ML20116E377

Proposed Tech Specs Allowing Repair of Defective SG Tubes by Electrosleeving

ML20116E377
Person / Time
Site:	Calvert Cliffs
Issue date:	07/26/1996
From:	BALTIMORE GAS & ELECTRIC CO.
To:
Shared Package
ML20116E360	List: ML20116E357 ML20116E377
References
NUDOCS 9608050229
Download: ML20116E377 (10)

Text

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ATTACIIMENT (3) 1 1

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1 UNIT 1 MARKED-UP TECHNICAL FTECIFICATION PAGES i

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j Revised Pages:

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3/4 4-13 3/4 4-14 i~

B 3/4 4-4 1

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9608050229 960726 PDR ADOCK 05000317 i

P PDR Baltimore Gas & Electric Company i

Docket Nos. 50-317 and 50-318 July 26,1996 l

s 3/404 _RIACTOR COOLANT SYSTEM i

SURVEILLANCE REQUIREMENTS (Continued) 4.4.5.4 Acceptance Criteria l

a.

As used in this Specification:

1 1.

Tubina or Tube means that portion of the tube or sleeve which fonns the primary system to secondary system pressure

{

boundary, i

2.

Imperfection means an exception to the dimensions, finish or l

contour of a tube froin that required by fabrication drawings or specifications.

Eddy-current testin 20% of the nominal tube wall thickness,g indications below 2

if detectable, may be considered as imperfections.

3.

Dearadation means a service-induced cracking,

wastage, wear j

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

{

4.

Dearaded Tube means a tube containing imperfections > 20% of l

1 the nominal wall thickness caused by degradation.

5.

% Dearadation means the percentage of the tube wall thickness I

affected or removed by degradation.

1 6.

Defect means an imperfection of such severity that it exceeds the plugging or repair limit. A tube containing a defect is defective. Any tube which does not permit the passage of the

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eddy-current inspection probe shall be deemed a defective i

tube.

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7.

Pluccina or Repair Limit means the imperfection depth at or i

beyond which the tube shall be removed from service by plugging, or repaired by sleeving in the affected area because it may become unserviceable prior to the next 3

inspection. The plugging or repair limit imperfection depths are specified in percentage of nominal wall thickness as j

follows:

a.

ori gi nal tube wal l................................ 40%

j q

b.

Westinghouse laser welded sleeve wall.............

40%

8.

Unserviceable describes the condition of a tube if it leaks l

or contains a defect large enough to affect its structural j

integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedwater line j

break as specified in 4.4.5.3.c. above.

9.

Tube Inspection means an inspection of the steam generator tube from the point of entry (hot leg side) completely around the U-bend to the top support of the cold leg.

CALVERT CLIFFS - UNIT 1 3/4 4-13 Amendment No.

4

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3/4.4 REACTOR COOLANT SYSTEM 1

SURVEILUUICE ret)UIREMENTS (Continued) i

10. Tube Renair refers to a process that reestablishes tube serviceability. Acceptable tube repairs will be perfonned by l

the following process:

1 i

a) Westinghouse Laser Welded Sleeving as described in the i

proprietary Westinghouse Reports WCAP-13698,' ' Revision 2,

" Laser Welded Sleeves for 3/4 Inch Diameter Tube Feedring-Type and Westinghouse Preheater Steam i

Generators Generic Sleeving Report," April 1995; and i

WCAP-14469, " Specific Application of Laser Welded Sleeving for the Calvert Cliffs ower Plant Steam Generators," November 1995J de i

Tube repair includes the removal of plugs that were i

previously installed as a corrective or preventive measure.

j A tube inspection per Specification 4.4.5.4.a.9 is required prior to returning previously plugged tubes to service.

i b.

i The steam generator shall be detennined OPERABLE after completing the corresponding actions (plug or repair all tubes exceeding the j

plugging or repair limit and all tubes containing through-wall j

cracks) required by Table 4.4-2.

