ML20077P950

Proposed Tech Specs 4.4.5, Steam Generators Surveillance Requirements & Bases 3/4.4.5, Steam Generators

ML20077P950
Person / Time
Site:	Davis Besse
Issue date:	08/16/1991
From:	CENTERIOR ENERGY
To:
Shared Package
ML20077P944	List: ML20077P940 ML20077P945 ML20077P950
References
1927, NUDOCS 9108200142
Download: ML20077P950 (11)

Text

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Dockot Nu2b3r 50-346 j Licence Nunbar.NPF-3 i h Sarial Nu2bar'1927 E Attachsent'l' L Pest 8 ' REACTOR COOLANT SYSTEM STEAM GENERATORS l

l l.IMITING CONDITION FOR OPERATION 3.4.5 lEach steam generator shall be OPERABLE with a water level between l L 18 and 348 inches. 1 L .  !

APPt.ICABILITY: MODES 1, 2, 3 and 4. l l .

L ACTION:

a. With one or more steam generators inoperable due to steam generator tube imperfections, restore the inoperable generator (s)

.to~ 0PERABLE status- prior to increasing T,',, above 200TJ

b. With one or more steam generators-inoperable due to-the water-

. level being outside the limits, be in at least HOT' STAND 8Y within 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s- and in COLD SHUTD0681 within the next= 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> p

SURVEILLANCE REQUIREMENTS l-4.4.5.0 - Each steam generator shall be demonstrated OPERABLE by performant of'the following augmented inservice inspection program and the requirements of- Specification 4.0.5.  ;

4.4.5.1. Stens Generator-Sample Selection and Inspection - Each steam '

generator shaL) be osterminec OPERABLE during shutdown by selecting and inspecting at least the minimum number of steam. generators specified in "

=

L: Table 4.4-1. ,

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4.4.5.2 st'eam Generator Tube Sample Selection-and-Inspection - The steam generator tube minimum sample size, inspection result classification, and the corresponding action required shall be as specified in Table 4.4-2.

The inservice inspection of steam generator tubes shall be perfomed at the -

i i

frequencies specified in- Specification _4.4.5.3 and the inspected tubes shall '

' be _ verified, acceptable per the acceptance criteria of Specification 4.4.5.4.

The. tubes selected for each inservice inspection shall-include at least 3t 'i

.i

$ct- of the total number of tubes in'all steam generators; the tubes selected l

' mo $8[ for these inspections shall be selected on a random basis ext;pt:

l 38 a. The first sample inspection during each inservice inspection l (subsequent to the baseline inspection) of each steam generator >

< shall include: I or MC S ceveS I

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$' wo$

SO 1. All ubes"that previously had detectable wall L

$- nei- beer piv l penetrations (> 20".)NE hav. repair <A W sleevig M vhe, aFre.'

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+ 0. 0- 2. At least 50* of the tubes inscreted shall be in those  :

areas where experience has indicated potential problems.- [

r Amendment No.f.1 A

. _.._ ._DAV. I.S._-BESSE UNIT 1- - - -3/4

- 6_

---.-..-_ __ _ _r

Docket Numb:r 50-346 Licenso Numbar NPF-3 Serial' Numb:;r 1927 9 CTOR COOLANT SYS1TM SURVEILLANCE REOUIREMENTS (Continued) "l1l) [1l["GRM AT' E E EE E EM FE E M NE E

3. A tube inspection (pursuant to SpecetMiM3I.M5MW.M shall be performed on each selected tube. If any selected tube does not permit the passage of the eddy current probe for a tube inspection, this shall be recorded and an adjacent tube shall be selected and subjected to a tube inspection,

b. Tubes in the following groups may be excluded from the first random sample if all tubes in a group in both steam generators are inspected. No credit will be taken for these tubes in meeting minimum sample size requirements.

1. Group A-1: Tubes within one, two or three rows of the open inspection lane.

2. Group A-2: Tubes having a drilled opening in the 15th support plate.

3. Group A-3: Tubes included in the rectangle bounded by rows 62 and 90 and by tubes 58 and 76, excluding tubes included in Group A-1 *

c. The tubes selected as the second and third samples (if required by Table 4.4-2) during each inservice inspection may be subjected to less than a full tube inspection provided:

1. The tubes selected for these samples include the tubes from those areas of the tube sheet array where tubes with imperfections were previously found.

