ML19257A554

Forwards Request for Addl Info Needed for OL Application Review.Response Should Be Submitted by 800228

ML19257A554
Person / Time
Site:	Zimmer
Issue date:	12/10/1979
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Borgmann E CINCINNATI GAS & ELECTRIC CO.
References
NUDOCS 8001040619
Download: ML19257A554 (18)

Text

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NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 su'.,...../

DEC 101979 s

Docket No. 50-358 Mr. Earl A. Borgmann Vice President - Engineering Cincinnati Gas & Electric Company P. 0. Box 960 Cincinnati, Ohio 45201

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION (Wm. H. Zimmer, Unit No. 1)

In order that we may continue our review of your application for a license to operate the Zimer Nuclear Power Station, Unit No.1, your response to the enclosed request for additional information is needed. The request is bared uoan information contained in your apolication as amended through Revision 62 and your resconses to our previous requests. We will need your response to this request prior to February 28, 1980.

Please contact us if you desire information or clarification regarding the enclosure.

Sincerely,

/

c JJ,L 5

Jo n F. Stolz, Chief:

M ght Water Reactors Branch No. 1 Division of Project Management

Enclosure:

Request for Additional Information cc:

See next page 1689 160 800104o $ k

d DEC 101979 cc:

Troy 3. Conner, Jr., Esc.

David 3. Fw.nauser, ?-3 Conner, cor,e & Corter 2569 :ine.::e Roao 1747 Pennsylvania Avenue, N. W.

Cincinnati, Chio 45230 Wasnington, 3. C.

ZCCC5 Dr. Frank F. dooner Mr. William J. Mars, School of '.a:Jeal Rescurces General Couns.1 University Of "ichigan The Cincinnati Gas and Electric Ann Accor, Micnigan n C9 Ccmaany P. O. Box 960 Mr. 5:epnen i: nun:acner Cincinnati, Onia 25201 Miami '!aile.. :c.,er Pr: mc:

P. O. Box 15.

I'r. William G. Porter, Jr.

Cay: n, Ch:c 45401 Porter, Stanley, Artnur anc Pla::

tis. Augusta :-ince, Chair:erson 37 'aes: 3 road Street 601 Stanie> -venue Colum0us. Oh1o 43215 Cincinnati, :nio 45225 itr. Steven G. Smitn, Manaaer Charles Secnneefer, Esc, Chairman Engineering & Project Control Atcmic Safe:y i Licens ng 3carc The Dayton Power anc LIgnt Panel Company U. S. tiuclear Regula:Ory ;;m. mission 3

O. Box 1247 Wasning::n, J. C.

20555 Cayton, Ohio 45401 Mr. Glenn 0. 3rian:

J. Robert Newlin, Counsel Atcmic Safe:" anc Licensing Tne Dayton Pcwer and Lign:

3 aro :anel Comoany U. 5. ':uclear ?ecula::"/ C:mmission P. C. Box 1207 Wasning:Or., 2. C.

5

5 Cayton, Ohio 45401 Lean S. Kos;<, Esc.

Mr. James D. Flynn 3454 Corne'l ?laca Manager, Licensing Cincinnati, Ohio 45220 Environmental Af fairs The Cincinnati Gas anc W. Peter.meile, Esq.

Elec:ric Comoany Assistant City Solici ce P. O. Box 960 Room 214, City Hall Cincinnati, Ohio 45201 Cincinnati, Unio 45220 Mr. J. P. Fenstermaker Atomic Safety and Licensing 5:ard Senior Vice Presicent-Coerations Panel Colum::us and Southern Ohio U. 5. Nuclear Regula::ry C;mi s sion Electric Company

'!asnington, 3. C.

2:555 215 Nortn Front Street Columaus, Ohio 43215 Atcmic Safe:j anc Licensing A:::eal Scard U. 5. Nuclear Pecula:."' Co=ission Wasaington, O. C.

205~i 1689 lbl

ENCLOSURE RE0 VEST FOR ADDITIONAL INFORMATION WM. H. ZIMMER ROUND-TWO OVESTTONS Introduction This enclosure consists of the twenty-eighth in a series of positions (and requests for additional information). We will need your response in order to complete our safety evaluation of your Zimmer OL application. The request is in the area of:

020.0 Auxiliary and Power Conversion Systems It will be helpful to us if your responses are in a " Position and Response" format using the same number designation as the position.

The first number designated the review area and the second (in parentheses) designated the associated section of the FSAR. Of course, your responses should include revision to the FSAR wherever appropriate.

