ML20093L763
| ML20093L763 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 10/17/1984 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8410190157 | |
| Download: ML20093L763 (51) | |
Text
m-DUKE POWER GOMPANY
~
P.O. HOx 33180 CHARLOTrE. N.O. 28242 HAL B. TUCKER TELEPHONE vara enmannaw?
(704) 07:F4531 October 17, 1984
-uu.
Mr.-Harold R._Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission
' Washington, D. C.
20555
. Attention:
Ms.-E. G. Adensam, Chief Licensing Branch No. 4
'Re: Catawba' Nuclear Station Docket Nos. 50-413 and 50-414 I
Dear Mr.~Denton:
'A meeting was' held on August. 21, 1984 between representatives of Duke Power Company and'the NRC staff to discuss safety-significant deviations in the Plant Specific Technical Guidelines from NRC-approved generic technical guidelines. The material presented by Duke Power at that meeting is included as Attachment 1.
Further clar-ification of.these deviations was presented in a letter dated August 29, 1984.
During the meeting, unresolved deviations between the Westinghouse Emergency Response
' Guidelines (ERGS) and the Catawba Emergency Procedure Guidelines were identified.
This letter states,the: Duke Power proposal for resolution of these items.
1)-'The absence o5 a steam generator tube Tupture cooldown guideline using the blowdown system.
Resolution:
See Attachment 2 for a discussion of this item. Duke Power does not intend to include a cooldo, guideline using blowdown.
- 72) - The continuous venting of condensible voids vs. the controlled venting of voids which might contain hydrogen.
Resolution:. Duke Power.will delete the guideline steps referring.to con-densible void venting and adopt the Westinghouse ERG approach on void re-fmoval by controlled venting.
- 3) The initiation of feed-and-bleed cooling during a LOCA outside containment to increase sump inventory and reduce unrecoverable inventory losses.-
Resolution: This method will remain a part of the guidelines pending final NRC' approval. Additional justification of the appropriateness of feed-and-bleed initiation will be submitted to the NRC by April 1, 1984.
,4)
The postponement or omission of lower priority critical safety function res-toration > actions due to earlier entry into or exit from the inadequate or degraded core cooling guidelines.
Resolution: Attachment 3 gives additional justification for this item.
Duke Power proposes to continue using the higher setpoints.
AON 8410190157 841017 PDR ADOCK 05000413 h/
F PDR th
\\
E Duke' Power understands that these are the only outstanding items concerning deviations of'the Catawba' Emergency Procedure Guidelines from the Westinghouse ERGS.
Very truly yours, dk/
Hal B. Tucker' HJL/gib~
. Attachments cc:
Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Catawba Nuclear Station ifr. Robert Guild, Esq.
Attorney-at-Law P. O. Box.12097 Charleston, South Carolina 29412
. Palmetto Alliance 2135 Devine Street
. Columbia, South Carolina 29205 Mr. Jesse L. Riley Carolina' Environmental Study Group 854 Henley Place Charlotte, North Carolina 28207
.w....
NRC:--DUKE POWER MEETING J
' CATAWBA NUCLEAR STATION DEVIATIONS FROM. GENERIC EMERGENCY RESPON.cE-GUIDELINES AGENDA
~
I.
DISCUSSION OF UNRESOLVED DEVIATIONS
.II..
PLANT. SPECIFIC DESIGN FEATURES-
'III.: RVLIS UTILIZATION
. IV.
SETPOINTS V..SSER ITEMS-
\\
AUGUST 21, 1984
3 7
I.
DISCUSSION OF UNRESOLVED DEVIATIONS DEVIATION 7 THE GENERIC GUIDELINE ES-3.2B, SGTR ALTERNATE C00LDOWN USING
$ TEAM GENERATOR BLOWDOWN, HAS BEEN DELETED FROM THE EPGS SINCE THE CATAWBA BLOWDOWN SYSTEM CANNOT ACCOMMODATE THE FLUID VOLUME GENERATED USING THIS C00LDOWN APPROACH.
THE GENERIC GUIDELINES INCLUDE THREE OPTIONS FOR C00LDOWN OF AN ISOLATED AND RUPTURED STEAM GENERATOR.
