ML20129G907
| ML20129G907 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, Catawba, McGuire  |
| Issue date: | 09/26/1996 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M92619, TAC-M92620, TAC-M92625, TAC-M92626, NUDOCS 9610070347 | |
| Download: ML20129G907 (26) | |
Text
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DukeIbwerCompany M S naua 2.0 Bar 2006 Senior Vice hesident Osarlotte, NC28201-1006 NuclearGeneration (704)382-2200OWice (704)3824360Far t
D(NGEPOMGUT September 26, 1996 U. S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555
SUBJECT:
Duke Power Company Request for Relief from ASME Boiler and Pressure Vessel Code,Section III Requirements Duke Power Request for Relief 95-GO-002 Additional Information (TAC Nos. M92625, M92626, M92619, M92620 McGuire Nuclear Station Docket Nos. 50-369, 370 Catawba Nuclear Station Docket Nos. 50-413, 414 In a letter dated January 18, 1996 the NRC Staff requested additional information on the scope of Duke Power Request for Relief from ASME Section III Requirements (RR) No. 95-GO-002.
This request for relief was initially submitted to the NRC in a letter dated June 15, 1995.
The NRC Staff requested Duke to discuss the extent of manual block valves at McGuire and Catawba located in series with overpressure prot.ection devices and subject to Article NC/ND-7153 of the ASME Code and the provisions of 10 CFR 50.55a.
As originally submitted, RR 95-GO-002 only addressed manual block valves associated with the Volume Control Tank and the Regenerative Heat Exchangers that were specifically identified in Westinghouse Nuclear Safety Advisory Letter NSAL-94-009.
Attachments 1, 2,
and 3 provide Duke's response to the January 18 NRC request for additional information.
Included in Attachments 1 and 2 (for McGuire and Catawba respectively) are the additional components for which Duke is requesting relief under RR 95-GO-002, the proposed alternative to the applicable code requirements, and the failure consequences., provides diagrams showing the various configurations of the additional relief valves / block valves for both McGuire and Catawba.
The applicable code requirements, the code requirements from 14bM/~7 'I 9610070347 960926 PDR ADOCK 05000369 P
PDR emw m,-v=arw
U.
S. Nuclear Regulatory Commission September 26, 1996 Page 2 which relief is requested, and the principal bases for relief for these additional components remain the same as described in the original Duke submittal of June 15, 1995.
Questions on this request for relief should be directed to J.
S. Warren at (704) 382-4986.
Very truly yours, As. % L M.
S.
Tuckman MST/JSW ATTACEMENTS:, Additional Information for McGuire,
Additional Information for Catawba,
Configuration Diagrams for McGuire and Catawba xc:
S.
D.
Ebneter NRC Regional Administrator, Region II V. Nerses NRC Project Manager (McGuire) j ONRR P.
S. Tam NRC Project Manager (Catawba)
ONRR R.
J.
Freudenberger NRC Senior Resident Inspector (Catawba)
S. M.
Shaeffer NRC Senior Resident Inspector (McGuire)
l-McGuire Nuclear Station 4
Request for Relief 95-GO-002 - AdditionalInformation I
ADDITIONAL COMPONENTS FOR WHICH RELIEF IS REQUESTED I
Valve INB287 i.
l Relief previously requested for locked open block valves INB066 or INB084 is extended to j
include locked open block valve INB287 (Sce Configuration 1). Although shown in Figure 3 in j
the original 95-GO-002 Relief Request, locked open block valve IND287 was not specifically addressed in the June 15,1995 letter. Relief valve 2NV170 provides pressure relief protection for i
the Unit 2 Volume Control Tank. It depends on locked open manual valve INB287 for a relief path to either Recycle Holdup Tank A or B (in addition to either of two locked open block valves INB066 or INB084 which were previously discussed in the relief request). Valve INB287 is an i
i inter-unit isolation valve between McGuire Units 1 and 2 which is maintained in the locked open j
position.
Recycle Evaporator Supply Header
}
Relief previously requested for locked open block valves INB.s66 or INB084 is extended to include the potentially blocked flow path for relief valve INB003 (Sec Configuration 1).
j Although shown in Figure 3 in the original 95-GO-002 Relief Request, relief valve INB003 was not specifically addressed in the June 15,1995 letter. Relief valve INB003 provides pressure l
relief protection for the supply header to the Recycle Evaporator Fced Demineralizers. It depends i
on either of two locked open block valves INB066 or INB084 for a relief path to Recycle Holdup
]
Tank A or B respectively. Both of these block valves were previously discussed in the relief j
request. The parallel arrangement of these valves allows maintenance isolation of either Recycle Holdup Tank without isolating the opposite tank and thus maintain a relief discharge path.
Emergency Core Cooling System (ECCS) Suction and Discharne Headers f
Reliefis requested for locked open block vah c 1(2)NC060 (See Configuration 2). The Emergency Core Cooling System suction and discharge relief valves discharge back into j
containment because of the potential for post accident coolant discharge. This includes the Safety l
Injection (NI) System, the Residual Heat Removal (ND) System, the Containment Spray (NS) i System, and the Centrifugal Charging (NV) System. The outlet of ECCS Pressure Relief valves 1(2)ND056,061,064,1(2)NI102,119,151,161,1(2)NS002,019 and 1(2)NV229 depend on locked open manual valve 1(2)NC060 for an open relief path to the Pressurizer Relief Tank a
(PRT). The components protected by these relief valves are the N1 and ND System Pumps and j
discharge piping to Reactor Coolant (NC) System Cold Legs. and Hot Legs and NI, ND, NS, l
and NV System suction headers. Valve 1(2)NC060 is maintained open except for maintenance isolation of the Pressurizer Relief Tank during No Mode when ECCS systems are not required to be operable. Relief valves 1(2) nil 02 and 1(2)NV229 also have block valves on their inlet piping
}
which is discussed later.
