ML20217M174

Forwards Correction to Page 7 of Safety Evaluation Re Acceptance Ltr for Referencing of Pressure Temp Limits Rept

ML20217M174
Person / Time
Site:	Farley
Issue date:	04/03/1998
From:	Jacob Zimmerman NRC (Affiliation Not Assigned)
To:	Dennis Morey SOUTHERN NUCLEAR OPERATING CO.
References
TAC-M99338, TAC-M99339, NUDOCS 9804080025
Download: ML20217M174 (5)

Text

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Mr. D. N. Morey, Vice President Farley Project Southem Nuclear Operating Company, Inc.

Post Office Box 1295 Birmingham, Alabama 35201-1295

SUBJECT:

JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2, CORRECTION TO ACCEPTANCE LETTER FOR REFERENCING OF THE PRESSURE TEMPERATURE LIMITS REPORT (TAC NOS. M99338 AND M99339)

Dear Mr. Morey:

On March 31,1998, the U.S. Nuclear Regulatory Commission issued an acceptance letter for referencing of the Pressure Temperature Limits Report for Joseph M. Farley Nuclear Plant j (Farley), Units 1 and 2. The acceptance letter documented the staffs review of your '

methodology associated with pressure temperature (P/T) limit curves, the residual heat removal system relief valves used for overpressure mitigation, and the P/T limits report. The staff found this methodology acceptable for referencing in the administrative controls section of the Farley, Units 1 and 2, technical specifications (TS) to the extent specified and under the limitations delineated in your submittals, and the staffs associated Safety Evaluation (SE).

On page 7 of the staffs SE, the staff erroneously stated that the Farley P/T limit curves assume one reactor coolant pump and two residual heat removal (RHR) pumps are operating below ,

110 *F, with a 25 psi adjustment, instead of a 27 psi adjustment, which is consistent with your  !

February 12,1998, submittal. In addition, on page 7 of the staffs SE, the staff stated that to l account for RHR relief valve setpoint drift, the setpoint is set 3 percent below the TS-required j setpoint so that the setpoint can drift while not violating the TS requirement. This statement I has been modified to eliminate the 3 percent value and incorporate the following statement: 3, "The RHR relief valves are currently calibrated for a 1% drift and will be recalibrated to "

I incorporate a 3% drift at each units next refueling outage." This clarification is needed to allow the RHR relief valve setpoints to be recalibrated during the next refueling outage without impacting current plant operations. In addition, you indicated that the following safety impacts exist if recalibration of the RHR safety valves is performed at power: (1)increasedoperator [

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• D. N. Morey April 3, 1998 dose from working in containment; (2) worker safety issues associated with working in the vicinity of the unisolated pressurizer relief tank; and (3) removal from service of each RHR train to recalibrate the relief valves.* Therefore, resetting the RHR relief valves during the next refueling outage for each unit is acceptable.

' Sincerely, ORIGINAL SIGNED BY:

Jacob 1. Zimmerman, Project Manager Project Directorate 11-2 Division of Reactor Projects - 1/11 Office of Nuclear Reacter Regulation Docket Nos. 50-348 and 50-364 DISTRIBUTIO']

Docket File BSheron JStrosnider BBoger

Enclosure:

Safety Evaluation PUBLIC GHolahan ESullivan JZwolinski PDll-2 RF TCollins KWichman HBerkow cc w/ encl: See next page OGC EWeiss BElliott CJackson ACRS RCaruso JMedoff MWeston LPlisco,Ril LLois WBeckner PSkinner, Ril i

DOCUMENT NAME: G:\FARLEY\M99338.COR Indicate in the box: "Q" = Copy w/o enci "E" = Copy w/ encl"N",=Mo copy OFFICE- PM:P%fg PM:PDll-2 d Qs l0/ CISRXB:b3SA l NAME JZirffiSprffan:cn l: Berry W TCollins W DATE y/'#/96" L//'k/98 4 / 2 /98 OFFICE - PD:P@2, l L f(i NAME HBerh$v' DATE 4/)/98 OFFICIAL RECORD COPY x

D. N. Morey_ dose from working in containment; (2) worker safety issues associated with working in the vicinity of the unisolated pressurizer relief tank; and (3) removal from service of each RHR train to recalibrate the relief valves. Therefore, resetting the RHR relief valves during the next ~

refueling outage for each unit is acceptable.

