ML19276E865

Requests Addl Info Arising from First Round Review of FSAR Re Auxiliary Sys & Power Sys

ML19276E865
Person / Time
Site:	Grand Gulf
Issue date:	03/01/1979
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Stampley N MISSISSIPPI POWER & LIGHT CO.
References
NUDOCS 7903210518
Download: ML19276E865 (20)

Text

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o UNITED STATES j'

NUCLEAR REGULATORY COMMISslON

( Jg WASHINGTON, D. C. 20555

.....f MAR 1 7979 s

Docket flos:

50-416 and 50-417-Mr. N. L. Stampley, Vice President Production and Engineering Mississippi Power & Light Company P. O. Box 1640 Jackson, Mississippi 39205

SUBJECT:

FIRST-ROUND REQUESTS FOR ADDITIONAL INFORf/ATION - GRAND GULF NUCLEAR STATION, UNITS 1 AND 2 As a result of our review of the information contained in the Final Safety Analysis Report for the Grand Gulf Nuclear Station, Units 1 and 2, we have developed the enclosed first-round requests for addi-tional information.

As suggested by our review schedule, a copy of which was forwarded to you by our letter dated December 8,1978, additional first-round requests are being developed by other review branches.

We will forward these additional requests as they become available.

In order to maintain our current review schedule, we request that you amend your Final Safety Analysis Report to reflect your responses to the enclosed requests by June 1, 1979.

If you cannot meet this date, please advise us as soon as possible so that we may consider the need to revise our review schedule.

Please contact us if you desire any discussion or clarification of the enclosed requests.

Sincerely, oh F. Stolz, Chief L'

t Water Reactors Branch No. 1 Division of Project Management

Enclosure:

Requests for Additional Information cc:

See next page 79032105l2

• 040.78 Assure that a high energy line failure of the turbine by-pass system (10.4.4)

(TBS) will not have an adverse effect or preclude operation of any safety-related equipment or turbine overspeed protection components or systems located close to the TBS.

(SRP 10.4.4; Part III, Item 4).

040.79 Provide the results of a failure mode and effects analysis to determine (10.4.4) the effect of malfunctions of the turbine by-pass system on the opera-tion of the reactor and main turbine generator unit.

(SRP 10.4.4, Part III, Item 4).

040. 72 (10.2) In Section 10.2.3.6, Inservice Inspection, you state that the main steam stop and control valves, the LP stop and control valves, the bypass stop and control valves, and the turbine protective devices are to be excer-cised using the ATT at periodic intervals.

Indicate the frequency of these intervals.

Also include the inservice inspection and frequency of test (or exercise) for each of the extraction steam non-return valves.

(SRP 10.2, Part II, Item Sb).

040.73 Discuss the measures taken to prevent corrosion / erosion of condenser (10.4.1) tubes and components.

(SRP 10.4.1, Part III, Item 1).

04P./4 Discuss the possible mechanisms for hydrogen production in the secondary g10.4.1) side water.

Discuss the effectiveness of the means to prevent hydrogen buildup.

(SRP 10.4.1, Part III, Item 1).

040.75 In section 10.4.1.4 you have discussed tests but not Inspection.

Pro-(10.4.1) vide information on inspections as per regulatory guide 1.70.

040.76 You state in subsection 10.4.4.2 that the bypass stop valves autcmatically (10.4.4) trip closed whenever tre vacuum in the main condenser falls below a preset valve.

Describe the chronological sequence of events and effect on the turbine, turbine by-pass system and reactor on loss of condenser vacuum.

Provide the condenser vacuum rccdings where each event occurs.

040.77 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 principle of operations, construction, set points, capacity of each valve, and the malfunctions and/or modes of failure considered in the design of the turbine by-pass system.

(SRP 10.4.4, Part III, Item 1).

. 040.70 Expand your discussion of the turbine speed control and overspeed (10.2) protection system.

Provide additional explanation of the turbine and generator electrical load following capability for the turbine speed control system with the aid of system schematics (including turbine control and extraction steam valves to the heaters).

Tabulate the individual speed control protection devices (normal, emergency and backup), the design speed (or range of speed) at which each device begins operation to perform its protective function (in terms of percent of normal turbine operating speed).

In order to evaluate the adequacy of the control and overspeed protection system provide identifying numbers to valves and mechanisms (mechanical and electrical) on schematics.

