Nu:bar 50-346 Lle:nse Nunb;r NPF-3 Sarici Numb 3r 1886 Attachment 1 Page 1 SAFETY EVALUATION

1.0 DESCRIPTION

1.1 Purpose The purpnse of this safety evaluation is to review the proposed change to Appendix A, Technical Specifications (TS), of the Davis-Besse Nuclear Pover Station (DBNPS), Unit 1 Operating License, as presented in Facility Change Request (FCR) 86-0018. The change to TS Limiting Condition for Operation (LCO) 3.7.1.3, Condensate Storage Tank, deletes the reference to the Deaerator Storage Tanks (DSTs) as condensate storage facilities for the Auxiliary Feedvater System (AFVS). The reason for this change is that the alignment of the DSTs to the Auxiliary Feedvater Pumps (AFPs) is not allowed, Secause the high-temperaturo vater from the DSTs can damage tha APPs' bearings, and the AFP discharge vould be censidered a high energy line if cuction vere taken from the DST.

Additionally, since the deletion of DSTs from TS 3.7.1.3 leaves the Condensate Storage Tanks (CSTs) as the only condensate storage facilities, and for the sake of consistency and simplicity, all instances of " condensate storage facilities" in TS LCO 3.7.1.3, TS Surveillance Requirement 4.7.1.3.1, and TS Basis 3/4.7.1.3 are being replaced with " condensate storage tanks". Also, the singular " tank" is being changed in all these TS sections to the plural " tanks".

TS 3.7.1.3 requires that the condensate storage facilities be operable with a minimum contained volume of 250,000 gallons. This requirement is satisfied by the two CSTs, which hold 250,000 gallons each. The existing procedure that satisfies the surveillance requirement of TS 3,7.1.3 does not take credit for condensate stored in the DSTs.

1.2 Discussion The original design of the Davis-Besse Auxiliary Feedvater System was such that the two AFPs and the Start Up Feedvater Pump (SUFP) shared n common 10" supply header, which received condensate from either the DSTs or the CSTs. The SUFP was operated during plant startups and shutdowns, with suction from the DSTs and discharge to the Main Feedvater System (MPVS). During power operation, the SUFP was secured, and the CSTs aligned to be the source of water supply to the AFVS. At that time, the DSTs vere considered the first backup to the CSTs; they were therefore included within the scope of TS 3.7.1.3.

, The AFPa normally receive bearing cooling supply from their own discharge line. The maximum allovable bearing metal temperature is 210'F; hence, hot condensate from the DSTs, at a temperature of 213'F to 300'F, is not an adequate source of pump bearing cooling vater.

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' Docket-Number 50-346 License Number NPF-3 Social Number 1886-Attachment 1 Page 2 The condensate from the CSTs instead typically ranges from 40*F tn 80'F. In order to allow the AFPs to pump condensate received from the DSTs, their bearing cooling vater source vould'have to be svitched over to the Service Vater System (SVS).- Doing this requires the manual local actuation of several bearing vater supply line valves. Additionally, AFP suction from the DSTs vould classify AFP discharge as a high energy line, which would create high energy line break concerns.

In 1984, it vas determined that there existed hazards associated with high and moderate energy line breaks in the SUFP supply and discharge lines that run within the AFP rooms. These rancerns were resolved by installing the Motor Driven Feedvater Pump (HDFP) and its associated-

-piping. The HDFP performs the previous functions of the SUFP at plant startups and cooldowns, arv is also-capable of providing feedvater to the steam generators in the event of the loss of the steam turbine driven AFPs. The headet that brought conden-a*- ' rom the DSTs to the AFPs and SUFP was then diverted to the HDr? nrough-this and other plant modifications, the possibility of r Tplying DST vater to the AFPs has been eliminated. This improves the overall reliability of the AYVs because, as disch* sed above, the hot condensate from the DSTs can disable the AFPs if the supply for pump bearing cooling is not switched over to the SUS.

2.0 SYSTEMS AND COMPONENTS AFFECTED Auxiliary Feedvater System / Auxiliary Feedvater Pumps.

Condensate Storage System / Condensate Storage Tanks.

