ML17331B240

Proposed Tech Specs Incorporating Acceptance Criterion for SG Tube Degradation in Tubesheet Region Known as F*

ML17331B240
Person / Time
Site:	Cook
Issue date:	02/15/1994
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
Shared Package
ML17331B239	List: ML17331B238 ML17331B240 ML17331B241 ML17331B242
References
NUDOCS 9402250131
Download: ML17331B240 (12)

Text

ATTACHMENT 2 TO AEP:NRC:1166K EXISTING TECHNICAL SPECIFICATION PAGES MARKED TO REFLECT PROPOSED CHANGES v40215 9402z5oisz, '05000315 ADOCK 'PDR

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Tubes in those areas where ezperience has indicated potential problems.

3. k, tube inspection (pursuant to Specification 4.4.5.4.a.8) shall be performed on each selected tube. Zf 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.

Zba tabes selected as tbs second and tblzd staples (dd tetndzed by TabLe 4.4-2) during each inservice inspection may be subjected to a partial tube inspection provided:

L. The tubes selected for the samples include the tubes fromsthose 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.

'mplementation of the steam generator tube/tube support plate interim plugging criteria for one fueL cycle (Cycle 13) requires a 100% bobbin coil inspection for hot leg tube support plate intexsections and cold leg intersections down to the Lowest cold leg tube support pLate with known outer diameter stress corrosion cracking indications..

(ODSCC)

'I,, ~ e The xesults of each sample inspection shall be classified into one of the following three categories:

CategoOX ec esu ts C-1 Less than 5% of the total tubes inspected are degraded tubes and none of the inspected tubes are defective.

C-2 One or more tubes, but not more than L% of the total tubes inspected are defective, or between 5t and LOt of the total tubes inspected are degraded tubes.

C-3 Hore than L0%. of the tota1 tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.

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4.4.5.4

a. hs used in this Specification:

contour oi a tube or sleeve from that required by fabrication dravings or speci'fications. Eddy-current testing indications belov 20% 'of the nominal vali thickness, if detectable, may be considered as imperfections.

2.

general corrosion occurring on either inside or outside.of a tube or sleeve.

3. Dc aded Tube o ccv means an imperfection greater than or equal to 20t of the nominal vali thickness caused by dcgradatlon.

4. e cnt De ada means the amount of the vali thickness aiicctcd or removed by degradation.

5. ~e the

~repair limit.imperfection of means an such severity that it exceeds

6. c a u n means the i".perfection depth at or beyond vhich thc tube or sleeved tube shall be repaired or removed

~f ~Ns 4>O< from'service. Any tube vhich, up n inspection, exhibits tube

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vali degradation of 40 percent or vore of the nominal tube vali thickness shall be plugged or repaired prior to returning the po r stcam generator to service. Any sleeve vhich, upon inspection, s va egradation of 29 percent or more of the nominal g~ ~g W~(o- vali thickness shall be plugged prior to returning the steam generator to service. In addition, any sleeve exhibiting any ui>~~n c~ measurable vali loss in sleeve expansion transition or veld zones shall be plugged. This definition does not apply for fo~ tubes experiencing outer diameter stress corrosion cracking confirmed by bobbin probe inspection to be vithin the thickness of the tube support plates. See 4,4.5.4.a.l0 for the plugging limit for use vithin the thickness of the tuba support plate.

7.

leaks or contains a defect large enough to affect ita structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or fcedvater line break aa specified in 4.4.5.3.c, above.

8. /~eclat determines the condition of or sleeve from the point of entry (hot the steam generator tube leg aide) completely COOK NUCLEAR PLANT - UNIT 1 3/4 4-10 AMENDMENT NO 04 444, y66 JUL 2 8 1992

around the U-bend to the top support of the cold leg. For a tube in vhich the tube support plate elevation interim plugging limit has bean applied, the inspection rill include all the hot leg intersections and all cold leg intersections dovn to, at least, the level of the last crick indication.