NOTE: The CL review of your plant in this area was completed some time prior to issuance of NUREG/CR 0660 (February 1979) and its recommendation regarding the enhancement of onsite emergency diesel generator reliability. We recognize that implementation of scre of the recomr.endations may have been covered in the prior review and have been adecuately documented in the FSAR.

Mowever, due to the time lapse, we cannot ascertain this in a timely manner.

Therefore, you are recuested to respond to the complete set of questions and positions enclosed.

Reference to an FSAR section which contains the requested information will be an acceptable response.

}b09 b

ENCLO5URE 2 C;0.39 Provide a discussion of the measures tnat have been taken in the design

'9.5.6) of the standby diesel generater air starting systen to preclude the fouling of the air start valve or filter with moisture and contaminants such as oil carryover and rust.

(SRP 9.5.6, Part :II, item 1).

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020.40 Experience at some operating plants has shown that diesel engines have (9.5.a) failed to start due to accumulation of dust and otner delf terious material on electrical equipment associated with starting of the diesel generators (e.g., auxiliary relay contacts, control switches - etc.).

Describe the provisions that have been made in ycur diesel generator building design, electrical starting system, and combustion air and ventilation air intake design (s) to preclude this condition to assure availability of the diesel generator on demand Also describe under normal plant oneration what nrocedure(s) will be used to minimi:e accumulation of dust in the diesel generator room; specifically address concrete dust control.

In your response also consider the condition when Unit 1 is in operation and Unit 2 is under construction (abnormal generation of dust).

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U20.41 The diesel generators are required to start automatically on 'oss of (9.5.5) all offsite power and in the event of a LOCA. The diesel generator sets should be capable of operation at less than full load for extended periods without degradation of perfor ance or reliability. Should a LOCA occur with availability of offsite power, discuss the design provisions and other parameters that have been considered in the selection of the diesel generators to enable them to run unicaded (on standby) for extended periods witnaut degradation of engine performance or reliability.

Expand yeur PSAR/FSAR to include and explicitly define the capability of your design with regard to this requirement.

(SP.? 9.5.5, Part III, Item 7).

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020.42 Section 9.5.4.1 emergency diesel engine fuel oil storage and transfer system (9.5.4)

(ECEFSS) does not specifically reference ANSI Standard N195 " Fuel Oil Systems for Standby Diesel Generators".

Indicate if you intend to comply with tnis stan-dard in your design of the EDEFSS; otherwise provide justification for non-c: pliance.

(5RP 9.5.4, sev.1, Part II, item 12).

020.43 Assume an unlikely event has occurred requiring operation of a diesel generator (9.5.*)

for a prolonged period that would require.eplenishment of fuel oil without in-terrupting operation of the diesel generator. What provision will be made in the design of the fuel oil storage fill system to minimi:e the creation of tur-bulence of the sediment in the bottom of the storage tank. Stirring of this sediment during addition of new fuel has the potential of causing the'overall cuality of the fuel to become unacceptable and could potentially leac to the degradation or failure of the diesel generator.

02U.0 Discuss the precautionary measures that will be taken to assure One quality (9:5.4) and reliability of the fuel oil supply for emergency diesel generator operation.

Include the type of fuel oil, impurity and quality limitations as well as diesel index number or its equivalent, cloud point, entraine: moisture, sulfur, parti-culates and other deliterious int luble substances; procedure for testing newly delivered fuel, periodic sampling and testing of on-site fuel oil (including interval between tests), interval of time between per1ccic eemoval of concen-sate fren fuei tanks and periodic system inspection.

In your discussion in-clude reference to industry (or other) standard wnich will be folicwed to assure a reliable fuel oil supply to the emergency generators.

(ORP 9.5.4, Part III, items 3 and 4).

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020.45 Operating experience has shown that a';cumulation of water in the starting

/.i.6) 95P air system has been one of the most frequent causes of diesel engine failure to start on demand. Condensation of entra f r.ed moisture in com-pressed air lines leading to control and starting air valves, air start motors, and condensation of moisture on the working surfaces of these com:enents has caused rust, scale and water itself to build up and score and jam the internal working parts of these vital com;onents thereby preventing starting of the diesel generators.

In the event of loss of offsite power the diesel generators must function since they are vital to the safe shutdown of the reactor (s).

Failure of the diesel engines to start from the effects of moisture condensation in air starting systems and from other causes have lowered their operational reliability to substantially less than the desired reliability of 0.99 as specified in Brancn Technical Position ICSB (PSB) 2 "Oiesel Generator Reliability Testing" and Regulatory Guide 1.108 " Periodic Testing of Diesel Generator Units Used as Cnsite Electric Pcwer Systems at Nuclear Power Pl ants."