4.4.5.5 Reports Following each inservice inspection of steam generator tubes, the a.

i number of tubes plugged or repaired in each steam generator shall l

i be reported to the Consnission within 15 days pursuant to Specification 6.9.2.

b.

The complete results of the steam generator tube inservice inspection shall be included in the Annual Operatin the period in which this inspection was completed (g Report for 1

pursuant to i

Specification 6.9.1.5.b).

This report shall include:

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1.

Number and extent of tubes inspected.

2.

Location and percent of wall-thickness penetration for each j

indication of an imperfection.

1 j

3.

Identification of tubes plugged or repaired.

l c.

Results of steam generator tube inspections which fall into i

Category C-3 require verbal notification of the NRC Regional Administrator by telephone within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to resumption of j

plant operation. The written follow-up of this report shall 1

provide a descriptior, of investigations conducted to determine cause of the tube degradation and corrective measures taken to i

prevent recurrence and shall be submitted within the next 30 days j

pursuant to Specification 6.9.2.

i f

CALVERT CLIFFS - UNIT 1 3/4 4-14 Amendment No.

.1

l l4 3/4.4 REACTOR C00LANT SYSTEM BASES 4

l adequate structural margins against burst during all normal operatin transient, and accident conditions until the end of the fuel cycle. g,This evaluation would include the following elements:

i l

1.

An assessment of the flaws found during the previous inspections.

j 2.

An assessment of the structural margins relative to the criteria of Regulatory Guide 1.121, " Bases for Plugging Degraded PWR Steam l

Generator Tubes," that can be expected before the end of the fuel cycle or 30 months, whichever comes first.

l 3.

An update of the assessment model, as appropriate, based on comparison of the predicted results of the steam generator tube i

integrity assessment with actual inspection results from previous inspections.

l i

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 y

negligible corrosion of the steam generator tubes.

If the secondary I

coolant chemistry is not maintained within these limits, localized

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I corrosion may likely result in stress corrosion cracking. The extent of i

cracking during plant operation would be limited by the limitation of steam i

I generator tube leakage between the Primary Coolant System and the Secondar 11 i Coolant System (primary-to-secondary leakage = 1 gallon per minute, total)y Cracks having a primary-to-secondary leakage less than this limit during i

{

L operation will have an adequate margin of safety to withstand the loads i

imposed during normal operation and by postulated accidents. Operating

(

plants have demonstrated that primary-to-secondary leakage of 1 gallon j

q ()l perminute can readily be detected by radiation monitors of steam generator blowdown. Leakage in excess of this limit will require plant shutdown and Li an unscheduled inspection, during which the leaking tubes will be located O

and plugged or repaired. Defective tubes may be repaired by a Westinghouse Later ideldec Sleova. The technical bases for Westinghouse Laser Welded Sleeve are cescr' bed in the proprietary Westinghouse Reports WCAP-13698, e

i Revision 2. " Laser Welded Sleeves for 3/4 Inch Diameter Tube Feedring-Type and Westinghouse Preheater Steam Generators, Generic Sleeving Report,"

April 1995; and WCAP-14469, " Specific Application of Laser Welded Sleeving j

C for the Calvert Cliffs Power Plant Steam Generators " November 1995.f Wastage-type defects are unlikely with proper chemistry treatment of the secondary coolant. However, even if a defect should develo) in service, it will be found during scheduled inservice steam generator tu>e examinations.

Plugging or repair will in required for all tubes with imperfections at or exceeding the plugging or repair limit of 40% of the original tube nominal wall thickness.

If a tube contains a Westinghouse Laser Welded Sleeve with 1

imperfection exceeding 40% of nominal wall thickness,. it must be plugged.

j j

The Das1s for the sleeve plugging limit is based on Regulatory Guide 1.121

~

analyses, and is described in the Westinghouse6 sleeving technical report %

4 mentioned above.