Describe in detail, with references to the identifying numbers, the sequence of events in a turbine trip including response times, and show that the turbine stabilizes.

Pro-vide the results of a failure mode and effects analysis for each of the overspeed protection systems. Show that a single steam valve failure or failure of any high or moderate energy line cannot disable the turbine overspeed trip from functioning.

(SRP 10.2, Part III, itens 1, 2, 3 and 4).

040.71 Provide the closure times for ai' the valves (turbine stop, control, (10.2) reheat stop and control, and extraction) and show that stable turbine operation will result after a turbine trip.

(SRP 10.2, Part III, Item 4).

-F M E2 Y

. 040. 69 In subsection 10.2.2.5.4, Overspeed Protection, you state that the (10.2) turbine overspeed protection system is not a safety related system and is provided for protection of the turbine equipment only. While this is partially true, General Design Criterion 4 " Environmental and Missile Design Bases" of Appendix A, " General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, " Licensing of Produc-tion and Utilization Facilities," requires that structures, systems and components of nuclear power plants important to safety be appropriately protected against the effects of missiles that might result from equipment failures.

Demonstrate that in the event of a high or moderate energy piping failure at the turbine or failure of the connection from the low pressure turbine condenser, damage will not occur to the turbine overspeed protection system to a degree that could result in genera-tion of destructive missiles and possibly affect safe plant shutdown.

Discuss what protection will be provided the turbine overspeed protection system equipment, electrical wiring and hydraulic lines from the effects of a high and moderate energy pipe failure so that the turbine overspeed protection system will not be damaged to a degree to preclude its intended function (SRP 10.2, Part III, item 8).

Also describe under normal plant operation what procedure (s) will be used to minimize accumulation of dust in the diesel generator room.

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

n(9. 5. 8)

You state in subsection 9.5.8.3 that the standby and HPCS diesel 40.67 generator exhaust pipes extend, respectively, approximately 3 feet and 5 feet above the diesel building roof (El.172'-0").

Figures 9.5-21 and 9.5-22 show the arrangement of the diesel generators, auxiliary equipment and location of ihe air intakes and diesel exhaust pipes.

Discuss the ability of the exposed inline diesel exhaust pipes to withstand tornado missiles and assurance that one tornado missile will not damage all diesel exhuast pipes.

040.68 (9.5.8)

Expand the discussion on safety evaluation in section 9.5.8 to include possibility of the accidental release of any of the stored gases men-tiened in section 9.5.1 (carbon ~ dioxide for fire prctection) and in section 10.2 (carbon dioxide and hydrogen for the main generator) and the possible effects on diesel generator operation.

er

. 040.62 In Table 9.5-6, Diesel Generators Lubrication Systems Components, (0.5.7) provide the inlet and outlet design temperatures, flow rate, and design margin for the tube and shell sides for lube oil heat exchangers for both the standby and HPCS diesel generators.

040.63 In subsection 9.5.7.4 you state that the frequency of testing is (9.5.7) given in section 16.3.

However, section 16.3 is not in the FSAR.

Provide this information in subsection 9.5.7.4 of the FSAR.

040.64 Provide a failure modes and effects analysis of the diesel generator (9.5.7) lubrication system.

(SRP 9.5.7, Part III, Item 4).

040.65 Provide a discussion to explain how the diesel engine combustion (9.5.8) air intake and exhaust system is protected from:

1) possible clogging during operation, including standby, from abnormal atmospheric conditions (heavy rain, freezing rain, dust storms, ice, and snow); and 2) damage of the air intake opening by tornado missiles that could prevent operation of the diesel generator on demand.

(SRP 9.5.8, Part III, Iterr 4 and 6b).

040. 66 Experience at some operating plants has shown that diesel engines have (9.5.8) failed to start due to accumulation of dust and other deleterious materials on electrical ecuipment associated with starting of the diesel generators (e.g. auxiliary relay contacts, control switches-etc). Describe the provisions made in your diesel generator electrical starting system design to preclude this condition to assure availability of the diesel generator on demand.

. 040.59 Expand the FSAR section 9.5.6 in reference to Figure 9.5-17, (9.5.6) sheet 2, riPCS Air Start System relative to the following:

1) During the starting cycle does the normal mode of operation in starting involve the engagement of two or all four of the air motor pinions to the flywheel ring gear of each diesel engine?

2) Describe in detail the normal mode of starting the HPCS diesel engine.