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Shutdown Tanks
]
Reliefis requested for locked open isolation valves IWG140 and IWG142 (See Configuration 3).
Pressure Relief Valves IWG146 and IWG153 depend on locked open block valves IWG140 and i
IWG142 for an open relief path to the Unit Vent. Components protected by these relief valves i
includes the shared A and B Shutdown Tanks.
I i
i i
t a.,
, ~.
l-McGuire Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation CA & NV Pumo Suction Reliefis requested for locked open block valves ICA025,1CA030, ICA019,1(2)NV224, j
i 1(2)NV230,1(2)NV498 and 1(2)NV499 (See Configuration 4).
The Unit 1 Auxiliary Feedwater (CA) System pump suction pressure relief valves ICA167,168, and 128 depend on locked open manual valves 1CA025,030, and 019 (respectively) for n open relief path to the atmosphere. These mamial valves are maintained locked open except for system maintenance at which time the affected train is declared inoperable. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge bne pressure sources and opening of a system vent to provide overpressure protection when the relief valve path is blocked. The components protected by these relief valves includes: Motor Driven J
Auxiliary Feedwater Pumps I A and IB and Turbine Driven Auxiliany Feedwater Pump 1 respectively. (The Unit 2 relief valves are on the pump side of the respective block valve and therefore comply with the Code.)
The inlet of NV System Pump suction pressure relief valve 1(2)NV229 depends on locked open manual block valves 1(2)NV224 and 1(2)NV498 for an open relief path to the PRT for providing relief protection for NV Pump 1(2)A. Similarly relief valve 1(2)NV229 depends on locked open manual block valves 1(2)NV230 and 1(2)NV499 for an open relief path to the PRT for providing 1
relief protection for NV Pump 1(2)B. These manual valves are maintained locked open except for maintenance at which time the affected train is declared inoperable. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection when the relief valve path is blocked.
ND & Ni Pumo Suction Reliefis requested for normally open system isolation valves 1(2)ND004B,1(2)ND019A, 1(2) nil 03A and 1(2) Nil 35B (See Configuration 5).
The inlet of NI System Pump suction pressure relief valve 1(2)NI102 depends on normally open motor operated valves 1(2) Nil 03 A for an open relief path to the PRT for 1(2)A NI Pump.
Similarly relief valve 1(2) Nil 02 depends on motor operated valve 1(2) Nil 35B for an open relief path to the PRT for providing relief protection for 1(2)B N1 Pump. The normally open recirculation valves for each pump also provide relief protection for discharge check valve leakage. These motor operated valves are normally maintained open except for maintenance at w hich time the affected train is declared inoperable. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection when the relief valve path is blocked.
The inlet of ND System Pump suction pressure relief valve 1(2)ND003 depends on normally open motor operated valve 1(2)ND019A for an open relief path to the PRT for providing relief protection for 1(2)A ND Pump. Similarly relief valve 1(2)ND003 depends on nonnally open motor operated valve 1(2)ND0048 for an open relief path to the PRT for providing relief protection for 1(2)B ND Pump. These motor operated valves are normally maintained open except for maintenance at which time the affected train is declared inoperable. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection when the relief valve nath is blocked.
2
McGuire Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation I
l KC Eauipment Thermal Relief Valves i
Reliefis requested for normally open containment isolation valves 1(2)KC429B and
)
1(2)KC430A, normally open block valves 1(2)KC427 and 1(2)KC432, locked open block valve j
IKC103 and normally open flow control valves 1(2) kcl 49 and 1(2)KC156 (See Configurations 6,7, and 8).
(Configuration 6) - The Component Cooling System thermal relief valves located inside the Reactor Building are subject to containment isolation which would close valves 1(2)KC429B and 1(2)KC430A and isolate all of the relief valve discharges from the KC Drain Tank. The relief j
valve discharges also depend on normally open manual valves 1(2)KC427,1(2)KC432 and i
locked open manual valve IKC103 for an open relief path to the tank. This includes the following relief valves: 1(2)KC313, 330, 355, 361, 374, 380, 386, 392, 404, 410, 490, 491, 492, and 493. The components protected by these thermal relief valves includes: 1(2) Excess Letdown and 1(2) Reactor Coolant Drain Tank Heat Exchangers,1(2)A(B,C,D) Reactor Coolant Pump i
Motor Upper and Lower Bearing Coolers, and 1(2)A(B,C,D)l(2) Reactor Vessel Support Coolers.
(Configuration 7) - The Component Cooling System thermal relief valves located outside the Reactor Building depend on locked open manual valve IKC103 for an open relief path to the shared KC Drain Tank. This includes the following relief valves: 1(2)KC061,079,086,104, 138,147,154,161,187,193,199, 205, 211, 217, 223, and I KC 170, 234, 241, 248, 261, 268, l
275,458,461, and 472. The components protected by these thermal relief valves includes:
4 1(2)A(B) Residual Heat Removal and Fuel Pool Heat Exchangers,1(2) Letdown and Seal Water Heat Exchangers,1(2)A(B,C,D) Steam Generator Blowdown Sample R at Exchangers,1(2) j Pressurizer, Residual Heat Removal Loop, and Reactor Coolant Hot Leg Sample Heat Exchangers, l A(B) Waste Gas Compressor and Waste Gas Hydrog:n Recombiner Heat Exchangers, Waste, and Recycle Evaporator Condensers, and Distillate Coolers, and Waste, and Recycle Evaporator Vent Condensers.
(Configuration 8) - The Fuel Pool Heat Exchanger A and B thermal relief valves depend on normally open (Fail Open) air operated control valves 1(2)KC149 and 1(2)KC156 for an open relief path to the shared KC Drain Tank. Any time the KF (Fuel Pool Cooling) system is aligned to the heat exchanger, these valves are maintained at least partially open to provide cooling for the heat load maintained by these heat exchangers except for maintenance at which time the affected train is declared inoperabic. The maintenance valve tagout includes closure of the heat exchanger inlet isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection uhen the relief valve path is blocked.
