ML18038A402

Forwards Response to Request for Addl Info to Support NRC Mark I Containment Enhancement Program.Proposals for Improvement of Containment Requested to Be Submitted to BWR Owners Group for Review & Comment

ML18038A402
Person / Time
Site:	Nine Mile Point
Issue date:	06/06/1988
From:	Terry C NIAGARA MOHAWK POWER CORP.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NMP1L-0265, NMP1L-265, NUDOCS 8806150362
Download: ML18038A402 (12)

Text

7 NIASARA U MOHAWK NIAGARAMOHAWKPOWER CORPORATION/301 PLAINFIELDROAD, SYRACUSE, N.Y. 13212/TELEPHONE (315) 474-1511 June 6, 1988 NMPlL 0265 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Re: Nine Mile Point Unit 1 Docket No. 50-220 DPR-63 Gentlemen:

Enclosed please find our response to your Request for Information to Support the Nuclear Regulatory Commission Mark I Containment Enhancement Program, reference Mr. R. A. Benedict letter to Mr. C. V. Hangan dated May 25, 1988.

Niagara Mohawk is a member of the Boiling Water Reactor Owners'roup (BWROG)

Committee on Severe Accident Containment Integrity. We, therefore, request that a copy of the staff's proposals for Mark I containment improvement be submitted to the BWROG for review and comment. In addition, there are several other industry organizations involved in this issue (e.g. NUMARC). They should also have the opportunity to review and comment on the staff's proposals.

In evaluating the attached, please note that Nine Mile Point Unit has two 1 separate isolation (emergency) condenser systems that automatically initiate on high reactor pressure or on low-low reactor water level (after a ten-second time delay). Although these systems do not provide alternate water injection capability, they do provide emergency cooling capability for many design basis accidents and transients (reference Final Safety Analysis Report Sections VIE and XV). Isolation condensers have the potential for mitigating what might otherwise become a severe accident. Accordingly, we believe that Mark I plants with isolation condensers should be given special consideration in your proposals for containment improvements.

The data provided herein is the most complete and accurate information that could be obtained in the limited time available. If you need additional information, please do not hesitate to call.

Very truly yours, N IAGARA MOHA OWER CORPORATION C. D. Te ry Vice President Nuclear Engineering and Licensing KBT/pns/5084G Enclosure xc: Regional Administrator, Region I Mr. R. A. Capra, Director Mr. R. A. Benedict, Project Manager Hr. W. A. Cook, Resident Inspector Records Management SS06150362 SS0606 PDR ADOCK 05000220 nr.rI

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A. ALTERNATE HATER INJECTION CAPABILITY The attached table identifies the significant water sources which can be injected into the reactor vessel and/or containment under a severe accident environment.

B. ALTERNATE POHER SUPPLIES NHICH COULD BE MOBILIZED IN SEVERE ACCIDENT CONDITIONS Listed below are alternate power supplies which could be hooked up to the plant systems and can substitute for failed power in severe accident situations.

a. James A. Fitzpatrick Nuclear Power Station Emergency Diesel Generators:

1) The fuel required to generate the alternate power is diesel fuel oil.

2) The time it will take to align this alternate power supply through the 115KV swi tchyard will be one to three hours.

3) This alternate power source would operate continuously in a severe accident environment at rated power.

b. Nine Mile Point Unit 2 Emergency Diesel Generators:

1) The fuel required to generate the alternate power is diesel fuel oil.

2) The time it will take to align this alternate power supply through the 115KV switchyard will be four to eight hours.

3) This alternate power source would operate continuously in a severe accident environment at rated power.

c. Bennett's Bridge Hydroelectric Station:

1) No fuel is required.

2) The time it will take to align this alternate power supply through the 115KV switchyard will be one to two hours.

3) This alternate power source would operate continuously in a severe accident environment at rated power.

d) Oswego Steam Station:

1) The fuel required to generate the alternate power is ¹6 fuel oil.

2) The time it will take to align this alternate power supply through the 115KV switchyard will be one to three hours.

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3) This alternate power source would operate continuously in severe accident environment at rated power.

e) Various mobile engine driven generators at 120V, 600V or 4KV.

1) The fuel required to generate the alternate power is diesel fuel oil or gasoline.

2) The time it will take to align this alternate power supply to various station buses would be between one hour and several days.

3) These alternate sources of power are not environmentally qualified, but are expected to operate as long as a fuel supply is available. The rating of these generators range from 4KW to 1500KW.

C. EMERGENCY VENTING CAPABILITY The following table identifies the vent paths which are suitable for emergency venting under severe accidents.

Controlling Design Valve Max. Total Vent Step No. Pipe Size Pressure Power Op. Press. Length

~Pathwa (EOP-4.1) <)nch) ~<s< Su 1 ~(si ) (ft) 1 1 12 35 AIR/ELEC 35 350 2 2 20 35 AIR/ELEC 35 200 3 3 12 35 AIR/ELEC 62 370 4 4 20 35 AIR/ELEC 62 260 5 5.1 8 35 AIR/ELEC/MAN 390 6 7 10 35 AIR/ELEC/MAN 62 230

2. The vent piping for NMP1 is all hard pipe with a design pressure of 35 psig until it enters ductwork near the stack. The vent piping is, therefore, not expected to fail. We have not identified any equipment that is likely to fail as a consequence of vent piping or duct failure.