Verify that the diesel generator starting system (DGSS) is designed with redundant starting systems for each of the tandem diesels (engine "A" and engine "B") such that each redundant starting system has the capability of cranking a cold diesel engine five times without rechargir.g the receivers.

040.60 Expand the FSAR section 9.5.6 in reference to Figures 9.5-11 and 12, (9.5.6)

Standby Diesel Generator System, relative to the following:

1) During the starting cycle does the normal mode of operation in starting involve the engagement of two or all four of the air motor pinions to the flywheel ring gear of each diesel engine?

2)

Figures 9.5-11 and 12 combine diagrams cf the fuel oil storage and transfer system, the cooling water system, the starting system and the lubrication system.

Consequently they don't include the detail of information we normally receive. For example, the starting system does not show the air starting motors, valves, etc. Provide a complete P&lD for each of the above diesel engine auxiliary systems in the FSAR.

040.61 Provide a failure modes and affects analysis of the standby and HPCS (9.5.6) diesel engine starting systems.

(SRP 9.-5.6 Part III, Item 6).

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as the capability for five starts per redundant train is required.

It is also not clear if the five starts mentioned for the standby diesel generator is for each redundant system.

Clarify these state-ments. We require that the DGSS be capable of providing five starts per redundant train when using the minimum number of starting devices recommended by the diesel generator manufacturer. However, if all starting devices are engaged in starting the diesel generator (to improve first start reliability) the combined capacity of each diesel engine air starting system should not be less than five starts without recharging the air receiver (s) by the air compressor.

040.57 Discuss the means of monitoring filters and strainers in the air (9.5.6) starting system for cleanliness and also indicate if alarms are pro-vided, and where they annunciate. Show this information on the P&lD's for both the standby and HPCS diesel generators.

040.58 Provide symbols on Figures 9.5-11 and 9.5-12 Standby Diesel Engine (9.5.6)

Air Start System and Figures 9.5-16, sheet 1 and 9.5-17, sheet 2, HPCS Diesel Eligine Air Start System, to show the seismic category and quality class of the equipment including the air receivers and piping.

The FSAR has a Figure 9.5-16, sheet 1 and a Figure 9.5-17 sheet 2.

It appears that these sheets 1 and 2 should have the same figure number.

Clarify this.

. 040.55 In subsection 9.5.6.2.1 you state that you have desiccant type (9.5.6) 4 air dryers to remove moistures from the air starting system of the standby diesel generators.

1) Describe this type of dryer, its operation and effectiveness in removing moisture from the diesel engine air starting system.

In your discussion compare the effectiveness of desiccant type air dryers to the refrigerant type air dryers and reasons for

-1 choosing tre desiccant type.

2) Figure 9.5-12 shows a starting air aftercooler in the air start-ing system.

In subsection 9.5.6.2.1 describe the aftercooler and its mode of operation.

3)

In subsection 9.5.6.2.2 discuss the provision made for removing moisture in the HPCS diesel generator air starting system.

In your discussion provide a detailed description of the type of system J

used and its effectiveness in removal of moisture from the HPCS diesel generator air starting system.

040.56 Subsection 9.5.6.1.1 states that "the diesel generator starting system (9.5.6)

(DGSS) for both standby and HPCS diesel engines is provided with indep-endent and redundant starting trains, with either train capable of starting its respective engine five times without recharging the associated air receiver." However, in subsection 9.5.6.3, Safety Evaluation, you state that "the system for the HPCS diesel generator has adequate air storage capacity to start the engine three consecutive times without recharging by the compressors." This is not acceptable 4

'F 040.51 You indicate in Section 9.5.5 that the diesel generator cooling (9.5.5) water system (DGCWS) provides a sufficient heat sink to permit the standby and HPCS diesel engine to start and operate for 25 seconds without stand-by service water (SSW) flow through the diesel generator cooling water heat exchangers. You also state that this margin is provided since there is a 10 second delay until SSW and HPCS service water pumps are started af ter the diesel generators are started. Provide additional information on this condition.

Is the actual margin 25 seconds minus the 10 second delay for the pumps to start or 15 seconds or is the total time span from the initial start 25 plus 10 seconds or 35 seconds? Provide a detailed explanation.

040.52 In Table 9.5-3, Diesel Generator Cooling Water Component Data, provide (9.5.5) the inlet and outlet design temperatures and flow rates for the tube ar.d shell sides for the jacket cooling water heat exchangers for both the standby and HPCS diesel generators and also the design margins for heat removal.