II.
PROPOSED ALTERNATIVE TO CODE REQUIREMENTS As an alternate to ASME Code Section til requirements, Duke Power is proposing to maintain proper configuration of the affected components by means of the following administrative controls:
Valve INB287 Proposed alternative to code requirements for valve INB287 were previously addressed in the relief request submitted in our June 15,1995 letter under heading " Volume Control Tank" 3
t-McGuire Nuclear Station Request for Relief 95-GO-002 - AdditionalInfonnation Recycle EvaDorator Supply Header Procedure OP/0/A/6200/03 Enclosure 4.3 lists the normal position for Recycle Holdup Tank inlet block valves INB066 and INB084 as " locked open". In addition, procedure PT/l(2)/B/4700/23 3.4 requires these valves to be verified locked open semi-annually.
Emereency Core Cooline System ECCS) Suction and Discharge Headers Procedure OP/l(2)/A/6150/04 Enclosure 4.8 lists the nonnal position for ECCS Relief Header to Pressurizer Relief Tank inlet block valves 1(2)NC06') as " locked open". In addition, procedure PT/l(2)/B/4700/24 Enclosure 13.1 requires these valves to be verified locked open at each cold shutdon since they are located inside containment.
Shutdown Tanks i
Procedure OP/0/B/6200/96 lists the nonnal position for the Waste Gas Discharge Monitor isolation valves IWG140 and IWG142 as " locked open". In addition, procedure PT/0/B/4700/19 requires these valves to be verified locked open periodically.
CA & NV Pumo Suction Procedure OP/1/N6250/02 Enclosure 4.8 lists the normal position for CA Pump suction block valves ICA019,1CA025 and ICA030 as " locked open". It also gives a limit and precaution to verify the appropriate recirculation valve opens prior to stopping a CA Pump to ensure suction i
piping is not overpressurized when stopping a pump. Procedures OP/l(2)/A/6200/01 Enclosure 4.16 list the normal position for NV Pump suction block valves 1(2)NV224,230,498, and 499 as
" locked open". In addition, procedures PT/l(2)/B/4700/23 Enclosure 13.4 requires the position of
)
these (CA & NV Pump suction block) valves to be verified semi-annually.
ND & N1 Pumo Suction Procedures OP/l(2)/N6200/04 Enclosure 4.11 list the normal position for ND Pump suction isolation valves 1(2)ND004B and 1(2)ND019A as "open". Procedures OP/l(2)/N6200/06.1 list the normal position for N1 Pump suction isolation valves 1(2)N1103 A, and 4
1 1(2) Nil 35B as "open". In addition, cach of these valves is included in the NRC Reg. Guide 1.47 alarm panel which gives a visual and audible alann whenever these valves are closed. Since these valves do not receive an open (safety injection) signal, the associated pumps are considered to be j
out of service any time the associated suction valve is closed. These valves must be capable of i
closing to provide train separation to maintain an operable train of ECCS for certain failures of the redundant train.
KC Eauipment Thermal Relief Valves Procedure OP/1/N6400/05 A Enclosure 4.3 lists the normal position for Component Cooling Drain Tank inlet block valves IKC103 as " locked open". In addition, procedure PT/l(2)/B/4700/23 Enclosure 13.4 requires this valve to be verified locked open semi-annually.
Procedures OP/l(2)/N6400/05A Enclosures 4.1 and 4.2 list the normal position for containment isolation valves 1(2)KC429B and 1(2)KC430A and block valves 1(2)KC427 and 1(2)KC432 as i
"open" and flow control valves 1(2) kcl 49 and 1(2)KC156 as " throttled" 4
3-McGuire Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation Ill FAILURE CONSEQUENCES Valve INB287 i
Failure consequences for valve INB287 were previously addressed in the relief request submitted in our June 15,1995 letter under heading " Volume Contml Tank" Reevele Evaporator Supolv Headgr The parallel arrangement of these valves allows maintenance isolation of either Re ycle Holdup Tank without isolating the opposite tank and thus maintain a relief discharge path. The alternate path would be available any time one valve might be closed for maintenance on the respective RHT. Therefore it is extremely unlikely that the relief header to at least one RHT would ever be unavailable when needed.
Emergency Core Coolinn System (ECCS) Suction and Discharge Headers Relief valves 1(2)ND056,061,064,1(2) nil 19,151.and 161 provide protection for the ND, and NI discharge headers which might be subjected to pressure higher than design pressure due to primary isolation valve (PIV) leakage. Relief valves 1(2)NI102,1(2)NS002,019 and 1(2)NV229 provide protection for NI, NS, and NV suction headers u hich might be subjected to pressure higher than design pressure due to either PIV leakage, leakby from interfacing systems, or pump discharge check valve leakage.
Each of these pressurization paths is subjected to periodic leakage testing to verify sullicient isolation capability of valves that isolate high/ low pressure interfaces. The N1, and NV systems are also protected from overpressurization by normally open pump minimum flow paths that will diven pump discharge check valve leakage to the FWST or VCT. While the ND system minimum flow branches do not afford such protection, the ND System discharge and suction j
pressure is monitored during and following operation of the pumps (when check valve seat J
leakage could change). If pressurization occurs in such operation, action is taken to vent the system pressure and re-establish the differential pressure on the check valves.
