ML19291C195

Forwards Response to 791022 Ltr Re Requirements for Auxiliary Feedwater Sys.Valves Locked in Required Position to Insure Flow Path to Generators.Emergency Procedures Changed for Sources of Water to Feedwater Tank

ML19291C195
Person / Time
Site:	Fort Calhoun
Issue date:	01/14/1980
From:	William Jones OMAHA PUBLIC POWER DISTRICT
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
NUDOCS 8001230103
Download: ML19291C195 (18)

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. t1 -vas Omaha Public Power District 1623 HARNEY OMAHA, NE5RASKA 68102 i TELEPHONE 536 4000 ARE A CODE 402 January lh, 1980 Mr. Darrell G. Eisenhut, Director Divisicn of Operating Reactors Office of Nuclear Reacter Regulation U. S. Nuclear Regulatcry Cctrission Washington, D. C. 20555

Reference:

Docket No. 50-285

Dear Mr. Eisenhut:

The Craha Public Power District received the Ccesissicn's letter of October 22, 1979, on the subject of NRC Requirements fcr Auxiliary Feedvater Systems at Fort Calhoun Station Unit No. 1. Enclosure 1 of the letter identified the Staff's re-quirements fer the staticn. The enclosure to this letter iterizes those requirements and provides the District's imple-mentatica plans and schedules for each iten.

Enclosure 2 of the Staff's letter will te addressed, as it applies to the safety grade auterstic auxiliary feedvater system, under separate cover.

Sincerely, s

5 '

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! - [: ';el,',;,

W. C. Jcnes Divisicn Manager Producticn Operations WCJ/KJM/PJH:jn:

Enclosure

}[))g ec: LeSceuf, Lamb, Leiby L MacRae 1333 New Hanpshire Avenue, N. W. Washingtcn, D. C. 20036 fo4A 5

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Enclosure X.3 3.1.1 Recen=endation GS-2 The licensee should leek cpen single valves or =ultiple valves in series in the AFW system pump suction piping and lock open other single valves or multiple valves in series that could interrupt all AFW flow. Menthly inspecticns should be perfer ed to verify that these valves are Iceked and in the open position. .These inspections should be proposed for incorporation into the surveillance requirements of the plant Tech-nical Specifications. See Recc=:endatien GL-2 for the longer tern resolutien of this concern. Res;cnse The appropriate valves have been Iceked in the required position to insure a flev path to the stess generators. An additional surveillance test is being prepared and vill be i=plemented prior to startup frc= refueling (scheduled to ectmence January 13, 1980) to check the position of critical valves in the auxi-liary feedvater system on a scnthly tasis. An auxiliary feedvater systen normal line up checklist has been completed to verify proper valve position. The District vill perfcr= these checks on a monthly basis during pcVer cperation until the above referenced surveillance test is implemented. The proposed change to Technical Specificatica sectica 3 9 re-quiring the sonthly surveillance test is attached to this enclosure. This change vill be formally submitced under separate cover. 17?! 200

X.3.3.1.2 Recc=nendation GS L Emergency procedures for transferring to alternate sources of AFW supply should be available to the plant operatcrs. Those procedures should include criteria to inform the operater when, and in what order, the transfer to alternate water sources shculd take place. The following cases should be covered by the procedures: The case in which the primary water supply is not initially available. The precedures for this case should include any operator action required to protect the AFW systen pumps against self-damage before water ficv is initiated; and The case in which the primary water supply is being depleted. The procedure for this case should provide the transfer to the alternate water scurces prior to draining of the primary water supply. Respense The appropriate operating instructions and emergency procedures vill be changed as necessary to incorporate the emergency sources of water for the energency feedvater tank including criteria for when they vill be used. The procedures and asscciated training vill be ec=pleted by the end of the 1980 refueling which vill begin en January 18, 1980, with a plant startup scheduled for approximately March 15, 1980.