Ir an effort toward improving diesel engine starting reliability we require that compressed air starting system designs include air dryers for the removal of entrained moisture. The two air dryers.mst commonly used are 1689 167

the dessicant and refrigerant types. Of these two types, the refrigerant type is the one most suited for this application and therefore is pre-ferred. Starting air should be dried to a dew point of not nore tnan 500F when installed in a normally controlled 100F environment, otherwise the starting air dew point should be controlled to at least 100F less nan the lowest expected ambient temperature.

Revise your design of the diesel engine air starting system accordingly, describe this feature of your design.

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l 020.d6 Operating experience at certain nuclear power plants which have 'two (3.3).

ASP cycle turbocharged diesel engines manufactured b.' :he Electromotive Division (EMD) of General Motors driving emergency generators have exoerienced a sienificant number of turbocharger T.echanical gear drive fail ures. The failures have occurred as the result of running the emergency diesel generators at no load or light load conditions for extended periods. No load or light load operation could occur during periodic equipment testing or during accident conditions with availability of offsite power. When this equipment is opera:N under no load conditions insufficient exhaust gas volume is generated to operate the turbotnarger.

As a result the turaccharger is driven mechanically from a gear crive in order to supply enough combusion air to the engine to maintain rated speed. The turbocharger and mechanical drive gear normally supplied with these engines are not designed for standby service encountered in nuclear power plant application where the equipment may be called upon to operate at no load or light load condition and full rated speed for a prolonged period. The EMD equipment was originally designec for locomotive service where no load speeds for the engine and generator are much lower than full load speeds. The locomotive turbocharged diesel hardly ever runs at full speed except at full load. The EMD has strcngly recommended to users of this diesel engine design against operation at no load or light load conditions at full rated speed for extended periots because of the short life expectancy of the turbocharger memdfal gear drive unit normally 1689 169

furnished, N load or light lead operation also causes general dete-faration in any diesel engine.

To cope with the severe service the equipment is r:rmally :ubjected to and in the interest of reducing failures and increasing the availability o' their eeutoment EMD has developed a heavy duty turtocharger drive gear unit that can replace existing equipment. This is available as a replacement kit, or engines can be ordered with the heavy duty turco-charger drive gear assembly.

To assure octimum availability of emergency diesel generators on demand, Applicant's who have on order or intend to order emergency genera, tors driven by two cycle diesel engines manufactured by EMD should be provided with the heavy duty turbocharger mechanical trive gear assembly as recommended by EMD for the class of service encour,tered in nuclear power pl ants. Confirm your compliance with this require.ent.

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320.17 Provide a detail discussion (or plan) of the level of training proposed (3.3) for your operators, maintenance crew, quality assurance, and supervisory personnel responsible for the operation and maintenance of the emergency diesel generators. Identify the number and type of personnel that will be dedicated to the operations and maintenance of tne emergency diesel generators and the number and type that will be assigned from your general plant operations and maintenance groups to assist when needed.

In your discussion identify the amount and kind of training that will be received oy each of the above categories and the :ype of ongoing training program planned to assure optimum availability of the e.mergency generators.

Also discuss the level of education and minimue. experience requirements for the various categories of operations and maintenance personnel associated with the emergency diesel generators.

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020.48 Several fires have occurred at some operating plants in the area of (3.5.7)

P.5 P the diesel engine exhaust manifold and inside the turbocharger hou;ing which have resulted in equipment unavailability. The fires were started from lube oil leaking and accumulating on :ne engine exhaust manifold and accumulating and igniting inside the turbocharger housing.

Accumulation of lube oil in these areas, on some engines, is apparently caused from an excessively long prelube period, generally longer than five minutes, prior to manual starting of a diesel generator. This condition does not occur on an emergency start since the prelube period is minimal.

When manually starting the diesel generators for any reason, to minimize the potential fire hazard and to imorove equipment availability, the prelube period should be limited to a maximum of three to five minutes unless otherwise recommended by the diesel engine manufacturer. Confirm your compliance with this requirement or provide your justification for requiring a longer prelube time intervai perior to manual starting of the diesel generators.

Provide the prelube time interval your diesel engine will be exposed to prior to manual start.

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020.40 An emergency diesel generator unit in a nuclear power plant is normally (3.5.7)

AIF in the ready standby mode unless there 4 a loss of offsite power, an accident, or the diesel generator is under test. Long periods on standby have a tendency to drain or nearly empty the engine lube oil piping system. On an emergency start of the engine as much as 5 to 14 or more seconds may elapse from the start of cranking until full lute oil pressure is attained even though full engine speed is generally reached in about five seconds. With an essentially dry engine, the momentary lack of lubrication at the various moving parts may damage bearing surfaces pro-ducing incipient or actual component failure with resultant equipment unavailability.

