ML19262C540
| ML19262C540 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/29/1980 |
| From: | Burwell S Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002140369 | |
| Download: ML19262C540 (16) | |
Text
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'o, UNITED STATES
! ' ) o ()g/ h NUCLEAR REGULATORY COMMISSION
- 7-W /, c WASHINGTON, D. C. 20555
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.f JAN 2 H 1980
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Docket Mos:
50-445 and 50-446 APPLICANT:
TEXAS UTILITIES GENERATING COMPANY FACILITY:
COMANCHE PrAV, STEAM ELECTRIC STATION, UNITS 1 AND 2
SUBJECT:
SUMMARY
OF JANUARY 10, 1980 MEETING ON FIRE PROTECTION CRITERIA TO BE USED FOR THE REVIEW 0F COMANCHE PEAK
SUMMARY
A meeting was held on the morning of January 10, 1980 in Bethesda, Maryland with representatives of the Texas Utilities Generating Company.
The purpose of the meeting was to discuss the criteria and requirements for the fire protection design of the Comanche Peak Steam Electric Stc. ion, Units 1 and 2, and the NRC staff plans to conduct the review.
In particular we discussed the considerations of transient fire loads by the staff, and our requirements to demonstrate a capability to achieve safe shutdown for this postulated An attendance list is attached as Enclosure 4.
event.
Meeting Details We described the NRC procedures for the operating license review of the station fire protection design.
We will plan to issue our fire protection questions based on our review of the FSAR Section 9.5.1 about two months prior to our "onsite" fire protection review. Our onsite review should be scheduled when approximately 90 percent of the cable trays have been installed.
All cable trays should be marked to show the separation of respective safety divisions in the electrical, instrumentation and control cables.
We will issue our second rmnd questians and staff positions on the fire protection design shortly after the onsite review.
The draft SER input will be prepared upon the applicant's response to the second round questions and staff positions.
The applicant estimated that cable tray installation will reach the 90 percent installed milestone this summer.
The applicant will advise on a more specific date efter checking with the construction group.
In response to the applicant's inquiring about the nature of the staff review and experiences on other plants we identified the Safety Evaluation Report on the Fire Protection Program for North Anna Power Station, Units 1 and 2, dated February 1979, Similar safety evaluations of the fire protection programs have been prepared for the Farley and Zimmer nuclear power plants.
He also identified Question 1 on the fire protection post-site review for the Virgil C. Summer Nuclear Station (issued October 22, 1979) as a signifi-cant matter considered by the staff in its fire protection review.
This s o 02140 369
Texas 'Jtilities Generating Co.
2-JA N 2 " Let Question 1 and its enclosures are attached as Enclosures 1 and 2 to this meeting sunnary.
A statement on the related staff position on safe shutdown capability is attached as Enclosure 3.
Question I requires that the fire protection design consider the effects of a postulated fire involving permanent or transient combustibles on systems, cable trays or equipr. nt required for safe shutdown. Ne commented that the FSAR does not presently contain the information needed to complete our re';iew of Question 1 and the staff position on safe shutdown capability.
Relative to our experierces in reviewing other applications we noted that others had.found it more feasible to provide an alternate shutdown system than to provide the separation described in Question 1 for the cable spreading "com.
We also noted a strong preference for installing a water sprinkler ;ystem in the cable spreading room. We have no data confirming the suppression of deep-seated cable fires by gas systems, while there is a wealth of information on suppression with water systems. We have accepted combination systems; i.e., initial gas suppression with a back-up water sprinkler system.
We requested that the applicant be prepared to discuss their responsus to Questions I and the safe shutdown position during our onsite review.
/ ;n 4,
t.
,5 Spottswood B. Burwell, Project Manager Light Water Reactors Branch No. 2 Division of Project Management
Enclosures:
1.
Request for Additional Information for Sumner Nuclear Station, Oct. 22, 1979 2.
Staff Requirements for Alternate Shutdown Systems, Oct. 22, 1979 3.
Staff Position, Safe Shutdown Capability 4.
Meeting Attendance List cc:
See next page
Mr. R. J. Ga ry Mr. R. J. Gary Executive Vice President and General Manager Texas Utilities Generating Company 20t ' Bryan Towers Dallas, Texas 75201 Nicholas S. Reynolds, Esq.