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X.3.3.1.3 Reconnendaticn GS-o The licensee should confirm flow path availability of an AFW system ficv train that has been cut of service to perform periodic testing or maintenance as follows: Precedures shculd be inplemented to require an operater to determine that the AFW sycte valves are prcperly aligned and a second Operater to independently verify that the valves are properly aligned. The licensee should propose Technical Specificaticn to assure that prior to plant startup folleving an extended cold shut-down, a flev test would be perferred to verify the normal flow path frcm the primary AFW systen vater scurce to the steam generatcrs. The flow test should be conducted with AFW systen valves in their ncrmal alignment. Fes;cnse The current procedures fer tagging equipment cut of service at Fcrt Calhoun Station requires confirnation that a system is re-turned to service folleving maintenance. All valves are returned to their normal pcsition. The current maintenance crder system at Fcrt Calhcun provides for verifying system cperability at the ec pletion of the maintenance task. This insures that the systen is cperable at that time. A second indeper. dent verification of valve pcsition vill be provided en the scnthly test proposed in .(.3.3.1.1. Perfernance of the surveillance test fclleving naintenance en the auxiliary feedvater systen vill be required. Technical Specifications requiring a flew test to verify the normal flev path after a cold shutdown are attached. These speci-fications vill be formally submitted under separate ccver.

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h-X.3 3.1.k Recc==endation GS-7 The licensee should verify that the autc=atic start AFW sys-tem signals and associated circuitry are safety-grade. If this cannot be verified, the AFW system automatic initiatien system should be modified in the short-term to meet the functional re-quirements listed below. For the longer ter=, the autc=atic initi-ation signals and circuits should be upgraded to meet safety-grade requirements as indicated in Recc==endation OL-5 The design should provide for the autcmatic initiation of the auxiliary feedvater system flow. The autc=atic initiation signals and circuits should be designed so that a single failure vill not result in the loss of auxiliary feedvater system function. Testability of the initiation signals and circuits shall be a feature of the design. The initiatica signals and circuits should be povered frc= the emergency buses. Manual capability to initiate the auxiliary feedvater system frc= the centrol roc = should be retained and should be imple-mented so that a single failure in the manual circuits vill not result in the loss of system functice The alternating current noter-driven pumps and valves in the auxiliary feedvater system should be included in the auto-

       =atic actuaticn (simultaneous and/or sequential) of the leads to the emergency buses.

The autc=atic initiation signals and circuits shall be de-signed so that their failure vill not result in the loss of manual capability to initiate the AFW system frc= the centrol roc =. Restense This item is discussed in the Omaha Public Pcver District's response to :iUREG-0573, ita= 2.1.7.a, dated December 31, 1979 A 4 - 1"//i 203

_5_ X.3.3.1 5 The licensee should pz apare a procedure that assures that the operator manually connects the =ctor-driven pump train to the bus powered by the emergency diecel generater folleving loss of offsite power. Resycnse This ite= is discussed in the Cnaha Public Power District's respense to :iURIG-0573, ite= 2.1 7.a, dated Dece=ber 31, 1979 b 1/v1 204

X.3.3.1.6 Since valves FW Thh and 745 in ene of the AFW pu=p discharge headers are normally open, a postulated break in this header would cause loss of the capability to provide AFW flow to both steam generators. The licensee should re-evaluate the positicn of these valves considering such a postulated pipe break to revise the valve alignment to reduce the impact of such an event en the AFW capability (e.g. , close valves FW Tkh and FW Th5). Pesecnse The valves FW-7hh and FW-Th5 vill be normally =aintained in the closed positien to mitigate the consequences of a pipe break between FW-744, FW-Th5, and FW-Th6. These valves vill be placed in the closed position by January 21, 1980.