Steam generator tube inspections of operating plants have i

i demonstrated the capability to reliably d t et degradat on that has fift) (AWOA CALVERT CLIFFS - UNIT 1 B 3/4 4-4 Amendment No.

i

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Insert A c.

Framatome Electrosleeve wall 20%

Insert B:

b)

Electrosleeving as described in the proprietary Framatome Technical Report BAW-10219P, Revision 1, "Electrosleeving Qualification for PWR Recirculating Steam Generator Tube Repair," March 1996.

Insert C:

The technical bases for Framatome Electrosleeve are described in the proprietary Framatome Technical Report BAW-10219P, Revision 1, "Electrosleeving Qualification for PWR Recirculating Steam Generator Tube Repair," March 1996.

Insert D:

or a Framatome Electrosleeve with imperfection exceeding 20% of nominal wall thickness

I ATTACHMENT (4) 1 l

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UNIT 2 MARKED-UP TECHNICAL SPECIFICATION PAGES Revised Pages:

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3/4 4-13 I

3/4 4-14 i

i B 3/4 4-4 i

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4 4

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i Baltimore Gas & Electric Company Docket Nos. 50-317 and 50-318 July 26,1996

3/4.4 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) i

)

4.4.5.4 Acceptance Criteria a.

As used in this Specification:

i 1.

Tubino or Tube means that portion of the tube or sleeve which forms the primary system to secondary system pressure j

boundary.

+

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 j

considered as imperfections.

3.

Dearadation means a service-induced cracking,

wastage, wear l

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

4.

Deoraded Tube means a tube containing imperfections t 20% of l

j the nominal wall thickness caused by degradation.

5.

% Dearadation means the percentage of the tube wall thickness l

j affected or removed by degradation.

6.

Defect means an imperfection of such severity that it exceeds the plugging or repair limit. A tube containing a defect is defective. Any tube which does not pemit the passage of the eddy-current inspection probe shall be deemed a defective tube.

7.

Pluaaina or Repair Limit means the imperfection depth at or beyond which the tube shall be removed from service by j

plugging, or repaired by sleeving in the affected area i

because it may become unserviceable prior to the next inspection.

The plugging or repair limit imperfection depths are specified in percentage of nominal wall thickness as follows:

a.

ori gi nal t ube wal l................................ 40%

b.

Westinghouse l aser welded sleeve wall............. 40%

I 8.

Unserviceable describes the condition of a tube if it leaks I

or contains a defect large enough to affect its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, 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 (hot leg side) completely around the U-bend to the top support of the cold leg.

CALVERT CLIFFS - UNIT 2 3/4 4-13 Amendment No.

(

3/4.4 REACTOR C0OLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)

10. Tube Repair refers to a process that reestablishes tube serviceability. Acceptable tube repairs will be performed by the following process:

a) Westinghouse Laser Welded Sleeving as described ia the proprietary Westinghouse Reports WCAP-13698, Revision 2

" Laser Welded Sleeves for 3/4 Inch Diameter Tube Feedring-Type and Westinghouse Preheater Steam Generators, Generic Sleeving Report," April 1995; and WCAP-14469, " Specific Application of Laser Welded Sleeving for the Calvert Cliffs ower Plant Steam Generators," November 1995j or Tu e repair includes the removal of plugs that were previously installed as a corrective or preventive measure.

A tube inspection per Specification 4.4.5.4.a.9 is required prior to returning previously plugged tubes to service, b.

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

4.4.5.5 Reports Following each inservice inspection of steam generator tubes, the a.

number of tubes plugged or repaired in each steam generator shall l

be reported to the Comission within 15 days pursuant to Specification 6.9.2.

i 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 (pursuant to Specification 6.9.1.5.b).

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 repaired.

l Results of steam generator tube inspections which fall into c.