9. ~v~

spans a tube is permitted only in ireas vhera the sleeve the tubesheet area and vhose lover joint is at the primary fluid tubasheet face.

10. is used f'r disposition of a steam generator tube for continued service that is experiencing outer diameter initiitad stress corrosion cracking confined vithin the thickness of tha tube support plates. For application of the tube support plate interim plugging limit, tha tube's disposition for continued scrvt.cc vill be based upon standard bobbin probe signal amplitude. The plant-specific guidelines used for all inspections shall be amended as appropriate to accommodate the additional information needed to evaluate tube support plate signals vith respect to the above voltage/depth parameters. Pending incorporation of the voltage vcrification requirement in ASKE standard verifications, an AS}{E standard calibrated against the liboritory standard vill be utilixcd in the Donald C. ook Nuclear Plint Unit 1, stcam generator inspections for ccnsistcnt voltage normalization.

1. A tube can remain in service if the signal amplitude of a crack indication is less than or equal to 1.0 volt, regardless of the depth of tube vali penetration, if, as a result, tha projected cnd-of-cycle dis'tribution of crack indications is verified to result in primary-to-sccondary leakage less than 1 gpm in tha faulted loop during a postulated steam line break event. The methodology for calculiting expected leak rates from the projected crack distribution must be consistent vith VCAP-13ldl, kev. 0.

2. A tube should be plugged or repaired if the signal amplitude of the crack indication is greater than 1.0 volt except as noted in 4.4.5.4.a.l0.3 balov.

3. h tuba can remain in service vith a bobbin coil signal amplitude greater than 1,0 volt but less than or equal to 4.0 volts if a rotating pancake probe inspection docs not detect degradation. Indications of g~r f ll ) t 2. degradation vith a bobbin coil signal amplitude greater than 4.0 volts vill be plugged or repaired.

COOK NUCLEAR PLANT - UNIT 1 3/4 4-11 AMEHDMEHT HO. 04, kR,166 JUL 2 9 1992

INSERT ll. W Distance is the distance from the bottom of the hardroll transition toward the bottom of the tubesheet that ha's been conservatively determined to be 1.11 inches (not including eddy current uncertainty).

12. ~Tube is a tube with degradation, below the Fe distance, equal to or greater than 40X, and not degraded (i.e., no indications of cracking) within the W distance.

b. The steam generator shall be determined OHRASIE after coapleting the corresponding actions (plugging or sleevtng all tubes exceeding the repair limit and all tubes containing through-eall cracks ) required by Table 4. 4-2.-

C. Steam generator tube repairs may be made in accordance vith the methods described in either VCQ-12623 or CEH-313-k.

4.4.5.5 a ~ Folloving each inservice inspection of steam generator tubes, there are any tubes requiring plugging or sleeving, the number of tubes plugged or sleeved in each steam generator shall be reported to the Commission vithin 15 days.

b. The complete results of the steam generator tube inservice inspection shall be included in the Annual Operating Report for the period in vhich this inspection vas completed. This report shall include:

1. Number and extent of tubes inspected.

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

3. Zdentificati.on of tubes plugged or sleeved.

C ~ Results of steam generator tube inspections vhich fall into Category C-3 and require prompt notification of the Commission shall be reported pursuant to Specification 6.9.1 prior to resumption of plant operation. The m'itten follcnrup of this report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.

d. The results of inspections performed under 4.4.5.2 for all tubes in vhf.ch the tube support plate interim plugging criteria ""s been applied hall be reported to the Commission rithin 15 .hays f olla ing ~ inspection. The report shall include:

tsting of applicable tubes.

2. Location (applicable intersections per tube) and extent of degradation (voltage).

~. The results of steam line break leakage analysis performed under T/S 4.4.5,4,a.10 vill be reported to the Commission prior to restart for Cycle 13.

