ML20199L685

Provides Info Re Seabrook Station Rv Matl Data as Requested by Staff During 981123 & 1210 Telcons.Determination of Limiting Rv Beltline Matl,Revised

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)

Text

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North Atlantic Energy Smice Corporation

.NOftb.

1 I'M" 3M 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 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 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.

In the Seabrook Station Reactor Vessel Surveillance Capsule Report, dated June 5,1998 I

(NYN-98078), North Atlantic reported the limiting reactor vessel beltline material to be the plate 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 g'<,g j on November 20,1995 (NYN-95094). Tab'e 2 of the response to the generic letter states that plate R1808-3 was projected to exhibit the highest ART a @ EOL based on the methodology of p

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_ RT a @ EOL is calculated to be 10l*F. This value was determined by p

combining RT + ART + 17 F.

j i

During the teleconferences, the Staff stated that all available surveillance data must be used in l

the determination of the limiting RT a @ EOL. Since Seabrook Station's reactor vessel p

. 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 9901290094 990118

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r PDR ADOCK 05000443 P

PM

U.S. Nuclear Regulatory Commission 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 RT a @ EOL p

to 107 F.

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 RT u p

@ EOL will now be the basis for the Seabrook Station reactor vessel pressure / temperature (P/T) l limit curves ifit is greater than plate R1808-3 using both longitudinal and transverse specimen data. Accordingly, the limiting material is plate R1808-1 having a calculated RT a @ EOL of l

p 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 RT a @ EOL value for the originally p

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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I 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

l Ted C. Feigenbaum[ dent and l

Executive Vice Presi Chief Nuclear Officer i

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U.S. Nuclear Regul:. tory Commission NYN-99007 / Page 3 -

b. J. M lier, NRC Region I Administrator cc:

J. T. Harrison, NRC Project Manager, Project Directorate 1-3 R. K. Lorson, NP.C Senior Resident Inspector

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8 9

4 d

ENCLOSURE TO NYN-99007 l

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e 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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