ML20136F850

Requests Relief from Certain ASME Code Requirements for Inservice Testing & Insp for Plant.Relief Request RR-A14 Requests Relief from Section XI of ASME Code,1896 Edition for Exam of Class 1,2 & 3 Integrally Welded Attachments

ML20136F850
Person / Time
Site:	Davis Besse
Issue date:	03/07/1997
From:	Jeffery Wood CENTERIOR ENERGY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2450, NUDOCS 9703170074
Download: ML20136F850 (11)

Text

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e CENTERDOR ENERGY 5501 N. State Route 2 419-249 2300 John K. Wood Oak Harbor, OH 43449 FAX: 419-3218337 Vce President - Nuclear Davis-Besse Docket Number 50-346 License Number NPF-3 Serial Number 2450 March 7, 1997 I

United States Nuclear Regulatory Commission Document Control Desk Washington , D. C. 20555-0001

Subject:

Request for Relief From Certain ASME Code Requirements for Inservice Testing and Inspection for the Davis-Besse Nuclear Power Station Ladies and Gentlemen:

The purpose of this letter is to request relief pursuant to 10 CFR 50.55a(f)5(iii) and (g)(5)(iii) from certain .equirements of Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. The requests for relief deal with: surface and volumetric examination of longitudinal welds intersecting the circumferential welds required to be examined; examination of integral attachments to certain components; hydrostatic testing of Class 1,2 and 3 systems; and pressure testing of containment penetration piping. Details concerning the requested relief are provided in the attached Relief Requests RR-A13, RR-A14, i RR-A15 and RR-B8.

1 Relief Request RR-A13 requests relief from Section XI of the ASME Code,1986 Edition, Code item B9.12, Table IWB-2500, and Code Item C5.52, Table IWC-2500 which require surface and volumetric examination of longitudinal piping welds. Toledo Edison proposes to examine j longitudinal piping welds in accordance with Code Case N-524. This code case provides )

alternative requirements for the surface and volumetric examination of longitudinal piping welds j specified in Examination Categories B-J, C-F-1, and C-F-2. Implementation of Code Case N 524 will reduce the man-hours and personnel exposures necessary to perform the examinations by eliminating unnecessary examinations.

Relief Request RR-A14 requests relief from Section XI of the ASME Code,1986 Edition for examination of Class 1,2 and 3 integrally welded attachments. Toledo Edison proposes to perform the examination of inteoral a~hment welds in accordance with Code Case N-509.

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Document Number 50-346 License Number NPF-3  !

Serial Number 2450 Page 2 Code Case N-509 requires that Class 1,2 and 3 component supports be selected for examination in accordance with IWF of the 1989 Edition with the 1990 Addenda. Toledo Edison Relief RR-A9 permits the use of Code Case N-491 for the selection and examination of Class 1,2 and 3 component supports. As code Case N-491 was incorporated into the 1990 Addenda, the use of Code Case N-491 will meet the 1989 Edition,1990 Addenda.

Implementation of the Code Case N-509 sampling plan will significantly reduce the manpower necessary for preparation and performance of examinations. Based on the sampling percentages permitted by Code Case N-509, it is expected that occupational radiation exposure involving Class 1,2 and 3 piping systems could be reduced by up to 27%

)

Relief Request RR-A15 requests relief from Section XI of the ASME Code,1986 Edition, for hydrostatic testing of pressure-retaining components each inspection interval. Toledo Edison proposes to use alternate requirements for hydrostatic testing of Class 1,2 and 3 systems as allowed by Code Case N-498-1. System pressure tests would be performed as an alternative to hydrostatic tests. System pressure tests are performed at normal operating pressures and temperatures. Test pressures are not significantly lower than hydrostatic test pressures and any pressure boundary leakage will be readily apparent.

Relief Request RR-R8 requests relief from Section XI of the ASME Code,1986 Edition, to allow use of 10 CFR 50 Appendix J testing as an alternative to pressure testing of piping that penetrates a containment vessel when the piping and isolation valves that are part of the containment system are Class 2, but the balance of the piping system is outside the scope, as permitted by Code Case N-522. Performing a system pressure test or hydrostatic test on the same components tested by the Appendix J test imposes a burden of duplicate testing.

