ML20086P268

Provides Response to 10CFR50.61(b)(1) Re Projected Values for RT-PTS of Any Matl in Reactor Vessel Beltline Projected to Exceed PTS Screening Criteria & Forwards WCAP-13106, Evaluation of PTS for Beaver Valley Unit 1

ML20086P268
Person / Time
Site:	Beaver Valley
Issue date:	12/16/1991
From:	Sieber J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20086P271	List: ML20086P268 ML20086P273
References
NUDOCS 9112260308
Download: ML20086P268 (3)

Text

1 Q Beaver Va ey Power Stahon Shippinoport. PA 15077 6 4

{417) 393-5255 JOHN D SIEBER Vice President - Nuclear Group December 16, 1991 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Subject:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 10 CFR 50.61 (b) (1) RT-PTS Submittal Thia submittal is provided in response to the reporting requirements contained in 10 CFR 50.67 (b) (1) which requires utilities to submit projected values of RT-PTS if any material in the reactor vessel beltline region is projected to exceed the pressurized thermal shock screening criterion (270*F for plates, forgings, and axial weld materials or 300*F for circumferential veld materials) before the expiration date of the operating license. The Unit No. 1 operating license expires January 29, 2016. Attached is WCAP-13106,

" Evaluation of Pressurized Thermal Shock for Beaver Valley Unit 1",

which projects that the lower shell plate {B6903-1) will have a RT-PTS value of 272*F at 32 EFPY (end of life). This is the only material projected to exceed the screening criterion.

In order to identify the RT-PTS value corresponding to this submittal date, information must be extracted from the test report of reactor vessel surveillance capsule W (WCAP-12005) which was submitted to the NRC on January 24, 1989. This report identifies the capsgle as receiving of an removal, average fast 1 neutron fluence of 9.49E + 18 January 1988. A plot of the RT-PTS n/cm at the time values versus fluence for the most limiting material, lower shell plate B6903-1,- is given in HCAP-13106 (figure 2). From this figure the current RT-PTS value appears to be approximately 210*F using surveillance capsule data. Capsule W was removed at 5.89 EFPY. Unit

'No. 1 is currently at 8.45 EFPY (as of Octor1r 22, 1991).

The value of projected RT-PTS was calculated utilizing the data contained in WCAP-12005 for surveillance capsule W. The copper and nickel content has remained the same as that previously submitted to the- Commission in our criginal response to the PTS rule (letter dated January 21, 1986). The fluence values have changed from those previously subn itted as a result of the more recent reactor vessel surveillance capsale analyses performed on capsule W. It should also

.be noted that WCAP-12005 makes reference to our implementation of low leakage loading patterns. It is assumed in our cciculations,'

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((d22IO50bbb/k4 P-

e t-10CFR50.61 (b) (1) _ RT-PTS Submittal Page 2 (WCAP-13106) that we will continue utilizing this fuel management scheme. Since- our data is plant specific (i.e., derived from implementation of our Unit No. 1 reactor vessel radiation surveillance program; WCAP-8457), these values of RT-PTS are considered bounding for the Unit No. 1 reactor vessel.

Calculations of the RT-PTS values for all beltline region materials at end of life were completed in accordance with 10 CFR 50.61 and are summarized on Table 4 of WCAP-13106. Two sets of results are documented for the lower shell plate B6903-1 and the longitudinal weld seams 19-714A and B. The first set is calculated in accordance with the procedures given in 10 CFR 50.61 (b) (2) . From these calculations all materials fall below the PTS screening criterion. However, if there' exists plant specific surveillance data which is deemed credible as defined by Regulatory Guide 1.99, revision- 2, then additional calculations must be performed as specified in. 10 CFR 50.61 (b) (3) . The results of these calculations are also included on Table 4 and indicate plate B6903-1 will exceed the PTS screening criterion.

The calculations completed per 10 CFR 50.61 (b) (3) were performed utilizing margin as defined in regulatory position C.2 of Regulatory Guide 1.99, revision 2. Paragraph (b) (3) does not specify what value of margin is correct for this calculation when plant specific surveillance capsule data is available. Paragraph (b) (2) directs the use of a margin value of 34' but also requires use of chemistry factors as provided in (b) (2) . Therefore, the methodology for margin and- chemistry factor determination contained in Regulatory Guide 1.99 was utilized in the attached WCAP-13106.

We are requesting NRC approval of this methodology for margin determination. Our analyses and schedule for implementation of a future flux reduction program, and subsequent submittal by March 16, 1991, (10 CFR 50.61 (b) (4 ) ) is dependant on the NRC response to our request to use a margin factor derived from Regulatory Guide 1.99, revision 2. Therefore, we are requesting NRC approval by January 31, 1991,- in order to proceed with actions necessary to satisfy the submittal requirements of 10 CFR 50.61 (b) (4) .

If you have any questions regarding this submittal, please contact Mr. Steve Sovick at (412) 393-5211.

Sincerely, yb/s toS s "3. D. Sieber GSS/cag Attachment

t 10CFR500 61l (b) (1) RT-PTS Submittel Page'2 e

cc: Mr. J. Beall, Sr. Resident Inspector Mr. T. T. Martin, NRC Region I Administrator

-Mr. A. W. DeAgazio, Project Manager i

Mr. M. L. Bowling (VEPCO) w/o att.

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