ML20198C785

Safety Evaluation Concluding That Util Pressurized Thermal Shock Screening Criteria for Reactor Pressure Vessels Complies w/10CFR50.61

ML20198C785
Person / Time
Site:	Farley
Issue date:	05/16/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20198C477	List: ML20198C471 ML20198C785
References
REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR TAC-59953, TAC-59954, NUDOCS 8605230049
Download: ML20198C785 (4)

Text

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ENCLOSURE SAFETY EVALUATION RY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO COMPLIANCE WITH THE FRESSURIZED THERMAL SHOCK RULE 10 CFR 50.61 DATED JUNE PO, 1985 4

FOR REACTOR PRESSURE VESSELS JOSEPH M. FARLEY NUCLEAR PLANT UNITS 1 AND 2 Introduction By letter dated January 20, 1986, Alabama Power Company (APCol, the licensee for the Joseph M. Farley Nuclear Plant Units 1 and 2, submitted WCAP-11047 dated January 1986. The licensee's submittal is in conformance with the Pressurized Therwel Shock (PTS 1 regulation,10 CFR 50.61 (50 FR 29944 dated July 23, 1985), requiring licensee submittals by January 23, 1986. For pressurized water reactors, such as the Farley units, projected reference temperature calculations of reactor vessel beltline materials are to be adjusted for the effects of neutron radiation for the period of service life remaining. These calculations, provided in WCAP-11047, are evaluated herein.

Evaluation of Unit 1 Reactor Vessel for PTS Two elements relatina to fracture toughness for protection against PTS must

! be considered as follows:

1) the controlling beltline material properties, and i

2) the fast neutron fluence (E greater than or equal to 1.0 MeV1 level projected for the future life of the reactor vessel.

APCo provided a summary of pertinent chemical and mechanical properties of the beltline region materials in the Unit I reactor vessel in Table III.3-1 of WCAP-11047. In addition, APCo provided calculations including at preser.t, the

end-of-license, and at 32 effective full power years (EFPY1 of operation for the PTS reference temperatures shown in Table IV.1-1 of WCAP-11047. The controlling beltline material from the standpoint of PTS susceptibility was ,

identified as the Lower Shell Plate B6919-1.  !

The material properties of the controlling material (Plate B6919-1) and the l associated margin and chemistry factor are as follows: l l

1 e

i p ADOCK O M 348 POR

WCAP-11047 Staff Evaluation Cu (copper content, %) = 0.14 0.14 Ni (nickel content, %) = 0.55 0.55 I (Initial RTNDT, F) = 15 15 M (Margin, "F) = - 48 CF (Chemistry Factor, *F) = -

83 We agree that the controlling material has been properly identified. The justification given for the copper and nickel contents and the initial RT are acceptable. ThemarginhasbeenderivedfromconsiderationofthebaNI for these values, following the PTS Rule. Assuming that the reported values of fluence are correct, Equation 1 of PTS rule governs, and the chemistry factor is as shown above.

Therefore, the Equation 1, specified in 10 CFR 50.61, is applicable for the Farley Unit 1 pressure vessel calculations as follows:

RT PTS = I + M + (-10 + 470.Cu + 350.Cu.Ni)f* 7 Where: I = initial RT 15*F M =

uncertaint h =48"F Cu = w/o Copper in the lower shell plate P6919-1 = .14 Ni = w/o Nickel in the lower shell plate R6919-1 = .55 f = or equal to 1.0 MeV) peakfluence(Egreateygthag/n=5.04 on plate B6919-1 x 10~ cm then: RT = 15+48+ (-10 + 470 x.14 + 350 x .14x 55) 5.04 27 PTS = 63+82.8 x 1.548 = 63 + 128 + 191 'F less than or equal to 270*F The RT 191*F meets the 10 CFR 50.61 criterion of less than 270*F by en adequa$IS=rgin.

ma To gain a quantitative estimate of the margin let us calculate the fluence required to reach the screening criterion, i.e.,

RT PTS

= 270*F. From the above:

270 = 63+82.8 x f.27 f.27 = 2.5 whJch yields f = 29.7* and 29.5/5.04 = 5.9 f.e., the fluence projected for 32 EFPY of operation is a factor of almost 6 smaller than the fluence required to reach the screening criteria. Therefore, the Farley Unit 1 pressure vessel meets the criteria and is acceptable.

• This value of fluence is outside the range of available experimental data in Regulatory Guide 1.99.

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!s Evaluation and Conclusion for Unit ? Reactor Vessel As for Unit 1 above, the same elements relating to protection against PTS of the Unit 2 reactor pressure vessel are considered. Tables III.3-2 and IV.1-2 of WCAP-11047 describe the summary of data for the Unit 2 vessel.

The controlling beltline material from the standpoint of PTS susceptibility was identified as the Intermediate Shell Plate R7212-1. The material l properties of the controlling material (plate B7212-1) and the associated margin and chemistry factor are as follows:

, WCAP-11047 Staff Evaluation i Cu (copper content, %) = 0.20 0.20 Ni (nickel content, %) = 0.60 0.60 .

I (Initial RTNDT, F) = -10 -10 M (Margin, *F) = -

48 CF (Chemistry Factor, *F) = -

176 We agree that the controlling material has been properly identified. The justifications given for the copper and nickel contents and the initial i RT are acceptable. The margin has been derived from consideration of the

, ban for these values, following the PTS Rule. Assuming that the reported ,

values of fluence are correct, Equation 1 of the PTS rule governs, and the chemistry factor is as shown above.

Therefore, Equation 1, specified in 10 CFR 50.61, is applicable for Farley Unit 2 pressure vessel calculations as follows:

RT PTS = I + M + (-10 +470.Cu + 350.Cu.Nf)f.27 where: I = initial RT = -10*F M = uncertaint h 48*F Cu = w/o Copper in the intermediate shell plate B7212-1 = .20 Ni = w/o Nickel in the intennediate shell plate B7212-1 = .60 ,

f = peak fluence (E greate or equal to 1.0 Mevi onplateB7?I2-1x10~{gthag/n=5.04 cm then: RT 10+48+(-10pj *g 0 x.20 + 350 x PTS = 20x.60)x5.04

= 38+126x1.547 = 233*F less than or equal to 270*F The RT adequaN3= mar gin.233*F To gain meets the 10 CFR a quantitative 50.61 criterion estimate of less of the margin letthan us 270*F by an calculate the fluence required to reach the screening criterion, i.e.,

RTPTS = 270*F. From the above:

770 = 38+126 x f.27 which yields f = 9.6 and 9.6/5.04 = 1.9 1.e., the fluence projected for 32 EFPY of operation is a factor of almost 2 smaller than the fluence required to reach the screening criteria. Therefore, the Farley Unit 2 pressure vessel meets the criteria and is acceptable.

Principal Contributors:

P. Randall L. Lois E. Reeves l

l

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