ALL THREE OPTIONS ARE NOT REQUIRED TO BE AVAILABLE AT EACH. PLANT, AND THE 1 ELECTION OF WHICH OPTIONS ARE INCORPORATED INTO EMERGENCY PROCEDURES IS LEFT TO THE DISCRE-TION OF THE UTILITY BASED ON PLANT SPECIFIC DESIGN AND OPER-ATING PREFERENCE.
THE REMAINING TWO OPTIONS ARE INCORPORATED INTO THE GUIDELINES ES-3.1, POST-SGTR C00LDOWN AND DEPRESSUR-
-IZATION, AND ES-3.2, SGTR ALTERNATE C00LDOWN USING BACKFILL.
'THE FOLLOWING IS STATED IN THE ERG PSSIC SER (PP 3-16, 19) 3.2.3.1. Alternate SGTR Cooldown Guidelines ES-3.2(L)
Steam Generator Tube Rupture procedures instruct the operator to depressurize the ruptured steam generator by dumping steam to the condenser, if it is avail-able, or.to the atmosphere if the offsite doses are calculated to be below the 10 CFR 20 guidelines. If neither of these conditions is met, the operator is referred to alternate methods for depressurizing the ruptured steam generator.
The low pressure guidelines also instruct the operator to utilize alternate methods if the ruptured steam generator-is overfilled. The Westinghouse owners have developed two sets of guidelines for this purpose, only one of which would be developed into plant procedures. This determination of which guideline to use would be based on the specifics of the plant design, Plants with a small blowdown storage capacity would utilize Guidelines ES-3.2 A(H), ES-3.1A(L)
"SGTR Alternate Cooldown By Backfilling RCS."
Plants utilizing phosphate secondary chemistry would utilize Guideline E-3.2B(H), ES-3.lB(L) "SGTR Alternate Cooldown Using Steam Generator Blowdown."
3.2.3.4 Staff Conclusions Regarding the SGTR Guidelines The staff concludes that the actions prescribed to treat SGTR are acceptable for implementation. The areas which require improvement are identified below.
The staff will report on those items in an SER supplement.
2 DEVIATION 7 BASIS e
ES-3.2, SGTR ALTERNATE C00LDOWN USING BACKFILL, IS AVAILABLE TO PROVIDE THE ALTERNATE CAPABILITY TO COOL DOWN:AND DEPRESSURIZE A RUPTURED STEAM GENERATOR e
CONSISTENT WITH THE NRC REVIEW 0F ERG-BASIC e
STRONG INCENTIVE NOT TO INTRODUCE CONTAMINATED PRIMARY WATER INTO THE SECONDARY PLANT SYSTEMS
-0 CONTAINMENT ENTRY IS REQUIRED TO ALIGN BLOWDOWN TO THE STEAM GENERATOR DRAIN TANKS.
THESE DRAIN TANKS ARE NOT NECESSARIlY EMPTY.
e BLOWDOWN CAN ONLY BE REMOTELY ALIGNED TO THE CONDENSER e
atowDOWN IS V6R Y : rMTGb ZN CAPA czTY OTHER COMMENTS e
WOG PROGRAM TO FURTHER ADDRESS THE ACCEPTABILITY OF
- POST-SGTR C00LDOWN AND DEPRESSURIZATION, PARTICULARLY THE UTILIZATION OF NON-SAFETY GRADE EQUIPMENT, THE TIMING OF OPERATOR ACTIONS, AND DOSE C6NSEQUENCES.
O STEAMING A RUPTURED STEAM GENERATOR IS EXPLICITLY AVOIDED WHENEVER POSSIBLE.
STEAMING TO THE CONDENSER IS ATTEMPTED BEFORE STEAMING TO ATMOSPHERE 0
THIS ITEM IS NOT IN FACT A DEVIATION
3 x
x
+
. DEVIATION 10 THE EPGS INCLUDE ' AN ADDITIONAL ~ GUIDELINE ~ ECA-1.2, LOCA im 0VTSIDE1 CONTAINMENT, IN ORDER TO ADDRESS AN NRC REQUIREMENT
-FOR DEVELOPMENT OF SUCH A GUIDELINE AS STATED IN THE ERG-
~
[
BASIC SER ON P.- 4-4 (ITEM 3). -ECA-1,2 DIRECTS THE OPERATOR TO ATTEMPT T0 ISOLATE POTENTIAL CAUSES OF A LOCA OUTSIDE CONTAINMENT, AND :TO INITI ATE MAKEUP TO THE REFUELING WATER
-STORAGE TANK SINCE A LOSS 10F ECCS SUCTION INVENTOR IS
' OCCURRING.
