ML19210F024

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Responds to NRC 791030 Ltr Re Implementation Methods & Schedules for NUREG-0578.Util Will Complete Tasks According to Schedule Except Those Requiring Cold Shutdown.Pressurizer Heaters & Level Mods Scheduled for 1980 for 1981 Outages
ML19210F024
Person / Time
Site: Fort Calhoun Omaha Public Power District icon.png
Issue date: 11/27/1979
From: William Jones
OMAHA PUBLIC POWER DISTRICT
To: Harold Denton
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0578, RTR-NUREG-578 NUDOCS 7912130416
Download: ML19210F024 (9)


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Jw bK Omaha Public Power District 1623 MARNEY OMAMA. NESRASMA 68102 TELEPMONE 536 4000 AREA CODE 402

Icvember 27, 1979
'r. Haroli R. Centen, Director Office f .Iuclear Reactcr Regulation U. S. :Iuclear Regulatcry Cc=issicn dashingt:n, D. C. 20555

Reference:

Docket :lo. 50-285 Oear fir. Centen:

The Ctaha Public ?:ver District is in receipt of your Octcber 30, 1979, letter in regard to implementaticn methcds and schedules fcr

FJRE0-0578. As discussed in our letter of Octcher 25, 1979, all in-plementation methcis for :UJREG-0578 tasks are in acccrdc=ce with the Staff's requirements, except as described in Attachment i to this letter. It is the District's intention to cceplete these tasks according to schedules provided in :FJREG-0573, except that modifi-cations identified in the attachment to our Octater 25, 1979, letter which require a shutdcvn to ecsplete and are designated to be in-plemented by January 1, 1980, or January 1, 1981, will be ccepleted during the 1980* cr 1981 refueling cutage at the Fort Calhoun Station, as applicable. Attachment 1 centains an explanation for cc pleting tasks during refueling cutages. These implementaticn schedules depend upcn the availability of equipment fcr modifications. We have not identified any tasks which cannot be implemented due to equipment delivery delays at present. However, equipment delivery times are difficult to predict and suppliers have not been identi-fied for all :lL* REG-0578 tasks.

The District believes that there is just cause for postpcning nodifications which require a shutdcun to cceplete to the next re-fueling cutage scheduled after the implementaticn date of the :TJREG.

This belief is based upon the considerations delineated belov.

1. Health and safety impact. The 1980 and 1981 refueling cutages are scheduled to ec==ence in January, 1980, and March, 1981, respectively. Implementation of tasks during the 1980 refueling cutage vculd cause the Fort Calhoun Station to be cperable without :IUREG-0578 shcrt ter: 1980 tasks i=plemented for only two weeks past the January 1,1980, implementatien date. The 1981 refueling outage cc==ences apprcximately 90 days past the :iUREG-0578 implementatica date for January 1,1981, tasks. All required =cdifications would be implemented "The 1980 refueling cutage vill cc==ence no later than January lh, 1980.

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Mr. Harold R. Denton November 27, 1979 Page Two v.

prior to unit startup after the respective refueling out-age. It is not believed that operatin,: the facility fcr approximately 100 lays withcut NUREG-0578 tacks ccmpleted would jeopardize the health and safety of the public or in any way significantly increase the probability of a nuclear incident occurring at the station.

2. Econcmic censideraticna. Perforcing NUREG-0573 taska during a scheduled refuelin-: cutage vcula encure m1xinun unit availability and mininum pcVer coats to the Dis-trict's ratepayers. Should the unit te shut dcyn solely to implement NUREG-0578 tacks, more costly replacement power vculd be needed, possibly originating frcm cil fired peaking units or purchased frem other utilities.

It is impcrtant to maximize unit availability during the vinter months when pcver usage is at a peak, in order that unforeseen unit chuticvna and/cr :ther con-tingencies can be handled assuring continued availability cf power to cur custcmers.

3. Conservaticn. A 2peci21 shutdevn of the Tcrt Calbcun Staticn to implement NUREG-0573 tasks during the high power demand vinter conths may require the use of oil fired peaking units to compensate for lost pcVer. In the interest of ccnservation of oil resources and in adherence with cur naticnal energy pclicy, it woula be better to generate with nuclear fuels.

L. Thernal cycling. Performing NUREG-0578 tack: lurin,; a refueling cutage would minimize the number cf required ple.nt cutages ana resulting thermal stresces en safety-related systems. Thermal stress cauced by changing pcVer leads is a kncvn centributcr to piping failures.