Main Feedvater System /Deaerator Storage Tanks.

3.0 DOCUMENTS AFFECTED DBNPS, Unit 1-Operating License, Appendix At TSs.

DBNPS Updated Safety Analysis Report (USAR).

4.0 SAFETY FUNCTION OF SYSTEMS AND COMPONENTS AFFECTSD l

The emergency function of the AFVS is to-provide emergency feedvater to the Once-Through steam Generators (OTSCs) for the removal of reactor decay heat, in the absence of main feedvater, or following the loss-of-offsite power. The AFV1 can also be used to promote p natural'eltculation of the Reactor Coolant' System (RCS) if all four Reactor Coolant Pumps (RCPs) are lost, i.e., forced circulation of the RCS is not available. The AFPs provide the motive power for the l coolant that is used as emergency-feedvater, i

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l' Dockot Number 50 .)46 License Number NPF-3 Serial Number 1886 Attachment 1 Page 3 The function of the Condensate Storage System is <- ore conder. mate and deliver it to the AFVS. The condensate storegt anks contain sufficient vater to maintain the RCS at he'* ttandby conditions for 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> with steam discharge to atmos).he' to cool down the RCS to less than 280'T under normal conditio. , loss-of-of(site power).

Tvo condensate storage tanks are provic, ' h each tank contait.ing a capacity of 250.000 gallons.

E 5.0 EFFECTS ON SAFETY The DBNPS USAR, Section 9.2.6, Condensate Storage Facilities, does not refer to th, DSTs as either a prilitary or backup source of condensate for the AFVS. The primary supply is from the non-seismic CSTs, with a seismic Claus I backup from the SVS. The switchover is

?utomatic, on a lov AFP suction pressure signal.

The DSTs are also non-seismic. USAR Section 9.2.6.2 mentions that they typically contain en additional 106,000 gallons of condensate.

No USAR sccident analysis * *s this additional inventory, because adequate supply is assumed trom the CSTs, or from the SVS following a seismic event.

The two CSTs are capable of containing a combined total of 500,000 gellons of condensate. The tanks are interconnected via normally open valves (See USAR Figure 10.4-11), hence both tanks have the same lev 61. The surveillance requirement specified in TS 4.7.1.3.1 is satisfied as part of ST $099.01, which checks that the CSTs contain a combined water volume of at least 250,000 gallons. Accordingly, the DST inventory is not needed, and it is not taken .ato account in the surveillance.

In conclusion, deleting the DSTs from TS 3.7.1.3 vill not adversely impact the safety of the planti rather, it vill insure that no credit '

can be taken for the DST inventory, which should not and cannot be supplied to the AFVS. The condensate in the DSTs is too hot to act ar. cooling water for the AFPs, which might damage the pumps, and vould force the AFP discharge to be :onsidered a high energy line.

6.0 UNREVIEVED SAFETY OUESTION EVALUATION The proposed change to DBNPS TS LC0 3.7.1.3

1. Does not increase the probability of an accident previously evaluated in the USAR, because this change has no effeet on any plant system, equipment or procedure.

[10 CFR50.39(a)(2)(i)}

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i l- . Dock 3t Nu;bar 50-346 License Nu bar NPF-3 Sariol Nu bar 1986

. Attachment 1 Page 4

2. Does not increase the ennsequences of an accident previously evaluated in the USAR because condensate from the DSTs is not used to mitigate any accident analyzed in the USAR that requires actuation of the AFVS. The change insures that the full 250,000 gallon inventory taken credit for by the USAR is available from the CSTs. [10 CFR 50.59(a)(2)(i)]

3. Does not increase the probability of a malfunction of equipment iraportant to safety previously evaluated in the USAR, because this change does not involve any modifications of plant systems, equipment or procedures. This change insures that no use vill be mede of DST vater, vhich can actually cause a malfunction of the ATPs. [10 CFR 50.59(a)(2)(i)]

4. Does not increase the consequences of a malfunction of equipment important to safety previously evaluated in the USAR because no USAR accident analysis uses condensate from the DSTs. The appropriate condensate inventory is provided by the CSTs.

