ML20214G761
| ML20214G761 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 06/02/1977 |
| From: | Rosa F Office of Nuclear Reactor Regulation |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0181, CON-WNP-181 NUDOCS 8605220482 | |
| Download: ML20214G761 (15) | |
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l JUN 2 i977 FEHORANDUM FOR:
S. Varge, Chief Light Water Reactors Branch No. 4. OPM FROM:
Faust Rosa Chief, Power Systems Branch, DSS
SUBJECT:
ACCEPTANCE REVIEW INPUT FOR WPPS UNIT 2 Plant Name: HPPS Unit 2 Docket No.: 50-397 Licensing Stage: OL Milestong No.: 04-04 Responsible Branch: LWR-4 and Pro.fect N nager:
H. D. Lynch Requested Completion Date:
N/A Review Status: Complete The Power Systems Branch has completed its pre 11minary review of the WPPS Unit 2 FSAR. We have determined that the FSAR is sufficiently complete in detati to be acceptable for docketino. Our review concentrated on Chapter 8 and parts of Chapters 9 and 10.
We have prepared the enclosed set of questions that havs resulted from our preliminary review. We request that ti,ese be transmitted to the applicant with a recommendation that appropriate responses be incor-porated in the FAAR before formel docketing.
Faust Rosa, Chief Power Systems Branch Division of Systems Safety
Enclosure:
As stated:
i cc:
- 8. Martauer M. D. Lynch Distribution:
R. Heineman R. Tedesco Docket File R. Royd T. Ippolito W. Mcdonald V. Benareya NRR Reading File J. Glynn M. Fiolds PSB Reading File F. Rosa R. Fitzpatrick RFitzpatrick Reading File Contacts:
MFields Reading File M. Fields /R. Fitzpatrick T'/
Extension: 27276 DSS:PSB
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,DS,S : P o,,,c e RFitzpatrick MFields//
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- D17 fEMORANDUM FOR:
S. Varga, Chief, Light Water Reactors Branch No. 4, DPM FROM:
Faust Rosa, Chief, Power Systems Branch, DSS
SUBJECT:
ACCEPTANCE REVIEW INPUT FOR WPPS UNIT 2 Plant Name: WPPS Unit 2 Docket No.: 50-397 Licensing Stage: OL Milestone No.: 01-04 Responsible Branch: LWR-4 and Project Manager:
M. D. Lynch Requested Completion Date:
N/A Review Status: Complete The Power Systems Branch has completed its preliminary review of the WPPS Unit 2 FSAR. We have determined that the FSAR is sufficiently complete in detail to be acceptable for docketing. Our review concentrated on Chapter 8 and parts of Chapters 9 and 10.
We have prepared the enclosed set of questions that have resulted from our preliminary review. We request that these be transmitted to the applicant with a recommendation that appropriate responses be incor-porated in the FSAR before formal docketing.
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Faust Rosa, Chief Power Systems Branch Division of Systems Safety
Enclosure:
As stated cc:
S. Hanauer M. D. Lynch R. Heineman R. Tedesco R. Boyd T. Ippolito W. !!cDonald V. Benaroya J. Glynn M. Fields R. Fitzpatrick Contacts:
M. Fields /R. Fitzpatrick Extension: 27276 6
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ACCEPTANCE P.EVIEW QUESTIONS WPPS 2 040.1 Evaluate the design of your facility's Class IE electrical distribution system to determine if the operability of safety related equipment in-cluding associated control circuitry or instrumentation, can be adversely affected by short term or long term degradation in the grid system voltage within the range where the offsite power is counted on to supply important equipment. Your response should address all but not be limited to the following:
a.
Describe the plant conditions under which the plant auxiliary systems (safety related and non-safety related) will be supplied by offsite power.
Include an estimate of the fraction of normal plant operating time in which this is the case.
b.
The voltage used to describe the grid distribution system is usually a " nominal" value. Define the normal operating range of your grid system voltage ar.d the corresponding voltage values at the safety related buses.
c.
The transformers utilized in power systems for providing the required l
voltage at tne various system distrioution levels are normally provided with taps to allow voltage adjustment.
Provide the results of an analysis of your design to determine if the voltage profiles at the safety related buses are satisfactory for the full load and no load conditions on the system ar.d the range of grid voltage.
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-2 d.
