ML19354D858
| ML19354D858 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 01/05/1990 |
| From: | Brey H PUBLIC SERVICE CO. OF COLORADO |
| To: | Weiss S NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| P-90006, NUDOCS 9001230009 | |
| Download: ML19354D858 (12) | |
Text
.
.- ...h ,
M Public Service' .
Company of Colorado 2420 W. 26th Avenue, Suite 100D, Denver, Colorado 80211 i
L January 5, 1990 Fort St. Vrain Unit No. 1 P-90006f i U. S. Nuclear Regulatory Commission ATTN: Document Control Desk >
Washington, D.C. 20555 i Attention: Mr. Seymour H. Weiss, Director '
Non-Power Reactor, Decommissioning l and Environmental Project Directorate Docket No. 50-267 3
SUBJECT:
Safety Assessment of Proposed ~
Changes to ^the Fire Protection Program Plan
REFERENCE:
PSC Letter, Crawford to Weiss, dated November 8, 1989~(P-89431)
Dear Mr. Weiss:
PSC submitted Revision 3 to -the Fire Protection-Program Plan (FPPP) l in the referenced letter for the NRC's review. Subsequently, Mr.
Pete Erickson of your staff _ requested that PSC' submit.a. safety assessment of the major changes proposed'in Revision 3 to the-- FPPP.
This safety assessment is attached.
It.is PSC's position that only the proposed FPPP changes' addressed.in
- the safety assessment require.NRC review. The other FPPP. changes can be processed by PSC under the provisions of 10 CFR 50.59. :Therefore, your review of the FPPP changes addressed in the safety assessment is' requested.
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9001230009 900105 PDR ADOCK 05000267 0.0 F PDC ,
P-90006 Page 2 January 5, 1990 If have any questions regarding this submittal, please contact Mr. youM. H. Holmes at (303)-4BO-6960.
Very truly yours, N
H. L. Brey Manager, Nuclear Licensing and Resource Management Division n Attachment' HLB /JRJ:tmk cc: Regional Administrator, Region IV ATTN: Mr. T. F. Westerman, Chief Projects Section B Mr. Robert E. Farrell Senior Resident Inspector Fort St. Vrain Mr. D. J. Kubicki U. S. N. R. C. Fire Protection Engineer-Chemical Engineering Branch !
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SAFETY ASSESSMENT
1.0 INTRODUCTION
PSC has requested NRC approval of revised Fire Protection Cooldown Trains for FSV. The existing three trains are comprised of two forced circulation cooling trains (Fire Protection Shutdown /Cooldown Trains A and B) relied on for cooldown following fires outside Congested Cable Areas (CCAs), and one PCRV liner cooliag train (Alternate Cooling Method) relied on for cooldown following fires in any of the CCAs. The proposed new trains (Fire Protection Cooldown Trains 1 and 2) both me PCRV liner cooling for decay heat removal.
PCRV liner coolirg is supplied with firewater in an open loop mode for Train 1. Trrin 2 relies on one Reactor Plant Cooling Water Pump to supply PCRV iiner cooling, with heat removal via the Reactor Plant-Cooling Water Heat Exchangers cooled by service water.
Other Fire Protection Program Plan changes evaluated herein, and requiring NRC review, include modified Fire Protection Operability Requirements (FPORs) and revised Fire Suppression requirements.
1.1 Acceptance Criteria for Shutdown Cooling Following a Fire 10 CFR 50.48 and 10 CFR 50 Appendix R established new requirements for fire protection. The following acceptance criteria define j limiting consequences of FSV fires in CCAs and non-CCAs (Reference ;
1):
"For any single fire in a congested cable area means shall be available to shut down and cool down the ' reactor in a manner 1 such that the consequences of_ DBA-1, as defined in FSAR- t AppendixD(Rev.1),arenotexceeded."
