ML20080M846
| ML20080M846 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/27/1995 |
| From: | Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9503060062 | |
| Download: ML20080M846 (6) | |
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-10CFR50.55a -
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.' PECO ENERGY 2f 27"L.
965 Chesterbrook Boulevard -
Wayne, PA 19087-5691 February 27,1995 Docket Nos. 50-277 50-278 -
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License Nos. DPR-44 DPR-56.
U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Peach Bottom Atomic Power Station, Units 2 and 3
.1 Adoption of Code Case N-498-1 (Relief Request No. RR 14 Revision 3) and Altemative Pressure Testing Requirements for Welded Repairs or Replacements (Relief Request No. RR-20, Revision 0)
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Dear Sir:
Attached for your review and approval are Relief Request No. RR 14, Revision 3, and Relief Request No. RR-20, Revision 0, for the Peach Bottom Atomic Power Station (PBAPS), Unts 2 '
and 3, Second Ten-Year Interval Inservice inspection (ISI) Program.
Relief Request No. RR-14, Revision 3 requests authorization to utlize' Code Case N-4961.
Adoption of this Code Case, as identified in the relief request, wHl allow the substitution of a system pressure test, conducted at the nominal operating pressure, for the ten year hydrostatic test required for ASME Code Class 1,2, and 3 piping systems.
Relief Request No. RR-20, Revision 0, requests approval of attemative ' pressure testing.
requirements following welded repair, or installation of replacement items by welding, to ASME Class 1,2, and 3 pressure boundary components. Altemate inspection provisions are also provided We request your review and approval by July 1,1995.
If you have any questions or require additional information, ple.ae do not hesitate to contact us.
Very truly yours, AQ.Q.p.
G. A. Hunger, Jr.,
Director - Licensing Attachment cc:
T. T. Martin, Administrator, Region I, USNRC W. L Schmidt, USNRC Senior Resident inspector, PBAPS y' l./ I m
I 9503060062 950227 PDR-.ADOCK 05000277 g
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ATTACHMENT 1 Peach Bottom Atomic Power Station Units 2 and 3 Inservice inspection Program Relief Request No. RR-14, Revision 3 1
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Specification M-733, Rev. _
4' PBAPS 2 & 3 ISI Program Appendix A-14
- Page 1 of 2 RELIEF REQUEST NO. RR 14 Revision 3
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SCOPE This relief request has been developed to request approval for the use of specific ASME Section XI Code Cases in this ISI Program. These Code Cases have not yet been specifically endorsed for use by the NRC, in Regulatory Guide 1.147 (reference 1.1.24).
11.
DISCUSSION Code Cases are periodically published by the ASME for the purpose of either clarifying the intent of Code requirements or for providing requirements for circumstances which are not currently covered by existing Code, but need to be addressed in a timely manner. Use of these non-mandatory Code Cases for inservice inspection is subject to NRC acceptance of the Code Case (s) Regulatory Guide 1.147 lists those Code Cases that have been reviewed by the NRC and are generally acceptable for implementation in an ISI Program. Other Code Cases may be used provided specific authorization is secured pursuant to 10CFR50.55a.
The purpose of this relief request is to request authorization for the adoption of specific Code.
Case (s) for implementation in the PBAPS, Units 2 and 3 Second interval ISI Program.
IIL CODE CASE (S) REQUIRING AUTHORIZATION The Code Case (s) requiring specific authorization for use in the PBAPS, Units 2 and 3 ISI Program are identified on the attached Table (s).
IV.
ALTERNATE PROVISIONS The alternative provisions of the Code Case (s) identified in Section lll above, shall be implemented in the PBAPS, Units 2 and 3 ISI Program for the second inservice inspection interval Any deviations from these requirements are identified in the referenced Tables. These Tables address the specific application of the associated Code Case in the ISI Program.
V.
BASIS FOR RELIEF The Code Case (s) referenced in Section 111 above, represent technically acceptable alternative requirements to the ASME Section XI Code requirements. The fact that the Code Case (s) has-
' not been endorsed in the Regulatory Guide in no way detracts from their technical adequacy, since the major reason for their omission is the timing of their publication with respect to the most recent revision of the Regulatory Guide. That is, the subject Code Case (s) is relatively recent and it is expected that it will be accepted in a subsequent revision of the Regulatory Guide. Adoption of the Code Case (s) provides an acceptable level of quality and safety and does not compromise the adequacy of the PBAPS, Units 2 and 3 ISI Program in meeting the intent of ASME Section XI.
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PBAPS 2 & 3
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Page 2 of 2
. RELIEF REQUEST NO. RR-14 (CONTD).
Revision 3 ~-
3 Table RR 141 CODE CASE N-4981 -
1.
- IDENTIFICATION OF COMPONENTS :
j PBAPS, Units 2 and 3 Class 1,2, and 3 systems.