Toledo Edison requests that these relief requests be approved by March 1,1998, to support the testing and inspections required for the eleventh refueling outage scheduled for April 1998.

Should you have any questions or require additional information, please contact Mr. James L.

Frects, Manager - Regulatory Affairs, at (419) 321-8466. 1 Very truly yours, DI L 1 I

Attachments

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cc: A. B. Beach , Regional Administrator, NRC Region 111 A. G. flansen, NRC Project Manager S. Stasek, DB-1 NRC Senior Resident inspector Utility Radiological Safety Board i

Docket Number 50-346

. License Number NPF-3 Serial Number 2450 l Attachment l Page'l RELIEF ltEQUEST I IIR A13 1

Component Descrintion: l l

l Longitudinal Welds in Cbss 1 snd 2 Piping - Request for Approval to use Code Case N-524 l 88 Class 1 Longitudinal Welds l 77 Class 2 Longitudinal Welds ASME Code Class:

1 ASME Section XI, Class 1 and 2 l l

ASME Examination Reauirements. ASME Section XI.1986 Edition. No Addenda:

l Code item B9.12, Table IWB-2500, requires a surface and volumetric examination of at l least a pipe diameter length, but not more than 12 inches, of each longitudinal weld I intersecting the circumferential welds required to be examined by Examination Categories i B-F and B-J. l l

Code Item C5.52, Table IWC-2500, requires a surface and volumetric examination of the j longitudinal weld for a length of 2.5t at the intersecting circumferential weld.

Basis for Relief:

Code Case N-524 provides alternative requirements for the surface and volumetric examination of longitudinal piping welds specified in Examination Categories B-J, C-F-1, l and C-F-2. This code case recognizes that the longitudinal piping welds are not made in the field, but are made and examined by the piping manufacturer under controlled conditions I and procedures. This code case further recognizes that the most likely area where defects l may occur is at the intersection of the longitudinal and circumferential welds. As this area is examined as part of the circumferential weld examination, additional examination of the longitudinal weld outside this area is unnecessary to ensure weld quality is maintained.

Implementation of the Code Case N-524 will also reduce the man-hours and personnel exposures necessary to perform the examinations by eliminating unnecessary examinations.

Code Case N-524 has been approved by the ASME Boiler and Pressure Vessel Code Committee and the Board on Nuclear Codes and Standards as an acceptable alternative to the rules of the ASME Boiler and Pressure Vessel Code,Section XI.

Alternative Examination:

Examination of longitudinal welds will be performed in accordance with Code Case N-524.

When Code Case N-524 is approved in Regulatory Guide 1.147, any additional limitations recommended by the NRC staff v ill also be incorporated.

Docket Number 50-346 t ,

l License Number NPF-3 l Serial Number 2450

Attachment I ' Page'2

RELIEF REQUEST l RR A14 1

-  ! Comoonent Descrintion:

l Class 1,2, and 3 Integrally Welded Attachments - Request for Approval to use Code Case

! N-509 i

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ASME Code Class:

I ASME Section XI, Class 1,2, and 3 Component Supports i

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.ASME Examination Reauirements. ASME Section XI.1986 Edition. No Addenda:

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Examination Category B-H, Integral Attachments for Vessels i j-Examination Category B K-1, Integral Attachments for Piping, Pumps, and Valves I

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• Examination Category C-C, Integral Attachments for Vessels, Piping, Pumps, and Valves l 1 ,

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• Examination Category D-A, Systems in Support of Reactor Shutdown Function l 1

1 4-l Examination Category D-B, Systems in Support of Emergency Core Cooling, Containment Heat Removal, Atmospheric Cleanup, and Reactor Residual Heat Removal Examination Category D-C, Systems in Support of Residual Heat Removal from Spent Fuel Storage Pool Basis for Relief:

Table IWB-2500-1, Exaniination Category B-K-1, and Table IWC-2500-1, Examination Category C-C, limits the examination of integrally welded attachments to only those  ;

attachments with a base material design thickness of 5/8 inches or greater. Thirty-three

- (33%) percent of the Class 1 and 37% of the Class 2 integrally welded attachments installed at Davis Besse have attachments which meet these thickness requirements. On the Class 2 Main Feedwater System,100% of the supports require examination, while 65% require examination on the Class 2 Main Steam System.

