ML20083A691
| ML20083A691 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/04/1995 |
| From: | Feigenbaum T NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NYN-95044, NUDOCS 9505110101 | |
| Download: ML20083A691 (8) | |
Text
._..
3. Nort1m.
North Atlantic Energy Service Corporation L
g.O. 3,,300
' Atlantic Seabrook, Nil 03874 (603)474-9521, Fax (603)474-2987 The Northeast Utilities System Ted C. Feigenbaum i
NYN-95044 Senior Vice President 8.
Chief Nuclear Officer May 4,1995 United States Nuclear Regulatory Commission Washington, D.C. 20555 t
Attention:
Document Control Desk
References:
(a)
Facility Operating License No. NPF-86, Docket No. 50-443 i
(b)
Nonh Atlantic Letter NYN-95029, dated March 30,1995, " Request to Use Alternatives to ASME Code Section XI," T. C. Feigenbaum to USNRC (c)
Teleconference between J. Peschel, North Atlantic, and A. De Agazio USNRC, on April 14,1995, requesting supplemental info mation to support NYN-95029,
" Request to Use Alternatives to ASME Code Section XI"
Subject:
Supplemental Infonnation Regarding Request to Use Alternatives to ASME Code Section XI Gentlemen:
The purpose of this letter is to provide supplemental information regarding North' Atlantic Energy Service Corporation's (Nonh Atlantic) relief request [ Reference (b)] to use alternatives to the ASME i
!! oiler and Pressure Vessel Code,Section XI,1983 edition, through summer 1983 addendum for Seabrook j
Station pursuant to the provisions of 10 CFR 50.55a(a)(3). Specifically, North Atlantic requests approval to use the provisions of the following three ASME Code cases:
Code Case N-416-1, " Alternative Pressure Test Requirement for Welded Repairs or Installation of Replacement items by Welding, Class 1,2 and 3,Section XI, Division 1."
Code Case N-498-1, " Alternative Rules for 10-Year System flydrostatic Testing of Class 1,2, and 3 Systems,Section XI, Division 1."
[
Code Case N-522, " Pressure Testing of Containment Penetration Piping,Section XI, Division 1."
Enciosures 1,2, and 3, provide the bases for the aforementioned relief requests and include the supplemental infonnation requested via Reference (c). These enclosures also describe proposed alternative examinations that will be conducted in lieu of the Code required examinations to ensure system integrity and operational readiness. North Atlantic believes that the proposed alternative testing is capable of providing an acceptable level of quality and safety while concunently reducing hardship.
i 9505110101-950504 PDR ADOCK 05000443 P
PDR Ii
United States Nuclear Regulatory Commission May 4,1995 Attention: Document Control Desk Page two Should you have any questions concerning these relief requests, please contact Mr. James M.
Peschel, Regulatory Compliance Manager, at (603) 474-9521, extension 3772.
Very truly,you'rs, f
d&
,J TCF:JES/sm
/
Ted C. Feigenbaum Enclosure cc:
Mr. Thomas T. Martin Regional Administrator U.S. Nuclear Regulatory Commission Region i 475 Allendale Road King of Prussia, PA 19406 Mr. Albert W. De Agazio, Sr. Project Manager Project Directorate I-4 Division of Reactor Projects U.S. Nuclear Fegulatory Commission Washington, DC 20555 Mr. John B. MacDonald NRC Senior Resident Inspector P.O. Box 1149 Seabrook, Nil 03874 l
REOUEST FOR RELIEF FROM INSERVICE INSPECTION REOUIREMENTS (CODE CASE N-416-1) 1.
, Code Reauirement for Which Reliefis Reauested System hydrostatic test per IWA-4400. The 1983 ASME Code through the Summer of 1983 Addenda,Section XI, IWA-4400, requires that a system hydrostatic test be performed in accordance with IWA-5000 after repairs by welding on the pressure retaining boundary.
2.
Anoticable Construction Code and Class for Seabrook Station ASME Section III,1977 through Winter 1977 Addendum ASME Section XI,1983 through Summer 1983 Addendum.
3.
Reference Code Case Code Case N-416-1, " Alternative Pressure Test Requirement for Welded Repairs or Installation of Replacement items by Welding, Class 1,2 and 3,Section XI, Division 1."
4.
Components for Which Exemption is Reauested This request is for ASME Class 1,2, and 3 Piping Systems.
5.