ALSO, THE OPTION OF INITIATING FEED AND BLEED COOLING.IS AVAILABLE AND'THE DECISION TO DO S0 IS-LEFT TO THE-DISCRETION OF: STATION MANAGEMENT.
THE BASIS FOR INI-
- TIATING FEED:AND BLEED.IS THE DESIRABILITY OF ACCUMULATING WATER IN'THE CONTAINMENT-SUMP TO ENABLE RECIRCULATION MODE
-UPON DEPLETION OF'THE REFUELING WATER STORAGE TANK INVEN-
-TORY.
'IN ADDITION,' BLEEDING OF' REACTOR COOLANT SYSTEM INVENTORY WILL MELT ICE IN THE ICE CONDENSER WHICH WILL
'ALSO ACCUMULATE IN THE CONTAINMENT SUMP.-
INITIATING FEED
'AND BLEED COOLING IS ALSO INCLUDED AS AN OPTION FOR A n"
SGTR WHICH HAS RESULTED.IN A:SIGNIFICANT DEPLETION OF ECCS SUCTION INVENTORY DUE T' A NON-ISOLABLE TUBE LEAK.
0 I
- THIS SCENARIO IS EALSO ESSENTIALLY A LOCA-0UTSIDE CONTAIN-MENT.
~
y f.
E
,,.w...,-m.uo_
._,w.,
,.m..
l F
. l>
4
~
DEVIATION 10 BASIS 8
A LOCA.0UTSIDE CONTAINMENT WILL POTENTIALLY DEPLETE THE REFUELING WATER STORAGE TANK INVENTORY AND THEREFORE IS AN EXTREME ~ CHALLENGE TO LONG TERM CORE COOLING.
THE
-CONTAINMENT SUMP MAY NOT BE AVAILABLE FOR RECIRCULATION.
9: ALL MITIGATION OPTIONS SHOULD BE BROUGHT TO THE ATTENTION
'0F THE OPERATOR S
THE:LARGE VOLUME OF ICE IN THE ICE. CONDENSER IS A POTENTIAL SOURCE 10F ECCS INJECTION INVENTORY WHICH IS NOT AN OPTION IN THE GENERIC PLANT WHICH IS THE BASIS FOR THE GENERIC GUIDELINES 8 -INITIATING FEED AND BLEED WILL DEPRESSURIZE THE RCS AND REDUCE-THE DRIVING HEAD AND INVENTORY LOSS OUT THE BREAK
.0--MAKEUP TO THE REFUELINGLWATER STORAGE TANK IS ATTEMPTED PR'IOR TO INITIATING FEED AND BLEED 8
ADDITIONAL ~ CRITERIA ARE USED TO ASSIST'THE.0PERATOR IN DECIDING IF FEED AND. BLEED SHOULD BE INITIATED:
- SUMP LEVEL GREATER THAN 1.5 FEET
- ECCS ALIGNED IN INJECTION MODE
- CONTAINMENT SPRAY PUMPS OFF
- RWST LEVEL LESS THAN 50% AND GREATER THAN 20%
~
-0THER COMMENTS 0
THE PRESSURIZER RELIEF TANK WILL RUPTURE DURING ANY F & B SEQUENCE WHICH-LASTS MORE THAN A VERY SHORT TIME 1
~
., _. ~. _....... _. - - _.... _.,... _ _ - _.. _..,. _, _.,. _, _, -.. _ _
5 e
SOME FRACTION 0F.THE BLEED ENERGY WILL NOT RESULT IN ICE MELT AND WILL INSTEAD BE ABSORBED BY-STRUCTURES, ETC.
THE~ TOTAL PORV CAPACITY OF 600,000 LB/HR ENSURES THAT ICE MELT WILL OCCUR.
~ ( b + g.7 inch diame4er LotAY THIS DEVIATION IS A REFINEMENT TO THE GENERIC GUIDELINES 0
.WHICH UTILIZES THE UNIQUE CAPABILITY TO MELT ICE IN ORDER TO ESTABLISH A CONTAINMENT SUMP INVENTORY AND-ENABLE ALIGNMENT'FOR RECIRCULATION MODE 4
7
,.-.-,. ---s-y.y r,,.. - -r
--y ve,..y.cy..,-
-cy...-.w,,
,,_.,.y,,-%-w,.