The examination percentages for the examination of integral attachment welds exceed those percentages required for both piping and the supports associated with these attachment welds. Statistical principles recognize that 100% inspection is not necessary to ensure overall system integrity. These statistical principles are already implemented through I

Docket Number 50-346

. License Number NPF-3 Serial Number 2450 Attachment Page'3 sampling plans permitted in Subsections lWB and IWC in which 25% of the Class 1 piping welds and 7.5% of the Class 2 piping welds require examination. Similarly, ASME has recognized through Code Case N-491 and the 1990 Addendum to the 1989 Edition of Section XI that component and piping support integrity could be verified by examining 25%

of Class 1,15% of Class 2, and 10% of Class 3 of piping supports.

Implementation of the Code Case N-509 S:,mpling Plan will significantly reduce the manpower necessary to support scaffold erection and insulation removal, as well as actual performance of the examinations. In many cases, scaffold erection and insulation removal is only for the attachment weld examination, as the hanger associated with the attachment weld does not require examination. Based on the sampling percentages permitted by Code Case N-509, it is expected that occupational radiation exposure involving Class 1,2, and 3 piping systems could be reduced by as much as 23%,27%, and 2% respectively over that expected if the present Code required inspections were performed. Furthermore, the Code-required examinations are only required on those integral attachments with a base material thickness 5/8 inches or greater. This population represents only 22% of the total number of integral attachment welds. Application of Code Case N-509 will allow the population available for examination to include all types of integral attachments, not just those which have a base material thickness 5/8 inches or greater.

Code Case N-509 requires that the Class 1,2, and 3 component supports be selected for examination in accordance with IWF of the 1989 Edition with the 1990 Addenda. Toledo

Edison Relief Request RR-A9 permits the use of Code Case N-491 for the selection and examination of Class 1,2, and 3 component supports. As Code Case N-491 was incorporated into the 1990 Addenda, the use of Code Case N-491 will meet the 1989 Edition,1990 Addenda.

Code Case N-509 has been approved by the ASME Boiler and Pressure Vessel Code Committee and the Board on Nuclear Codes and Standards as an acceptable alternative to the rules of the ASME Boiler and Pressure Vessel Code,Section XI.

Alternative Examination:

Examination of integral attachment welds will be performed in accordance with Code Case N-509 with the exception that Code Case N-491 will be used for component support selection rather than the 1989 Edition with the 1990 Addenda. When Code Case N-509 is approved in Regulatory Guide 1.147, any additional limitations recommended by the NRC staff will also be incorporated.

Docket Number 50-346 '

License Number NPF-3 Serial Number 2450 l i

Attachment Page'4 RELIEF REQUEST RR-Il8 P

Comoonent Descrin*isin Pressure Testing of Containment Penetration Piping - Request for Approval to use Code Case N-5'" 1 The following penetrations will be tested using Code C. 2 NJ22.

Penetration Line Number DescrintinD i P1 1"-CCB-17 Pressurizer Sample Line  ;

P8A thru 8J 8"-H BB-19 Eight Containment Vacuum Relief Lines P12 3"-HCB-40 Component Cooling Wa:er Supply to the Control Rod Drives P13 4"-118B-2 Containment Vessel Normal Sump Drain P14 2%"-CCB-21 Letdown Live to Purification Deminerali<as P16 3"-HCB-33 Containment Vessel Equipment Vent Header Pl7 8"-HCB-49 Containment Vessel Leak Test Line P21 4"-HCB-23 Demineralized Water Supply Line P23 29" ID Fuel Transfer Tube P24 29" ID Fuel Transter Tube I