Basis for Requestinn Relief Consistent with the philosophy of ASME Code Case N-416-1, this request is based on performing VT-2 examinations at nominal operating pressures in lieu of hydrostatic pressure tests for welded repairs or installation of replacement components by welding. A review of all the repair hydrostatic pressure tests performed at Seabrook Station (1986 to present) has shown that no post-repair testing has identified leaks m either base or weld metal.
Ilydrostatic pressure testing is primarily a means of enhancing leak detection during the examination of components under pressure rather than solely as a measure to determine the structural integrity of the components. North Atlantic believes that testing at nominal operating pressure is sufficient to identify leakage.
ASME Code Case N-416-1 has been approved by the ASME Boiler and Pressure Vessel Code Committee and the Board of Nuclear Codes and Standards as an acceptable altemative to the requirements of the ASME Code,Section XI.
The burdens imposed by post-repair hydrostatic testing in accordance with IWA-4400 are as follows:
System isolation and coordination required for hydrostatic testing at elevated pressures potentially increases refueling outage critical path time, increases overall duration and cost as opposed to testing at nominal operating pressure.
1
m Since hydrostatic test pressure is higher than nominal operating pressure, hydrostatic pressure testing fiequently requires significant effort to set up and perform. The need to use special i
equipment, such as temporary attachment of test pumps and gages, and the need for individual valve lineups can cause the testing to be on critical path. These actions also have the potential to increase personnel exposure.
The time required to complete system hydrostatic tests compared to system pressure tests results in a significant increase in work scope and man-hours, radiological exposure, and radwaste from hydrostatic equipment decontamination without a compensating increase in the level of quality or safety.
6.
Altemate Examination In lieu of performing post repair hydrostatic testing in accordance with IWA-4400, North Atlantic will perform alternate examinations in accordance with ASME Code Case 416-1 for welded repairs or installation of replacement components by welding in Class 1,2, and 3 piping, as follows:
Non destructive examination (NDE) of the welds will be performed in accordance with the methods and acceptance criteria of the applicable Subsection of the 1992 Edition of Section Ill.
A system pressure test and visual examination (VT-2) will be performed using the 1992 Edition of Section XI, in accordance with paragraph IWA-5000, at nominal operating pressure and temperature. This testing will extend to all components included in the repaired portions of the systems.
The system will be pressurized to nominal operating pressure for a least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated
+
systems and 10 minutes for non-insulated systems. The system will be maintained at nominal operating pressure during the performance of the VT-2 visual examination.
The VT-2 visual examination will include all components within the boundary identified above.*
7.
Conclusio_q Based on the foregoing, North Atlantic concludes that the proposed alternate examination provides reasonable assurance of operational readiness while concurrently reducing hardship.
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O REOUEST FOR RELIEF FROM INSERVICE INSPECTION REOUIREMENTS (CODE CASE N-498-1) 1.
Code Reauirement for Which Reliefis Reauested System hydrostatic test per ASME IWD-5223: Categories D-A, D-B, and D-C; Items DI.10, D2.10, and D3.10. liydrostatic testing under ASME IWD-5223 is perfcrmed at Seabrook Station every 10 years in accordance with Inspection Program B.
2.
Applicable Construction Code and Class for Seabrook Station ASME Section 111,1977 through Winter 1977 Addendum ASME Section XI,1983 through Summer 1983 Addendum.
3.
Reference Code Case Code Case N-498-1, " Alternative Rules for 10-Year System liydrostatic Testing of Class 1, 2, anc. 3 Systems,Section XI, Division 1."
4.
Components for Which Exemption is Reauested This request is for all ISI Class 3 system hydrostatic tests to be performed during each remaining ISI inspection interval. In accordance with examination categories in ASME Table IWD-2500-1, this request applies to systems that support a Reactor Shutdown Function, Emergency Core Cooling, Containment lleat Removal, Atmosphere Cleanup, Reactor Residuallleat Removal, and Residuallleat Removal from Spent Fuel Storage Pool. For Seabrook Station, these categories specifically include the following systems: Chemical and Volume Control, Component Cooling, Service Water, Containment Building Spray, and Spent Fuel Pool Cooling.
5.
Basis for Reauestina Relief Consistent with the philosophy of ASME Code Case N-498-1, this request is based on performing VT-2 examinations at nominal operating pressures in lieu of the interval hydrostatic pressure tests. A review of all the Class 3 hydrostatic pressure tests performed at Seabrook Station (1979 to present) has shown that only one test identified a through-wall leak in an expansion joint. Specifically, during an ISI inspection in 1992, a leak was found in an expansionjoint in the Service Water System. Notwithstanding this, North Atlantic believes that this defect would have been identified via functional testing at normal system operating pressure. No other hydrostatic testing has identified leaks in either base or weld metal.