The emergency condition of readiness reputres this ecui; ment to attain full rated speed and enable automatic sequencing of electric load within ten seconds. For this reason, and to improve upon the availability of this equipment on demand, it is necessary to establish as quickly as possible an oil film in the wearing parts of the diesel engine. Lubricating oil is normally delivered to the engine wearing parts by one or more engine driven pump (s). During the starting cycle the pump (s) ac:alerates slowly with the engine nd may not supply the required cuantity of lubricating oil where needed fast enougn. To remedy this condition, as a minimum, an electrically driven lubricating oil pump, powered from a reliable CC power supply, snould be installed in the lube oil system to operate in parallel with the engine 1689 173

driven main lube pump, The electric driven prelube pump should coerate only during the engine cranking cycle or until satisfactory lube oil pressure is established in the engine main lube distribution header.

The installation of this prelube pump should be ccordinated with :he respective engine manufacturer, Some diesel engines include a lube oil circulating pump as an intregal part of the lube oil preheating system which is in use while the diesel engine is in the stancby mode, In this case an additional prelube oil pump may not be neeced.

Can'irm your compliance with the above requirement or provide your justification for not installing an electric prelube ofi pump,

020.50 Periodic testing and test loading of an emergency diesel generator (3.3)

SP in a nuclear power plant is a necessary function to camonstrate One operability, capability and availability of the unit on demend.

Periodic testing coupled with good preventive maintenance practices will assure optimum equipment readiness and availability on demand. This is the desireddeal.

To achieve this optimum equipment readiness status tne the following requirements should be met:

1 The equipment should be tested with a minimum loading of 25 percent of rated load. No lead or light load operation will cause incomplete combustion of fuel resulting in the formation of gum and varnish deposits on the cylinder walls, intake and exhaust valves, pistons and piston rings, etc., and accumulation of uncurned fuel in the turbocharger and exhaust system. The consequences of no load or light load operation are potential equipment failure due to the gum and varnish deposits and fire in the engine exhaust system.

2 Periodic surveillance testing should be performed in accordance with the applicable NRC guidelines (R.g.1.108), anc with the rec mmendations o f the engine manufacturer. Conflicts between any such recommendations and the NRC guidelines, particularly with respe:t to test frecuency, loading and duration, should be identified anc justified.

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3.

Preventive maintenance should go beyond the normal routine adjust-ments, servicing and repair of components wnen a mal function occurs.

Preventive maintenance should encompass investigative testing of components which have a history of repeated ma' functioning and require constant. attention and repair.

In such cases consideration should be given to replacement of those components with other products which have a record of demonstrated reliability, rather than repetitive recair and mainterance of the existing components. Testing of the unit after adjustments or repairs have :cen made only confirms that the equipment is operable and does not necessarily mean that the root cause of the problem has been eliminated or alleviated.

4 "pon completion of repairs or maintenance and prior to an actual start, run, and load test a final equipment check should be mace to assure that all electrical circuits are functicnal, f.e., fuses are in place, switches and circuit breakers are in their proper position, no loose wires, all test leads have been removec, and all valves are in the proper position to permit a manual start of the equipment. After the unit has cecn satisfactorily started and I;od tested, return the unit to ready automatic standby service and un:er the control of the control room operator.

Provide a discussion of how the above requirements have been implemented 19 the emergency diesel generator system design ana how they will te considered wnen the plant is in commercial opera icr.,

i.e., by what means will the above requir-ments be enfor:Ed.

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020.51 The availability on demand of an emergency diesel gencr: tor is (3.3)

5F dependent upon, among other things, the proper func

icning of its controls and monitoring instrumentation. This equipment is generally panel mounted and in some instances the panels are mounted directly on the diesel generator skid. Major diesel engine damage has occurred at some operating plants from vibration induced wear on skid mounted control and monitoring instrumentation. This sensi:ive instrumentation is not made to withstand and function accurately for prolonged periods under continuous vibrational stresses normally encountered with internal combustion engines. Operation of senstive instrumentation under this environment racidly deteriorates calibration,. accuracy and control signal output.

Therefore, except fer sensors and other equipment that must be directly mounted on the engine or associated piping, the controls and monitoring instrumentation should be installed on a free stancing floor mounted panel separate from the engine skids, and locateo on a vibration free floor area or equipped with vibration mounts.

Confirm your comoliance with the above requirement or provide justification for noncompliance.

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