2. The inspections include those portions of the tubes where imperfections were previously found.

The results of each sample inspection shall be classified into one of the following three categories:

Category Inspection Results C-1 Less than 5% of the total tubes inspected are degraded tubes and none of the depected tubes are defective.

C-2 One or este tubes, but not more than 1% of the total tubes inspected are defective, or between 5% and 10% of the total tubes inspected are degraded tubes.

C-3 More than 10% of the total tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.

. Tubes in Group A-3 shall not be excluded after completion of the fifth refueling outage.

DAVIS-BESSE, UNIT 1 3/44-7 Amendment No. e4,113

.7 _.

Dock 3t Numb 2r 50-346 Lictnsa Numb 2r NPF-3 Ssriel Nurb2r 1927 Attachment 1 "* '

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Paga 10 PiACTOR COOLANT SYSTEM TiGl*"h f ggh SURVEILLANCE REQUIRDIENTS (Continued) rann as f ra Pb D 0 "

't9 y N hbh kb'l ! E Notes: (1) In all inspections, previously degraded tubes must exhibit significant (> 107.) further wall penetrations to be included in the above percentage calculations.

(2) Where special inspections are performed pursuant to 4.4.5.2.b, defective or degraded tubes found as a result of the inspection shall be included in determining the Inspection Results Category for that special inspection but need not be included in determining the Inspection Results Category for the 8eneral steam generator inspection.  !

4.4.5.3 Inspection Frecuencies - The above required inservice inspections of steam generator tubes shall be performed at the following frequencies:

a. The baseline inspection shall be performed w coincide with the first scheduled refueling outage but no later than April 30. 1980.

Subsequent inservice inspections shall be performed at intervals of not less than 12 nor more than 24 calendar months after the '

previous inspection. If the results of two consecutive inspec-tions for a given group

• of tubes following service under all volatile treatment (AVT) conditions fall into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional '

degradation has occurred, the inspection interval for that group may be extended to a maximum of 40 months.

b. If the results of the inservice inspection of a steam generator performed in accordance with Table 4.4-2 at 40 month intervals for a given group

• of tubes fall in Category C-3, subsequent inservice inspections shall be performed at intervals of not i

less than 10 nor more than 20 calendar months after the previous inspection. The increase in inspection frequency shall apply until a subsequent inspection meets the conditions specified in 4.4.5.3a and the interval can be ext-oded to 40 months.

c. Additional, unscheduled inservice inspections shall be l

performed on each steam generator in accordance with the first sample inspection specified in Table 4.4-2 during the shutdown l

subsequent to any of the following conditions:

1. Primary-to-secondtry tube leaks (not including leaks originating from tube-to tube sheet welds) in excess of l

the limits of Specification 3.4.6.2.

• A group of tubes means: .

(a) All tubes inspected pursuant. to 4.4.5.2.b, or (b) All tubes in a steam generator less those inspected pursuant to 4.4.5.2.b.

l 1

DAVIS-BESSE, UNIT 1 3/4 4-8 Amendment No. 21

Dock 3t Nu b2r 50-346 Licens2 Numb 2r NPF-3

'Saricl'Numbar 1927 Attcchm:nt 1 ,

Pcge_11 REAETCR COOLANT SYSTEM SURVEILL ANCE REOUIREMENTS (Continued) 2-,

A seismic occurrence greater than the Operating Basis Earthcuake.

3. -

A luss-of-coolant accident requiring actuation of the engineered safeguards. i t

4 A main steam line or feecwater line break, c.

The provisions of Specification 4.0.2 are not applicable.

-- s 4.4.5.4 Acceotance Criteria  ; 1.Tv b i no or- Tu be Ol m os O d orMon of

a. e +vbe orfvbe sleeve which errns As used in this Specificati 4

1f.