Sincerely, 3

cob 1. Zimmerman, Project Manager Project Directorate Il-2 Division of Reactor Projects - 1/II Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364

Enclosure:

Safety Evaluation cc w/ encl: See next page I

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,.:.m .

Joseph M. Farley Nuclear Plant cc:

Mr. R. D. Hill, Jr. '

General Manager-Southem Nuclear Operating Company Post Office Box 470 Ashford, Alabama 36312 Mr. Mark Ajiuni, Licensing Manager Southem Nuclear Operating Company

~

Post Office Box 1295 - - - -' ~

Birmingham, Alabama 35201-12g5 Mr. M. Stanford Blanton l Balch and Bingham Law Firm -

Post Office Box 306 1710 Sixth Avenue Nonh Birmingham, Alabama 35201 Mr. J. D. Woodard Executive Vice President Southem Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201 State Health Officer Alabama Department of Public Health 434 Monroe Street Montgomery, Alabama 36130-1701 Chairman  !

Houston County Commission Post Office Box 6406 Dothan, Alabama 36302 Regional Administrator, Region ll U.S. Nuclear Regulatory Commission Atlanta Federal Center 61 Forsyth Street, S.W., Suite 23T85 Atlanta, Georgia 30303 Resident inspector

. U.S. Nuclear Regulatory Commission ,

7388 N. State Highway 95 Columbia, Alabama 3631g i

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overpressure protection is required,325 'F. The staff finds this acceptable for both units.

Additionally, the licensee raised the minimum bolt-up temperature to 75 Y to include instrumentation uncertainties to prevent an overpressure event below where the P/T limit curves are calculated. Based on the above discussion, the staff finds the temperatures where

~ LTOP is required acceptable and the ir thodo;ogy used to determine the temperatures where LTOP is required acceptable.

3.3.2 RHR Relief Valve Satpo nt TS 3.4.10.3 requires that the two RHR relief valves be set less than or equal to 450 psi. The methodology requires that setpoints be verified acceptable to protect the P/T limit curves.- This - -- --:-

is performed by analyzing the limiting mass and energy addition transients. These transients are performed in accordance with the approved Westinghouse methodology, WCAP-14040-NP-A. The limiting mass addition transient is the start of one charging pump below 180 P and the start of all three charging pumps above 180 *F. TS 3.1.2.3 prohibits having more than one charging pump capable of injecting below 180 T, except while swapping charging pumps, to preclude a more severe mass addition transient. The limiting energy addition transient is the start of a single RCP with the secondary SG temperature 50 P higher than the primary system.

TS 3.4.1.3 prohibits starting a RCP with the SG temperature greater than 50 Y higher than the RCS to preclude an more severe heat addition transient.

The analysis conservatively models the overpressure transients. The analysis credits only one of the two RHR relief valves. To account for valve accumulation no relief flow is modeled prior to 10% higher than the setpoint. Rather than modeling the valve to gradually open from 0-10%,

'it is assumed to fully open at the 10% accumulation. No pressurizer bubble was assumed during the transient. These are all conservative assumptions. To account for relief valve tolerance drift or setpoint uncertainty the licensee noted that because the ASME Code allows relief valves to drift, the setpoint of the valve must be set below the TS value of 450 psi. To account for setpoint drift, the setpoint is set below the TS-required setpoint so that the setpoint can drift while not violating the TS requirement. The RHR relief valves are currently calibrated for a 1% drift and will be recalibrated to incorporate a 3% drift at each units next refueling outage.-

The steady state Appendix G curves were used to verify that the RHR relief valve setpoints are acceptable because an overpressure transient is most likely to occur at steady state conditions.

The P/T limit curves include an adjustment to account for the pressure difference between the limiting vessellocation and the pressure sensor. The pressure difference is made up of the static head, associated with the elevation difference, and the dynamic head associated with the operation of the RCPs and the RHR pumps. The curves assume one RCP and two RHR pumps are operating below 110 T, with a 27 psi adjustment, and three RCPs and two RHR pumps above 110 *F, with a 60 psi adjustment.- A note has been added to TS 3.4.1.4 to l

preclude operation of more than one RCP below 110 *F except to keep continuous flow while taking a pump out of service. As a result, the staff finds current setpoints and the methodology ,

used to verify the setpoints are acceptable. j l

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