'32 3"-IICB-32 Reactor Coolant System Drain Line to Reactor Coolant Drain Tank P33 48-if B-17 Containment Vessel Purge Inlet Li P34 48"-H BB-18 Containment Vessel Purge Outlet Line l

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. Docket Number 50-346

'. License Number NPF Serial Number 2450 i Attachment

[ Page'5 Penetration Line Number Descriotion

P41 2"-HCB-7 Pressurizer Quench Tank Circulating Inlet Line P42A. 1 %"-HBB-9 Service Air Supply Line

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P43A 1"-HBB-10 Instrument Air Supply Line l P44A 1"-FCB-1 Core Floe' ling Tank Fill and

! Nitrogen Supply Line i

! P44B 1"-H BB-14 Containment Nitrogen Supply

) Header l P47A 1"-FCB-3 Core Flooding Tank Sample l Line P47B 1"-FCB-1 Core Flooding Tank Vent Line l P48 3"-HCB-22 Pressurizer Quench Tank j Circulating Outlet Line

P49 8"-HCB-11 Refueling Canal Fill Line P52 1 %"-FCG 1 Reactor Coolant Pump Seal

- Water Supply l P53 1 %"-FCB-3 Reactor Coolant Pump Seal j i Water Supply

P54 1 %"-FCB-3 Reactor Coolant Pump Seal

Water Supply j P55 1 %"-FCB-3 Reactor Coolant Pump Seal )

j Water Supply P56 1"-CCB-20 Reactor Coolant Pump Seal

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. Water Return P59 8"-HCB-43 Secondary Side Chemical

Cleaning Line ]

1 i P68A 1"-HCB-26 Pressurizer Quench Tank

,Sampic Line P71C 1"-FCB-1 Core Flooding Tank Fill and Nitrogen Supply Line

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Docket Number 50-346

. License Number NPF-3 Serial Number 2450 Attachment Page' 6 ASME Code Class:

ASME Section XI, Class 2 ASME Examination Reouirements. ASME Section XI.1986 Edition. No . Addenda:

Code item C7.30, Table IWB-2500, requires a system pressure test of piping each inspection period.

Code Item C7.40, Table IWB-2500, requires a r tem hydrostatic test of piping each inspection interval, j i

Code Item C7.70, Table IWB-2500, requires a system pressure test of valves each inspection period.

Code item C7.80, Table IWB-2500, requires a system hydrostatic test of valves each  ;

inspection interval. l Basis for Relief: ,

1 l

I Code Case N-522 permits the use of 10 CFR 50 Appendix J testing as an alternative to the rules in Table IWC-2500-1, Category C-H, for pressure testing piping that penetrates a  !

containment vessel when the piping and isolation valves that are part of the containment .

system are Class 2, but the balance of the piping system is outside the scope of Section XI. l With the exception of penetrations P1, P44A, P47A, and P47B, the penetration piping is  !

Class 2 solely because it forms part of the containment pressure boundary. The balance of I I

t'r e penetration's piping system is outside the scope of Section XI.

For penetration P1 (Pressurizer Sample Line), the piping through the containment is Class 2 solely because it forms part of the containment pressure boundary. The piping outside the containment vessel is outside the scope of Section XI. The containment isolation valve inside containment serves as a boundary valve between the Class 1 Reactor Coolant System and the Class 2 containment penetration piping.

Similarly, the piping for penetrations P44A (Core Flooding Tank Fill and Nitrogen

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Supply Line), P47A (Core Flooding Tank Sample Line), P47B (Core Flooding Tank Vent Line), and P71C (Core Flooding Tank Fill and Nitrogen Supply Line) through the containment are Class 2 solely because they form part of the containment pressure boundary. The piping outside the containment vessel is outside the scope of Section XI.

The containment isolation valve inside containment serves as a boundary valve between the Class 2 Core Flood System and the Class 2 containment penetration piping.

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Docket Number 50-346 l License Number NPF-3 l Serial Number 2450 Attachment Page'7 l For eacli containment penetration blank flange or isolation valve which is closed or capable of automatic closure, isolate the Class 2 piping from'the non-Code piping. Containment integrity is the only safety-related function associated with this piping.