( g g ndar .the primary syskrw[ 4o

_Imoerfection means an except1on to the dimensions, finish or contourorofspecifications.

drawings a tube from that required by fabricatica '

Eddy-current testing indication'g below 20% of the nominal tube wall thickness, if detectable ra may be censidered as imperfections.  ;

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d Oeoradation means a service-induced cracking, wastage, wear or of general corrosion occurring on either inside or n- Nl outside a tube. E & w ,

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Deoraded 9 minal Tube wall means h kne a tube a

containing imperfections > 20

$ 4 has n e de rada tion.

}E y 5.f.  : eora a 1 een regm meeving in4he.4W am +2 8

oe ep c - gf usihbiub I

,g_ tatekness affected or rem e 1 Jdi

- e ation. g I , =3 de ecfivedo eis a

' 6, jf. Defect means an imperfec 10thi p N .

exceeds the f u;ging311mit. A tube containin severity that it E j.

}% is defcctite. repair-def " P

• gN Repa;r, by plu33i n3 or e, red by ,[ Tg 7 f. DIM"" limit means the 1rperteC k sleevin in M e,a a rea gy y'

o. at r eyono

)(q 3 m q wnicn the tute sna11 be removed from service because it may become unserviceable prior to the next inspection and h 1 is L equal to 40". of the nominal tube wall thickness, jlo'lin gf.

3 cE D Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its j ,

'@ - structural integrity in the event of an Operating Basis Nn ,cd_Wu !! Earthquake, a loss-of-coolant accident, or a steam line i

or feedwater line break as specified in 4.4.S.3.c, above.

f h4 9,Jf.

Tube insoection means an inspection of the steam generator '

tube f rom the point of e 1try ccmpletely to the point of exit. l DAVIS-EESSE, UNIT 1 3/4 4-9 Amendment No.

21

Dockot Nunbar 50-346 Liesnpa Nu;bar NPF-3

.Ssrial Numb 2riAC70: COCLAti* SYS . J 1927 ll UEVEIlliNCE EEOUIREFENTS (Centinuec)

Attachment I Pig 2 12 10./. Droserive Insoection means an inspection of the full l ieng:n or eacn ;use in eacn steam genera cr performeo

, by tody current technicues rior to service to establisn a baseline conoition of the tuting. This inspection shall be performee orier :: initial POWER OPERATION using the ecuiement anc technicues excected to be used curina subsequent inservice inspections.

re pair

b. The steam generator shall be datamined OPERABLE after moleting the corresponding actions (plu '--"-

limit and all tubes containing all tubes exceeding trougn-wall the Ire E cracks) recu by Table 4.4-2. ~

4 . , . :, . :, Reoorts or repair g sleevinj In the, diecM areas

a. :o11owing each inservice insoec icn of steam generator tubes.

ne numner of tubes ciugged in each s: cam generator shall be reported to ,the Cc.. :ission within 15 days.

b. The complete results of the steam generater tube inservice inspection sna11 be submitted on an annual basis in a reocr -

for :ne period in wnich this inspection was ccmsleted. Tnis recort shall incluce:

1. Number and extent of tubes inspected.

2. Locatien and percent of wall-thickness penetration fer each indicatien of an immer#ection.

3. Identification of tubes pluggedx or sleeved l

c. Results of steam generator tube inscectiens wnich fall into Category C-3 and require promet nctification of the Comission sna11 be reported pursuant to Specification 6.9.1 prior e resummtion of plant operation. The written follawup of this recor: shall provice a descriptien of investi;ctions concucted to determine cause of the tube degracation ano corrective measures taken to prevent recurrence.

a.4.5.! Tne s: sam generator shall be demonstrated OPERABLE by verifying steam genera:ce level to be within limits at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, r4.4.5.7 When steam generater tube inspection is performed as per Section 4.4.5.2., an additional but totally separate inspection shall be performed on special interest peripheral tubes in the vicinity of the secured internal auxiliary feedwater header. This testing shall only be required on the steam generator selected for inspection, and the test shall require inspection only between DAVIS-BESSE, UNIT 1 3/4 a-10 Amendment No. $, U, EE

Docket Number 50-346 Licensb Number NPF-3 5erial Number 1927 Attachment 1 Page 13 REACTOR COOLANT SYSTEM SURVEILCANCE REOUIREMENTS~(Continued)

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the upper tube sneet and the 15th tube support plate. The tubes '

selected for inspection shall represent the entire circumference of the steam generator and snall total at least 150 pertpneral tubes.