Debevoise & Liberman 1200 Seventeenth ^treet Washington, D.C.
20036 Spenc r C. Relyea, Esq.
Worsham, Forsythe & Sampels 2001 Bryan Tower Dallas, Texas 75201 Mr. Homer C. Schmidt Project Manager - Nuclear Plants Texas Utilities Generating Canpany 2001 Bryan Tower Dollas, Texas 75201 Mr. H. R. Rock Gibbs and Hill, Inc.
393 Seventh Avenue New York, New York 10001 Mr. G. L. Hohmann Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230 Richard W. Lowerre, Esq.
Assistant Attorney General Environmental Protection Division P. O. Box 12548, Capitol Station Austin, Texas 78711 Mrs. Juanita Ellis, President Citizens Association for Sound Energy 1426 South Polk Dallas, Texas 75224 Geoffrey M. Gay, Esq.
West Texas Legal Services 406 W.T. Waggoner Building 810 Houston Street fort Worth, Texas 76102
Mr. R. J. Gary Ms. Nancy Holdam Jacobson Citizens for Fair Utility Regulation 1400 Hemphill Fort Worth, Texas 76104 Mr. Richard Fouke 1668-B Carter Drive Arlington, Texas 76010 Resident Inspector. > 'nche Peak Nuclear Power Station c/o U. S. Nuclear Regulatory Cormission P. O. Box 38 Glen Rose, Texas 70642
ENCLOSURE 1 OCT 2 2 379 REQUEST FOR ADDITIONAL INFORMATION ON THE FINAL SAFETY ANALYSIS REPORT F0k THE VIRGIL C. SUMM.ER NUCLEAR STATION FIRE PROTECTION POST SITE REVIEW REQUEST FOR INFORMATION AND STAFF POSITIONS 1.
You state in your Fire Hazards Analysis how various safety-related cable trays, conduit and equipment are separated by distance from its redun-dant counterpart, and the triteria that were used to establish barriers between these redundant trains.
In order to provide a defense-in-depth design, so that a fire will not prevent the performance of necessary safe plant shutdown functions, a detailed fire hazards analysis should be conducted for each plant area.
It is assential that the analysis include the effects of postulated fire involving pemanent and/or transient combustible; (exposure fires) on systems, circuit cable trays or equipment required for safe plant cold shutdown.
The fire hazards analysis should identify all the redundant mechanical and electrical systems and components necessary for safe cold shutdown which are separated only by distance (no fire barriers and with redun-dant trains 20 ft. or less from each other). Redundant trains within 20 ft. of each other, as a minimum, will be required to be pmtected by a half hour fire rated barrier as well as area automativ sprinklers.
This does not mean that in some instances, such as the auxiliary feedwater systen, redundant trains separated by more than 20 ft, will not require additional protection.
The fire hazards analysis need to demonstrate that, assuming failure of the primary suppression system, a fire on installed or transient combustibles will not result in the loss of
. OCT 2 2 SS capability to achieve safe cold shutdown. Where this cannot be demonstrated, an alternate means of assuming safe plant shutdown (cold shutdown) should be provided.
We request that you demonstrate:
(1) Safe shutdown from the main control room where a fire disables any safe shutdown equipment including conduit / cable trays centrolled from remJte locations.
(2) Safe shutdown from remote locations when the main control room is unin-habitable due to a fire or when fire disables safe shutdown equipment of the relay room, cable chase areas, or the cable spreading areas.
Remote location need oniy be provided for the essential instrumentation, controls and equipment necessary to bring the plant to a hot standby condition. Fire damace to systems necessary to achieve and maintain cold shutdown should be limited so that repairs can be made and cold shutdown condition achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Enclosure fio. 2 presents our require-runts for al ternate shutdown systems.
OCT 2 21979 ENCLOSURE 2 STAFF REQUIREMENT:, FOR At TERNATE SHUTDOWN SYSTEMS 1.0 Minimum safe shutdown systems when one division of all safety systems is not available.
1.1 Following any fire, the plant can be brought to hot shutdown conditions using equipment and systems that are free of fire damage.