"For any single fire in a non-congested cable area means !
shall be available to shut down and cool down the reactor in a manner such that no fuel damage occurs (i.e. maximum fuel particle temperature does not exceed 2900 degrees F). There shall be no simultaneous rupture of both a primary coolant ]
boundary and the associated secondary containment boundary i such that no unmonitored radiological releases of primary ;
coolant occur." i The Alternate Cooling Method (ACM) powered PCRV liner cooldown meets the acceptance criteria for fires in CCAs. However, PCRV liner 1 cooling previously could not provide adequate decay heat removal to-prevent fuel damage for fires in CCAs which result in loss of forced circulation from reactor operation at elevated power levels.
Therefore, two redundant forced circulation trains were identified, Fire Protection Shutdown /Cooldown Trains A and B (the existing Fire Protection trains). Both Trains A and B are capable of_ providing sufficient decay heat removal so that no fuel failure would occur following prolonged operation at 83.2% reactor power and a 90 minute interruption of forced circulation. -Forced circulation Trains A and B meet the separation requirements of 10 CFR 50 Appendix R Section III.G.2, with the exception of exemptions approved by the NRC in i Reference 2. '
Attachment to P-90006 Page 2 2.0 EVALUATION 2.1 Description of Existing Fire Protection Shutdown /Cooldown Trains As stated above, the existing trains consist of two forced circulation trains, Train A and Train B, and one PCRV liner cooling train, the ACM. Train A relies on a small condensate pump to supply water to a steam generator and a helium circulator water turbine drive in loop 1. Train B relies on a firewater pump to supply water to a loop 2 steam generator and a loop 2 circulator water turbine drive. Firewater pressure is increased by a booster pump before injection to the circulator water turbine drive.
The ACM establishes PCRV liner cooling by means of. the Peactor Plant Cooling Water Pumps in System 46, powered by. the ACM diesel-generator. In addition, the ACM diesel generator powers equipment in the service water system and service water is relied on to remove heat from the Reactor Plant Cooling Water Heat Exchangers. The ACM_
is the cooling mode currently relied on for fires in _CCAs, since these fires have the potential to cause loss of forced circulation.
2.2 Description of Proposed New Fire Protection Cooldown Train 1 The ACM Diesel Generator (K-4804) is the power supply for Train 1 1 electrical equipment. The motor-driven fire water. pump (P-4501) supplies cooling water to the loop 2 PCRV. liner cooling tubes._ ;
System 46 valves are positioned in the " redistribute" mode, manually _
if required, to maximize cooling to the PCRV top head area.: After ;
passing through the loop 2 PCRV liner _ cooling tubes, firewater is i directed outside the Reactor Building to a yard drain in an open-loop '
cooling configuration. Makeup water is provided to the suction- of-the motor-driven firewater pump (firewater pump pit) by a circulating ;
water makeup pump, either P-4118 or P-4118S, which takes suction'.on j the storage ponds, j Train 1 is relied upon for cooldown following a fire in a CCA, since i none of the Train 1 cables or components are located in any of the 1 CCAs.
2.3 Description of Proposed New Fire Protection Cooldown Train 2 1
Electric power is supplied to Train 2 electric equipment by the:1B StandbyDieselGenerator(K-9202). One of the loop'2 Reactor Plant Cooling Water Pumps (P-4602 or P-4602S) supplies cooling water to the loop 2 PCRV liner cooling tubes. System 46 valves are positioned in-the " redistribute" mode, manually if required, to maximize cooling to j
the _PCRV top head area. Train 2 is a closed loop cooling configuration in which heat is removed by both loop 2 Reactor Plant Cooling Water Heat Exchangers (E-4602 and E-4604).- The' heat ,
exchangers are cooled by service water. The service water system 1 operates in a closed loop mode, utilizing either Service Water Pump k 1A or 1B (P-4203 or P-4204). The Service Water Cooling Tower E-4201 1 1
Attachment to.
P-90006 Page 3 and its fan (C-4201X) are relied on to exhaust heat to atmosphere.
Any necessary makeup water is provided to the service water cooling tower basin by the domestic water supply.