COOK NUCLEAR PLAHT - UNIT 1 3/4 4-12 AHEHDMEHT HO. )PP,]G6

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ATTACHMENT 3 TO AEP:NRC:1166K PROPOSED REVISED TECHNICAL SPECIFICATION PAGES

REACTOR COOLANT SYSTEM SURVEILLANCE RE UIREMENTS Continued 2~ Tubes in those areas where experience has indicated potential problems.

3. A tube inspection (pursuant to .Specification 4.4.5.4.a.8) 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.

c~ In addition to the sample required in 4.4.5.2.b.l through 3, all tubes which have had the F* criteria applied will be inspected in the zoll expanded region. The roll expanded region of these tubes may be excluded from 4.4.5.2.b.1.

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

The tubes selected for the 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.

e. Implementation of the steam generator tube/tube support plate interim plugging criteria for one fuel cycle (Cycle 13) requires a 100% bobbin coil inspection for hot leg tube support plate intersections and cold leg intersections down to the lowest cold leg tube support plate with known outer diameter stress corrosion cracking (ODSCC) indications.

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

~Cate or Ins ection Results C-l Less than 5% of the total tubes inspected are degraded tubes and none of the inspected tubes are defective.

C-2 One or more 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.

COOK NUCLEAR PLANT UNIT 1 3/4 4-8 AMENDMENT NO. 98, +5k, 466

'EACTOR COOLANT SYSTEM SURVEILLANCE RE UIREMENTS Continued 4.4.5.4 Acce tance Criteria

a. As used in this Specification:

contour of a tube or sleeve from that recpxired by fabricati.on drawings or specifications. Eddy-current testi.ng indications below 20% of the nominal tube wall thi.ckness, be considered as imperfections.

if detectable, may 24 general corrosion occurring on either i.nside or outside of a tube or sleeve.

3~ De raded Tube or Sleeve means an imperfecti.on greater than .or equal to 20% of the nomi.nal wall thickness caused by degradation.

4. Percent De radation means the amount of the tube wall thickness affected or removed by degradation.

5 Defect means an imperfection of such severi.ty that the repair limi.t.

it exceeds Re air Plu in Limi.t means the imperfecti.on depth at or beyond which the tube or sleeved tube shall be repaired or removed from service. Any tube whi.ch, upon inspection, exhibits tube wall degradation of 40 percent or more of the nominal tube wall thickness shall be plugged or repaired prior to returning the steam generator to service. This definition does not apply to the portion of the tube i.n the tubesheet below the F* distance for F* tubes. Any sleeve which, upon inspecti.on, exhibits wall degradati.on of 29 percent or more of the nominal wall thi.ckness shall be plugged prior to returning the steam generator to servi.ce. In addi.ti.on, any sleeve exhibi.ti.ng any measurable wall loss in sleeve expansion transi.tion or weld'ones shall be plugged. Thi.s definition does not apply for tubes experiencing outer diameter stress corrosion cracking confirmed by bobbin probe inspection to be within the thickness of the tube support plates. See 4.4.5.4.a.10 for the plugging limit for use within the thickness of the tube support plate.

7~ Unserviceable descri.bes the condition of a tube or sleeve if it leaks or contai.ns a defect large enough to affect its structural integrity i.n the event of an Operating Basis Earthcpake, a loss-of-coolant accident, or a steam line or feedwater line break as specified i.n 4.4.5.3.c, above.

8.

or sleeve from the point of entry (hot leg side) completely COOK NUCLEAR PLANT - UNIT 1 3/4 4-10 AMENDMENT NO. 98i 45k, 466

REACTOR COOLANT SYSTEMS SURVEILLANCE RE UIREMENTS Contin'ued around the U-bend to the top support of the cold leg. For a tube in which the tube support plate elevation interim plugging limit has been applied, the inspection will include downall the hot leg intersections and all cold leg intersections to, at least, the level of the last crack indication.

9. ~eleevin a tube is pereitted only in areas where the sleeve spans the tubesheet area and whose lower joint is at the primary fluid tubesheet face.

