ML20206H689

Safety Evaluation Supporting Amend 127 to License NPF-1

ML20206H689
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	04/09/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20206H643	List: ML20206H640 ML20206H658 ML20206H689
References
NUDOCS 8704150417
Download: ML20206H689 (3)

Text

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[ UNITED STATES

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,j NUCLEAR REGULATORY COMMISSION WASHINGTOld, D. C. 20555

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.127 TO FACILITY OPERATING LICENSE NO. NPF-1 PORTLAND GENERAL ELECTRIC COMPANY THE CITY OF EUGENE, OREGON PACIFIC POWER AND LIGHT COMPANY TROJAN NUCLEAR PLANT DOCKET NO. 50-344 INTRODUCTION ,

In a letter from B. D. Withers to S. A. Varga, dated October 31, 1986, the Portland General Electric Company (the licensee) submitted License Change

Application (LCA) 147 requesting amendment of Operating License NPF-1. This LCA addresses the Trojan Nuclear Plant reactor vessel pressure-temperature limits and surveillance capsule removal schedule. The bases for the proposed heatup and cooldown limits and the surveillance capsule removal schedule are the test results from the Tro.ian surveillance program submitted for staff review in a letter from B. D. Withers to S. A. Varga dated January 23, 1986.

This January 23, 1986 letter contained the Westingh'ouse Report WCAP-10861,

" Analysis of Capsule X From Portland General Electric Company Trojan Reactor Yessel Radiation Surveillance Program," by S. E. Yanichko, S. L. Anderson, and W. T. Kaiser, and dated June 1985.

l DISCUSSION AND EVALUATION <

j Pressure-temperature limits must now be calculated in accordance with the l revised requirements of Appendix G, 10 CFR 50, which became effective on j

! July 26, 1983. Pressure-temperature limits that are calculated in accordance j l

with the requirements of Appendix G,10 CFR 50, are dependent upon the initial reference temperature (RT closure flange regionsN of Ske) reactorfor vesselthe limiting materials and the increase in the beltline in RT and resulting from neutron irradiation damage to the limiting beltline $[erial.

The licensee indicated that the initial RT for the limiting materials in the closure flange and beltline regions of E[e Trojan vessel was estimated using the method recommended by the staff in Branch Technical Position MTEB 5-2, " Fracture Toughness Requirements", which is documented in the Standard Review Plan, Section 5.3.2, " Pressure-Temperature Limits."

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l The limiting beltline material is the lower shell plate (heat' no. B9883-1).

'The welds are not limiting because their copper composition and initial P.TNDT are lower than that of the plate materials. The licensee indicates that of 10*F for the Branch lower shell Technical plate B9883-1. Position MTEBThe licensee 5-2 results in an initial indicated RT"kImiting closure that the flange region material is the closure head flange, in which the initial RTNDT

• is estimated as 20 F.

The increase in RT resulting from neutron irradiation damage depends upon thepredictedamoukTof neutron fluence and the rate of embrittlement of the limiting reactor vessel beltline material. Thelicenseeestimatedtgtthe2 neutron fluence at the inside surface of the vessel will be 0.9 x 10 n/cm at10effectivefullpoweryears(EFPY).

The increase in RT resulting from neutron irradiaiton damage was estimated by the licensee ac5Nding to Regulatory Guide 1.99 Rev.1, "Effect of Residual .

Elements on Predicted Radiation Damage to Reactor Vessel Materials." Table 1 compares the observed increase in RTN of the surveillance lower shell plate (heatno.C5583-1)tothatpredictedNcordingtoRegulatoryGuide1.99Rev.1.

The surveillance plate material is not from,the same heat lot as that in the limiting beltline material. The surveillance material test results indicated that the increase in RT of the surveillance material is less than that predicted by Regulatory Nide 1.99 Rev. 1. Hence, the Regulatory Guide should provide a conservative estimate as to the amount of increase in RTN resultingfromneutronirradiationfortheTrojanlimitingreactorgssel beltline material.

TABLE 1 .

Comparison of Observed and Calculated Increase in RT of Lower Shell Plate C5583-1 in Surveillance Capsu1NT Surveillance Capsule Increase in RT NDT Increase in RT Capsule Fluence Measured CalculatedUsik R.G. 1.99 Rev. 1 2 (op) (.p)

(n/cm )

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I9 44 78 U 0.388x10 19 X 1.77 x10 95 166 i

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t , t The staff has used the unirradiated RT for beltline and closure flance materials, which were previously discubd, the neutron fluence estimates of the licensee, the Regulatory Guide 1.99 Rev. I method of estimating neutron

• irradiation damage, and the Standard Review Plan 5.3.2 method of calculating 4 pressure-temperature limits to evaluate the licensee's proposed pressure-temperature limits. Our evaluation indic'ates that the proposed pressure-temperature limits meet the safety margins of Appendix G,10 CFR 50, for a period of time corresponding to 10 EFPY. We have also used ASTM E 185-8?

to evaluate the licensee's proposed surveillance capsule removal schedule and have determined the proposed schedule to be acceptable.

ENVIRONMENTAL CONSIDERATION I This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the amendment involves no significant increase '

in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual J

or cumulative occupational radiation exposure. The Comission has previously published a proposed finding that the amendment ipvolves a no significant hazards consideration and there has been no public coment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 651.22(cM9). Pursuant to 10 CFR {51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

I CONCLUSION l

l We have concluded, based on the considerations' discussed above, that (1) there is reasonable assurance that the health and safety 'of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance l

of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

j' Dated: April 9, 1987 PRINCIPAL CONTRIBUTOR:

S. Lee

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