2.4 Compliance of Proposed New Fire Protection:Cooldown Trains With Acceptance Criteria The consequences of a loss of forced circulation (LOFC) following 100 days shutdown after prolonged operation at 83.2% power have been analyzed using the RECA code-(Reference 3). The RECA transient-analysis results indicate that, with one PCRV liner cooling loop operating with flow redistributed to the top head liner, maximum fuel temperatures, outer insulation cover plate temperatures, maximum liner temperatures and maximum concrete temperatures remain within 4 those experienced during normal operation. It was conservatively assumed that liner cooling does not start until 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the initial LOFC. .The peak fuel temperature for this event is 1510 degrees F (Reference 4). Neither the PCRV liner 'nor the PCRV concrete exceeded 113 degrees F.
In addition to cooling the PCRV, auxiliary cooling loops of the T Reactor Plant Cooling Water System provide cooling to the Fuel Handling Machine and the Fuel Storage Wells. Auxiliary cooling loop 2, supplied by either firewater (Train 1) or one Reactor Plant Cooling Water Pump (Train.2), will adequately cool fuel elements in the Fuel Handling Machine or the Fuel Storage Wells, even under worst case fuel loading conditions.
1 Due to the relatively low levels of decay heat generation during i defueling, PCRV liner cooling alone is adequate to meet the- above stated limiting consequences in the acceptance criteria for fires in non-CCAs of no fuel failure and no simultaneous breach-of the primary coolant boundary and secondary containment boundary. Forced circulation cooling is no' longer a prerequisite to preventing fuel damage. The propon d new Fire Protection'Cooldown Trains 1 and 2 .
would replace the three existing trains consisting of ACM for fires in CCAs and Trains A and B for fires-outside of the CCAs. Both prcrosed new Fire Protection Cooldown Trains establish PCRV liner ,
cooling without forced circulation. 1 2.5 Use of Common Piping / Instrumentation for Both Proposed New Fire l P_rotection Cooldown Trains {
As stated in the above paragraphs, both of the proposed new Fire Protection Cooldown Trains supply water to the same loop, loop 2, of the PCRV liner cooling tubes. This is acceptable because PSC can :
take credit for water-filled piping in the fire area (Reference 1). l The applicable acceptance criteria states:
Water-filled mechanical components, such as pipiag and valves, necessary for safe reactor shutdown /cooldown which ,
3 are within the area, room or zone encompassed by a single
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Attachment to P-90006 Page 4 postulated fire shall not be considered damaged by the fire.
Water-filled valves and mechanical components with manual operators in the fire area, room, or zone shall be considered to be manually operable within one hour after the start of the fire."
This is based on the NRC staff's consideration that manually operable mechanical components containing water would not .be damaged by a postulated fire.
The system instrumentation for monitoring the outlet conditions of.
the PCRV liner cooling is the same instrumentation for both Train 1 and Train 2 since both Trains use loop 2 piping of the PCRV liner cooling system. The instrumentation is all local mechanical devices ;
(pressure and temperature indicators). Since the instrumentation is-at different locations, a postulated fire within the Reactor Building could not render all the instr: mentation inoperable. A fire could, however, damage instrumentation common- to both Fire Protection Cooldown Trains. Both the pressure indicators are water filled and therefore failure by a fire is unlikely. However, to provide ,
assurance of adequate monitoring, dedicated repair kits containing '
spare pressure and temperature indicators and all necessary fittings, tools, etc. will be maintained on site. Establishing-liner cooling (either Train 1 or Train 2) is not required until 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s- - following.
an LOFC. This time duration is- sufficient to assess _ system conditions and replace any damaged instrumentation for monitoring PCRV outlet conditions.
2.6 Time Available to Establish PCRV Liner Cooling Using Either Fire Protection Cooldown Train 1 or Train 2 L J
The defueling LOFC analysis was based on.the postulated occurrence of. ,
a permanent LOFC at 100 days after reactor shutdown, following "
prolonged operationat83.2% power (ieference4). The initial decay -i heat generation rate utilized in this analysis was 0.49 MW. . Actual decay heat generation rates decreased below 0.30 MW by November 27, !
