ML20150E298

Forwards Projected Ref Temp Values for PTS Events Per NRC Request.Data Developed for Facility by Westinghouse,Based on Methods & Generic Assessment Outlined in 10CFR50.61

ML20150E298
Person / Time
Site:	Seabrook
Issue date:	07/08/1988
From:	George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NYN-88090, NUDOCS 8807150062
Download: ML20150E298 (3)

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George S. Thomas I Vice President Nuclect Production Ib l NYN- 88090 Pub 5c Serece of New Hampshire July 8, 1968 New Hampshi' 9 YanFw D:visbn United States Nuclear Regulatory Commission Washington, D C. 20555 Attention: Document Control Desk

. Ref eren.ce : Facility Operating License No. NPF-56, Docket No. 50-443

Subject:

Projected Referenta Temperature Valuer For Pressurized Thermal Shock Events Gentlemen:

i-This is provf.ded in response to a request oy the NRC Staff for information pertaining-to the reference temperatures (RT) for pressurized ther a.1 rihock (PTS) events. Enclosure 1 provides data developed for New Ham, dirst Yankee (NrfY) by Vestinghouse Elect.ric Corporatien for the Seabrook Station Unit I reactor vessel. The Westinghouse information is based on the methods a nd generic asscsstaent as outlined in 10CFR50.61(b), and is provided in Enclosure 2. Westinghot 1 has provided i.he sama calcul<tions for other similarly designed Pressurized Water Reactors.

Should you have any questions or require further assistance, please contr.ct Mr. Timothy G. Pucke at (603) 474-9574 extension 4'428.

Very truly yours, l

/

Geor S. Thomas Enclosure cci Mr. Victor Nerses, Project Hansger Project Directorate I-3 ,

Division of Reactor Projects l United States Nuclear Regulatory Commission kashington, DC 20555 ho opr A Mr. William T. Russell

$$1 Reglenal Administrator 08 United States Nuclear Jegulatory Commission co o Region I

' Ny 425 Allendalo Koad g King of Prussia. PA 19406

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CA i 7 Mr. Antone C. Cerne 1 j' y NRC Senior Resident Inspector l 1

j co o Seabrook Station

! Seabrook, NH 03874 k P.O. Box 300. Seabrook Nil 03874 . Telephone (603) 474 9574 u _ _

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ENCLOSURE 1 TO NYN . 88090 RTpys VALUES - SEABROO UNIT NO.' 1 REACTOR VESSEL

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32 EFPY Cu- Ni- I* + M + ARTNDT = RTPTS SCREENING COMTONENT CODE NO. FLUENCE (n/ca,') (Wtg.%) (Wtg.%) (*F) (*F) ' (*F) (*F)- VALUE/*F Intermediate Shell R1806-1 3.1 x 1019 0.04 0.64 40 +1 48' + 24- = 112 370 Interneuiate Shell R1806-2 3.1 x 1019 'O.05- 0.65 0 + 48' +. 34' = 82 270:

Intermediate Shell R1806-3 3.1 x 1019 0.07 .0.65 10 + 48 + 53 - 'lli 270 "

.ower Shell R1808-1 3.1 x 1019 0.05 0.58 40. + 48- + 32 = 120- 270' 1.ower Shell R1808-2 3.1 x 1019 0.05 0.57 10 + '48 + 32 = 90 270 Ls ser Shell R1808-3 3.1 x 1019 0.06 0.57 40 + 48 + 41 - 129 270 Inter to Lower Shell C1.72 3.1 x 1019 0.07 0.02 -50 + 48 + 32 = 30' '300 Girth Weld Seam Inter and Lower She'1 G1.72

_ 3.1 x 1019 ** 0.07 0.02 -50 + 48 + 32 = 30L 270 Long Weld Seam

• All of the initial reference temperatures that are shown are measured valves.

• • Although only a few of these six longitudinal welds are located near the peak flux regions around the core, the peak fluence was used for all of the longitudinal' welds as a conservatism.

DEFINITIONS:

I - Initial Reference Temperature of the unirradiated material as defined in ASME Code Section III, PP NB-2331.

M - Margin to cover uncertainties in material properties as defined in 10CFR50.61(b)(ii).

RTPTS - I + M + RINDT-t

a g - .

/7, M f,..

g' ENCLOSURE 2 TO NYN- 88090 THE CALCULATION OF RT PTS

-In the PTS Rule, the NRC Staff has selected a conservativo and uniform method for determining plant-specific values of RTPTS at a given time. The prescribed equations in the PTS Rule for. calculating RTPTS are actually one of several ways to co.lculate RTNDT. For the purpose of comparison with the Screening Criterion, the value of RTPTS for the reactor vessel must he calculated for each weld and plate, or forgoing in the beltline region as given below.- For each material, RTPTS is the lower of the results given by Equations 1 and 2.

Equation 1:

0.270 RTPTS = I + M + (-10 + 470(Cu) + 350(Cu)(Ni)) f RT

- NDT F4 uation 2:

0 RT PTS " I +'M + 283 f .194

- RT NDT where.

I means the initial reference transition temperature of the unirradiated material measured as defined in the ASME Code, PP NB-2331. If a measured value is not available, the.following generic mean values must be used:

0 F for welds made with Linde 80 flux, and -56 F for welds made with Linde 0091, 1092 and 124 and ARCOS B-5 weld fluxes.

M means the margin to be added to cover uncertainties in the values of initial RTNDT, copper and nickel content, fluence, and calculation procedures. In Equation 1, M-48 F if a measured value of I was used, and M-590 F if the generic mean value of I was used. In' Equation 2. M=0 F if a measured value of I was used, and M-340 F if the generic mean value of I was used.

Cu and Ni means the best estimate weight percent of copper and nickel in the material.

f means the maximum neutron fluence, in units of 1019n/cm2 (E greater than or equal to 1 MeV), at the clad-base-metal interface on the inside surface.of the vessel at the location where the material in question receives the highest fluence for the period of service in question.

Note that since the chemistry values given in Equations 1 and 2 are best estimate mean values, and the margin, M, causes RTPTS values to be upper bound predictions, the mean material chemistry values are to be used, when available, so as not to compounc' -ervatism.

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