040. 53 Figures 9.5-11 and 9.5-12 show the cooling water system for (9.5.5) the standby diesel generator and figure 9.5-15 shows the cooling water system for the HPCS diesel generator. Provide symbols on these figures to show both the seismic and non seismic portions of the system together with the quality class.

040.54 Provide a failure modes and effects analysis of the standby and (9.5.5)

HPCS diesel engine cooling systems.

(SRP o.5.5, Part III. Itm M.

. 1) A flame arrestor is shown on the fuel oil day tank vent line but not for tre fuel oil storage tank. The fuel oil storage tank -

vent line should also be provided with a flame arrestor.

Provide clear indications on the above figures that the fuel oil storage tank vent lines include flame arrestors.

2) Discuss your provisions for draining the fuel oil day and storage tarks, and removal of accumulated water.

Discuss also the time intervals when accumulated water in each tank (s) will be removed.

3) Discuss the use of fuel oil filters and strainers in the design of the fuel oil system and methods to indicate when in need of cleaning.

040.49 Provide symbols on figures 9.5-12, 9.5-13 and 9.5-14 to show the (9.5.4) seismic category and quality class of the piping of the diesel generator fuel oil storage and transfer system for both the standby and HPCS diesel engines. Also note any piping and equipment that is not seismically qualified.

040.50 In section 9.5.4 you state that the frequency of the diesel (9.5.4) generator tests and the capacity requirements of the day and storage tanks are given in Section 16.3.

However, Section 16.3 is nat in the SAR. Prcvide this information in Section 9.5.4.

5-No. 2 fuel oil will be accepted in two different standards for the two types of diesels? Provide a detailed explanation.

b.

How do the above values conform to the requirements of ASTM-D975, and justify any differences if they exist.

040.46 In section 9.5.4 you state that additional fuel oil supplies for (9.5.4) the diesel generator can be obtained for replenishment of the storage tanks by truck delivery from sources locally and 25 to 40 miles away.

Provide a listing of these sources, and discuss their delivery under abnormal environmental conditions (i.e., dust storm, high winds, heavy rain etc.).

040.47 Provide a drawing showing the plan and elevation views of the diesel (9.5.4) generator underground fuel oil storage tanks and connecting piping with indications of the ground elevation. Discuss the possible effect of ground water level and PMF relative to the possibility of hydrodynamic forces causing lifting of the storage tanks. This draw-ing should also include the location and routing of all piping and valves between the fuel oil storage tanks and day tanks.

040.48 In reference to Figures 9.5-11 and 9.5-12, Standby Diesel Generator (9.5.4)

System, Figure 9.5-13 HPCS Diesel Generator Systems and Figure 9.5-14, HPCS Fuel Oil System:

. 040.42 Subsection 1.2.2.2 states that the diesel generator building is (1.2) sho.<n in Figure 1.2-3.

However, Figure 1.2-3 does not show the diesel generator building but Figure 1.2-4 does. Correct this discrepancy.

040.43 Discuss your conformance to regulatory guides 1.26, 1.29, 1.68, (9.5.4)

(9.5.5) 1.102 and 1.117 relative to the diesel generator auxiliary systems (9.5.6)

(9.5.7) including:

1) the fuel oil storage and transfer system; 2) the cool-(9.5.8) ing water system; 3) the starting system; 4) the lubrication system and; 5) the combustion air intake and exhaust system.

040.44 Discuss your conformance to regulatory guide 1.137 and also to (9.5.4)

ANSI N-195 relative to the diesel generator fuel oil storage and transfer system.

040.45 In subsection 9.5.4.2 you list the diesel generator fuel oil speci-(9.5.4) fications that you meet for both the standby and also the HPCS diesels.

For several items the indicated values are shown to be different for each diesel type. For example:

Stan_dby HPCS Ash, % (Maximum) 0.10 0.02 Water and sediment, % (maximum) 0.50 0.05 Distillation, F(90% point-max) 675 650 Provide the following information:

a.

Are the above maximum values recommended by the diesel generator manufacturer, and if so does this mean that delivery of the

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. (e)

Describe the pe'rfomance requirements and tests that the above onsite working stations cccu:unication systems will be required to pass in order to be assured that effective comunication with the cortrol rom or emergency shutdown panel is possible under all conditions.