Shutdown Tanks j
In addition to the administrative control for IWG140 and IWG142 (maintained locked open to assure WG system relief capability), the inherent design and operation of the WG system are sufficient to prevent an overpressurization event. The Shutdown Tanks are provided with high pressure alarms to provide warning of approach to relief valve setpoints. Shutdown Tank B is utilized infrequently during start-up and shutdown in support of primary degas operations. Only one Waste Gas Decay Tank (WGDT) or Shutdown Tank B can be in senice at a time. The WGDTs individually relieve to Shutdown Tank A which is administratively maintained below 5 psig to ensure as adequate relief capacity for the insenice WGDT. If a WGDT relieved, Shutdown Tank A has suitable capacity to accommodate a single WGDT without lifting the relief valve on Shutdown Tank A. Therefore it is extremely unlikely that the relief header would ever discharge to the WG vent header CA & NV Pump Suction The only time these pumps are isolated from their respective suction relief valve is during maintenance on the affected pump. Since the pump discharge is isolated and a vent on the affected pump is opened as part of the valve tagout for such maintenance, the operator aligning 5
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-... _ - -. -.. _ - -. ~ _ _ -. _. -..
_.. - -.. -. ~.
_ ~ -. -.
l Attachment I McGuire Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation valves for the maintenance would obsenc any excessive or continuing vent flow and would take appropriate action to avert any situation which might lead to an ovcipressure event.
ND & N1 Pumo Suction The system isolation valves on ND and N1 pump suction are maintained open during normal operation so that both trains of each system will be available as required to perform their ECCS function. For shon durations valves at a quarterly frequency 1(2) Nil 35B,1(2)ND004B and 1(2)ND019 A are stroke tested during normal operation since they only affect the associated train.
It is highly unlikely that the pump suction would be overpressurized for the short duration that the suction valve would be closed for stroke testing. (l(2)N1103 A is maintained open during Modes 1-3 to provide B train ECCS recirc to the NV system.) Also as mentioned in the ECCS section above, the NI pump minimum flow path would provide a pressure relief path for the short time 1(2) Nil 35B might be closed.
For longer out of service durations these pumps arc isolated from their respective suction relief valve, the pump discharge is isolated and a vent on the afTected pump is established as part of the valve tagout. The operator aligning valves for the maintenance would observe any excessive or continuing vent flow and would take appropriate action to avert any situation which might lead to an overpressure event.
KC Eauipment Thermal Relief Valves Although a considerable list of equipment is included in the KC system relief valves that potentially can be isolated, the relief discharge volume from thermal expansion is considered to be an insignificant volume compared to the available gas volume expected to reside in these drain headers since they are not vented to remove air. Heat exchangers needed to perform post accident functions (i.e. Residual Heat Removal Heat Exchangers) would not be expected to be isolated and thus would not require thermal relief. In service Fuel Pool Heat Exchangers likewise would not be isolated except for maintenance at which time a vent on the affected heat exchanger or cooler is established as pan of the valve tagout. The operator aligning valves for the maintenance would observe any excessive or continuing vent flow and would take appropriate action to avert any j
situation which might lead to an overpressure event.
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Catawba Nuclear Station Request for Relief 95-GO4)02 - AdditionalInformation I
ADDITIONAL COMPONENTS FOR WHICH RELIEF IS REQUESTED Valve INB287 Relief previously requested for locked open block valves INB066 or INB084 is extended to include locked open block valve INB287 (See Configuration 9). Although shown in Figure 1 in the original 95-GO-002 Relief Request, locxed open block valve INB287 was not specifically addressed in the June 15,1995 letter. Relief valve 2NV223 provides pressure relief protection for the Unit 2 Volume Control Tank. It depends on locked open manual valve INB287 for a relief path to either Recycle Holdup Tank A or B (in addition to either of two locked open block valves INB066 or INB084 which were presiously discussed in the relief request). Valve INB287 is an inter-unit isolation valve between Catawba Units 1 and 2 w hich is maintained in the locked open position.
Recycle Evaporator Supolv Header Relief previously requested for locked open block valves INB066 or INB084 is extended to include the potentially blocked flow path for relief vah c INB003 (Sec Configuration 9).
Although shown in Figure 3 in the original 95-GO-002 Relief Request, relief valve INB003 was not specifically addressed in the June 15,1995 letter. Relief valve INB003 provides pressure relief protection for the supply header to the Recycle Evaporator Fced Demineralizers. It depends I
on either of two locked open block valves INFi)66 or INB084 for a relief path to Recycle Holdup Tank A or B respectively. Both of these block valves were previously discussed in the relief request. The parallel arrangement of these valves allows maintenance isolation of either Recycle Holdup Tank without isolating the opposite tank and thus maintain a relief discharge path.
S Treency Core Coolina System (ECCS) Suction and Discharce Headers Relief previously requested for locked open block valves INB066 or INB084 is extended to include potentially blocked flow paths for relief valves in the ECCS pump suction and discharge headers. For Unit 2 ECCS suction :.nd discl arge relief valves, reliefis additionally requested for i
block valves INB287, INB378, and INB395 (Sec Configurations 9 and 10). The Emergency Core Cooling System suction and discharge relief valves discharge into the safety related Recycle Holdup Tenks (RIiTs) because of the potential for post accident coolant discharge. This includes the Safety Injection (NI) System, the Residual Heat Removal (ND) System, the Containment Spray (NS) System, and the Centrifugal Charging (NV) System. The RHTs incorporate a flexible diaphragm which collects fission product gases.
The outlet of ECCS Pressure Relief valves 1(2)ND031,035,064,1(2)N!!02,119,151,161, 1(2)NS002,019 and 1(2)NV273 depend on either of two locked open block valves INB066 or INB084 for a relief path to Recple Holdup Tank A or B respectively. Both of these block valves were previously discussed in the relief request. The parallel ananr,went of these valves allows maintenance isolation of either Recycle Holdup Tank without isolaw g the opposite tank and thus maintain a relief discharge path. Unit 2 inputs to the Recycle Holdup Tank header include additional locked open salves, INB287, INB378, and INB395 which are available to provide a maintenance isolation boundary between the units.
The components prc:ccted by these relief valves are the NI and ND System Pumps and discharge piping to Reactor Coolant (NC) System Cold Legs, and Hot Legs, and N1. and NV System suction headers. Relief valves 1(2) nil 02 and 1(2)NV273 also have block valves on their inlet piping which is discussed later.