ASME Code Case N-498-1 has been approved by the ASME Boiler and Pressure Vessel Code Committee and the Board of Nuclear Codes and Standards as an acceptable alternative to the requirements of the ASME Code,Section XI.
The burdens imposed by Class 3 hydrostatic testing (IWD-5223) are as follows:
1
System isolation and coordination required for hydrostatic testing at elevated pressures potentially increases refueling outage critical path time, increases overall duration and cost as opposed to testing at nominal operating pressure.
Since hydrostatic test pressure is higher than nominal operating pressure, hydrostatic pressure testing frequently requires significant effort to set up and perform. The need to use special equipment, such as temporary attachment of test pumps and gages, and the need for individual valve lineups can cause the testing to be on critical path. These actions also have the potential to increase personnel exposure.
The time required to complete system hydrostatic tests compared to system pressure tests results in a significant increase in work scope and man-hours, radiological exposure, and radwaste from hydrostatic equipment decontamination without a compensating increase in the level of quality or safety.
6.
Altemate Examination In lieu of performing interval hydrostatic testing, North Atlantic will perform alternate examinations in accordance with ASME Code Case 4981 as follows:
A system pressure test will be conducted during each inspection interval of Inspection Program B.
System pressure testing will extend to all Class 3 components included in those ponions of systems required to operate or support the safety system function up to and including the first normally closed valve, including a safety or relief valve, or valve capable of automatic closure when the safety function is required.
The system wi!! be pressurized to nominal operating pressure for a least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for non-insulated systems. The system will be maintained at nominal operating pressure during the performance of the VT-2 visual examination.
The VT-2 visual examination will include all components within the boundary identified above.
7.
Conclusion Based on the foregoing,. North Atlantic concludes that the proposed alternate examination provides reasonable assurance of operational readiness while concurrently reducing hardship.
i 2
e a.
REOUEST FOR RELIEF FROM INSERVICE INSFECTION REOUIREMENTS (CODE CASE N-522) 1.
Code Reauirement for Which Reliefis Reauested System pressure testing in accordance with ASME IWC-5220; Category C-H, items C7.30 and C7.70.
Specifically, ASME IWC-5220 requires a system pressure test during system functional and system inservice tests, which are performed every 40 months.
2.'
Applicable Construction Code and Class for Seabrook Station ASME Section 111,1977 through Winter 1977 Addendum ASME Section XI,1983 through Summer 1983 Addendum.
3.
Reference Code Case Code Case N 522, " Pressure Testing of Containment Penetration Piping,Section XI, Division 1."
4.
Components for Which Exemption is Reauested This request is for all piping that penetrates a containment vessel, when the piping and isolation valve that are part of the containment system are Class 2, but the balance of the piping system is outside the scope of ASME Section XI.
5.
Basis for Reauestine Relief Consistent with the philosophy of ASME Code Case N-522, this request is based on performing a 10 CFR l
50, Appendix J test in lieu of the Table IWC-2500-1 pressure test, when the piping and isolation valves i
that are part of the containment system are Class 2, but the balance of the piping system is outside the scope of ASME Section XI. Penetration piping is classified as Class 2 because ofits function as part of the containment pressure boundary. The remaining portion of the system is non-nuclear related and the integrity of the system in relation to its primary function is not within the scope of ASME Section XI.
Since containment integrity is the only safety related function performed by this piping, it is logical to test the penetration portion of the system to the Appendix J criteria.
The Seabrook Station Updated Final Safety Analysis Report (UFSAR) requires 10 CFR 50, Appendix J testing for containment penetrations. Performing a hydrostatic pressure test on these same components imposes a burden of duplicate testing. Duplicate testing results in a significant increase in work scope and radiological exposure without a compensating increase in the level of quality or safety.
ASME Code Case N-522 has been approved by the ASME Boiler and Pressure Vessel Code Committee l
and the Board of Nuclear Codes and Standards as an acceptable alternative to the requirements of the ASME Code,Section XI. ASME Code Case N-522 has been published in ASME Code Cases: Nuclear l
Components,1992 Edition, Supplement No. 7.
)
1 i
1 1
e 6.
Alternate Examination Class 2 piping and isolation valves that are part of the containment system, but the balance of the piping system is outside the scope of ASME Section XI, will be tested in accordance with 10 CFR 50, Appendix J.
7.
Conclusion Based on the foregoing, North Atlantic concludes that the proposed alternate examination provides reasonable assurance of operational readiness while concurrently reducing hardship.
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