ML20199L685
| ML20199L685 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 01/18/1999 |
| From: | Feigenbaum T NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| RTR-REGGD-01.099, RTR-REGGD-1.099 GL-92-01, GL-92-1, NYN-99007, NUDOCS 9901280094 | |
| Download: ML20199L685 (5) | |
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%. North Atlantic Energy Smice Corporation 1 I'M" 3M I
.NOftb. Seabrook, Nll 03874 Atleinitic 1603,474.,32i The Northeast Utilities System January 18,1999
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Docket No. j NYN-99007 Ref.: GL 92-01, R1 i NYN-95094 I NYN-98085 l NYN-98078 i
United States Nuclear Regulatory Commission l Attn.: Document Control Desk j Washington, DC 20555-0001 1
Seabrook Station Revision to Limitine Reactor Vessel Beltline Material North Atlantic Energy Service Corporation (North Atlantic) provides the following information l regarding Seabrook Station's reactor vessel materia? Nta as requested by the Staff during j teleconferences on November 23 and December 10,1998. North Atlantic niso hereby revises its
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determination of the limiting reactor vessel beltline material. !
1 In the Seabrook Station Reactor Vessel Surveillance Capsule Report, dated June 5,1998 l (NYN-98078), North Atlantic reported the limiting reactor vessel beltline material to be the plate ,
I designated as R1808-3 which is the surveillance capsule material. This is consistent with the most limiting material reported in North Atlantic's responsa to Generic Letter 92-01, Revision 1 on November 20,1995 (NYN-95094). Tab'e 2 of the response to the generic letter states that g'<,g j plate R1808-3 was projected to exhibit the highest ARTpa @ EOL based on the methodology of Regulatory Guide (RG) 1.99 Revision 2 and the plate's best estimate chemistries and initial !
mechanical properties. Using only the transversely oriented specimen surveillance data for the sWect plate, the_ RTp a @ EOL is calculated to be 10l*F. This value was determined by combining RTi + ART + 17 F. j During the teleconferences, the Staff stated that all available surveillance data must be used in l the determination of the limiting RT pa @ EOL. Since Seabrook Station's reactor vessel
. surveillance capsules also contain longitudinally oriented specimens of plate R1808-3, this data would also have to be considered. North Atlantic had previously used the transversely oriented specimen surveillance data in the determination of the limiting RTpa @ EOL based on the r
9901290094 990118 ~
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, U.S. Nuclear Regulatory Commission I NYN-99007 / Page 2 guidance pr6vided in ASTM Designation E185-82, " Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels, E706 (IF)."
Specifically, Section 6.2 of E185-82 states "... tension and Charpy specimens from base metal !
l shall be oriented so that the major axis of the specimen is parallel to the surface and normal to j the principal rolling direction for plates..." The application of both transversely and i longitudinally oriented surveillance data for plate R1808-3 increases the projected RTp a @ EOL l to 107 F.
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' i As a result of the above, surveillance plate R1808-3 will not be considered the limitmg reactor vessel beltline material. The non-surveillance beltline material with the largest predicted RTpu
@ EOL will now be the basis for the Seabrook Station reactor vessel pressure / temperature (P/T) l l
limit curves ifit is greater than plate R1808-3 using both longitudinal and transverse specimen l l
data. Accordingly, the limiting material is plate R1808-1 having a calculated RTp a @ EOL of 120 F. Note, this value has been adjusted from the 122*F reported in Table 2 of the response to the generic letter to account for the lower end oflife fluence at the reactor vessel inside diameter as predicted by the surveillance capsule report. The higher RTp a @ EOL value for the originally i non-limiting plate, R1808-1, is the direct result of using the fuli Regulatory Guide (RG) 1.99 Revision 2 margin term of 34 F in the absence of credible surveillance data. RG 1.99 Revision 2 j allows the halving of the margin team with the availability of credible surveillance data as is the case for plate R1808-3. Refer to Table 1 for a summary of reactor vessel material data. ]
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As stated in the Seabrook Station Response to Information Request Regarding Reactor Vessel Integrity dated June 24,1998 (NYN-98085), North Atlantic concludes that the chemistry and material property data currently utilized to confirm the structural integrity of the Seabrook ,
Station Reactor Pressure Vessel (RPV) remain valid and maintain continued compliance with the !
requirements of 10 CFR 50.60,10 CFR 50.61 and Appendices G and H to 10 CFR 50.
l Should you require further information regarding this matter, please contact Mr. Terry L.
Harpster, Director of Licensing Services at (603) 773-7765.
Very truly yours, NORTH ATLANTIC ENERGY SERVICE CORP. l l
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! Ted C. Feigenbaum[ dent and Executive Vice Presi ;
l Chief Nuclear Officer i
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U.S. Nuclear Regul:. tory Commission NYN-99007 / Page 3 -
cc: b. J. M lier, NRC Region I Administrator J. T. Harrison, NRC Project Manager, Project Directorate 1-3 R. K. Lorson, NP.C Senior Resident Inspector
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4 d ENCLOSURE TO NYN-99007 l
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Table 1
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Summary of Reactor Vessel Material Data lRT, ID FF @ CF . Method of - Margin art,@ RT,,, @ . . Remarks *
( F) Fluence -EOL Determ CF ( F) EOL ( F) EOL ( F)
@ EOL*
R1808-1 40 237 El9 1.233 37 Tables 34 46 120 Limiting non surveillance R1808-2 10 237 E19 1.233 37 Tables 34 46 90 R1808-3 40 237 E19 1.233 35.6/40.8 " Surveillance 17 44/50 101/107 Surveillance Capsule R1806-1 40 237 E19 1.233 28.5 Tables 34 35 109 R1806-2 0 237 E19 1.233 37 Tables 34 46 80 R1806-3 10 237 E19 1.233 47.5 Tables 34 59 103 4P6052 (Welds) -60 237 E19 1.233 283/11.2 Table / Surveil. 56/28 35/14 31/-18
- Per NYN-98078 (Second Surveillance Capsule Report)
- Transverse data only / Longitudinal and Transverse data l
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