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_7_ X.3.3.2.1 Reccmmendatien The licensee should provide redundant level indications and low level alar =s in the centrol roc = for the AFW systen primary water supply to allow the operator to anticipate the need to make up water or transfer to an alternate water supply and prevent a lov pump sucticn pressure condition from occurring. The low level alarm setpoint should allow at least 20 minutes fo: operator action, assuming that the largest capacity AFW pump is cperating.

Response

To meet the requirements of this item, an additional level transmitter, level indicator, and associated alarm vill be added to the AFW syste= primary water supply during the 1980 refueling outage, scheduled to cctmence January 18, 1950. The alarm setpcint vill be set to allow at least 20 minutes for operatcr action. The above syste vill provide a control grade redundant level indicatien and icv level alarm to the AFW syste= primary water supply.

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                                     -S-x.3.3.2.2 Recon =endation The licensee should perform a 72-hour endurance test en all AFW syste= pumps, if such a test or continuous period of operation has not been acec=plished to date. Fellcving the T2-hcur pu=p run, the pumps should te shutdov:1 and cooled down and then restarted and run for one hour. Test acceptance criteria should include demonstrating that the pumps remain within design limits with res-pect to bearing / bearing oil temperatures and vibration and that pump roce ambient conditions (temperature, humidity) do not exceed enviren= ental qualification limits for safety-related equipment in the rec =.

Respcnse The feedvater water systen was tested as per the recctmendations of X.3.3.2.2. 3cth pumps were fcund to satisfactorily ec=plete the requirements of the S.E.R. Bulletin and all operating parameters remained within design limits. Pump test data is available at the Fcrt Calhoun Station for review. Specific Data: SP-EiDUR0-1 (72 Heur Endurance Test of FW-6) Pump was started on 0212 12/20/79 Pump vas stcpped on 0230 12/23/79 Pu=p was restarted en CSLC 12/23/79 The unit was run for cne hcur after 72 hours to prove operability. During the test, the folleving were meni-tored: =ater current, pump sucticn, discharge pressure temperature and vibration. SP-E'!DUF.0-2 (72 Hour Endurance Test of 74-10) Pump was started en 1652 12/29/79 Pump was stopped on 1701 1/1/S0 Pu=p was restarted en 1335 1/2/30 The unit was run for cne hour after 72 hours to prove operability. During the test, the following were =cni-tored: pump suction and diccharge, turbine oil temper-ature and pressure, steam supply pressure and varicus temperature and vibration cbservaticns. lis LdI

X.3.3.2.3 Reccmmendatien The licensee should i=plement the following requirements as specified by ite 2.1.7.b on page A-32 of NURIG-0578:

        " Safety-grade indication of auxiliary feedvater flow to each steam generator shall be provided in the control room."
        "The auxiliary feedvater fim- instrument channels shall be povered frc= the emergency buses consistent with satisfying the emergency power diversity requirements for the auxiliary feedvater systen set forth in Auxiliary Systems 3 ranch Tech-nical Position 10-1 of the Standard Reviev Plan, Section 10.k.9."

Restonse This ite= is discussed in the District's respense to NUREO-0578, iten 2.1.7.b, dated December 31, 1979

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X.3.3.2.h Recettendation Licensees with plants which require local =anual realignment of valves to conduct periedic tests on one AF4 system train, and there is enly one remaining AFW train available for creration, should prcpose Technical Specifications to provide that a dedicated indi-vidual who is in ect=unication with the control roc = te stationed at the manual valves. Upon instruction fren the centrol recm, this operator vould realign the valves in the AT4 systen train frem the test mcde to its operational alignment. Respence Local manual realignment of valves is not required to p rfern the present periodic testing requirements of the auxiliary feed-water system; therefore, no Technical Specification changes are proposed.