Assuming the facility auxiliary loads are being carried by the station generator, provide the voltage profiles at the safety buses for grid voltage at the normal maximum value, the normal minimum value, and at the degraded conditions (high or low voltage, current, etc.) which would require generator trip.
Identify the sensor location and provide the trip setpoint for your e.
facility's Loss of Offsite Power (undervoltage trip) instrumentation.
Include the basis for your trip setpoint selection.
f.
Assuming operation on offsite power and degradation of the grid system voltage, provide the voltage values at the safety related buses corresponding to the maximum value of grid voltage and the degraded grid voltage corresponding to the undervoltage trip setpoint.
g.
Utilizing the safety related bus voltage values identified in f.,
evaluate the capability of all safety related loads, including related control circuitry and instrumentation, to perform their safety 4
functions.
Include a. definition of the voltage range over which the safety related components, and non-safety compoaents, can operate continuously in the performance of their design function.
h.
Describe the bus voltage monitoring and abnormal voltage alarms available in the control room.
040.2 The functional safety requirement of the undervoltage trip is to detect the loss of offsite (preferred) power system voltage and initiate the 4
necessary actions required to transfer safety related buses to the onsite power system.
Describe the load shedding feature of your design (required prior to transferring to the onsite [ diesel generator] systems) and the capability of the onsite systems to perform their function if the load shedding feature is maintained after the diesel generators are connected to their respective safety buses.
Describe the bases (if any) for retention or reinstatement of the load shedding function after the diesel generators are connected to their respective buses.
040.3 Cafine the facility operating limits (real and reactive power, voltage, frequency and other) established by the grid stability snalyses cited in i
the FSAR.
Describe the operating procedures or other provisions presently in effect for assuring that your facility will be operated within these i
limits.
l 040.4 Provide a description of any proposed actions or modifications to your facility based on the results of the analyses performed in response to items 1-3 above.
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. 040.5 Your list of diesel generator protective trips retained during an accident includes " Incomplete Sequence". Provide a detailed discussion of this aspect of your design supplemented by drawings as required.
040.6 It is recognized that the HPCS diesel generator cannot meet the full guidelines of Regulatory Guide 1.9; however, the expected voltage and frequency transient responses must be provided for our review.
Provide this information.
040.7 You state that each diesel generator unit consists of two diesel engines driving one generator.
Expand the FSAR to include a detailed description of the dual diesel drive for each generator. Also, provide a balanced discussion of the considerations which lead to the selection of dual diesel drives per generator as compared to the more conventional single diesel engine driven generator.
040.8 The description of the DC-p;wer system should be augmented prior to FSAR decketing. The following items should be addressed:
a.
Description of switchyard control power.
b.
Description of philosophy and physical implementation of supplying power to non-class 1E loads, c.
Table 8.3-4 states that division 1 and 2 DC loads are similar whereas Figure 8.3-19 shows clearly that the loadings are different. Address this difference between the two divisions.
d.
Explicitly delineate the source of DC control power for all busses and mcc's for the entire plant electrical distribution system.
e.
Provide an analysis of the consequences of the total loss of either bus Sl-1 or Sl-2 for all modes of operation including anticipated transients and postulated accidents.
040.9 Section 7.5.2 references General Electric topical report NED0-10466 which describes PGCC (power generator control complex). This report is not acceptable to the staff for licensing purposes. Modify your application in a manner that will demonstrate the acceptability of this aspect of your design.
040.10 Diesel generator alarms in the control room: A review of malfunction reports of diesel generators at operating nuclear plants has uncovered that in some cases the information available to the control room operator to indicate the operational status of the diesel generator may be imprecise and could lead to misinterpretation. This can be caused by the sharing of a single annunciator station to alarm conditions that render a diesel generator unable to respond to an automatic emergency start signal and to also alarm abnormal, but not disabling, conditions. Another cause can be the use of wording of an annunciator window that does not specifically say that a diesel generator is inoperable (i.e., unable at the time to respond to an automatic emergency start signal) when in fact it is inoperable for that purpose.
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1 l Review and evaluate the alarm and control circuitry for the diesel generators at your facility to determine how each condition that renders a diesel gen-erator unable to respond to an automatic emergency start signal is alarmed in the control room.
These conditions include not only the trips that lock out the diesel generator start and require manual reset, but also control switch or mode switch positions that block automatic start, loss of control voltage, insufficient starting air pressure or battery voltage, etc. This review should consider all aspects of possible diesel generator operational conditions, for example test conditions and operation from local control stations. One area of particular concern is the unreset condition following a manual stop at the local station which terminates a diesel generator test and prior to resetting the diesel generator controls for enabling subsequent automatic operation.