5 3afety system challenges. Maintaining the plant in a cteady state of operaticn reduces the pctential for challenging safety systems. The Cot =1ssion has ex-pressed a desire through recent ccrrespcndence to minimize challenges to safety systems.

c. ALARA. :!inimizing the number of shutdevns required is censistent with ALARA policy. Every time the facility is brcught to a cold shutdevn for a sustained pericd of time, certain a= cunts of liquid and gaseous vastes are generated. These vastes must be prccessed through the radvaste treatment systems and released and/or dis-

"osed of in a centrolled manner. Waste handling results e

in in incremental radiation exposure to personnel handling the vaste, ac well as to the general public. These doses can be eliminated thrcugh ccnscienticus management of reactcr shutdowns.

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Mr. Harold R. Denton November 27, 1979 Page Three in additicn, deses vculd generally be less for perfern-ing =cdificaticns during a refueling cutage than a ncrtal cold shutdcvn because systems ccntaining radicactivity, which would centribute to radiaticn dose to verkers in-side the centainment, vculd normally be drained or flushed during a refueling cutage.

7 'IanpcVer availability. Increasing the number of plant cutages also increases the amount of time which the Dis-trict's staff cust dedicate to cutage planning and general plant cperaticns. These same personnel are also relied upon to respond to the concerns of NUREG-0578, as well as other licensing regulatory concerns.

The more time that is dedicated to cutage planning and shutdown cperaticns, the greater the amount Of

'*-a 'kat cannct be delicated tc meeting cur regulatcry cbligations.

In view cf the forescing consideraticns, it is believed that the TMI-2 lesscns Learnel Task Fcree short tern reccamendations can be acccmplished in a timely, respcnsible manner thrcugh the use of cur refueling cutages. In sc doing, the plant can be run econcaically, radiation doses can be kept to a minimum, and the safety and health cf the public can be maintained.

Sincerely, 9

W. C. Jcnes Divisicn Manager .

Production Operaticns

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Attachment ec: Le3ceuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N. W.

Washington, D. C. 20036 1552 316

ATTACE:E:C 1 TASK 2.1.1, EERGEI'CY PC'4ER SUPPLY REOUIRDE:0 Pressurizer Heaters A cold shutdown is required to perfor= =cdifications required by this task, since the =cdified circuitry can cnly be tested in a shutdown ecndition. In additicn, =cdificaticas to ecatrol circuitry should only be performed when the plant is shutdevn.

As a ec=pencatory measure for the two week pericd between January 1,1980, and ec==encement of our 1980 refueling outage, adequate overpressure during natural circulation can be provided by use of the pressurizer proportional heaters. These heaters would be available providing either off-site pcver is available er both diesel generaters are operable. The probability of having an incident which requires the use of these heaters and having a simultaneous loss of off-site pcVer 2nd loss of One diesel generatcr within the two week interi= pericd is believed to be acceptably small.

Pressurizer Level A plant shutdown is required to perfors =cdificaticns required by this task because the pressurizer level transmitters are located in an area which is inaccessible during pcVer operation. The pre-sent pressurizer level syste= is adequate for the interi= two week period between January 1, 1980, and ce==encement of the 1980 refuel-ing cutage because the =cdification vill only upgrade present level transmitters to safety grade. The pressurizer level indicaticn syste= is presently powered frc= energency pcver supplies and cables to the transmitters are LOCA qualified. Althcugh the presently in-stalled pressurizer level transmitters are not LOCA qualified, the pcssibility exists that they could function in a LCCA enviren=ent.

It is e=phasi:cd that noot of the requirements of this task vill bc set by January 1,1980.

PCRV and Block Valve Power Surely A plant shutdevn is required to perfor= =cdifications required by this task because areas must be entered which are nernally in-accessible during power operation. The presently installed syste=s provide for an e=ergency power supply to PORV and bicek valves.

Modifications will be perfor=ed only to provide adequate cable separ-atien and separation of pcVer supplies for the block valves. All other requirements of this task are =et. Therefore, the as-installed conditicn provides a sufficient 2y reliable pcVer supply to these valves for the intertn period between January 1, 19e0, and ec==ence-ment of the 1980 refueling outage. It is emphasized that = cst of -

the requirements of this task will be met by January 1,1980.

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PORV and Block Valve Pcver Supply The presently installed systems provide for an emergency power supply to PORV and block valves. Modificatiens will te perfer=ed only to provide adequate cable separation and separation of power supplies for the bicek valves. All ether requirements of this task are met. Therefore, the as-installed ecnditicn provides a sufficiently reliable power supply to these valves for the interim period between January 1,1980, and cc==encement of the 1980 refueling outage.

TASK 2.1.2, RE1IEF A'iD SATE"'Y VALVE TESTING A progrs: for testing PCRV's and safety valves used for pri-

=ary system pressure centrol under design bases cperating condi-tiens is being develcred by the CE Owners Grcup. These results will be available by January 1, 1980. It is nct possible for the District to ec==it to ec=pleting tests on these valves by July of 1981, since it is not currently kncvn what the nature of the testing progrsm vill be. The District will make every effort to ec=plete tests by July of 1981. Ecvever, the schedule cannot be resolved until the testing progrs= is formulnted.