(f)

Identify and describe the power source (s) provided for each of the cea::unications systems.

(g) Discuss the protective measures taken to assure a functionally operable onsite comunication system. The discussion should include the considerations given to component failures, loss of power, and the severing of a comunication line or trunk as a result of an accident or fire.

040.41 Identify the vital areas and hazardous areas where emergency (9.5.3) lighting is needed f - safe shutdown of the reactor and the evacuation of personnel in the event of an accident (including fire).

Tabulate the lighting system provided in your design to accomodate those areas so identified.

. The-information regarding the onsite,cecmunications system (Sectio'n 040.40 9.5.2 9.5.2) does not adequately cover the system capabilities during transients and a'ccidents. Provide the following information:

(a)

Identify all working stations on the plant site where it may be necessary for plant personnel to ccrm:unicate with the control room or the emergency shutdown panel during and/or following transients and/or accidents (including fires) in order to mitigate thE consequences of the event and to attain a safe cold plant shutdown.

(b)

Indicate the maximum sound levels that could exist at each of the above identified working statier.s for all transients and accident conditions.

(c)

Indicate the types of comunication systems available at each of the above identified working stations.

(d)

Indicate the maximum background noise level that could exist at each working station and yet reliably expect effective cerm:unication with the control room using:

1.

the page party comunications systems, and 2.

any other additional communication system provided that working station.

040.00 POWER SYSTEMS 040.37 The remote annunciations provided in the main control room are (8.3.1) discussed in paragraph 8. 3.1.1. 4.1. f ( 5 ). The number and nomenclature of these annunciators should be reevaluated from the standpoint of circuit simplification and knowledge of the tripped event provided to the operator.

For example, the " Generator Breaker Lockout Relay Tripped" signal energizes five (5) annunciation windows in the con-trol room; " Diesel

'X' out of Service", " Diesel Generator 'X' Lockout Relay Trip", 4160 V. Div.

'X' Diesel Generator Breaker Trip", " Diesel Generator 'X' Engine Trip", and " Diesel Generator 'X' Engine".

Con-sideration should be given to grouping the redundant signals into common annunciators with teminology such as " Diesel 'X' Not Ready to Start", " Diesel Generator 'X' in test" and " Diesel Generator 'X' Trip" to simplify the alarm information for operator action.

040.38 Load Shedding and Sequencina on ESF Buses (8.3.1)

Tab.e 8.3-9 indicates three distinct load shedding methods; BUV, LOP and LOCA.

Provide the rational for requiring three explicit shedding techniques.

040.39 The DC Load Center Nomenclature in paragraph 8.3.2.1.6.1 and the (8.3.2) nomenclature shown on the referenced figure (8.3-1) do not agree.

In addition, reference to the sources of AC power use different nomenclatures between the tcxt and referenced figure.

Resolve

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these discrepancies.

005.0 AUXILIARY SYSTEMS 005.1 In order 'to establish your compliance with the Codes and Standards Rule, Section 50.55a of 10 CFR Part 50, identify the edition of Section III of the ASME Boiler and Pressure Vessel Code and the applicable Code Addenda applied in the construction of each Quality Group A component within the reactor coolant pressure boundary.

305.2 Verify that all comoonents withi.1 the reactor coolant oressure boundary as defined in 10 CFR Part 50.2(V) are classified Quality Group A and constructed to Section III, Class 1, of the ASME Boiler and Pressure Vessel Code in compliance with the Codes and Standards Rule, Section 50.55a of 10 CFR Part 50, or as a minimum, are classified Quality Group B and constructed to Section III, Class 2, of the code if the components meet the exclusion requirements of the rule.

ENCLOSURE FIRST P.0VND REOUESTS FOR ADDITIONAL INFORMATION GRAND GULF NUCLEAR STATION UNITS 1 AND 2 DOCKET NOS. 50-416 AND 50 417 W

MAR 1 1979

r. N. L. Stampley_.-

-2_

cc:

Mr.; Robert B. McGehee, Attofney Wise, Carter, Child, Steen &

Caraway P. O. Box 651 Jackson, Mississippi 39205 Troy B. Conner, Jr., Esq.

Conner, Moore & Corber 1747 Pennsylvania Avenue, N. W.

Washington, D. C.

20006 Mr. Adrian Zaccaria, Project Engineer Grand Gulf Nuclear Station Bechtel Power Corporation Gaithersburg, Maryland 20760 4

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