ML19259C821
| ML19259C821 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 07/19/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Groce R YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 7908150239 | |
| Download: ML19259C821 (10) | |
Text
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'o UNITED STATES s1
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July 19, 1979
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Docket No.: 50-309 lir. Robert H. Groce Licensing Engineer Yankee Atomic Electric Company 20 Turnpike Road
'destboro, Massachusetts 01581
Dear Mr. Groce:
By letter dated May 31, 1978, you provided a respon.ie to Fire Protection SER Items 3.2.1, Safe Shutdown Capability, and 3.2.4, Fire Mains, for the Maine Yankee Facility. Our evaluation of SER Item 3.2.1 is enclosed. We have determined that more infomation is required, as identified in the enclosed evaluation and staff position, before the adequacy of safe shutdcwn capability in a fire emergency can be properly evaluated.
Please provide this information within 60 days from the date of this letter.
Sincerely, Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosures:
1.
Evaluation of Fire Protection SER Open Item 2.
Staff Position Safe Shutdown Capability cc w/ enclosures: See next page 79081509 34 Lb7140
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Yankee Atcmic Electric Company cc:
E. W. Thurlow, President Mr. Robert R. Rad:liffe Maine Yankee Atomic Power Company Office of Energy Resources 9 Green Street 55 Capitol Street Augusta, Maine 04330 Augusta, Maine 04330 Mr. Donald E. Vandenburgh Vice President - Engineering Yankee Atomic Electric Company 20 Turnpike Road Westboro, Massachusetts 01581 John A. Ritsher, Esquire Ropes ana Gray 225 Franklin Street Boston, Massachusetts 02110 Mr. John M. R. Paterson Assistant Attorney General State of Maine Augusta, Maine 04330 Mr. Nicholas Barth Executive Director Sheepscot Valley Conservation Association, Inc.
P. O. Box 125 Alna, Maine 04535 Wiscasset Public Library Association High Street Wi scasset, Maine 04578 Mrs. L. Patricia Doyle, President SAFE POWER FCR MAINE Post Office Box 774 Cancen, Maine 04843 OIdt.214U
MAINE YANKEE NUCLEAR POWER PLANT EVM yf ' '" c
diECTION SER OPEN ITEM 3.2.1 Safe Shutdown During our previous eva*uation we identified eleven plant areas in which there may be a potential for a fire to adversely affect redundant divisions of safety The licensee asserted, for each area of concern, that the facility systems.
has the capacity to safely shut down in the event of a fire. The licensee agreed to provide additional infonnation to demonstrate the capability to ac,ieve h
safe shut down conditions in the event of a fire in any one of the areas.
The additional infomation was required because prior submittals lacked an adequate description of the separation between redundant safe shutdown cables within the areas. This infomation was needed to allow the staff to detemine whether the existing separation, in conjunction with the fire p otecticn proposed by the licensee, was adequate to assure that safe shut-down capability would not be lost as a result of fire in these areas.
Without this infomation, the staff could not make such a determination and would then require that an alternate shutdown capability be p-ovided independent of the existing capability. The additional infomation has been provided in the licensee's submittal WMY 78-52, dated May 31, 1978.
In WMY 78-52, the licensee states that for each of the areas, safe shutdown capability does exist even if the area was completely burned out and briefly describes the shutdown capability that would be available. We have reviewed the infomation and find that in most of the areas addressed by the licensee, our minimum requirements regarding safe shutdown capability are not met and the description of separation and fire protection measures is not adequate to assure safe shutdown capability.
The licensee should show how our minimum requirements regarding safe shutdown capability are met for fires which cause loss of the cables for each of the identified areas. This provision of alternate shutdown capability is to satisfy separation concerns and does not relieve the licensee from providing fire protection for safety-related equipment and cables. Our minimum require-ments for safe shutdown capability are described in the attached staff position.
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STAFF POSITION SAFE SHUTDOWN CAPABILITY Staff Concern During the staff's evaluation of fire protection programs at operating plants, One or mere specific plant areas may be identified in which the staff does not have adequate assurance that a postulated fire will not damage both redundant divisions of shutdown systems.
This lack of assurance in safe shutdown capability has resulted frcm one or both of the following situations:
- Case A: The licensee has not adequately identified the systems and components required for safe shutdown and their location in specific fire areas.
Case 3: The licensee has not demonstrated that the fire protection for specific plant areas will prevent damage to bott redundant divisiens of safe shutdewn components identified in these areas.
For Case A, the staff has required that an adequate safe shutdcwn analysis be performed.
This evaluation includes the identification of the systers required for safe shutdown and the location of the system compenents in the plant. Where it is determined by this evaluation that safe shutdown compenents of cath redundant divisions are located in the same fire area, the licensee is required to demenstrate that a postulated fire will not damage both divisiens or provide alternate shutdcwn capability as in Case B.
For Case B, the staff may have required that an alternate shutdcwn capability be provided with is independent of the area of concern or the licensec may have proposed such a capability in lieu of certain additional fire protection modifications in the area. The specific modificatiens associated with the area of concern along with other systers and equipment already independent of the area form the alternate shutdcwn capability.