1989, 100 days after reactor shutdown.
Therefore, the core : heat 4 generation rate utilized in the analysis was approximately 60% :
greater than that which actually existed 100 days; after shutdown, l making the analysis extremely conservative. 1 Initiation of PCRV liner cooling at 5 -days into the LOFC from defueling conditions would be acceptable since it would prevent fuel '
damage aad prevent simultaneous rupture of both a primary coolant '
boundary and the associated secondary containment boundary, thus meeting the acceptance criteria for a fire outside of.a CCA'with i
substantial margin. PSC is requiring that PCRV liner cooling' be i established within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the start of an LOFC due to a- fire, '
which is conservative.
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Attachment to P-90006 Page 5 2.7 . Analysis of PCRV Liner Co_olinJ During a Defueling LOFC The analysis of the consequences of heat removal by-PCRV liner cooling in the event of a permanent LOFC froni defueling conditions was perfornied by GA Technologies, Inc., the FSV reactor vendor, using the P0KE and RECA computer codes. The P0KE code was used to determine initial core solid temperatures and heat generation rates.
The RECA code used this information and modelled the heat transfer from the core to the PCRV liner cooling system to compute core and-PCRV temperatures. As stated previously, the analysis' was-conservative since it assumed an initial decay heat generation rate '
of 0.49 MW, and actual decay heat generation rates decreased below 0.30 MW by November 27, 1989, 100 days after reactor shutdown. The analysis becomes more conservative as core heat generation continues to decay and as fuel is removed from the FSV core during defueling.
The analysis assumed that one of the two loops of PCRV-liner cooling was placed in service 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into a LOFC, with . flow redistributed-to maximize cooling to the PCRV top head area and with only'one of, the two PCRV liner cooling pumps in the loop operating. This is the same cooldown mode as that established by Fire Protection Cooldown Train 2. The analysis used cooling water flow rates of 1427 gpm to the PCRV liner cooling tubes and 157 gpm to auxiliary equipment 1 (including 102 gpm to the Fuel Storage Wells). These flow rates are from Table 2 of the System Description for System-46. The analysis assumed the water entering the PCRV liner cooling tubes was at 100 degrees F, Open loop PCRV liner cooling with firewater was-previously evaluated in EE-EQ-0019, Rev. B (Reference 6), which was submitted to the NRC-in Reference 7. This is the same cooldown mode established by Train '
- 1. This evaluation determined that a . single firewater pump would j supply 1508 gpm to system 46 for PCRV liner cooling with an additional 102 gpm to the fuel storage wells- for a firewater pump 1l discharge flow of 1610 gpm. EE-EQ-0019, Rev. B,' documents detailed 1 analyses of liner cooling system pressure drops, flow rates, heat i transfer, temperatures, and subcooled margin in the hottest tube. It concludes that this mode of cooling, with firewater supplied - to the liner cooling tubes in an open loop mode, is adequate to remove decay heat following shutdown from 35% power with the PCRV pressurized.
This condition requires a much greater heat removal rate than that of a liner cooldown following 100 days decay from 83.2% power with' the PCRV depressurized. i Reference 6 concluded that "the fire water system flows and pressures- !
will provide the same level of adequacy as does the reactor plant 4 cooling water system." Therefore, coo'1down with either Train 1 or '
Train 2 will pruvide sufficient cooling such that the accident '
consequences identified in theFSVDefuelingSAR(Reference 3)are not exceeded. Maximum temperatures of the fuel, outer insulation cover plate, PCRV liner, and concrete would remain within.those l
Attachment to P-90006 Page 6 experienced during normal operation for a PCRV liner cooldown during a defueling LOFC with either Train 1 or Train 2.