. The Davis Besse Technical Specifications require that containment penetrations be tested in accordance with 10 CFR 50 Appendix J. Performing a system pressure test or hydrostatic test on the same components tested by the Appendix J test imposes a burden of duplicate testing. Duplicate testing results in an increase in outage man-hours and personnel exposures without an increase in the level of quality or safety. The Appendix J testing, which is performed at maximum containment accident pressures, assures that the containment pressure boundary is being maintained at an acceptable level.

Code Case N-522 has been approved by the ASME Boiler and Pressure Vessel Code

, Committee and the Board on Nuclear Codes and Standards as an acceptable alternative to the rules of the ASME Boiler and Pressure Vessel Code,Section XI.

Alternative Examinatiom Pressure Testing of Containment Penetration w ill be performed in accordance with Code Case N-522. When Code Case N-522 is approved in Regulatory Guide 1.147, any additional limitations recommended by the NRC staff will also be incorporated.

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Docket Number 50-346 License Number NPF-3 Serial Number 2450 Attachment

' Page'8 RELIEF REQUEST RR-AIS Comnonent Descrintion:

liydrostatic Testing of Class 1,2 and 3 Systems - Request for Approval to use Code Case N-498-1 ASME Code Class:

ASME Section XI, Class 1,2, and 3 ASME Examination Reauirements. ASME Section XI.1986 Edition. No Addenda:

Table IWB-2500-1, Fxamination Category B-P requires hydrostatic testing of pressure retaining components each inspection interval.

Table IWC-2500-1, Examination Category C-H requires hydrostatic testing of pressure '

retaining components each inspection interval.

Table IWD-2500-1, Examination Categories D-A, D-B, and C-C require hydrostatic testing of pressure retaining components each inspection interval.

Basis for Relief:

Code Case N-498-1 provides alternative requirements for hydrotesting Class 1,2, and 3 Systems.11ydrostatic testing is performed to verify the pressure boundary integrity of the gnem.

l Ilydrostatic tests require that systems be taken out of service. This requires the tests be performed under outage conditions. Additional pumps are often required te abtain the necessary test pressures. As the hydrostatic test pressure is above the normal operating l pressures, relief valves which are installed to protect the system from overpressurization must be removed or gagged. The hydrostatic test also stresses non-pressure-retaining l components, such as gaskets, pump seals, and valve packing, increasing their likdihc- d to l leak during or following the hydrostatic test.

E: tensive outage scheduling is required for the hydrostatic test program as, the systems are i I

not available during testing. Although many of the systems are not required to be operable I in outage conditions, they are maintained functional to minimize shutdown risks during varied outage conditions. A typical hydrostatic test takes approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to perform with a crew of two to three people. Typical radiation levels in test areas is approximately 5 l mrem. This results in a total personnel dose of approximately 150 mrem per test.

Performing 60 hydrostatic tests would result in an accumulated dose of 9 Rem.

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Docket Number 50-346

. . ~ - License Number NPF-3 l

Serial Number 2450 l Attachment 1 Page'9 System pressure tests provide an acceptable alternative to hydrostatic tests. These system .

pressure tests are performed at normal operating pressures and temperatures. System I pressure test pressures are not significantly lower than hydrostatic test pressures. These tests are performed on systems which are in their normal lineups, reducing test preparation, performance time, and personnel exposures, while increasing system availability. Although I testing is performed at a lower test pressure, any pressure boundary leakage will be readily apparent, thereby ensuring the level of quality and safety of the system is maintained.

Code Case N-498-1 has been approved by the ASME Boiler and Pressure Vessel Code Committee and the Board on Nuclear Codes and Standards as an acceptable alternative to -

the rules of the ASME Boiler and Pressure Vessel Code,Section XI.

Alternative Examination:

Code Case N-498-1 will be used in lieu of the Table IWB-2500-1, Table IWC-2500-1, and Table IWD-2500-1 hydrostatic test requirements. When Code Case N-498-1 is approved in Regulatory Guide 1.147, any additional limitations recommended by the NRC staff will also be incorporated.

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