ML20197J597

Proposed Tech Specs Pages,Revising TS Surveillance Requirements for ISI Requirements of Internal Auxiliary Feedwater Header,Header to Shroud Attachment Welds & External Header Thermal Sleeves

ML20197J597
Person / Time
Site:	Davis Besse
Issue date:	12/23/1997
From:	CENTERIOR ENERGY
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Shared Package
ML20197J579	List: ML20197J576 ML20197J586 ML20197J597
References
NUDOCS 9801050033
Download: ML20197J597 (12)

Text

,

LAR 95-0015 Page 7 mC Ce<AN1 sv51 90 - '

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DAVIS-BESSE, UNIT ] 3/4 4-6a Amendment No.192

LAR 95-0015 Page 9 REACTOR COOLANT SYSTEM STEAM GENERATORS SURVEILLANCE REOUIREMENTS 4.4.5.0 Each steam generator shall be demonstrated OPERABLE by performance of the following augmented inservice inspection program and the requirements of Specification 4.0.5.

4.4.5.1 Steam Generator Samole Selection and Inspection - Each steam generator shall be determined OPERABLE during shutdown by selecting and inspecting at least the minimum number of steam generators specified in Table 4-4.1.

4.4.5.2 Steam Generator Tube Samolo 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 performed at the 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 3% of the total number of tubes in all steam generators; the tubes selected for these inspections shall be selected on a random basis except:

a. The first sample inspection during each inservice inspection (subsequent to the basu11ne inspection) of each steam generator shall include:

1. All tubes or tube sleeves that previously had detectable wall penetrations (> 20%) that have not been plugged or

• repaired by sleeving in the affected area.

2. At least 50% of the tubes inspected shall be in those areas where experience has indicated potential problems.

DAVIS-BESSE - UNIT 1 3/4 4-6b Amendment No.192

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

LAR 95 0015 Page 10 EACTOR COOLANT SYSTD1 SURVE!LI.ANCE EQUIMMDfTS (Continued)

3. A tube inspection (pursuant to Specification 4.4.5.4.a.9 )  !

shall be performed on er.ch selected tube. If any selected l 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 randos sample if all tubes in a group in both steas 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 dr'illed 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 classif t into one of the following three categories:

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

I C-2 One or sore tubes, but not more than 1% of the total tubes inspected are defective, or between 51 and 10% of

. the total tubes inspected are degraded tubes. .

l 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 l refueling outage.

DAVIS-RESSE,IJhfT 1 3/44-7 Amendment No. 21.IIJ.

1 c,,- - _

LAR 95 0015 INFORMATION ONLY

, REACTOR COOLANT SYSTDi

. SURVEILLANCE REQUIRDfENTS (Continued) .

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 i 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 general steam generator inspection.

4.4.5.3 Inspection Frequencies - The above required inservice inspections of steam generator tubes shal fbe performed at the following frequencies:

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

Subsequent inservice inspections shall be performed at it. Jals of not less t.han 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 tte inservice inspection of a stems generator performed in accordance with Table 4.4-2 at 40 month intervals for a given group

• of tubes tall in Category C-3, subsequent inservice inspections shall ae perforined at intervals of not less than 10 nor more than 20 calendar months af ter the previous inspection. The increase it, inspection frequency shall apply until a subsequent inspect 19n meets the conditions specified in 4.4.5.3a and the interval ;an be extended to 40 months.

c. Additional, unscheduled inscrvice inspections shall be perforlsed on each stna generator in accordance with the first sample inspection specified in Table 4.4-2 during the shutdown subsequent to any of the following conditions:

1. Primary-to-secondary tube leaks (not including leaks originating from tube-to tube sheet velds) in excess of 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.

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

LAIT 95-0015

* ' 2 REACTOR COOLANT SYSTEM INFORMATION ONLY SURVE!LLANCE REQUIREMENTS (Continued)

2. A seismic occurrence greater than the Operating Basis Earthquake.

3. A loss-of-coolant ucident requiring actuation of the engineered safeguards.

4. A main steam line or feedwater line break.

d. The provisions of Specification 4.0.2 are not applicable.

4.4.5.4 Acceptance Criteria _

a. As used in this Specification:

1. Tubing or Tube means that portion of the tube or tube sleeve  !

. which forms the primary system to secondary system boundary. I

2. Imperfection means an exception to the dimensions, finish or l contour of a tube from that required by fabrication drawings or, specifications. Eddy-current testing indications below 20% of the nominal tube wall thickness. if detectable, may be considered as imperfections.