For each plant, the modificatiens needed and the comoinations of systers which provide the shutdcwn functions may be unique for each critical area; however, the sh0tdown functions provided should maintain plant parameters within the bounds of the limiting safety consequences deemed acceptable for the design basis event.
Staff Positien Safe shutdown capability shculd be demonstrated (Case A) or alternate shutdewn cacability provided (Casa 3) in accordance with the guidelines proviced below:
- 1. Cesien Basis Event The design basis event for considering the need for alternate shutdewn is a postulated fire in a specific fire area centaining reduncant safe snutccwn cables / equipment in close proximity where it has been ce n-rinec that fire protection means cannot assure that safe snu:::wr capability will be preserved.
Two cases sncuid be c:r.sidered.
(l' effsite pewer is avaiiacle; and (2) Offsite pewer is not availacie.
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. 2 Limiting Safety Ccnsecuences and Recuired Shutdown Functions 2.1 No fissien product boundary integrity shall be affected:
a.
No fuel clad damage; b.
No ruptura of any primary coolant boundary; c.
No rupture of the containment boundary.
2.2 The reactor coolant system process variables shall be within those predicted for a loss of normal ac power.
2.3 The alternate shutdewn capability shall be able to achieve and maintain suberitical conditions in the reactor, maintain reactor c:olant inventory, achieve and maintain het standby
- conditions (hot shutdown
- for a BWR) for an extended period of time, achieve cold shutdown
- conditions within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and maintain cold shutdown conditiens thereafter.
As defined in the Standard Technical Specificaticns.
- 3. Performance Goals 3.1 The reactivity centrol function shall be ca:able of achieving and maintaining cold shutdown reactivity conditiens.
3.2 The reacter coolant makeup function shall be capable of maintaining the reactor coplant level above the top of the core for SWR's and in the pressurizer for PWR's.
3.3 The reactor heat removal function shall be capable of achieving and maintaining decay heat removal.
3.4 The process menitoring function shall be capable of providing direct readings of the process variables necessary to perform and centrol the above functions.
3.5 The succorting function shall be capable of providing the process cooling, lubricatien, etc. necessary to permit the Operati'n of the equipment used for safe shutdown by the systems identified in 3.1 - 3.4.
3.5 The equipment and systers us? ' te achieve and maintain hot standby conditions (hot shutdcwr. for a SWR) should ce (1) free of fire damage; (2) ca:able of maintaining such conditiens for an extended ti,v period longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if the equipment required to achieve and maintain cold shutdcwn is not available due to fire damage; and (3) powered by an ensite emergency power system.
3.7 The ecuf; ment and systems used to ach a and maintain cold shutdcwn conditicns shculd be either h 2e of fire damage or the fire damage to such systems snculd :e limited sucn that repairs can be mace and cold shutdcwn conditions acnieved Ecu : ment and systems used prior ta 72 hcurs d
witnin 72 hcurs.
after the fire sncul Se pcwered by an :nsite emergency power system; those used aftar 72 hcurs may be powered by bDcA$O
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. offsite pcwer.
3.8 These systers need not be designed to (1) sei'.71c category I criteria; (2) single failure criteria; or (3) cope with other plant accidents such as pipe breaks or stuck valves
( Appendix A BTP 9.5-1), except those portions of these systers which interface with or impact existing safety systees.
- 4. PWR Ecui: ment Generally Necessary For Hot Standby (1) Reactivity Centrol Reactor trip capability (scram). Boratien capability e.g.,
charging pump, makeup pump or high pressure injection pump taking suction frem concentrated borated water supplies, and letdown system if required.
(2) Reacter Ccolant Makeuo Reactor coolant makeup capability, e.g., charging pumps or the high pressure injection pumps. Pcwer operated relief valves may be required to reduce pressure to allow use of the high pressure injection pumps.
(3) Reactor Ccolant System Pressure Control Reactor pressure centrol capability, e.g., charging pumps or pressurizer heaters and use of the letdcwn systers if required.
(4) Decay Heat Remeval Decay heat removal capability, e.g., power operated relief valves.(steam generator) or safety relief valves for heat removal with a water supply and emergency or auxiliary feedwater pumps for makeup to the steam generator. Service water or other purcs may be required to provide water for auxiliary feed puro suction if the cendensate storage tank capacity is not adequate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
(5) Process Monitorino Instrumentation Process monitoring espability e.g., pressurizer pressure and level, steam generator level.
(6) Succert.
The equipment required to succert operation of the above described shutdcwn equipment e.g., ccmcenent cooling water service water, etc. anc ensite pcwer sources (AC, CC) witn their asscciated electrical distributica system.
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. 5. PWR Ecuicment Generally Necessary For Cold Shutdown _*
(1) Reactor Coolant System Pressure Reduction to Residual Feat Removal System (RNR) Cacao 11ity Reactor coolant system pressure reduction by cooldcwn using steam generator power operated relief valves or atmcspheric dump valves.