[10 CFR50.59(a)(2)(1)]

5. Does not create the possibility of an at ident of a different type than any evaluated previously in ths :SAR because it has no effect on any plant system, equipment or procedure.

[10 CFR 50.59(a)(2)(ii)]

6. Does not create the possibility of a malfunction of equipment of a different type than any evaluated previously in the USAR because the change insures that full use can be made of the primary qualified source of condensate for the AFVS, i.e., the CST inventory. [10 CPR 50.59(a)(2)(ii))

7. Does not reduce any margin of safety as defined in the basis for any TS because the full required condensate inventory of 250,000 gallons vill be available from the CSTs.

[10 CFR 50.59(a)(2)(iii)]

In conclusion, no unreviewed safety question exists.

. Dockot Necb:r 50-346 ,

Lic:nsa No;bdr NPF-3 Sericl Nu bar 1886 Attachment 2

. Page 1 SIGNIFICANT HAZARDS CONSIDERATION DESCRIPTION PURPOSE The purpose of this significant hazarIs consideration is to review proposed changes to Appendix A. Technical Specification (TS) 3/4.7.1.3 of the Davis-Besse Nuclear Power Station (DBNPS), Unit 1 Operating License. The change to TS Limiting Condition for Operation (LCO) 3.7.1.3, Condensate Storage Tank, deletes the reference to the Demerator Storage Tanks (DSTs) as

-condensate stc, ?e facilities for the Auxiliary Feedvater System (AFVS).

The reason for this change is that-the alignment of the DSTs to the Auxiliary Feedvater Pumps (AFPs) is not allowed, because the high-tMperkture water from the DSTs can damage the AFPs' bearings, and the AFPs' discharge piping vould be considered high energy lines, i Additionally, since the deletion of DSTs from TS 3.7.1.3 leaves the Condensate Storage Tanks (CSTs) as the only condensata storage facilities, and for consistency and simplicity, all instances of " condensate storage facilities" in TS LCO 3.7.1.3, TS Surveillance Requirement (SR) 4.7.1.3.1,

.and TS Basis 3/4.7.1.3 are proposed to be replaced-with " condensate storage tanks". Also,-the singular " tank" is being changed in all these TS sections-to the plural " tanks".

TS 3.7.1.3 requires that the condensate storage fas111 tics be operable with a minimum contained volume of 250,000 gallons. This requirement is satisfied by the two CSTs, which hold 250,000 gallons each. The existing ,

procedure that; satisfies SR 4.7.1.3 does not take credit for condensate l stored in the DSTs.

Discussion The original design of the DBNPS AFVS vas such that the two AFPs and the /

Start Up Feedvater Pump (SUFP) shared a common 10" supply header which received condensate.from either the DSTs or the CSTs. The SUFP was operated during plant startup and_ shutdown, with pump suction from the DSTs and pump discharge to the Main Feedvater System (MFWS).. During power operation, the.

SUFP was secured and the CSTs were' aligned as the source.of water supply to the AFVS. At that time, the DSTs were considned the first backup to the

'CSTs; they were, therefore included within the scope of TS 3.7.1.3. 1 4, The AFPs normally. receive bearing cooling st. ply f rotw their own discharge line. .The maximum allovable bearing metal' temperature is 210*F1 hence, hot condensate from the DSTs, at a temperature of 213'F to 300'F, i iiot an

) acceptable source of pump bearing cooling vater.- (The condensate from the CSTs instead typically ranges from 40'F to DJ'F). In order to allow the AFPs to pump condensate received from the DSTs, the AFP bearing cooling

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Docket Nunbar 50-346 Licens2 Nunbar NPF-3 Sarici Nunbar 1886 l i

Attachment 2 Page 2 vater source vould have to be transferred to the Service Vater System (SUS).

This vould require local manual actuation of several bearing vater supply line valves. Additionally, ATPs' suction from the DSTs vould classify AFPs' 1 discharges as high energy lines and vould create high energy line break concerns.