1.2 The plant should be capable of maintaining hot shutdown conditions for an extended time period significantly longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
1.3 Fire damage to systems necessary to achieve and maintain cold shutdown conditions should be limited so that repairs car be made and cold shutdown conditions achieved witnin 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
1.4 Repair protecures for cold shutdown systems should be prepared and material needed for strch repairs should be on tne site.
now 1.5 The hot shutdown condition must be achievable with power from the offsite power system, and upon its loss, with power from the onsite power system. A dedicated power supply may be substituted for the onsite power system.
l.6 The power needed to achieve the cold shutdown condition may be obtained from any one of the offsite power, onsite power, and dedicated power system.
1.7 When these minimum systems are provided their adequacy shall be verified by a thorougn evaluation of:
Systems required for hot shutdown; a.
b.
Systems required for cold shutdown; Fire damage to power distribution systems; and c.
d.
Interactions caused by fire camage to power and water suoply systems and to supporting systems, i.e., component cooling water supply.
- 2. 0 Minimum fire protection when dedicated or alternate shutdown systems are provided.
2.1 The fire protection systems in areas (such as cable spreading rooms) that contain cables for a large number of systems should consist of:
a.
Fire detection system; b.
Hose stations; and Fixed manual suppression system (gas or water) c.
NOTE: Consideration to preventing fire propagation via covered trays, fire retardant coating, barriers or blankets on a case-by-case basis.
. %T 2 2 :3N 2.2 Where access is difficult or impossible automatic systems should be provided.
2.3 Where modifications will not be implemented for an extended period, interim nrotection raeasures should be required to compensate for the lack of protection.
ENCLOSURE 3 STAFF POSITION SAFE SHUT 00WN CAPABILITY Staf* Concern During the staff's evaluation of fire protection programs at coerating clants, one or more specific olant areas may be identified in wnicn tne 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 snutcown capability nas resulted from one or both of the following si" ations:
Case a:
The licensee has not adequately identified the systems and comocnents recuired for safe shutdown and their locaticr. in specific fire areas.
Case B:
The licensee has not demonstrated that the fire protection for scecific olant areas will prevent damage to teth redundant divisions of safe shutdown components icentified in these areas.
For Case A, the staff has required tnat an adecuate safe shutdcwn analysis be performed.
This evaluation includes the identification of the systems required for safe shutdown and the location of the system comocnents in the olant. Where it is determined by this evaluation that safe snutdcwn components of both redundant divisions are located in the same fire area, the licensee is required to demonstrate that a oestulated fire will not damage both divisions or provide alternate snutdown capability as in Case B.
___ b For Case 3, the staff may have required that an alternate shutdown N
capability be provided his indeoendent of tne area of concern or the licensee may have proposed such a capability in lieu of certain additional fire protection modifications in the area. The scecific modifications associated with the area of concern along with ctner systems and equioment already independent of the area form the al terrate shutdcwn cacabili ty.
For each plant, the modifications needed and the ccmbinations of systems which provide the shutdown functions may be unique for eacn critical area; however, the shutdown functions provided should maintain plant carameters witnin the bounds of the limiting safety consecuences deemed acceptable for the design basis event.
Staff Position Safe shutdown cacability should be demonstrated (Case A) or alternate shutdcwn caoability provided (Case 3) in accordance with tne guidelines provided below:
1, Cesign Basis Event The design basis event for considering the need for alternate snutdown is a postulated fire in a specific fire area containing redundant safe snutdown cables / equipment in close proximity where it has been determined tnat fire protection means cannot assure that safe shutdcwn capability will be preserved.
Two cases should be considered:
(1) offsite power is available; and (2) offsite power is not a railable.
- 2. Limitine Safety Consecuences and Required Shutdcwn Functions 2.1 No fission product boundary integrity shall be affected:
a.
No fuel clad damage; b.
No rupture of any primary coolant boundary; c.
No rupture of the containment boundary.
2.2 The reactor coolant system process variables shall be within nose predicted for a loss of nornal ac power.
2.3 The alternate shutdown capability shall be able to achieve ano maintain subcritical conditions in the reactor, maintain reactor coolant inventor /, achieve and maintain 'ot star cby' conditicns (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 shutdcwn conditions thereafter.