The NRC contracted with ORNL to duplicate pressurized and depressurized cases of PCRV liner cooling with firewater from 35% >
reactor power, which had been previously analyzed with the RECA code. >
In the NRC's SER in Reference 8, " Authorization For Interim Operation- :
of FSV at 35 Percent of Full Power", the NRC concluded that:
"The NRC contractor, the Oak Ridge National Laboratory (ORNL), duplicated the calculation of these four cases -with :
1ts ORECA computer program. The peak fuel -temperatures, a which determine the failure of the fuel particle coatings, !
calculated by ORNL are about 200 degrees F less than those a calculated by the licensee. ORNL's calculated maximum liner I temperatures are somewhat higher than the licensee's, but not enough higher to cause liner failure. Thus, we conclude that for the depressurized mode of cooling, which is.the preferred mode, the licensee can operate the LCS with fire water to prevent significant damage to any of the fission product barriers."
It is concluded that PCRV liner cooling using either Train 1 or-Train 2 is acceptable. The analysis conservatively demonstrates that fuel damage will not occur' and the integrity of- the PCRV liner and concrete will be maintained. Substantial margin exists since analyses previously reviewed and found acceptable by the NRC staff determined PCRV liner cooling was adequate from substantially . higher ,
decay heat generation rates.
2.8 PCRV Liner Nil Ductility Temperature Considerations There is a potential for low PCRV liner temperatures, especially'in Train 1 cooling, since an open loop liner cooldown using l
will not maintain the PCRV liner above 100 degrees F, as r.- firewater equired by Technical Specification LC0 4.2.15.
The basis for Specification LC0 4 2.15 -refers to an initia1 Nil DuctilityTemperature(NDT)forthePCRV. liner of -60 degrees F.
This subject is discussed in detail in FSAR Section E.24.5 and in Reference 9. Assuming a total integrated neutron dose of 2.3 E18 nyt over the 30 year expected life of the plant, the NDT could increase by as much as 100 degrees F from -60 degrees F to +40 degrees F. To ensure operation above the fracture transition elastic temperature (FTE = NDT + 60 degrees F) over the expected 30 year life of the plant, the minimum liner temperature limit. set by LC0 4.2.15 is 100 degrees F. The 100 degrees F minimum temperature was ' determined - by the 30 year end-of-life total integrated dose.
As discussed in FSAR Section 5.7.2.2, integrated neutron' dose to the 1 PCRV liner over the assumed 30 effective f ull power year - (300 EFPD per each effective full power year) life was conservatively
e Attachment to P-90006 Page 7 calculated to be 2.3 E18 nyt. FSV has only operated for 890 EFPD, or 3.0 effective full power years. Assuming operation for 4 effective full power years, the method for calculating maximum neutron dose to the PCRV top head. liner used in FSAR Section 5.7.2.2 yields a neutron ,
dose of 3.12 E17 nyt. Using linear interpolation in assessing- NDT with increasing PCRV liner neutron exposure, an NDT of -46 degrees F is calculated. The FTE (NDT +60 degrees F) is thus +14 degrees F.
Based on this conservative calculation, it is concluded that PCRV liner temperatures will remain above the FTE even during Train 1 cooldown with firewater on a cold winter day and are therefore 7 acceptable because the PCRV liner is not expected to fracture.- .
2.9 Separation of Cables and Equipment of the Proposed New Fire Protection Cooldown Trains .
The proposed new Fire Protection Cooldown Trains are' greatly simplified compared to existing forced circulation Trains A ~and' B, and have much less equipment and cabling associated with them.
Nearly all of the equipment and cables for the proposed new Train. I are located outside the Reactor and Turbine Buildings..whereas the equipment and cables for Train 2, with the exception of service water equipment, are inside these buildings.
In Train 1, the ACM diesel generator powers the 4160 V ACM bus-and the 480 V ACM switchgear. The 480 V ACM switchgear'in turn supplies power, via transfer switches, to a circulating water makeup pump, the motor-driven firewater pump, and its associated ventilation fan. All of this equipment and assuciated cables,. including the ACM diesel generator and its 4160 V bus, tB0 V switchgear, and the associated transformer, are located outside the Reactor and Turbine Buildings.'