4.4.5.8 Visual inspections of the secured internal auxiliary feedwater header, header to shroud attacnment welds, and the external header thermal sleeves snall ' performed on eacn steam generator tnrougn the auxiliary feedwater injection penetrations.

These inspections shall be performeo during the tnird and fourth refueling outages and at the ten-year ISI.

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DAVIS-BESSE, UNIT I 3/4 4-10a Amendment No. 62

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.rva TABLE 4 4-1 C

2 MINIMUM NUMBER OF STEAM GENERATORS TO BE

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~' INSPECTED DURING INSERVICE INSPECTION Yes No Pseservice inspection Thsee Four Two Theee F our Two w No. of Steam Generators per Unit One Iwo Two

] All Fust Inservice Inspection I One? One 3 One One '

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Second & Subsequent inservice inspect 6ons crq;mg - g Table Notation:

D&

JN% of the 8**

The inservice inspection may be limited to one steam generator on i sainspetseons rotating schedute irwficate that toises ng _g entuessoasserw; l l. ammmmme (where N is the number of steam generators en the gelant)n il thetors results of the fwst or swev ouNote that und att steam generators are performing inIhe a most hkesevere manner.one or more steam generators may %be found so be mo conditions.

stances the sampir sequence shalf be modifred to inspei.

. The stord and subscinuene g 2.

The other steam generator not inspee ed eluring ve first enservice inspection shall be empected v

nas descrabed ne I above.

enspections should lotlow the instrus :

1 see seisticceed di,reng ste g Q ""3-y+

3 Exh of the other two steam genesatoes not inspected elueseig the forst enservict- =====s= c Wb nispectaseis s second avid theed inspecteoris

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asL r:cu C L'"

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$ W T Allt E 4 4 7 '

E EEOS

-358*

$1E AM GENEftATOR IUDE INSPECilON I2I , **[*g Dg c a tr

. e*awa M aM

' z., 2ND SAMPLE INSFEC110N 3540 SAMPt.E lNSPtC tuti

> 151 SAMPLE INSPECitOf4

" Action Required Hesult Act,mn Dequescal Result Acton Requised Hesult Sample Sire -,~

., N/A N/A NfA N/A d, $

C-1 None

'p A minimum of S Tu per - --m en '

C-1 N/A - N/Ap C-2 Plug ler sod inspect additional Plufdefective tubes C-l None gr rep = e kr sle.eviay 2

25 tubes in this S. G. C-2 end inspect additionat C-2 PLgtelecte$e luths ~

45 tubes irgthis S. G.

a Peeform action for

' 8 C-3 C-3 sesult of feest sample Petfo#m action for ,,

N/A N/A g g. gpe ar' C-3 J C-3 result of first *

• pygT j*' marmte C-3 Inspect all tubegin All other this S. G.. plus de- S G.s are None N/A N/A u C-1

% lective tubes and Inspect 25 tubes in Some S. G.s Perform action for N/A N/A

each other S. G. C-2 but no C-2 result of second y additional sample Prompt notification S. G. are to NRC pursuant C-3 to specification Additional inspect all tubes in p 6.9.1 S. G. Is C-3 each S. G. and plug

• 7" *P* *C defective tubes. 5kWW

- Prompt notification 7 N/A to NRC pursuant to specification 6.9.1

'a R 0) S-3 'ls

• "dusing en inspection

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(2) For tubes inspected pursuant to 4.4.5.2.b: tio act ion is required forFdr C-1 result s. f~o r

[ C-2 results in one or both steam generators plugg efectIve tubes. C.3 results in one

,o or both steara generators, plug defective tubes ard provide prompt nottftcstion of NfC g

g pursuant to Specification 6.6. .

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. Docket Numbar 50-346 License

• Number NPF-3 Serial Number 1927  !

l Attachment 1  !