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' 11.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED The 10-Year System Hydrostatic Pressure Testing requirements for Class 1,2, and 3 systems?
as identified in Section XI, Division 1, Table IWB-2500-1, Category B-P, Table IWC-2500-1, Category C-H, and Table IWD-2500-1, Categories D-A; D-B, and D-C respectively; as
- contained in the 1980 Edition of ASME Section XI, including addenda through the Winter 1981 Addendum.
~ 111.
BASIS FOR REllEF - Code Case N-498-1:
The burden imposed by the higher test pressures associated with the current 10 year i Hydrostatic Test requirement, is not commensurate with the increase in safety benefit. The d
1 experience gained by the performance of these tests indicates that the goal of the test (i.e. to
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discover pressure boundary leakage or evidence of structural distress) will still be achieved at
'j lower test pressures.
Adoption of this Code Case will allow substitution of a system pressure test, conducted at j
nominal operating pressure, for the ten year hydrostatic test, currently required for Class 1,2, i
and 3 systems, While this Code Case reduces the burden imposed by the. higher test pressures associated with -
the hydrostatic test, it introduces an new burden by imposing a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time (at test :
pressure), prior to performing the examinations of insulated compone'nts. This length of hold time is not practically achievable in some cases, due to equipment or system limitations.
l Damage to operating equipment could result if the equipment is required to run for this -
specified length of time. This fact has been recognized by the ASME Section XI Committee,
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and the Code Case is currently being revised to delete the requirement for hold times. Further, hold times are Inherently achieved by virtue of the period of time needed to both establish system pressurization, and then to perform the required visual examinations. While the length :
of this inherent hold time will vary between systems, sufficient time is expected to enable any leakage through degraded components to become evident.-
IV.
ALTERNATE PROVISIONS 3
As an alternative to the hydrostatic testing requirements, a system pressure test, at nominal operating pressure, may be conducted at or near the end of the Interval. The boundary, subject to test pressurization during this system pressure test, will extend to aj Class 1,2, and
. 3 components as identified on the ASME Section XI Boundary P & ID's.
No hold time will be required after attaining test pressure. The system will be maintained at test pressure during the conduct of the required VT-2 examinations.
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ATTACHMENT 2 Peach Bottom Atomic Power Station Units 2 and 3 Inservice inspection Program Relief Request No. RR-20. Revision 0 i
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. Specification 7,,N:
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PBAPS 2&3 ISI Pro 0 ram Appendix A '
Page 1 of 1
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RELIEF REQUEST NO.RR-20 Revision 0
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IDENTIFICATION OF COMPONENTS 1
PBAPS, Units 2 and 3,-ISI Class 1,2 and 3 pressure boundary cormonents.
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- II.
CODE REQUIREMENT FROM WHICH RELIEF IS REQUESTED ASME Section XI,1980 Edition, Winter 1981 Addenda, Article IWA-4000 and IWA-5000 hydrostatic-pressure test requirements.
Ill.
BASIS FOR RELIEF The above Articles require that hydrostatic pressure testing be performed after welded repair or installation of replacement items by welding on ASME Class 1,2 and 3 pressure boundary.
components.
l The burden imposed by the process of hydrostatic testing is not commensurate with the increased '
level of safety achieved. Hydrostatic pressure tests are performed at elevated pressures which require special maintenance activities for isolation of components to be tested, such as: temporary gagging or removal of relief valves installed to prevent overpressurization, leaktight repair of valving which does not normally serve a pressure isolation function, and installation of portable hydrostatic pressure pumps. The higher pressures imposed on the pressure boundary components during hydrostatic testing do not challenge the structuralintegrity of the material, and produce only a slight.
enhancement in leak detection capability. The additional leakage, above that which occurs during ;
a system pressure test at nominal operating pressure, is inconsequential in determining pressure boundary integrity. Therefore, the additional burden, and in some instances additional radiological dose to personnel associated with these maintenance activities, can be avoided.
IV, ALTERNATIVE PROVISIONS ASME Section XI Class 1,2 and 3 pressure boundary component welded repairs and installation welds for replacement items shall be pressure tested and inspected as follows:
A System Pressure Test, as defined in IWA-5211 (a), (b) or (c), and visual examination j
(VT-2) shall be performed prior to or immediately upon retum to service in accordance with the Code Edition and Addenda specified above. The components will be tested at nominal -
operating pressure. No hold time will be required after attaining test pressure. ' The components will be maintained at test pressure during the conduct of the VT-2 examinations.
Volumetric examination of Class 1,2, and 3 repair or replacement butt welds shall bei performed in accordance with the UFSAR license commitments. In the absence of
. i volumetric examination requirements, a surface examination of the root pass of the butt l
weld shall be performed.
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Surface examination of Class 1,2, and 3 repair or replacement socket welds shall be performed on the final pass of the socket weld.
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The above provisions provide an equivalent level of safety to that associated with hydrostatic -
testing, and are consistent with ALARA good practice.
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