I
Catawba Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation NV Pumn Suction Reliefis requested for locked open block valves 1(2)NV255,2NV275(Unit 2 only),1(2)NV483 and 1(2)NV486 (See Configuration 11).
The inlet of NV System Pump suction pressure relief valve 1(2)NV273 depends on locked open manual block valves 1(2)NV255 and 1(2)NV483 for an open relief path to the RHT for providing relief protection for NV Pump 1(2)A. Similarly relief valve 1(2)NV273 depends on locked open manual block valves 2NV275 and 1(2)NV486 for an open relief path to the RHT for providing elief protection for NV Pump 1(2)B. These manual valves are maintained locked open except for maintenance at u hich time the affected train is declared inoperable. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection when the relief valve path is blocked.
N1 Pumo Sueti.o_a Reliefis requested for nonnally open system isolation valves 1(2) nil 03A, and 1(2) Nil 35B (See Configuration 12).
The inlet of N1 System Pump suction pressure relief valve 1(2)N1102 depends on normally open motor operated valves 1(2) nil 03 A for an open relief path to the RHT for 1(2)A Ni Pump.
Similarly relief valve 1(2) nil 02 depends on motor operated valve 1(2) nil 35B for an open relief path to tbc RHT for providing relief protection for 1(2)B NI Pump. The normally open l
recirculation valves for each pump also provide relief protection for discharge check valve leakage. These motor operated valves are nonnally maintained open except for maintenance at w hich time the affected train is declared inoperabic. The maintenance valve tagout includes closure of the pump discharge isolation valve to isolate the discharge line pressure sources and opening of a system vent to provide overpressure protection when the relief valve path is blocked.
KC Eauipment Thermal Relief Valves Reliefis requested for locked open block valves 1(2)KC103 (See Configuration 13).
The Component Cooling System thermal relief valves located outside the Reactor Building depend on locked open manual valve 1(2)KC103 for an open relief path to the unit specific KC Drain Sump. This includes the following relief valves: 1(2)KC061,086,138,147,154,161, and IK(~ 70, '* 58,461, and 472. The components protected by these thermal relief valves includes:
1(2iA(B; Residual Heat Removal and Fuel Pool Heat Exchangers,1(2) Letdown and Seal Water Heat Exchangers, l A(B) Waste Gas Compressor and Waste Gas Hydrogen Recombiner Heat Exchangers.
II.
PROPOSED ALTERNATIVE TO CODE REQUIREMENTS As an alternate to ASME Code Section Ill requirements, Duke Power is proposing to maintain proper conV.tration of the affected components by means of the following administrative controls:
1 l
2 1
1 Attaciunent 2 i*
. Catawba Nuclear Station Request for Relief 95-GO402 - AdditionalInformation i
}
Valve INB287 Proposed alternative to code requirements for valve INB287 were previously addressed in the relief request submitted in our June 15,1995 letter under heading " Volume Control Tank".
f Recycle Evaporator Supolv Headg i
I Procedure OP/0/A/6200/03 Enclosure 4.6 lists the normal position for Recycle Holdup Tank inlet block valves INB066 and INB084 as " locked open". In addition, procedure PT/0/B/4700/40 i 3.1 requires these valves to be verified locked open annually.
l i
l Emergency Core Cooline System (ECCS) Suction and Discharge Headers j
1 i
Procedure OP/0/A/6200/03 Enclosure 4.6 lists the nonnal position for Recycle Holdup Tank inlet I
block valves INB066 and INB084 and Unit 2 isolation valves INB287, INB378, and INB395 as 2
" locked ogn" In addition, procedure l'T/0/B/4700/40 Enclosure 13.1 requires these valves to be i
verified locked open annually.
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i NV Pumo Suction Procedures OP/l(2)/A/6200/01 Enclosure 4.17 list the nonnal position for NV Pump suction block valves 1(2)NV255,2NV275(Unit 2 only),1(2)NV483 and 1(2)NV486 as " locked open". In addition, procedure PT/0/B/4700/40 Enclosure 13.1 requires the position of these NV Pump suction block) valves to be verified annually. Additionally, Operations Maintenance Procedure l-l 5 requires independent verification of the position of these valves any time they are repositioned.
l NI Pumo Suction Procedures OP/l(2)/A/6200/06 Enclosure 4.3 list the normal position for N1 Pump suction isolation valves 1(2) nil 03 A, and 1(2) Nil 35B as "open" Additionally, Operations Maintenance Procedure 1-5 requires independent verification of the position of these valves any time they are repositioned. In addition, each of these valves is included in the NRC Reg. Guide 1.47 alarm panel which gives a visual and audible alarm whenever these valves are closed. Since these valves do not receive an open (safety injection) signal, the associated pumps are considered to be out of service any time the associated su,; tion valve is closed. These valves must be capable of closing to provide train separation to maintain an operable train of ECCS for cenain failures of the redundant train.
KC Eauipment Thermal Relief Valves Procedure OP/l(2)/A/6400/05 Enclosure 4.6 lists the normal position for Component Cooling Drain Sump inlet block valves 1(2)KC103 as " locked open". In addition, procedure PT/0/B/4700/40 Enclosure 13.1 requires the position of these valves to be verified annually, Procedures OP/l(2)/A/6400/05 Enclosures 4.12 additionally specifies the Locked open position of 1(2)KC103 and opening of IKC433 when this procedure is used to pump the contents of the Unit 1(2) Component Cooling Drain Sump to Unit 2(1).
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Catawba Nuclear Station Request for Relief 95-GO-002 - AdditionalInformation 4
Ill FAILURE CONSEQUENCES Valve INB287 Failure consequences for valve INB287 were presiously addressed in the relief request submitted in our June 15,1995 letter under heading " Volume Control Tank".