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X.3.3.3.1 Rece=rendation GL-1 Licensees with plants having a =anual starting AFW systen should install a system to autecatically initiate the AFW syste= flow. This systes and associated autcmatic initiation signals should be designed and installed to meet safety-grade requirements. Manual AFW systen start and contrcl capability should be retained with manual start serving as backup to automatic AFW system initiatien. (Note: This recc= endatien is applicable to the motor-driven AFW pump subsysten upon the loss of offsite AC pcver.) Restense This item is discussed in the District's respense to :iUREG-0578, item 2.1.7.a, dated December 31, 1979

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X.3.3.3.2 Reccmmendation GL-2 Licensees with plants in which all (primary and alternate) vater supplies to the AFW systems pass through valves in a single flev path should install redundant parallel ficv paths (piping and valves). Re ponse The Fort Calhoun Station currently utilizes a single header frc= vater supplies to the AFW pumps suction. Redundant parallel ficv paths vill be installed during the 1981 refueling cutage, scheduled to ec=- mence in March,1981. A design descriptien vill be suhmitted to the Ccnaissien fer review by Septe=ter,1980. I/7l 271

X.3.3.3.3 Recommendatien GL-5 The licensee should upgrade the AT4 system autcmatic initiation signals and circuits to meet safety-grade requirements.

Response

This ites is discussed in the District's response to :."JREG-0573, item 2.1.7.a, dated Decenter 31, 1979 l/n.y 2/2

                                     -lk-X.3.3 3.h Pecennendaticn The licensee should evaluate the folleving ccncerns:

a. The discharge lines of both AFW pumps cc=bine into a single header through which all AFW vater must flow. A ptpe break in this single fiev path eculd res"'+ d-

                                                    e Icss of the entire AFW systen function,

b. The Fort Calhoun AFW systen design does not meet the high energy line break criteria in SRP 10.L.9 and Branch Technical Position 10-1; namely, that the AFW syste= shculd maintain the capability to supply the required AFW ficv to the steam gener-ator(s) assuming a pipe break anywhere in the AFW pump dis-charge lines concurrent with a single active failure.

The licensee should evaluate the postulated pipe breaks stated above and (1) determine any AFW systen design changes or precedures necessary to detect and isolate the break and direct the required feedvater flow to the steam generatcr(s) before they boil dry or (2) describe how the plant can be brcught to a safe shutdevn condition by use of other systens which vculd be available following such postulated events. Respense

a. The cischarges frc the two auxiliary feedvater pumps do ec=bine into a single header for feeding the stess generators through the auxiliary feedvater no::les. It is not believed, however, that a break in this header would result in the total loss of auxiliary feedvater systen function. If a break occurs in this con =cn header, it can be isclated by the closure of the following valves:

HCV-1107A and/cr 3 HCV-1108A and/cr 3 HCV-138k and/or FW-169 and/cr FW-170 FW-lT2 Valves FW-Thh, Tk5, and ~k6 would then be opened, and auxi-liary feedvater vould flow into the steam generators through the main feedvater lines; using either FCV-1101 and 1102 cr the bypass valves, HCV-1105 and 1106. Main feedvater isolaticn valves HCV-1385 and 1356 are closed by the Containment isolation Actuation Signal (CIAS). If it became necessary to use the main feedvater syste: 2nd CIAS cecurred, the CIAS closure of HCV-1335 and 1336 would be overridden. Evaluation of this concern vill continue, and the results of the cc pleted evaluation vill be suh=itted to the Oct=ission by September, 1980.

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b. This concern vill be evaluated with results of the ecmpleted evaluation submitted to the Cem:ission by September, 1980.

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D R a. ; . ,., Proposed '"echnical Specifications 3.9) The position of valves necess ey to ensure auxiliary feedvater flev to the Stes= Generators should be verified by a =0nthly inspection.

'.anual valves which could interupt auxiliary feedvater flow to the stes: 2;enerators shculd be 10cked in the desired position.

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3.9a Prior to exceeding 300 ? the electric driven a= ciliary feedvater pu=p vill be tested to veri.^/ the corrsi flev path for a= cilia:/ feedvater to the steam generators. e 9 /

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