Provide the details of your_ evaluation, the results and conclusions, and a tabulation of the following information:
(a) all conditions that render the' diesel generator incapable of responding to an automatic emergency start signal for each oper-ating mode as discussed above; (b) the wording on the annunciator window in the control room that is alarmed for each of the conditions identified in (a);
(c) any other alarm signals not included in (a) above that also cause the same annunciator to alarm; O
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. (d) any condition that renders the diesel generator incapable of responding to an automatic emergency start signal which is not alarmed in the control room; and (e) any proposed modifications resulting from this evaluation.
040.11 In Section 9.5.4.2 you state that the fuel oil transfer piping of diesel (9.5.4) generators 1 A and IB is arranged such that either transfer pump may transfer diesel oil from its storage tank to either day tank, if required. Describe the precautionary measures that will be taken to assure an adequate supply of fuel is supplied to at least one of the two day tanks assuming a rupture in any portion of the transfer piping.
040.12 Assume an unlikely event has occurred requiring operation of a diesel (9.5.4) generator for a prolonged period that would require replenishment of fuel oil without interrupting operation of the diesel generator. What provision has been made in the design of the fuel oil storage fill system to minimize the creation of turbulence of the sediment in the bottom of the storage tank.
1 Stirring of this sediment during addition of new fuel has the potential of causing the overall quality of the fuel to become unacceptable and could i
potentially lead to the degradation or failure of the diesel generator.
040.13 Discuss the precautionary measures that will be taken to assure the quality (9.5.4) of and reliability of the fuel oil supply for emergency diesel generator operation.
Include the fuel oil impurity and quality limitations as well as diesel index number or its equivalent, entrained moisture, sulfur,
1 particulates and other deliterious substances, periodic inspection, and periodic testing (including interval between tests) of fuel oil.
In your discussion include reference to industry (or other) standards which will be followed to assure a reliable fuel oil supply to the emergency generators.
(SRP 9.5.4, Part III, Items 3 and 4.)
040.14 Discuss what precautions have been taken in locating the fuel oil day tank (9.5.4) and connecting fuel oil piping with regard to possible exposure to ignition sources such as open flames and hot surfaces.
(SRP 9.5.4, Part III, Item 6. )
040.15 You state in Section 9.5.4.2.2 that the diesel generator fuel oil storage (9.5.4) tank is provided with an outside fill and vent line. Discuss how these lines are protected'from tornado missiles, and also from entrance of water into the storage tank during adverse environmental ccnditions.
Indicate the height these lines are terminated above finished ground grade.
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040.16 Indicate in the system description if the day tank associated with each (9.5.4) l diesel set is located at an elevation to assure a slight positive pressure at the engine fuel pumps (SRP 9.5.4, Part III, Item Sc.)
040.17 Indicate in the system description if there is an overflow line to return (9.5.4) l excess fuel oil delivered by the transfer pump back to the fuel oil storage l
tank.
Provide such a line on Figure 9.5-4. (SRP 9.5.4, Part III, Item 5d.)
040.18 Provide a tabulation showing the individual and total heat removal rates j
(9.5.5) l for each major component and subsystem of the diesel generator cooling l
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water system. Discuss the design margin (excess heat removal capability) included in the design of major components and subsystems.
(SRP 9.5.5, Part III, Item 1.)
040.19 Describe the provisions made in the design of the diesel engine cooling (9.3.5) water system to assure that all components and piping are filled with water.
(SRP 9.5.5, Part III, Item 2.)
040.20 Indicate the measures to preclude long-term corrosion and organic fouling (9.5.5) in the diesel engine cooling water system that would degrade system cooling performance, and the compatability of any corrosion inhibitors or antifreeze compounds used with the materials of the system.
Indicate if the water chemistry is in conformance with the engine manufacturers recommendations.
(SRP9.5.5,PartIII,ItemIc.)
040.21 The diesel engine generator sets should be capable of operation at less (9.5.5) than full load for extenced periods without degradation of performance or reliability.
Provide a discussion of your diesel engine operating parameters, including minimum load requirements, and relate this to anticipated minimum l
loads under accident recovery conditions and during accident standby operation when offsite power is available.
(SRP 9.5.5, Part III, Item 7.)