Eggygle Evaporator Supolv Headgr The parallel arrangement of these valves allows maintenance isolation of either Recycle Holdup Tank without isolating the opposite tank and thus maintain a relief discharge path. The alternate path would be available any time one valve might be closed for maintenance on the respective RHT. Therefore it is extremely unlikely that the relief header to at least one RHT would ever be unavailable when needed.
Emercency Core Coolina System ECCS) Suction and Discharce Headers Relief valves 1(2) ND031,035,064,1(2)NI119,151,and 161 provide protection for the ND, and N1 discharge headers w hich might be subjected to pressure higher than design pressure due to primary isolation valve (PIV) leakage. Relief valves 1(2)N1102,1(2)NS002,019 and 1(2)NV273 provide protection for NI, NS, and NV suction headers which might be subjected to pressure higher than design pressure due to either PlV leakage, leakby from interfacing systems, or pump discharge check valve leakage.
Each of these pressurization paths is subjected to periodic leakage testing to verify sufricient i
isolation capability of valves that isolate high/ low pressure interfaces. The NI, and NV systems are also protected from overpressurization by normally open pump minimum flow paths that will divert pamp discharge check valve leakage to the FWST or VCT. While the ND system minimum flow branches do not afTord such protection, the ND System discharge and suction pressure is monitored during and following operation of the pumps (w hen check valve seat leakage could change). If pressurization occurs in such operation, action is taken to vent the system pressure and re-establish the differential pressure on the check valves.
NV Pumn Suction The only time these pumps are isolated from their respective suction relief valve is during maintenance on the affected pump. Since the pump discharge is isolated and a vent on the affected pump is opened as part of the valve tagout for such maintenance, the operator aligning valves for the maintenance would observe any excessive or continuing vent flow and would take appropriate action to avert any situation which might lead to an overpressure event.
N1 Pumo Suction The system isolation valves on NI pump suction are maintained open during normal operation so that bcth trains of each system will be available as required to perform their ECCS function. For short durations at a quarterly frequency, valves 1(2) Nil 35B are stroke tested during normal operation since they only aliect the associated train. It is highly unlikely that the pump suction would be overp.csrurized for the short duration that the suction valve would be closed for stroke testing. l(2) nil 03 A is maintained cpen during Modes 1-3 to provide B train ECCS recirc to the NV system. Also as mentioned in the ECCS section above, the NI pump minimum flow path would provide a pressure relief path for the short time 1(2) Nil 35B might be closed.
4
i-Catanta Nuclear Station r
{
Request for Relief 95-GO-002 - AdditionalInfonnation f
For longer out of service durations these pumps are isolated from their respective suction relief valve, the pump discharge is isolated and a vent on the afTected pump is established as part of the valve tagout. The operator aligning valves for the maintenance would observe any excessive or continuing vent flow and would take appropriate action to avert any situation which might lead i
to an overpressure event.
}
}
KC Eauipment Thermal Relief Valves J
Although a considerable list of equipment is included in the KC system relief valves that 3
potentially can be isolated, the relief discharge volume from thermal expansion is considered to be an insignificant volume compared to the available gas volume expected to reside in these drain l
headers since they are not vented to remove air. The Auxiliary Building drain header is effectively vented via the KC Surge Tank overflow loop seals, so this acts as an additional flow path to atmosphere. Heat exchangers needed to perfonn post accident functions (i.e. Residual Heat Removal Heat Exchangers) would not be expected to be isolated and thus would not require thermal relief.
i f
I i
h i
_ _ _. ~ -. _ _. _ _.
l..
i-
/*
McGuire and Catawba Nuclear Stations Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams i
CONFIGURATION 1 j
RECYCLE HOLDUP TANKS 1
1 l
2NV0170 h?i.;,"
><-- K T
1NB0066 1NB0103 1NB0287 i
l L.O.
L.O.
~
FROM 1K!0170 Unit 2
\\
1 Volume Control Recycle Tank i
FROM Holdup Tank s 1NB0003 Unit 1 l
B (shared)
\\-
Volume 1NB0084 controi L.O.
Tank FROM NB System Supply l
Header (shared)
I i
1
i McGuire and Catawba Nuclear Stations Request for Relief 95 GO-002 - AdditionalInformation/ Configuration Diagrams i
CONFIGURATION 2 ECCS SUCTION AND DISCHARGE l
?
i i
f
?
PEN 1(2)M274 l
i Pressurizer
/
./
"A" Relief Tank N
N
/\\
1NCO284 1(2)NC60 1NC0059 (Unit 1 Only)
LO.
f FROM "B" (1(2)N10102: See Canfig. 5 1(2)NVo229: See Config. 4)
Valve "A" Description "B" 1(2)ND0056 1(2)A Residual Heat Removal Pump Discharge to Cold Legs 1(2)ND0061 Unit 1(2) Residual Heat Removal Pump Dirharge to Hot Legs 1(2)ND0064 1(2)B Residual Heat Removal Pump Discharge to Cold Legs 1(2)N10102 Unit 1(2) Safety injection Pump Suction Header 1(2)N10119 1(2)A Safety injection Pump Discharge to Hot Legs 1(2)N10161 1(2)B Safety injection Pump Discharge to Hot Legs 1(2)N10161 Unit 1(2) Safety injection Pump Discharge to Cold Legs 1(2)NS0002 1(2)A Containment Spray Pump Suction Header 1(2)NS0019 1(2)B Containment Spray Pump Suction Header 1(2)NV0229 Unit 1(2) Charging Pump Suction Header l
1 2
~ _.. _. __.._._..._.-___ _ _. _..
McGuire and Catawba Nuclear Stations Request for Relief 95-GO@2 - AdditionalInformation/ Configuration Diagrams CONFlGURATlON 3 SHUTDOWN 1ANKS
\\
Waste Gas
\\/
\\/
/
Discharge T UNIT VENT
[h
/\\
'\\
M "" '
1WG0140 1WG0142
' 1WG0146 L.O.
L.O.