As defined in the Standard Technical Saecifications.
- 3. Perfomance Goals 3.1 The reactivity controk function shall be cacable of achieving and maintaining cold shutdown reactivity conditions.
3.2 The mactor coolant makeup function shall be capable of mz.intaining the reactor coolant 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 crocess monitaring function shall be capable of providing direct readings of the process variables necessary to perfonn and centrol the above fur ctions.
3.5 The su:: porting function-shall be capable of providing the process cooling, lubrication, etc. necessary to pemit the operaticn of the equipment used for safe shutdown by the systems identified in 3.1 - 3.4 3.6 The equipment and systems used to achieve and maintain hot standby conditions (hot shutdown for a SWR) should be (1) free of fire damage; (2) capable of maintaining such conditions for an extended time 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 onsite emergency power system.
3.7 The equicment and systems used to achieve and maintain cold shutdcwn conditions should be ei:ner free of fire damage or the fire damage to such systems snould be limited such that repairs can be made and cold shutdown conditions achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Equipment and systems used prior to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after the fire should be powered by an onsite emergency power system; those used after 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> gay be powered by offsite power.
- 3. 3 These systems need not be designed to (1) seismic category I criteria; (2) single failure criteria; or (3) cope, with
~
otner plant accidents such as pipe breaks or stuck valves
- f. Accendix A STP 9.5-1), except those portions of these systems which interface with or impact existing safety systems.
- 4. ?WR Ecuicrent Generally Necessary For Hot Standbv (1)
Reactivity Control Reactor trip capability (scram).
Saration capability e.g.,
cnarging pump, makeup pump or hign pressure injection pump taking suction from concentrated borated water supplies, and letdown system if required.
(2)
Reactor Coolant Makeuo Reactor coolant makeup capability, e.g., charging cumos or the nign pressure injection cumps.
Power operated relief valves may be required to reduce pressure to allow use of the hign cressure injection pumos.
(31 Reactor Coolant System Pressure Control Reactor pressure contr01 capability, e.g., charging cumos or pressuri:er heaters and use of the letdown systems if required.
(4)
Decay ueat Removal Cecay heat removal capability, e.g., power operated relief valves (steam generator) or safety relief valves for heat removal wi91 water suoply and emergency or auxiliary feecwater pumps for makeup to the steam generator. Service water or other pumps may be required to provide water for auxiliary feed cumo suction if the condensate storage tank capacity is not acequate for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
-(5)
Process Mcnitoring Instrumentation Process monitoring capability e.g., pressurizer pressure and level, steam generator level.
(6)
Succort.
The equipment required to succort operation of the above describec shutdcwn equicment e.g., comconent cooling nater service water, etc. and cnsite power sources ( AC, DC) with tneir asscciated electrical distribution system.
- 5. PWR Eouipment Generally Necessary For Ccid_,",hutdown*
(1)
Reactor _ Coolant System Pressure Reduction to Residual Heat Removal System (RHR) Cacab11 i ty Reactor coolant system pressure reduction by cooldown using steam generator power ocerated mlief /alves or atmospneric dump valves.
(2)
Cecay Heat Removal Cecay heat removal caoatili ty e.g., residual hea*. removal system, component cooling water system arid service water system to removal heat and maintain cold shutdown.
(3)
Succort Support capability e.g., ensite power sources ( AC & DC) 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 sucoly the above equipment.
Equioment necessary in addition to that already orovided to maintain not stancby.
- 6. 3WR Ecuioment Generally Necessary For Hot Shutdown (1)
Reactivity Centrol Reactor trip capability (scram).
(2)
Reactor Coolant Makeuo Reactor coolant inventory makeup capability e.g., reactor core isolation cooling system (RCIC) or the high pressure coolant injection system (HPCI).
(3)
Reactor Pressure Control and Decay Heat Removal Depressurization system valves or safety relief valves for dump to the suppression pool.
The residual heat removal system in steam concensing mode, and service water system may also be used for neat removal to the ul'imate heat sink.
(4)
Sucaression Doni Coolino Residual heat removal system (in suppression pool cooling mode) service water sj 3 tem to maintain hot shutdown.