Category C-3 require verbal notification of the NRC Regional Administrator by telephone within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to resumption of plant operation. The written followup of this report shall provide a description of investigations conducted to detennine cause of the tube degradation and corrective measures taken to prevent recurrence and shall be submitted within the next 30 days pursuant to Specification 6.9.2.

CALVERT CLIFFS - UNIT 2 3/4 4-14 Amendment No.

3/4.4 REACTOR C0OLANT SYSTEM

}

BASES l

adequate structural margins against burst during all normal operating, i

transient, and accident conditions until the end of the fuel cycle. This j

evaluation would include the following elements:

1.

An assessment of the flaws found during the previous inspections.

i i

2.

I An assessment of the structural margins relative to the criteria of Regulatory Guide 1.121. " Bases for Plugling Degraded PWR Steam Generator Tubes," that can be expected u fore the end of the fuel cycle or 30 months, whichever comes first.

53<

3.

An update of the assessment model, as appropriate, based on

[

comparison of the predicted results of the steam generator tube j

integrity assessment with actual inspection results from previous

{

5 inspections.

i l

A d

The plant is expected to be operated in a manner such that the secondary l

A d

coolant will be maintained within those chemistry ifmits found to result in

i negligible corrosion of de steam generator tubes.

If the secondary 4

coolant chemistry is not maintained within these limits, localized I

4 corre: ion may likely result in stress corrosion cracking. The extent of d

cracking durir: plant operation would be limited by the limitation of steam generator tube leakage between the Primary Coolant System and the Secondar Coolant System (primary-to-secondary leakage = 1 gallon per minute, total)y 5i Cracks having a primary-to-secondary leakage less than this limit during i

i hJ operation will have an adequate margin of safety to withstand the loads imposed during nonnal operation and by postulated accidents. Operating 1

(

plants have demonstrated that primary-to-secondary leakage of 1 gallon per 4

minute can readily be detected by radiation monitors of steam generator j

j blowdown.

Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located g) and plugged or repaired. Defective tubes may be repaired by a Westinghouse J

9 Laser Welded Sleeve.. The technical bases for Westinghouse Laser Welded Sleeve are described in the proprietary Westinghouse Reports WCAP-13fAa, Revision 2, " Laser Welded Sleeves for 3/4 Inch Diameter Tube FeedringQpe and Westinghouse Preheater Steam Generators, Generic Sleeving Report "

April 1995; and WCAP-14469, " Specific Application of Laser Welded Sleeving

(

for the Calvert Cliffs Power Plant Steam Generators," November 1995. p

?

Wastsge-type defects are unlikely with proper chemistry treatment of the secondary coolant. However, even if a defect should develop in service, it will be found during scheduled inservice steam generator tube examinations.

i Plugging or repair will be required for all tubes with imperfections at or exceeding the plugging or repai: limit of 40% of the tube briginal nominal wall thickness.

If a tube contains a Westinghouse Laser Welded Sleeve with

"]

imperfection exceedina 40% nominal wall thickness., it must be plugged.

The basis for the sleeve plugging limit 's based on Regulatory Guide 1.121 analyses, and is described in the Westinghousq, sleeving technical report mentioned above.

Steam generator tube inspect ons of operating plants have demonstrated the capability to reliably detect degradation that has pr]c) h 2k1Y1A W $

CALVERT CLIFFS - UNIT 2 B 3/4 4-4 Amendment No.

,o Insert A:

c.

Framatome Electrosleeve wa..

20%

Insert B:

b)

Electrosleeving as described in the proprietary Framatome Technical Report BAW-10219P, Revision 1, "Electrosleeving Qualification for PWR Recirculating Steam Generator Tube Recair," March 1996.

i l

Insert C:

The technical bases for Framatome Electrosleeve are described in the proprietary Framatome Technical Report BAW-10219P, Revision 1, "Electrosleeving Qualification for PWR Recirculating Steam i

Generator Tube Repair," March 1996.

Insert D:

or a Framatome Electrosleeve vith imperfection exceeding 20% of nominal wall thickness