The ACM diesel oil transfer pumps, also powered off of the 480'V -ACM switchgear, are located in the inside auxiliary boiler room which is on the southwest perimeter of the Turbine Building Lat grade. level.
No Train 2 cables or equipment are located in the auxiliary boiler-room. The auxiliary boiler room is a fire area separate from the Turbine Building.
In Train 2, standby diesel generator 'IB (located in the standby diesel generator room IB fire area) powers 480 V essential buses 2 and 3 (located in the three room control complex fire area). These buses supply power to all the Train 2 equipment.
The degree of separation between the two proposed new trains is considerably enhanced as compared to the existing trains. The~ a separation meets the requirements of 10 CFR 50 Appendix R-Section III.G.2, without any new exemptions, and 'is therefore acceptable. ,
Siiice no Train 1 equipment is located in any of the CCAs, PSC will l rely on Train 1 for cooldown following a major fire in a CCA.
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Attachment to P-90006 Page 8 2.10 Fire Suppression FSV has two storage ponds, each having a capacity of approximately 12 million gallons, which provide water to the circulating water makeup pump structure. One 36 inch diameter line connect' each storage pond to the circulating water makeup pump structure, and snaintains the water level in this structure at the storage pond level by gravity feed. Three circulating water makeup pumps (CWMUPs), each with a capacity of 5340 gpm, are available to pump water via two redundant discharge lines to both firewater pump suction -pits. The water levels in the firewater pump suction pits are automatically maintained. PSC has proposed a change to the FPPP to account for the possibility that one storage pond may be drained in the future.
Paragraph E.2.(d) of Appendix A to BTP 9.5-1, Rev. 1, states that:
"Two separate reliable water supplies should be provided. If tanks are used, two 100 percent (minimum of ,300,000 gallons-each) system capacity tanks should be installed." ,
i However, Paragraph E.2.(f) cf Appendix A to BTP 9.5-1, Rev.1, states i that: !
" Lakes or fresh water ponds of sufficient size may qualify as sole source of water for fire protection, but require at least two intakes to the pump supply. When a common water supply is permitted for fire protection and the ultimate heat sink, the following conditions should also be satisfied: ;
(1) The additional fire protection water requirements are. .
designed into the' total storage capacity;'and (2) Failure of the fire protection system should not degrade the function of the ultimate heat sink."
i Each storage pond has only one intake line which supplies the
" rculating water makeup pump structure. However, there are ;
redundant CWMVPs and redundant supply lines to the firewater pump ;
suction pits. Since settling ponds are used to reduce particulates- !
before the circulating water enters the storage ponds, the possibility for clogging a 36 inch diameter line connecting a storage pond with the circulating water makeup pump structure is considered remote. The possibility of passive failure of'one of these gravity )
feed lines is considered remote since the lines are seismically i qualified and not pressurized.
PSC requires a minimum inventory of 10 million gallons in orie or both ponds. Assuming 300,000 gallons could be expended in fire suppression activities, the remaining 'nventory can support PCRV liner cooling with firewater (Train 1) for slightly over four days.
This is considered to be more than sufficient time to restore offsite
Attachment to P-90006 Page 9 power and operation of )ne of the river water pumps to provide makeup to a storage pond folloping a postulated fire.
Based on the above, t is concluded that a minimum inventory of 10 million gallons in both storage ponds, or in only one storage pond is accepteble. The firewater makeup system has suitable redundancy to withstand any single active failure of equipment, even with one storage pond drained.
2,11 Changes to the Fire Protection Operability Requirements (FPORs)
FPOR-16 Revision 3 of FPOR-16, which is currently in effect, specifies operability requirements for- the existing Fire Protection Shutdown /Cooldown Trains A and B. However. the applicability statement for FPOR-16 only places these requirements in effect when the reactor is operating at Power, Low Power, or during Startup.