3. The flow rate of the containment vent pathway is dependent on the given accident sequence and the vent path selected.

657. All of the above vent paths discharge to the base of the 305 foot tall stack: elevation 611 feet.

8. The. impact of vent operation is dependent on the given accident sequence.

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D. PRIMARY CONTAINMENT SPRAY NOZZLES There are two independent, full capacity containment spray loops, each capable of supplying full spray flow to the containment. Each loop is capable of providing the required containment spray flow (3000 gpm) to remove post accident core energy; with both loops operating, 6000 gpm is supplied 5600 gpm to the dry well and 400 gpm to the torus. The answers to the specific questions, given below, apply to each of the loops:

Each containment spray drywell loop has 2 spray spargers and contains 102 spray nozzles:

92 Protecto Spray nozzles (Grinnell) Type D3 ¹34 10 Protecto Spray nozzles (Grinnell) Type D3 ¹28 The orifice diameter of the ¹34 is 0.500 in., of the ¹28, 0.375 in.

all of the nozzles are mounted singly in the headers'.

~t11 E The containment spray torus loop is supplied from each of the two drywell spray loops; there are check valves in the supply lines to prevent reverse flow.

There are 40 spray nozzles mounted individually on the torus header.

Each is a Spraying Systems Co. full jet nozzle Model Number 1H 4.2, with a 7/32 in vane (controlling) and a 15/64 in orifice. Hith two loops operating, the design capacity of each nozzle is 10 gpm; with only one loop, the flow rate per nozzle would be less.

E. SECONDARY CONTAINMENT FIRE PROTECTION SYSTEM The fire suppression spray system is located in the secondary containment. It consists of four water preaction sprinkler systems on Elevation 237', HP-4076; El. 261', HP-4116; El. 298'nd 318',

HP-4237. These are all water preaction systems and require a sprinkler head to fuse from high temperatures before they will discharge water. Spray would b'e from individual heads only.

b. Flow rate of each pump is 3000 gpm at 100 psig.

c. The system is fed by either an electric or diesel fire pump located in the Screenhouse of the plant.

d. The fire system can be connected to the ECCS in two areas:

1) A spool piece for connecting fire water to the reactor feedwater system is located at elevation 261'f the Turbine Building near the Reactor Building.

2) An alternate source of make-up water to the emergency condenser make-up tanks.

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F. Survivability of Automatic Depressurization System (ADS) Following Severe Accidents

a. ADS Valve manufacturer: Electromatic Relief Valves by. Dresser Ind.

EPN s: NR-108A; NR-1088; NR-"108C; NR-108D; NR-108E; NR-108F.

b. ADS power source:

Power Source ~Eni ment Battery Board ¹ll (125 V.D.C.) NR-108A, NR-108B, NR-108E Battery Board ¹12 (125 V.D.C.) NR-108C, NR-108D, NR-108F Power Board ¹102 (120 V A.C.) ADS channel ¹1 1 (Logic circuit)

Power Board ¹103 (120 V A.C.) ADS channel ¹1 2 (Logi c circuit)

RPS MG set ¹162 (Bus ¹11) ADS channel ¹ll (RPS trip unit)

RPS MG set ¹172 (Bus ¹12) ADS channel ¹12 (RPS trip unit)

C. Maximum containment pressure at which ADS wi 1 1 still be operable; 49.5 psig which is above the 35 psig drywell pressure which occurs following a LOCA event.

d. Backup operating sources, such as accumulators/bottles; none; the ADS valves are electrically operated as opposed to air operated.

e. (}ualification of ADS operating cables for the harsh post-severe-accident environments:

GE Vulkene qualified for 2640 hours0.0306 days <br />0.733 hours <br />0.00437 weeks <br />0.001 months <br />, 355 F peak, 49.5 psig peak, 100%

RH, Demin water spray, 7.3E7 RADs TID.

Rockbestos XLPE qualified for 2640 hours0.0306 days <br />0.733 hours <br />0.00437 weeks <br />0.001 months <br />, 355 F peak, 49.5 psig peak, 100% RH, Demin water spray, 7.9E7 RADs TID.

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QUESTION A: ALTERNATE MATER INJECTION CAPABILITY INJECTS POWER RATED MATER VALVE OPER" SYSTEM SOURCE IN TO FLOM/PRESSURE SOURCE POMER SOURCE EMERGENCY TORUS WATER REACTOR DIESEL *(2) 288,888 GAL WATER CORE SPRAY GENERATOR 3488 GPM TANK CONDENSATE A/C VESSEL AND OFF 382 PSIG ~RAM MATER SITE POWER ~CONDENSATE MATER OFF SITE POMER CONDENSATE WATER REACTOR AND 7688 GPM +(2) 288,888 GAL FEEDMATER VESSEL DEDICATED LINE 1258 PSIG TANKS COND. MTR. A/C FROM BENNETTS >>RAM MATER BRIDGE HYDRO +DIESEL FIRE PUMP CONTAINMENT PRIMARY EMERGENCY 3888 GPM TORUS MATER DIESEL +RAW WATER AIR SPRAY CONTAINMENT 162 PSIG GENERATOR AND OFF SITE POWER OFF SITE POWER AND DIESEL BEN. CONDENSATE MATER CONTROL ROD REACTOR AUTO RESTART 85 GPM +(2) 288,888 GAL VESSEL WHEN POMER IS TANKS COND. MTR. AIR DRIVE HYDRAULIC 3768 FEET TDH <<48,888 GAL.

RESTORED TO THE BUS MAKE-UP DEM. MTR.

+ ALTERNATE MATER SOURCES CAN BE CONNECTED VIA VARIOUS VALVE MINIPULATIONS ACCESSIBILITY FOR MANUAl CONTROL IN POSTULATED SEVERE ACCIDENT ENVIRONMENTS DEPENDS ON THE SEVERE ACCIDENT SEQUENCE THE FIRE MATER SYSTEM (THE DIESEL FIRE PUMP) CAN BE CONNECTED TO THE FEEDMATER SYSTEM VIA A SPOOL PIECE. A SIMILAR CONNECTION IS PLANNED TO THE CONTAINMENT SPRAY SYSTEM ~

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