3. Degradation means a service-induced cracking, wastage, wear 1 or general corrosion occurring on either inside or outside of a tube.

4. Degraded Tube means a. tube containing imperfections > 20% of the nominal wall thickness caused by degradation that has not been repaired by sleeving in the affected area.

5.  % Degradation means the percentage of the tube wall thickness RTected or removed by degradation.

6". Defect means a'n . imperfection of such severity that it exceeds the repair limiti A defective tube is a tube containing a

• defect that has not been repaired by. sleeving in the affectec area or a sleeved tube that has a defect in the sleeve. ,

7. Repair Limit means the imperfection depth at or beyond which the tube shall be removed from service by plugging or repaired by sleeving in the affected area because it may become unservi:e-able prior to the next inspection and is 0gual to 40% of the nominal tube wall thickness. The Babcoca and Wilcox process described in Topical Report BAW-2120P will be used for sleeving.

8. Unserviceable describes the condition of a tube if it leaks or l contains a defect large enough to affect its structural integ-rity in the event of an Op'erating Basis Earthquake, a loss-of-coolant acciden'.. or a steam line or feedwater line break as specified in 4.4.5.3.c. above.

9. Tube Inspection means an inspection of the steam generator l tube from the point of entry completely to the point of exit.

DAVIS-BESSE UNIT 1 3/: :-7 Amendment No. H.lil

LAR 95-0015 Page 13 REACTOR COOLANT SYSTEM

_ SURVEILLANCE RE0VIREMENTS (Continued)

.10. . preservice Inspection means an inspection of the full length of each tube in each steam generator performed by eddy current techniquer prior to service to. establish a baseline condition'of.the tubing. This inspection shall be performed prior to initial POWER OPERATION using

. the equipment and techniqu4s exp. acted to,,be used during subsequent inservice inspeletions.'..

b.

The steam generator shall be 'detemfie'd OPER/'LE after completing the corresponding actions (plug or repair b' %eving in the '

affected areas all tubes exceeding the repa,. simit and all tubes containing through wall cracks) required by Table 4.4-2.

4.4.5.5 Reports ,

a.

Following each inservice inspection of steam generator tubes.

' the number of tubes plugged.in .sach s,taan reported to the Commission.within 15. days. generator shall be

b. The complete results of the steam generator tube inservice inspection shall be submit'.ed on an annual basis in a report for the period in which this inspection was coyleted. This report shall include:

1. Number and extent of tubes inspected. '

2. Location and percent of wall-thickness penetration for each indication of an imperfection.

3. Identification of tubes plugged or sleeved.

c.

Results of steam generator tube inspections which fall into Category C-3 and require notification of the Commission shall be reported prior to resumption of plant operation. This report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.

4.4.5.6 The steam generator shall be demonstrated OPERABLE by verifying steam generator 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 />.

4.4.5.7 When steam generator tube inspection is performed as per Section 4.4.5.2. an additional but totally separate inspection shall be perfomed 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 4-10 Amend;nent No. 8.27.62.171.I64 l

. LAR 95 0015 Page 14

{tEACTOR COOLANT SYSTEM SURVEll, LANCE REQUIREMENTS (Continued)

' he t upper tube sheet and the 15th tube support plate. The tubes selected for inspection shall re , resent the entire circumference of the steam generator and shall total at least 150 peripheral ttoes.

4.4.5.8 Visual inspections of the secured intemal auxiliary feedwater header, header to shroud attachment welds, and the extemal header thermal sleeves shall be performed on each steam generator through the auxiliary feedwater injection penetrations.