Shutdown f
Tank A (shared)
-~
/>1WG0153 Shutdown TankB (shared) 3
. ~. - -
. ~... -.. -.... _ - -... -.. _.. - -.. -...,... _ -
}
l McGuire and Catawba Nuclear Stations Request for Relief 95-G0-002 - AdditionalInformation/ Configuration Diagrams J
l i
CONFIGURATION 4 j
CA & NV PUMP SUCTION t
J "B".4 (1(2)NV0229: See Config. 2) -
\\
1 j
O l
PUMP "A" "C"
"D" L.O.
L.O.
s i
1 J
i Pump "A" Valve "B" Valve "C" Valve "D" Motor Driven Aux. Feed.1 A 1CA0167 1CA0025 n/a Motor Driven Aux. Feed.1B 1CA0168 1CA0030 n/a Turbine Driven Aux. Feed.1 1CA0128 1CA0019 n/a Centrifugal Charging 1(2)A 1(2)NV0229 1(2)NV0224 1(2)NV0498 Centrifugal Charging 1(2)B 1(2)NV0229 1(2)N v'0230 1(2)NV0499 4
j.
i 1
j McGuire and Cctawba Nuclear Stations.
Request for Relief 95-GO@2 - AdditionalInformation/ Configuration Diagrams 1
?
CONFIGURATION 5 ND & NI PUMP SUCTION 3
i j
i i
i FROM ND SYSTEM i
j (NI Pumps only)
"D"
- (N1:See Config. 2) l E
l 3
PUMP 1(2)A l
ngo J
i E
FROM FWST(ND & Ni Pumps)
[
"A.
FROM NC SYSTEM (ND Pumps only)
PUMP 1(2)B "C"
\\
FROM ND SYSTEM (Ni Pumps only)
Pumo "A" Valve "B" Valve "C" Valve "D" Residual Heat Removal (ND) 1(2)ND0019A 1(2)ND0004B 1(2)ND0003 Safety injection (NI) 1(2)NIO103A 1(2)N10135B 1(2)NIO102 i
1 l
l 5
1 McGuire and Catawba Nuclear Stations i
Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams CONFIGURATION 6 3
l REACTOR BUILDING KC DRAIN HEADER i
i i.
i 1
1(2pss22 -
From KC Au g C
~ R.B.
(See Config. 7) l_
c
~^~ $F-X X
X
)
1(2)KC0427 1(2)KC0429B 1(2)KC0430A 1(2)KC0432 V
1KC0103 FROM B,,
(LO.)
I 1KC0433 Valve "A" Description "B" 7-
]
1(2)KC0313 Unit 1(2) Excess Letdown HX COWONENT j
1(2)KC0330 Unit 1(2) Reactor Coolant Drain Tank HX
_oTn1&
i(2)KC0355 1(2)C Reactor Coolant Pump Motor Lower Brg Cooler (SHARED) 1(2)KC0361 1(2)C Reactor Coolant Pump Motor Upper Brg Cooler -
1(2)KC0374 1(2)B Reador Coolant Pump Motor Lower Brg Cooler I
1(2)KC0380 1(2)B Reactor Ooolant Pump Motor Upper Brg Cooler 1(2)KC0386 1(2)A Reactor Coolant Pump Motor Upper Brg Cooler
{
1(2)KC0392 1(2)A Reactor Coolant Pump Motor Lower Brg Cooler i
1(2)KC0404 1(2)D Reactor Coolant Pump Motor Upper Brg Cooler 1(2)KC0410 1(2)D Reactor Coolant Pump Motor Lower Brg Cooler 1(2)KC0490 1(2)C1 and 1(2)C2 Reactor Vessel Support Cooler 1(2)KC0491 1(2)B1 and 1(2)B2 Reactor Vessel Support Cooler 1(2)KC0492 1(2)A1 and 1(2)A2 Reactor Vessel Support Cooler 1(2)KC0403 1(2)D1 and 1(2)D2 Reactor Vessel Support Cooler 6
I --
McGuire and Catawba Nuclear Stations Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams l
)
CONFIGURATION 7 AUXILIARY BUILDING KC DRAIN HEADER Rs Bldg KC Relief Header (See Confg 6)
Z
~~
N YOo$ING 1
N f
f
( DRAINTANK "A"
1KC0103 1KC0433
\\ " )
L.O.
FROM "B" (1(2)KC0154 &
i 1(2)KC0161:
See Config. 8)
Valve "A" Description "B" 1(2)KC0061 1(2)A Residual Heat Removal HX 1(2)KC0079 1(2)A Residual Heat Removal Pump Mechanical Seal HX 1(2)KC0086 1(2)B Residual Heat Removal HX 1(2)KC0104 1(2)B Residual Heat Removal Pump Mechanical Seal HX 1(2)KC0138 Unit 1(2) Letdown HX 1(2)KC0147 Unit 1(2) Sea! water HX 1(2)KC0154 1(2)A Fuel Pool HX 1(2)KC0161 1(2)B Fuel Pool HX 1KC0170 1 A Waste Gas Compressor HX (shared) 1(2)KC0187 1(2)A Steam Generator Blowdown Sample HX 1(2)KC0193 1(2)B Steam Generator Blowdown Sample HX 1(2)KC0199 1(2)C Steam Generator Blowdown Sample HX i
1(2)KC0206 1(2)D Steam Generator Blowdown Sample HX 1(2)KC0211 Unit 1(2) Pressurizer Sample HX 1(2)KCO217 Unit 1(2) Residual Heat Removal Loop Sample HX 1(2)KCO223 Unit 1(2) Reactor Coolant Hot Leg Sample HX 1KC0234 Recycle Evaporator Condensar (shared) 1KC0241 Recycle Evaporator Distillate Cooler (shared) 1KC0248 Recycle Evaporator Vent Condenser (shared) 1KC0261 Waste Evaporator Condenser (shared) 1KC0268 Waste Evaporator Distillate Cooler (shared) 1KCO275 Waste Evaporator Vent Condenser (shared) 1KC0458 1B Waste Gas Compressor NX (shared) 1KC0461 1 A Waste Gas Hydrogen Recombiner HX (shared) 1KC0472 1B Waste Gas Hydrogen Recombiner HX (shared) 7
-..-_..-.. - -...~._.