10. The Tube Su ort Plate Interim Plu in Criteria is used for disposition of a steam generator tube for continued service that is experiencing outer diameter initiated stress corrosion cracking confined within the thickness of the tube support plates. For application of the tube suPPort plate interim plugging limit, the tube's disposition for continued service will be based upon standard bobbin probe signal amplitude. The plant-specific guidelines used for all inspections shall be amended evaluate as appropriate to accommodate the additional information needed to tube support plate signals with respect to the above voltage/depth parameters. Pending incorporation of the voltage verification requirement in ASME standard verifications, an ASME standard calibrated against the laboratory standard will be utilized in the Donald C. Cook Nuclear Plant Unit 1 steam generator inspections for consistent voltage normalization.

1 ~ A tube can remain in service if the signal amplitude of a crack indication is less than or equal to 1.0 volt, regardless of the depth of tube wall penetration, if, as a result, the projected end-of-cycle distribution of crack indications is verified to result in primary-to-secondary leakage less than 1 gpm in the faulted loop during a postulated steam line break event. The methodology for calculating expected leak rates from the projected crack distribution must be consistent with WCAP-13187, Rev. 0.

2~ A tube should be plugged or repaired if the signal amplitude of the crack indication is greater than 1.0 volt except as noted in 4.4.5.4.ae10.3 below.

3 A tube can remain in service with a bobbin coil signal amplitude

~

greater than 1.0 volt but less than or equal to 4.0 volts rotating pancake probe inspection does not detect degradation.

if a Indications of degradation with a bobbin coil signal amplitude greater than 4.0 volts will be plugged or repaired.

11. F* Distance is the distance from the bottom of the hardroll transition toward the bottom of the tubesheet that has been conservatively determined to be 1.11 inches (not including eddy current uncertainty).

12. F* Tube is a tube with degradation, below the F* distance, equal to or greater than 40%, and not degraded (i.e., no indications of cracking) within the F* distance.

COOK NUCLEAR PLANT UNIT 1 3/4 4-11 AMENDMENT NO. 98y 45k, 466

REACTOR COOLANT SYSTEMS SURVEILLANCE RE UIREMENTS Continued

b. The steam generator shall be determined OPERABLE after completing the corresponding actions (plugging or sleeving all tubes exceeding the repair limit and all tubes containing through-wall cracks) required by Table 4.4-2.

c~ Steam generator tube repairs may be made in accordance with the methods described in either WCAP-12623 or CEN-313-P.

4.4.5.5 ~Re orts as Following each inservice inspection of steam generator tubes, if are any tubes requiring plugging or sleeving, the number of tubes there plugged or sleeved in each steam generator shall be reported to the Commission within 15 days.

b. The complete results of the steam generator tube inservice inspection shall be included in the Annual Operating Report for the period in which this inspection was completed. 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 prompt notification of the Commission shall be reported pursuant to Specification 6.9.1 prior to resumption of plant operation. The written followup of this report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.

d. The results of inspections performed under 4.4.5.2 for all tubes in which the tube support plate interim plugging criteria has been applied or that have defects below the F+ distance and were not plugged shall be reported to the Commission within 15 days following the inspection. The report shall include:

Listing of applicable tubes.

2 ~ Location (applicable intersections per tube) and extent of degradation (voltage).

e. The results of steam line break leakage analysis performed under T/S 4.4.5.4.a.10 will be reported to the Commission prior to restart for Cycle 13.

COOK NUCLEAR PLANT UNIT 1 3/4 4-12 AMENDMENT NO. kQS, +66

ATTACHMENT 4 TO AEP:NRC: 1166K PROPRIETARY WCAP 13970 "W TUBE PLUGGING CRITERION FOR TUBES WITH DEGRADATION IN THE TUBESHEET ROLL EXPANSION REGION OF THE DONALD C. COOK UNIT 1 STEAM GENERATORS" AFFIDAVIT FOR WITHHOLDING WCAP 13970 FROM PUBLIC DISCLOSURE