These inspections cubs seswsdJntemaLauxilimy_ftedwatethradstJxader_to.ibmud attachment EC1d$dtgllhe extemal hradtL}htnnal slesyttshall be perlomied during the third period of.racF ltn ycDrjastedccJnsettlionIntenaltlS.h.6: t'":d and fece ::fu:!' S :::;::: d at S:

ten y:: l'i!, -

DAVIS BESSE, UNIT 1 3/4 4-10a Amendment No. 62

LAR 95-0015

* " INFORMATION ONLY t

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TABLE 4.4-2 SD o e 5 g$

o STEAM GENERATOR TUBEINSPECTION ,

Er g G

• X 1ST SAMPLE INSPECTION 2ND SAMPLE INSPECTION 3RD SAMPLE INSPECTION E

O SwA Stre Resut Acdon Required Result Ac5on Required a Resut Acson Required A.T.l.-i grtot C-1 None WA S lices per N/A NfA P&'A sap)

C-2 Plug or repaa by C-1 None N/A eisevmg defect.ve WA thes and hspect mumanaf 2Se C2 PW or repak by C-1 l None ee so 8% os'a@*e tubes and hsped C-2  % or espae tw a&ssonal 4S tees sseeweg deseave h NS S.G.  ; thes summme t' I Persa rmacssontar i

C-3 C-3 reout et strs

• M O

% C-3 h acnon &

C-3 feeut et fast sam gg gg g C-3 k W antubes h As coher - 13 n rws S.G, plug or S G s are None l repair by sieeweg C-1 WA gA

%,3 *3 defecive kbes ard mspecs 2S tees n S

"*g eacn emer S G. Some S Ci Ptsrfcym action for -

8A W so sne NaC prior so resumpetn C-2 but to acumonas C-2resum et m em gg gg g

g -

c, - g.g-e g n' N

'* . Addmonal S.G. as Inrgert all tides iss erb S.C. mal pits or O

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R ~g defect 1= txdes.

lireart to the leC P

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prus to res..,orn r

N r.

of P l at operat.icn.

pl S = 3"% Where N is the nurnber of steam generators h the unR, and n is the nurfter et steam generators W anInspecBon, I

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LAR 95-0015

'*" INFORMATION ONLY

. DEACTOR COOLANT SYSTEM BASES 3/4.4.4 PRES $URIZER ..

A steam bubble in th'e pressurizer ensures that the RCS is not'a hydraulically solid' system and is capable of accomodating pressure surges during operation.

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

The low level limit is based on providing enough water volume to prevent a reactor coolant system low pressure condition that would actuate the Reactor Protection System or the Safety feature Actuation System. The high leyel 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 he to design, manufacturing errors, or inservice conditions that lead to corr 2,lon. 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. A process equivalent to the inspection method described in Topical Report BAW-2120P will be used for inservice inspection of steam generator tube sleeves. This inspection will provide ensurance of RCS integrity.

The plant is expected to be operated in a manner such that the secondary coolant will be maintained within those chemistry limits found to result in negligible corrosion of the steam generator tubes. If the secondary coolant chemistry is not ma htained within these chemistry limits, localized corrosion may likely result in stress corrosion cracking. The extent of cracking during plant operation would be limited by the 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 operation will have an adequate margin of safety to withstand the loads imposed during normal DAVIS-BESSE. UNIT I B 3/4 4-2 Amendment No. IM 171 i

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INFORMATION ONLY l REACTOR COOLANT SYSTEM BdSES(Continued) o>eration and by postulated accidents. Operating plants have demonstrated t1at primary-to-secondary leakage of 1 GPM can be detected by monitoring the secondary coolaint. ' Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged or repaired by sleeving in the affected areas.

Wastage-type defects are unlikely with proper chemistry treatment of the secosidary coolant. However, even if a defect should develo) in service, it will be found during scheduled inservice steam generator tu)e examinations.

As described in Topical Report BAW-2120P, degradation as small as 20% through wall can be detected in all areas of a tube sleeva except for the roll expanded areas and the sleeve end, where the limit of detectability is 40%

through wall. Tubes with imperfections exceeding the repair limit of 40% of the nominal wall thickness will t'e 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 und the sleeve end, inspection results will be compared to those obtained during the baseline sleeved tube inspection.

Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results shall be reported to the Commission prior to resumption of plant operation. Such cases will be considered by the Commission on a case-by-case basis and may r::sult in a requirement for analysis, laboratory examinations, tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary. .

The steam generator water level limits are consistent with the initial assumptions in the USAR. While in MODE 3, examples of Main Feedwater Pumps that are incapable of supplying feedwater to the Steam Generators are Ripped pumps or a manual valve closed in the discharge flowpath. The reactivity requirements to ensure adequate SHUTDOWN MARGIN are provided in plant operating procedures.

DAVIS-BESSE, UNIT 1 B 3/4 4-3 Amendment No. 17J, JM , 192 l