TASK 2.1. 3.a, DIRECT INDICATIC:T OF VALVE PCSITICU. CA"'EGCRY A SAFE'~f GRADE A ccid shutdevn is required to perfcr= =cdifications required by this task, since primary syste relief and safecy valves are not accessible during normal operation. It is believed that adequate i indicatien of leakage past these valves exists for the two veek j interi period between January 1,1980, and cc==encement of the 1980 refueling cutage. Level and pressure of the pressuricer quench tank can be measured, as well as PORV and safety valve discharge line temperature.

TASK 2.1. 3.b , INS"'EUME'i'ATICU FCR INADEOUAE CCRE CCCLING Procedures to be used by an operator to recognice inadequate core cooling currently exist at the ?crt Calhcun Statien and ad-dress the use of existing instrumentaticn. (Refer to the District's letters of April 23, 1979, and August 10, 1979, in response to II Bulletin 79-C6B.) The design of new instrumentation to be used for this purpose which describes the functional design requirements for reactor level instrumentation vill be submitted to the Cc==issicn by January 1, 1980. This design is currently being prepared by our USSS vendcr.

Information required by the Cc==ission's Octcber 30, 1979, letter for this task, along with a description of a subecoling meter intended for use at the Fort Calhcun Statien, will be sub-mitted to the Con =issicn by January 1, 1980. Installation of the subecoling meter and new instrumentation other than the sub-cccling meter must be conducted during a plant shutdown because these systems uce sensors which =ust be placed in areas which are normally inaccessible during pcVer Operation. It is believed that existing instru=entation and procedures provide adequate informaticn to plant operatcrs to assess inadequate ccre cooling cenditions for the interim periods of January 1, 1980, to ec==ence-

=ent of the 1980 refueling cutage and frc= January 1,1981, to ec==encement of the 1981 refueling cutage. ~

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TASK 2.1.6.a, IN"EGRITY OF SYSTEMS OUTSIDE CCNTAI NENT LIKELY TO CCNTAIN RADICACTIVE MATERIALS By January 1,1980, the District vill sub=it a su==ary des-criptien of the program to reduce leakage frc= systems cutside containment that could contain highly radicactive fluids during a serious transient or accident. Included vill be a list of systems which are excluded frc= this progra=, Previous corres-pendence received frc= the Cc==ission did not include a require-

=ent to submit this information. These progra=s vill be i=plemented before January 1,1980, and will centinue thereafter.

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e . . . , . . $ ,2 e. r,d r.N The design review required by this task vill be ec=pleted by January 1, 1980. Modificatiens not requiring a plant shutdevn vill be ec=pleted by January 1,1981'. Those =cdifications that require a plant shutdown vill be completed during the 1981 refueling cut-age. Sc=e =odificatiens are expected to be ec=pleted before January 1, 1981, and others after that date. All =cdifications rould be cc=pleted prior.to startup folleving the 1981 refueling cutage.

TASK 2.1.7.a, AU-'CMATIC IN'T!ATICM CF "HE AL"CLIARY FIE4ATER SYS2! ,

Centrol Grade Syste=

A refueling outage is required to perfor= =cdificatiens re-quired by this task, since both auxiliary feedvater trains are re-quired to be re=cved frc= service at the same time to perform the required modificaticns. This vculd cause the plant to be placed into an unsafe operating condition and veuld violate Fort Calhcun ,

Station's Technical Specificaticas. For the interi= pericd between January 1, 1980, and ec==encement of the 1980 refueling cutage (approximately two weeks), a plant operator vill be assigned to

=cnitor the auxiliary feedvater centrols and take appropriate action as required. This assign =ent veuld be the operatcr's sole respen-sibility.

Safety Grade Syste=

A refueling cutage is required to perfor= =cdifications re-quired by this task for the same reason as noted above under "Centrol Grade Syste=". The centrol grade syste= is believed to provide adequate protecticn for the interim period frc= January 1, 1981, to ec==encement of the 1981 refueling cutage (apprcxt=ately 90 days).

TASK 2.1.7.b, AUXILIARY FEED'4A"ER FLC'4 INDICATION All requirements of this task are =et for the control grade indication system. Safety grade indication syste require =ents vill be met by performing =cdifications in two phases. The first phase vill be performed during the 1980 refueling cutage and vill consist of replacing s+.ea= generater level transmitters and auxi-liary feedvater flew trr.nc=itters with safety grade t;'.ansmitters.