Page 16 REACTOR COOLANT SYSTEM BASES 3/4.4.4 PRESSURIZER A steam bubble in the pressurizer ensures that the RCS is not a hydraulically solid system and is capable of accommodating pressure surges during operation.

The steam bubble also protects the pressurizer code safety valves and pilot operated relief valve against vater relief.

The low level limit is based on providing enough vater volume to prevent a reactor coolant system lov pressure condition that vould actuate the Reactor Protection System or the Safety Feature Actuation System. The high level limit is based on providing enough steam volume to prevent a pressurizer high level as a result of any transient.

The pilot operated relief valve and steam bubble function to relieve RCS pressure during all design transients. Operation of the pilot operated relief valve minimizes the undesirable opening of the spring-loaded pressurizer code safety valves.

3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained.

The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1. Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that lead to corrosion. Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken. @

The plant is expected to be operated in a manner such that the secondary coolant vill be maintained within those chemistry limits found to result in negligible corrosion of the steam generator tubes. If the secondary coolant chemistry is not maintained within these chemistry limits.

l localized corrosion may likely result in stress corrosion cracking. The l extent of cracking during plant operation vould be limited by the l

limitation of steam generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage = 1 GPM).

Cracks having a primary-to-secondary leakage less than this limit during l

operation vill have an adequate margin of safety to withstand the loads l

DAVIS-BESSE, UNIT 1 8 3/4 4-2 Amenament No. 135

Docket. Number 50-346

-Lic6nse Number NPF-3 Seria'i Nbmber 1927 Attathment 1 Pege 17-REACTOR COOLANT SYSTEM _

RMES imposed during normal operation and by postulated accidents. Operating plants have demonstrated that primary-to-secondary leakageinofexcess Laakage 1 GPM ofcan be detected by monitoring the secondary coolant.

this limit will require plant shutdown and an unscheduled inspection, l during wnich the leaking tubes wi re ar b s eevn mW affededarg 1 ty w t pro c em s ry treatment Wastagar-type defects are unHowever, even if a defect should develop in of the secondary coolant.

service, it will be found during scheduled inservice steam generator tube examinations @"hd d" M .wird fe- !!! tMr -le tn htt ;

enseedi ; te piogg4ag Matt-of

• ef the tube _.nastas! ell thickness, Ste- ;;;;nter trM-inspections-af ;; . ting-plants P.;w deonstrated-th =911 t ty ta -eM4bly MtMt de?Eetica *t %e ;ztestaqHRE-of th criginal trM --11-thickness, -l Whenever the results of any steam generator tubing inserv. ice inspec.

tion fall into Category C-3, these results will be promptly reported to J the Caunission pursuant to Specification 6.9.1 prior to resumption of plant operation. Such cases will be considered by the Cannission on a L

L

' case-by-case basis and may result in a requirement for analysis, labora-tory examinations, tests, additional addy-current inspection, and re-vision of the Technical Specifications, if necessary.

The steam generator water level limits are consistent with the initial

• assumptions in the FSAR.  !

l.-

L DAVIS-BESSE, UNIT 1 B 3/4 4-3

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l Dociat Number 50-346 Lic:nse Number NPF-3 l S rici Number 1927 l Attcchment 1 1 Pag] 18 INSERT A A process ocuivalent to the inspection method described in Topical Report BAW-2120P will be used for inearvico inspection of steam generator tube sleeves. This inspection will provide ensurance of RCS integrity.

INSERT B As described in Topical Report BAW-2120P. degradat' ion as small as 20% through wall can be detected in all areas of a tube sleeve except for the roll expanded areas and the sleeve end, where the limit of docectability is 40% through wall.

Tubes with imperfections exceeding the repair limit of 40% of the nominal wall thickness will be plugged or repaired by sleeving the affected areas. Davis-Besse will evaluate, and as appropriate implement, better testing methods which are developed and validated for commercial use so as to enable detection of degradation as small as 20% through wall without exception. Until such time as 20% penetration can be detected in the roll expanded areas and the sleeve end, inspection results will be compared to those obtained during the baseline sleeved tube inspection.

l l