...._ -..~...- -
~ -.... _ -.... -.
. -. - ~. -... ~ _ -. -.....
McGube and Catawba Nuclear Stations Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams 4
CONFIGURATION a 1
FUEL POOL HEAT EXCHANGERS
.i 1
5 4
(See Config. 7)
[
nga j
Manual Loader 1
J (h
Return F.O.
FUEL POOL HEAT EXCHANGER "A"
Supply Eaot. "A" Valve "B" Valve "C" 1(2)A 1(2)KC0149 1(2)KC0154 1(2)B 1(2)KC0156 1(2)KC0161 8
Attaciunent 3 McGuire and Catawba Nuclear Stations Request for Relief 95-GO-002 - Additional Information/ Configuration Diagrams CONFIGURATION 9 NB SYSTEM HEADER & UNIT 1 ECCS From Unit 2 ECCS (See Confir).10) 2NV0223 Recycle K Holdup i
N/
Ny Tank A
/N
/N y
(shared) 1NB0066 1NB0287 A{
L.O.
- L.O.
< 1NV0223 FROM Unit 2 (N
Volume
/ Recycle 'N Control Holdup
\\
N C
,,A,,
FROM Tank TankB
/
Unit 1 (shared) 1NB0084 volume L.O.
Control FROM "B" Tank Unit 1 ECCS and Shared i
Valve "A" Description "B" 1NB003 Recycle Evaporator Feed Demin. Inlet Header (Shared) 1ND031 1 A ND Cold Leg injection /Recire.
1ND035 Unit 1 ND Hot Leg injection 1ND064 1B ND Cold Leg injection /Recire.
1N1102 Unit i Ni Pump Suction Relief (See also Config.12) 1N1119 1 A NI Pump Discharge Relief 1N1151 1B Ni Pump Discharge Relief 1N1161 Unit 1 NI Pump Discharge to Cold Legs 1NS002 1B NS Pump Suction Relief 1NS019 1 A NS Pump Suction Relief 1NV273 1 A & 1B NV Pumps Suction Relief (See also Config.11) 9
l Attacionent 3 i
McGuire and Catawba Nuclear Stations
~,
Request forRelief 95-GO-002 - AdditionalInformation/Confguration Diagrams l
l CONFIGURATION 10 UNIT 2 ECCS i
f N
"B" t
/
\\
1NB378 A
L.O.
~,, FROM "C" "A
N
\\
Unit 2 1NB395 L.O.
l FROM "C" Unit 2 To NB System Header (See Config. 9)
Valve "A" Valve "B" Description "C" 2ND031 n/a 2A ND Cold Leg injection /Recirc.
2ND064 n/a 2B ND Cold Leg injection /Recirc.
n/a 2ND035 Unit 2 ND Hot Leg injection n/a 2N1102 Unit 2 NI Pump Suction Relief (See a;so Config.12)
{
n/a 2N!119 2A NI Pump Discharge Relief i
n/a 2N1151 2B NI Pump Discharge Relief n/a 2N1161 Unit 2 NI Pump Discharge to Cold Legs n/a 2NS002 2B NS Pump Suction Relief n/a 2NS019 2A NS Pump Suction Relief n/a 2NV273 2A & 2B NV Pumps Suction Relief (See also Config.11) 10
j
. Attachmen'. 3 McGuire and Catawba Nuclear Stations Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams CONFIGURATION 11
{
NV PUMP SUCTION 1
i b
i l
~~
(See Conf;g. 9 Unit 1 1(2)NV273{/
1 N.
See Config.10 Unit 2) 3 j
[N NV Pump N,/
N
(
1(2)A
/N
/
4 s
\\
1(2)NV2851(2)NV483 d
L.O.
L.O.
s FROM ND SYSTEM OR FROM FWST "Xst*"
X 2NV275 1(2)NV486 L.O.
L.O.
1 (Unit 2 only) l 1
)
I1
9 McGuire and Catawba Nuclear Stations Request for Relief 95-GO@2 - AdditionalInformation/ Configuration Diagrams CONFIGURATION 12 Ni PUMP SUCTION FROM ND SYSTEM 1(2)N1102
./
(see conr. 9 unit i o
See Confg.10 Unit 2)
";;yr" X
1(2)N1103A N
- FROM FWST
";;Yt" X
1(2)N!135B x
FROM ND SYSTEM J
12
~' -
f.
McGuire and Catawba Nuclear Stations Request for Relief 95-GO-002 - AdditionalInformation/ Configuration Diagrams CONFIGURATION 13 AUXILIARY BUILDING KC DRAIN HEADER Component Cooling Dra n Sump "A"
2KC0103 l
I FROM "B" Unit 2 1KC0433 A k
/
[
Coo ng h;A,,
Drain Sump N
1KC0103 Unit 1 L.O.
FROM "B" Unit 1 Valve "A" Description "B" 1(2)KC0061 1(2)A Residual Heat Removal HX 1(2)KC0086 1(2)B Residual Heat Removal HX 1(2)KC0138 Unit 1(2) Letdown HX 1(2)KC0147 Unit 1(2) Sealwater HX 1(2)KC0154 1(2)A Fuel Pool HX 1(2)KC0161 1(2)B Fuel Pool HX 1KC0170 1A Waste Gas Compressor HX (shared) 1KC0458 1B Waste Gas Compressor HX (shared) 1KC0461 1 A Waste Gas Hydrogen Recombiner HX (shared) 1KC0472 1B Waste Gas Hydrogen Recombiner HX (shared) 13