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TASK 2.1.7.b, AUXILIARY FEEDWATER FLOW IHDICATION (Continued)

Phase two vill consist of upgrading auxiliary feedvater 'ficv indi-cation cabling to meet separation requirements. Steam generator level cabling is LCCA qualified and already meets separation re-quirements. Auxiliary feedvater flow indicatica cabling is LCCA qualified. Cal.le upgrading vill be ec pleted pricr to January 1, 1981.

It should be noted that the District intends to use steam generator level indication as the redundant indication to auxi-liary feedvater flow indication. Each auxiliary feedvater flow path vill be equipped with a single ficv indication channel and each steam generatcr vill be equipped with four ceparace level indicatien channels.

TASK 2.1.8.a, POST-ACCIDENT SAMPLING It was the District's intention to supply the design review,  !

procedures, and descriptien of plant modificatiens required by }

this task by January 1,1980. Ecvever, the Cccaission's letter of Octcber 30, 1979, centains a clarification which significantly increases the scope of the original requirement. As such, it is uncertain at this time that information in regard to dissolved gas, pH, and centainment hydregen can be supplied by January 1,19d0.

Howevar, a sced faith effort will be made to meet this schedule.

Modifications required by this task vill be cc=pleted to the extent possible prior to January 1,1981, providing a plant shut-  !

down is not required. A plant shutdevn vill be required to tie these systems into containment, since containment integrity must be breeched. Current post-accident sampling techniques are be-lieved to be adequate for the interim period between January 1, 1981, and ec =encement of the 1981 refueling outage to provide for this functica.

TASK 2.1.8.b, HICH RANGE RADIATION MCNITCRS The proposed =cnitoring system designs will be submitted to the Ccnmission ist review by October 1, 1980. Effluent and in-containment scnitoring capabilities described in the NUREG will be achieved prior to heatup following the 1981 refueling outage.

These modificaticas require entry to areas which are normally in-accessible during pcVer operation.

It was the District's intentien to implement by January 1, 1980, procedures for estimating noble gas and radiciodine releases, if existing effluent instrumentation goes off scale. Ecvever, the Cc==issien's letter of October 30, 1979, contained clarifi-caticn for this task which significantly increased the secpe of verk required, causing the District's implementaticn schedule to be uncertain at this time. These precedures, when developed, vill be sufficient to estimate releases for the interim pericd between January 1,1981, and correncement of the 1981 refueling outage.

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TASK 2.1. 8.e , IMPROVED IN-PLANT IODI TE I!IS"'RUMENTATION The District intends to =eet the requirements of this task by January 1, 1980. Fortable iodine instrumentation vill be precured by that date, provided equipment is available. Equip =ent avail-ability has not been investigated to date.

TASK 2.2.1.b, SHIFT TECFNICAL A07!SOR It is intended that Shift Technical Advisors vill provide an operating experience assessment function as well as an accident assessment function.

TASK 2.2.2.b , ON-SITE TECHNICAL SUPPORT CE'""ER The permanent center vill be established and operable prior to January 1, 1981.

CONTAI:NE'I"' 'JATER LT/EL INDICATION This task rust be perfer=ed during a reacter shutdevn because the ecntainment susp is inaccessible during pcver operation.

The Cennissien's clarification letter of Octcher 30, 1979, required a range of c00,000 gallons for the vide range channel versus 500,0C0 as originally required. As described in the District's response of October 25, 1979, the meditied system would ecnform to the existing level channel, providing a maximum indicaticn of approxi-mately 550,000 gallens. The potential su=p volume folleving a LCCA is apprcximately 367,000 gallens. Based upcn the estimated LOCA volu=e, it is believed that the 550,000 gallen maximum indication level vould provide adequate level measure =ent.

It is believed that for the interim period between January 1, 1981, and cc==encement of the 1981 refueling cutage existing con-tain=ent vater level indication capability, as described in cur October 25, 1979, letter, is sufficient to provide cc=pensatory indication.

CONTAIME'IT HYDROGEN MONI"'OR A refueling outage is required to perfor= the =cdificaticas required by this task, since centainment integrity must be violated.

Since the Fort Calhoun Statica is currently equipped with a hydrc-gen =cnitar, it is believed that sufficient hydrogen =cnitcring capability exists for the interim pericd between January 1,1981, and the 1981 refueling outage to provide ec=pensatory hydrogen

=cnitoring capability.

CONTAIMENT PRESSURE MCNITCR A refueling cutage is required to perform this task because containment integrity must be violated in order to install equip-ment. Modificaticns vill be ec=pleted prior to January 1,1981, to the extent possible.

1552 321 RCS VE'ITING This =cdification which requires breeching of the reactor coolant syste= boundary vill be performed during the 1981 refuel-ing outage. A normal plant shutdown vould probably not be adequate to install a valve on the reactor head. A refueling outage vould be required. The 1981 refueling cutage is the first refueling outage following ec=pletion of the design for this task.

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