ML20195J776
| ML20195J776 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/15/1999 |
| From: | Jamie Benjamin COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9906210123 | |
| Download: ML20195J776 (5) | |
Text
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -
o nmn,,nw c. inn 4a ~,n o,nipan>
i l asalle Generaong Natoin 991 North list Road
\\t.irsallet 11 6146i9'%'
h 1 Hli 45 4,*61 June 15,1999 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374
Subject:
Submittal of Relief Request CR-23 LaSalle County Station performs inservice inspections in accordance with ASME Section XI,1989 Edition. The enclosed relief request addresses sections IWB-2500, IWC-2500, and IWD-2500.
Sections IWB-2500, IWC-2500, and IWD-2500 require examinations of integrally welded attachments. Relief request CR-23 requests relief from the Code Required selection and examinations of these integral attachments and proposes to u"'ze attemative selection and examination requirements similar to Code Case N-509.
Relief request CR-23 is applicable to both Units 1 & 2. Comed requests approval of this request by October 1,1999. In addition, Comed requests that the relief extend throughout the remainder of the Second 10-Year Inservice inspection Interval.
l 0
(,,
'A 9906210123 990615 PDR ADOCK 05000373 G
PDR j+
.k k nl((inI k AnIlf.Ill)
1 Juns 15,1999 U.S. Nucle:r Regulttory Commission P ge 2 l
l Should you have any questions conceming this letter, please contact Frank A. Spangenberg, Ill, Regulatory Assurance Manager, at (815) 357-6761, extension 2383.
Respectfully, Jeffrey A. Benjamin Site Vice President LaSalle County Station Enclosure cc:
Regional Administrator-NRC Region lli NRC Senior Resident inspector - LaSalle County Station l
ISI Program Plan LaSalle County Station Units 1 & 2. SecondInterval l
RELIEF REQUEST: CR-23 REVISION 0 (Page1of3)
COMPONENT IDENTIFICATION Code Classes:
1,2, and 3
References:
Table IWB-2500-1, Table IWC-2500-1, Table IWD-2500-1 Examination Categories:
B-II, B-K-1, C-C, D-A, D-B, D-C ltem Numbers:
B8.10, B8.20, B8.30, B10.10, B10.20, B10.30, C3.10, C3.20, C3.30, C3.40, Dl.20, Dl.30, DI.40, DI.50, Dl.60, D2.20, D2.30, D2.40, D2.50, D2.60
==
Description:==
Alternative Rules for the Selection and Examination of Class 1,2, and 3 Integrally Welded Attachments - Use of Code Case N-509 Component Numbers:
All Class 1,2, and 3 Integral Attachments Subject to Inservice Inspection CODE REOUIREMENTS Class 1 Attachments Table IWB-2500-1, Examination Categories B-II and B-K-1 require the performance of surface or volumetric examinations, as applicable, on integral attachments with a design thickness of 5/8" or greater, Class 2 Attachments i
Table IWC-2500-1, Examination Category C-C requires the performance of a surface examination on integral attachments with a design thickness of 3/4" or greater.
Class 3 Attachments i
Table IWD-2500-1, Examination Categories D-A, D-B, and D-C require the performance of a visual VT-3 examination on mtegral attachments.
l i
i I
151 Program Plan LaSalle County Station Units 1 & 2. SecondInterval RELIEF REQUEST: CR-23 REVISION 0 (Page 2 of 3)
HASIS FOR RELIEF Pursuant to 10 CFR 50.55a(a)(3)(i), reliefis requested on the basis that the proposed alternatives would provide an acceptable level of quality and safety.
Reliefis beibg requested to allow the use of alternate requirements for the examination and selection of Class 1,2, and 3 integral attachments detailed in Code Case N-509, with exception to the requirement to inspect the integrally welded attachments associated with the component supports selected for examination under the 1990 Addenda,IWF-2510 (Reference footnote 5 of Category B-K and Category C-C Code Case N-509 tables). The basis for this request is as follows:
1)
Integral attachment failures have been very rare within the commercial nuclear power industry. Failures and inservice defects that have been detected are usually associated with support damage caused by a system transient or other abnormal events during operational periods. Therefore, degradation is typically identified during inspections that are performed after a system transient or other abnormal events which have occurred.
Code Case N-509 requires the examination ofintegral attachments when deformation of the associated component support members is identined. This requirement will ensure degraded integral attachments are identified and therefore increase the level of quality md safety provided by these alternatives rules, as compared to the rules of the 1989 Edition of Section XI.
2)
Significant amount of man-rem exposure and cost associated with the scheduled examination of Class 1,2, and 3 integral attachments would be saved.
3)
Contrary to the requirements specified in ASME Section XI 1989 Edition, the alternate selection criteria of Code Case N-509 does not impose a minimum thickness requirement for the examination of an integral attachment. Therefore, a larger population ofintegral attachments will be available for examination beca-e the selection population will not be limited to those above an arbitrary thickness. This provision improves the quality and safety level established by these examinations.
4)
The alternate rules of Code Case N-509 provide an acceptable level of quality and safety.
5)
The selection of component supports for examination per Code Case N-491 is an acceptable alternative approved by the NRC in Revision 11 of Regulatory Guide 1.147.
ISI Program Plan LaSalle County Station Units I & 2. SecondInterval RELIEF REQUEST: CR-23 REVISION 0 (Page 3 of 3)
PROPOSED ALTERNATE PROVISIONS The requirements of Code Case N-509 will be used to select and examine integrally welded attachments, with exception to the requirement to inspect the integrally welded attachments associated with the component supports selected for examination under the 1990 Addenda, IWF-2510 (Reference footnote 5 of Code Case N-509 Category B-K and Category C-C). LaSalle is implementing Code Case N-491 for support selections and will inspect the integrally welded attachments associated with the component supports selected for examination under Code Case N-491. In addition to those conditions specified in Code Case N-509, a 10% minimum sample ofintegrally welded attachments for each item in each code class will be inspected. This minimum 10% sampling is consistent with Draft Regulatory Guide DG-1050, Revision 12 to Regulatory Guide 1.147, dated May 1997, The minimum 10% sample shall be distributed proportionally by system.
APPLICABLE TIME PERIOD Reliefis requested for the second ten-year inspection interval of the Inservice Inspection Program for LaSalle Unit I and Unit 2.