In 1984, it was determined that there existed harards associated with high and moderate energy line breaks in the SUFP supply and discharge lines that run within the AFP rooms. These concerns were resolved by installing the Hotor Driven Feedvater Pump (HDFP) and its associated piping during the June 1985 extended outage. The HDFP performs the previous functions of the SUFP during plant startup and cooldovn, and is also capable of providing feedvater to the steam generators in the event of the loss of the steam turbine driven AFPs. T'ie piping header that supplied condentste from the DSTs to the AFPs and SUFP vas rerouted to the HDFPs' suction during its installation. Through this and other plant modifications, the possibility of st.,,plyiag DST vater to the AFPs has been eliminated. This improves the overall reliability of the AFVS because, as discussed above, the hot condensate from the DSTs can disable the AFPs if the supply for the pump bearing cooling is not transferred to the SVS.

In conclusion, the DSTs, based on design and as-built configuration considerations, cannot provide con <lensate to the AFVS and should, therefore, be removed from TS 3.7.1.3.

SYSTEMS AND COMPONENTS AFFECTED AFVS/AFPs.

Condensate Storage System /CSTs.

HPVS/DSTs.

DOCUMENTS AFFECTED Davis-Besse Nuclear Power Station Unit 1 Operating License, Appendix A, Technical Specifications.

Davis-Besse Nuclear Power Station Updated Safety Analysis Report.

SAFETY FUNCTION OF SYSTEMS AND COMPONENTS AlFECTED l

The safety function of the AFVS is to provide emergency feedvater to the Once-Through Steam Generators (OTSGs) for the removal of reactor decay heat in the absence of main fatdvater or following the loss-of-offsite power.

The AFVS can also be used to promote natural circulation of the Reactor Coolant System (RCS) if the Reactor Coolant Pumps (RCPs) are lost, i.e.,

j forced circulation of the RCS is not available. The AFPs provide the motive power for the coolant that is used as emergency feedvater.

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. Docket Numb 2r 50-346 License Numb 2r NPF-3 S2 rial Numbar 1886 Attachunt 2 Page 3 The function of the Condensate Storage System is to store condensate for a suction Vater supply to the AFVS. The condensate storage tanks contain sufficient vater to maintain the RCS tt hot standby conditions for 13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> with steam discharge to atmosphere and to cool down the RCS to less than 280'F under normal conditions (no loss-of-offsite pover). Two condensate storage tanks are provided, with each tuk containing a capacity of 250,006 gallons.

EFFECTS ON SAFETY The DBNPS USAR, Section 9.2.6, Condensate Storage Facilities, does not refer to-the DSTs as either a primary or backup source of condensate for the AFVS.

The primary supply is from the non-seismic CSTs, with a seismic Class I backup from the SVS. The svitchover is automatic on a lov AFP suction pressure signal.

The DSTs are also non-seismic. Updated Safety Aunlysis Report (USAR)

Section 9.2.6.2 mentions that they typically conta.in an additional 106.000 gallons of condensate. No USAR accident analysis has taken credit for this additional-inventory because adequate supply is available from the CSTs, or from the SVS following a seismic event.

The two CSTs have a combined capacity of 500,000 gallons of condensate. The tanks are routinely inter-connected via normally open valvest hence, both tanks contain the same volume. The surveillance requirement, specified in CR 4.7.1.3.1, requires that the CSTs contain a combined vater volume of at least 250,000 gallons. Accordingly, the DST inventory is not needed, and it is not taken into account in satisfying the surveillance requirement.

In conclusion, deleting the DSTs from TS 3.7.1.3 vill not adversely impact the safety of the plant; rather, it vill ensure that no credit can be taken for the DST inventory, which should not and cannot be supplied to the AFVS.

-The condensate from the DSTs vould have too high of a temperature to be ,

the cooling water source for the AFPs as it may damage the pumps. In

• ddition, using the DSTs as the AFPs' suetion source vould require that the AFPs' discharges be considered high ene m lines which is an unanalyzed condition.