Revision 4 of FPOR-16 requires that both Fire Protection Cooldown Trains 1 and 2 (the proposed new trains) be operable at all times, including shutdown and defueling. The action statements require that ,
if either Train 1 or Train 2 is inoperable a fire watch shall be ?
established within one hour to patrol the operable train hourly and the inoperable train shall be restored to service within 7 days or j alternate compensatory measures established. If these efforts are not successful, then the failure to correct the inoperable condition s ,
must be explained in a report within 30 days, including cause, i actions taken and schedule for corrective actions. If both Train 1 !
and Train 2 are inoperable, then at least one train is required to be- ;
restored to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or all internal reactor '
vessel meintenance shall be terminated and a CRD0A installed in- any refueling penetration where primary and secondary closures have been removed.
i Revision 4 of FPOR-16 is more conservative than the requirements j currently in effect since it applies during shutdown conditions. '
Therefore, these operability requirements and associated action j statements are acceptable. 1 FPOR-17 FPOR-17, which governs ACM operability, is being deleted j since Train 1, PCRV liner cooling with firewater, will be relied on i for fires in the CCAs. Train 1 operability is governed by FPOR-16.
Train 1 is an acceptable method of PCRV liner cooling. Revision 3 of FPOR-17, which is currently in effect, is only applicable when the reactor is at Power, Low Power, or' during Startup. -The new requirements are more conservative than the existing, since operability requirements will be in effect during shutdown and defueling conditions. Deletion of FPOR-17 is therefore acceptable.
FPOR-21 FPOR-21 is a new FPOR which defines requirements for the ;
Site Fire Brigade. FPOR-21 is acceptable since the requirements in j FPOR-21 are equivalent to those presently in Technical Specification '
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3.0~ CONCLUSIONS ,
- Analyses indicate that the PCRV liner cooling modes established by' the two proposed new Trains, including. cooling to the FHM~ and Fueli .'
Storage Wells, are adequate ' to' prevent fuel failure and to: assure .
containment. There 'is substantial margin forj operator- error, equipment ' degradation, and conservative. calculational assumptions' before fuel damage or fission product release could occur. ;
The option- to drain one of the two storage ponds has been reviewed: .
and found acceptable since reliable. fire suppression is assured and !
an adequate volume of water exists for both fire-suppression and PCRV.. j
. liner cooling with firewater. ,The' revisions to FPORs-'16 and 17, andc a the new FPOR-21 'are acceptable' since these FPORs- are morei conservative than the FPORs' currently in effect. .
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REFERENCES:
Reference 1 - PSC letter dated August 17, 1984(P-84281),Leeto -
Johnson;
Subject:
"10 CFR 50 Appendix R Fire ,
Protection Regulatory Guidance".
Reference 2 - NRC letter dated May 10,1988(G-88171),Heitnerto- -
Williams;
Subject:
" Fire Protection for FSV".
Reference 3 - General Atomics Report GA-C19694, " Safety- Analysis Report for Reactor Defueling", August, 1989 (P-89287).
Reference 4 - General Atomics Report 909908. " Loss of Forced Cooling 100 Days After Shutdown From 83.2% Power", Issue- N/C,.
May18,1989(GP-3327)..
Reference 5 - ASME Boiler and Pressure Vessel Code..Section-III,-
Division 2, Table C8-3430-1,_1983 Edition.
Reference 6 - Engineering Evaluation, " Engineering Evaluation of Liner Cooling With Fire Water Following .High Energy:
Line Break From 35 Percent Power Operation at FSV", EE-EQ-0019, Rev. B, December 10, 1985.
Reference 7 - PSC letter dated December 10,1985(P-85460),Walkerto Berkow;
Subject:
" Confirmatory Actions in- ' Support of 35 Percent Power Restriction During EQ Schedule Extension Period".
Reference 8 - NRC letter dated February 7, 1986 (G-86062), Denton to Walker;
Subject:
" Authorization For Interim Operation of Fort St. Vrain'At 35 Percent of Full Power".
Reference 9 - PSC letter dated December 7, 1988 (P-88419), Williams to Document Control Desk;
Subject:
"PSC Response to NRC Position on Radiation Embrittlement of Reactor Vessel Materials and Its Impact on Plant Operations".
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