(5) Process Monitorinc 3rocess monitoring capability e.g., reactor vessel level and pressure and r.uopression pool temperature.
(6) Succort Support capability e.g., ensite power source (AC & DC) and their associated distribution systems to orovide for the shutdown equipment.
- 7. SWR Ecui rent Generally Necessary For Cold Shutdown
- At this point the equi: rent necessary for hot snutdown has reduced the primary system cressure and temperature to where the RHR system may be placed in service in RHR cooling mode.
(1)
Cecay Heat Removal Residual heat removal system in the RHR cooling mode, 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 systems to provide for shutdown equipment.
Equipment provided in addition to that for achieving hot shutdown.
- 3. Infor ation Recuired :or Staf' Review (a)
Description of the systems or portions tnereof used to provide the shutdown capability and modifications required to acnieve the alternate shutdown caJability if recuired.
(b)
System design by drawings which show no m al and alternate snut::own control and power circuits, location of components, and that wiri.1g which is in the area and the wiring which is out of the area that reouired the alternate system.
(c) Verification that changes so safety systems will not degrace safety systems.
(e.g., new isolation switches and control switches should meet design criteria and standards in FSAR for electrical equipment in the system that the switch is to be installed; cabinets that the switches are to be mcunted in should also meet the same criteria (FSAR) as other safety related cabinets and canels; to avoid inadvertent isolation from the control room, the isolation swit nes should be keylocked, or alamad in the control room if in the " local" or " isolated" cosition.
periodic checks should be made to verify switch is in the procer position for nor-nal aceration; and a single transfer switen or otner new cevice should not be a source #or a single failure to cause loss of redundant safety systems).
(d) Verification :nat wiring, including power sources #cr the c:ntrol circuit and ecuicment oceration for the alterna:e shutdown method, is independent of equioment wiring in the area to be avoided.
.g.
(e)
Verification that alternate shutdown power sources, including all breakers, have isolation devices on control circuits thtt are routed througn the area to be avoided, even if the breake r is to be operated manually.
( f) Verification that licensee procedure (s) have been developed wnich describe the tasks to be perfomed to effect the shutdown me thod.
A survnary 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 ocwer to control circuits used for the shutdown method and may be blcwn by the effects of a caole spreading room f:re.
The spare fuses snould be located convenient to the existing fuses.
The shutdown procedu'e should inform the operator to check tnese fuses.
(h) Verification that the manpcwer required to ::erform the snutcown functions using One procedures of (f) as well as to provide fire brigade members to fight the fire is available as required by the fire brigade tecnnical s::eci ficati ons.
(i) 7rification that adequate acceptance tests are performed.
Inese should verify that: equipment operates from the local control station wnen the transfer or isolation switch is pl ced in the " local" position and that the equipment canne be coerated from the control room; and that equip-ment ::erates from the control room but cannot be operated at tt.; local control station when the transfer or isolation switch is in the " remote" position.
(j) Technical Specificativ. 4 of the surveillance requirements and limiting conditions for coeration for that equipment not already covered by existing Tech. Specs.
For example, if new isolation and control switches are added to a service water system, the existing Tech. Spec. surveillance require-ments on the service water system should add a statement similar to the following:
"Ever/ third cumo test should also verify that the pumo starts from the alternate shutdown statio1 af ter moving all service water system isolation sw'tcres to the local control position."
(k) Verification that the sys tems availa' le are adequate to perform the necessary shutdown functions.
' h=, functions required snould be based on previous analyses, if possible (e.g.,
in the FSAR), such as a loss of normal a.c. power or shutdown on a Group I isolation (SWR).
The equipment recuired for the alternate capability should be tne see or equivalent to that relied on in the above analysis.
. (1) Verification that repair procedures for cold shutdown systems are develcDed and material for repairs is maintained on site.
ENCLOSURE 4 MEETING ATTENDANCE LIST COMANCHE PEAK STEAM ELECTRIC STATION JANUARY 10, 1980 NRC - STAFF _
S. B. Burwell G. A. Harrison M. S. Hudson TEXAS UTILITIES GENERATING COMPANY C. K. Feist it. L. Greer T. Jenkins GIBBS & HILL Farid Farkouh M. S. Kumar