040.22 Provide a discussion of the measures taken in the design of the standby (9.5.6) diesel generator air starting system to preclude the fouling of the starting air valve or filter with contaminents such as oil carry over and rust.
(SRP9.5.6,PartIII, Item 1.)
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. 040.23 For the diesel engine lubrication system in Section 9.5.7 provide the (9.5.7) following information: 1) define the temperature differentials, flow rate, and heat removal rate of the interface cooling system external to the engine and verify that these are in accordance with recommendations of the engine manufacturer; 2) discuss the measures that will be taken to maintain the required quality of the oil, including the inspection and replacement when oil quality is degraded; 3) describe the protective features (such as blowout panels) provided to prevent unacc'eptable crankcase explosion and to mitigate the consequences of such an event; and 4) describe the capability for detection and control of system leakage.
(SRP 9.5.7, Part II, Items 8a, 8b, 8c, Part III, Item 1.)
040.24 Describe the seasors and alarms provided in your design of the diesel (9.5.7) engine lubrication system to warn the operators when design parameters exceed the ranges recommended by the engine manufacturer.
Discuss the operator actions during alarm conditions.
(SRP 9.5.7, Part III, Item le.)
040.25 What measures have been taken to prevent entry of deliterious materials (9.5.7) into the engine lubrication oil system due to operator error during recharging of lubricating oil or normal operation.
(SRP 9.5.7, Part III, Item Ic.)
040.26 Provide the results of an analysis that demonstrates that the function of (9.5.8) the diesel engine air intake exhaust system will not be degraded to an extent which prevents developing full engine rated power or cause engine d
. shutdown as a consequence of any meteorological or accident condition.
Include in the discussion the potential and effect of fire extinguishing (gaseous) medium, recirculation of diesel combustion products, accidental releases or gases stored in the vicinity of the diesel intakes, restriction of inlet airflow, and airborne dust being drawn into the combustion air system, on the performance of the diesel generators.
040.27 Provide the criteria and bases for the various steam and condensate (10.1) instrumentation systems. The FSAR should differentiate between operating and required safety instrumentation.
040.28 Expand your discussion of the turbine speed control protection system.
(10.2)
Discuss with the aid of drawings and tabulate the individual speed control protection devices (e.g., normal speed-load control, emergency overspeed, and backup overspeed), the design speed (or range of speed) at which each device begins operation to perform its safeguard function (in terms of per-cent of normal turbine operating speed), and identify the valve (s) and other components in the control sy' tem which are subsequently activated s
to complete the turbine trip.
(SRP 10.2, Part III, Items 1 and 2.)
040.29 Describe with the aid of drawings, the bulk hydrogen storage facility (10.2) including its location and distribution system.
Include the protective measures considered in the design to prevent fires and explosions during operations such as filling and purging the generator, as well as during normal operations.
. 040.30 Discuss the effects of a high and moderate energy piping failure or failure (10. 2 )
(10.4.1 ) of the connection from the low pressure turbine to condenser on nearby safety related equipment or systems.
Discuss what protection will be provided the turbine overspeed control system equipment, electrical wiring and hydraulic lines from the effects of a high or moderate energy pipe failure so that the turbine overspeed protection system will not be damaged to preclude its safety function.
(SRP 10.2, Part III, Item 8, SRP 10.4.1, Part III, Item 3a.)
040.31 In the turbine generator section discuss:
- 1) the valve closure times and (10.2) the arrangement for the main steam stop and control and the reheat stop and intercept valves in relation to the effect of a failure of a single valve on the overspeed control functions; 2) the valve closure times and extraction steam valve arrangements in relation to stable turbine operation after a turbine generator system trip; 3) effects of missiles from a possible turbine generator failure on safety related systems or components.
(SRP
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10.2, Part III, Items 3, 4.)
l 040.32 Provide a discussion on the inservice inspection program for throttle-stop, (10.2) l control, reheat stop and interceptor steam valves and the capability for testing essential components during turbine generator system operation.
(SRP Section 10.2, Part III, Items 5 and 6.)
(SRP 10.2, Part III, Item 6.)
040.33 Provide additional description (with the aid of drawings) of the turbine (10.4.4) by-pass valves and associated controls.
In your discussion include the e
I number, size, principle of operation, construction, set points, and capacity of each valve and the malfunctions and/or modes of failure considered in the design of the turbine by-pass system.
(SRP10.4.4,PartIII, Item 1.)
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