SIGNIFICANT HAZARDS CONSIDERATION The Nuclear Regulatory Commission (NRC) has provided standards in 10 CFR 50.92(c) for determining whether a significant hazard exists due to a proposed amendment to an Operating License for a facility. A proposed amendment to an Operating License for a facility involves no significant hazards if operation of the facility in accordance with the proposed change vouldi (1) Not involve e significant increase in the probability or consequences of an accident previously evaluated; (2) Not create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Not involve a significant reduction in a margin of safety. Toledo Edison has revieved the proposed change and determined that a significant hazards consideration does not exist because operation of the DBNPS, Unit Number 1, in accordance with these changes vouldt

. Dockst Nunbar 50-346 License Nu2bar NpF-3  :

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Page 4 i la. Not involve a significant increase in the prohnbility of an accident previously evaluated because no accident conditions and assumptions are affected. Revising TS 3.7.1.3 to delete the DST as t. source of conden.; ate does not increase the probability of an accident since there are no changes to any plant system, equip:aent or procedure. The accident analysis assumes a volume of water equal to 250,000 gallons be available for ATVS operation.

This volume is available from CSTs, and has always been available 4

from this source. Therefore, the volume of the DST is not needed nor has it been credited in USAR analyses. The changes to Surveillance Requirement (SR) 4.7.1.3.1 and Bases Section 3/4.7.1.3 are editorial only.

i Ib. Not involve a significant increase in the consequences'of-an

-accident previously evaluated because no accident conditions and assumptions are affected. Revising TS 3.7.1.3 to delete the DST as a source of condensate does not affect the consequences of i an accident since the accident analysis assumes a volume of-vater equal to 250,000 gallons be available for AFVS opera *.lon. This volume is available from the CSTs, and has always been available from this source. Therefore, the volume of the DST is not needed

-nor has it been credited in USAR analyses. The chan6es to SR 4.7.1.3.1 and Bases Section 3/4.7.1.3 are editorial only.

2a. Not create the possibility of a new kind of accident from any accident previously evaluated because no accident conditions and -

assumptions are affected. Revising TS 3.7.1.3 to delete the DST as a source of condensate does not create the possibility of a new kind of' accident since there are no changes to ao/ plant system, equipment or procedure. The accident analysis assumes only that a volume of vater equal to 250,000 gallons be available for AFVS operation. This volume is available from the CSTs, and has always been available from this source. Therefore, the volume of the DST is not needed nor has it been credited in USAR. i

. analyses, and deletion of this potential source from the TS does  ;

not create any new type of accident. The changes to-SR 4.7.1.3.1

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and Bases Section 3/4.7.1.3 are editorial only.

2b. Not create the possibility of a different kind of accident from any accident previously evaluated because no accident conditions and assumptions are affected. Revising TS 3.7.1.3 to delete the DST as a source of condensate does not create the possibility of a different kind of accident.since there are no changes to any plant system, equipment or procedure. The accident analysis assumes only that a volume of water equal to 250,000 gallons be available for AFVS operation.- This volume is availehle from the CSTs, and has always been available from this source. Therefore, the volume of the DST is not ..eeded nor has it been credited in USAR analyses, and deletion of this potential source from the TS does not create any new type or accident. The changes to SR 4.7.1.3.1 and Bases Section 3/4.7.1.3 are editorial only, i

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3. Not involve a significant reduction in a margin of safety because the condensate volume requirements to meet analysis assumptions are not changed. Revising TS 3.7.1.3 to delete the Deaerator Storage Tank as a source of condensate only provides for a change in the cited source of condensate; however, it should be noted that the deaerator storage tank has never been considered in meeting the TS 3.7.1.3 volume requirements. The margin of safety has not been reduced because at 1 cast 250,000 gallons of condensate remain required by the TS. The changes to SR 4.7.1.3.1 and Bases Section 3/4.7.1.3 are editorial only and do not reduce the margin of safety.

CONCLUSION On the basis of the above, Toledo Edison has determined that the License Amendment Request does not involve a significant hazard consileration.

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