(2) Decay Heat Removal Decay heat removal capability e.g., residual haat rtmoval system, component cooling water system arrd service water system to removal heat and maintain cold shutdcwn.
(3) Succort Support capability e.g., ensite power sources ( AC & CC) or offsite after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the associated electrical distribution system to supply the above equiprnent.
Equipment necessary in addition to that already provided to maintain hot standby.
- 6. BWR Eauioment Generally Necessary For Hot Shutdewn (1) Reactivity Control Reactor trip capability (scram).
(2) Reactor Coolant Makeuo Reactor coolant inventory makeup capability e.g., reactor core isolaticn cooling system (RCIC) or the high pressure coolant injection system (HPCI).
(3) Reactor Pressure Control and Decav Heat Removal Cepressurization system valves or safety relief vilves for dump to the suppression pcol. The residual heat removal system in steam cendensing mode, and service water system may also be used for heat removal to the ultimate helt sink.
(4) Suceression Pool Coolinc Residual heat removal system (in suppression pool cooling moce) service water system to maintain het shutdcwn.
(5) Pmcess Mcnitorinc
? recess menitoring cacacility e.g., reactor vessel level and pressure and suporession pool temoerature.
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. (6) Succort Support capability e.g., onsite pcwer source (AC & DC) and their associated distribution systems to provide for the shutdown equipment.
- 7. SWR Ecuioment Generally Necessary For Cold Shutdown
- At this point the equipment necessary for hot shutdown has reduced the primary system pressure and temperature to where the RHR system may be placed in service in RHR cooling mode.
(1) Decay Heat Removal Residual heat removal system in the RHR cooling =cde, service water system.
(2) Succort Onsite sources (AC & CC) or offsite af ter 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and their associated distribution systers to provide for shutdcwn equipnent.
Equipnent provided in addition to that for achieving hot shutdewn.
- 8. Information Recuired For Staff Review (a) Description of the systems' or portions thereof used to provide the shutdown capability and modifications required
, to achieve the alternate shutdown capability if recuired.
(b) System des.gn by drawings which show normal and alternate shutdown centrol and power circuits, location of components, and
. that wiring which is in the area and the wiring which is cut of the area that required the alternate system.
(c) Verification that changes to safety systems will not degrade safety systems.
(e.g., rew isolation switches and control switches shculd meet design criteria and standards in FSAR for electrical equipment in the system that the switch is to be installed; caoinets that the switches are to be mounted in shculd also meet the same criteria (FSAR) as other safety related cabinets and panels; to avoid inadvertent isolatien from the centrol recm, the isolatien switches should be keylocked, or alarmed in the centrol room if in the
- local" or "isclated" position; periodic checks should be made to verify switch is in the precer position for normal operation; and a single transfer switch or other new device should not be a scurce for a single failure to cause loss of redundant safety syste ~ ).
(c) Verification that wiring, including pcwer sources for the c ntrol circuit and equi: ment operation for the alternate snutdcwn metned, is independent of equipment win ng in the area to be avoided.
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(e) Verification that alternate shutdown pcwer sources, including all breakers, have isolation devices en control circuits that are routed through tho area to be avoided, even if the breaker is to be operated manually.
(f) Verification that licenses procedure (s) have been developed which describe the tasks to be performed to effect the shutdown me thod. A sicrr.ary of these procedures should be reviewed by the staff.
(g) Verification that spare fuses are available for control circuits where these fuses,may be required in supplying power to control circuits used for the shutdown method and may be blown by the effects of a cable spreading room fire. The spare fuses shculd be located convenient to the existing fuses. The shutdown procedure should inferm the operator to check these fuses.
(h) Verification that the manpcwer required to perform the shutdown functions using the precedures of (f) as well as to provide fire brigade members to fight the fire is available as required by the fire brigade tecnnical speci fications.
(i) Verification that adequate acceptance tests are performed.
These should verify that: equiprent operates frca the local centrol station when the transfer or isolation switch is placed in the " local" nesition and that the equipment cannot be operated from the control recm; and that equip-ment operates from the centrol rocm but cannot be operated at the local centrol station when the transfer or isolation switch is in the " remote" position.
(j) Technical Specifications of the surveillance requirements and limiting conditions for operation for that equipment not a'iready covered by existing Tech. Specs. For exarole, if new isolation and centrol switches are added to a service water system, the existing Tech. Spec. surveillance require-ments en the service water system should add a statement similar to the following:
"Every third pump test should also verify that the pe=p starts from the alternate shutdewn station after moving all service water system isolation switches to the local control pcsition.*
(k) Verification that the systems available are adequate to perform the necessary shutecwn functiers. The functions required shculd be based on previcus analyses, if pessible (e.g.,
in the FSAR), such as a less of normal a.c. pcwer or shutdown en a Grcuo I isolation (SWR). The etui; ment required for the alterr. ate cacability shculd be tne same er ecuivalent to
- nat relied en in tne abcve analysis,
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7-(1) Verification that repair procedures for cold shutdcwn systems are developed and material for repairs is traintained en site.
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