,-,,y-w,,,_,,
Ab 6-
..- j 1a o
! ^ W-A DEVIATION 27-
.IN THE GENERIC ERG ECA-2, LOSS OF ALL AC POWER, STEP 3.C.2 DISABLES AUTOMATIC? SEQUENCING OF LARGE LOADS PRIOR'TO RES-
'TORATION OF POWER TO THE EMERGENCY BUS.
SUBSEQUENT LOADING OF LARGE-LOADS IS PERFORMED MANUALLY.
IN THE EPGS, AUTO-MATIC SEQUENCER LOADING IS RESTORED FOR THE CASE WHERE A SAFETY INJECTION SIGNAL IS PRESENT.
THIS DEVIATION HAS BEEN~ IMPLEMENTED IN' ORDER TO LESSEN THE BURDEN OF MANUAL
' OPERATOR ACTIONS AND TO EXPEDITE THE LOADING PROCESS.
.ALTHOUGH UNLIKELY, THE POTENTIAL FOR A.N OPERATOR ERROR IS
'ALSO PRECLUDED.
NO REDUCTION IN RELIABILITY IS ASSOCI-ATED WITH THE CHANGE.
L U
._...._..__--,-._.....m-.
. ~ _. -. -. _ _,. _ - -.,,. -, _ - -,. -..
7
.c 7,
4-DEVIATION 27-BASIS 8. AUTOMATIC SEQUENCER LOADING IS FASTER AND AN
' EXPEDITIOUS RECOVERY'IS DESIRED IF A SAFETY INJECTION SIGNAL HAS OCCURRED 0
UTILIZING;THE SEQUENCER LESSENS THE BURDEN OF MANUAL OPERATOR ACTIONS S
ALTHOUGH UNLIKELY, THE POTENTIAL FOR OPERATOR ERROR
. DURING MANUAL LOADING IS AVOIDED.
8 MANUAL' LOADING IS PRESCRIBED AS A BACKUP IF SEQUENCER LOADING IS UNSUCCESSFUL 5
0 LOADING OF ADDITIONAL LOADS OR UNLOADING SEQUENCER LOADED LOADS CAN BE PERFORMED BY THE OPERATOR AS REQUIRED
.4.
NO~ REDUCTION IN RELIABILITY HAS BEEN IDENTIFIED 3,
e Acc6tEKkTGb LOAbING 7LkNr STSCIFZC FSATues e
SGQ UENCGK ALZGNS (f AL V6s 86F026 STAArrNc,- Ecc.s PtvfPS w
a 4--..._.,,.m... _.
,,_,.....,,..,,m,_,
..,_.m..,_....,,,,...
,,,,,,-..m,.
- +
g 4
J J
- DEVIATION 28 ie
. IN-THE GENERIC ERG FR-C.1, RESPONSE T0 INADEQUATE CORE COOLING, DEPRESSURIZATION OF THE RCS BY OPENING PRESSUR-
-IZER PORVS IS NOT UNDERTAKEN UNLESS CORE EXIT THERMO-LCOUPLE TEMPERATURES ARE GREATER THAN 1200*F.
THE EPGS IMPLEMENT THIS ACTION-IF CORE EXIT THERMOCOUPLE TEMPER-ATURES ARE GREATER THAN 700*F AND INCREASING.
THIS MOD-
- IFICATION AVOIDS WAITING FOR THE' CORE-T0 HEAT UP IF THE
- MITIGATION ACTIONS ALREADY PERFORMED HAVE NOT BEEN SUCCESSFUL.
THIS DEVIATION CAN-BE CONSIDERED AS AN EN-HANCEMENT OF THE-GENERIC GUIDELINES.
THE LOSS OF IN-VENTORY IN THE FORM OF STEAM RELIEF THROUGH THE PRES-SURIZER PORVS IS OFFSET BY THE INCREASE IN THE SAFETY INJECTION.FLOWRATE RESULTING FROM THE RCS DEPRESSURIZA -
TION.
t e
w g mee g
w g-
" w Twa-~
==**
C 9
DEVIATION 28 BASIS S
USE OF THE CRITERION " GREATER THAN 700F AND INCREASING" ENSURES THAT THE INADEQUATE CORE COOLING MITIGATION ACTIONS ALREADY IMPLEMENTED HAVE NOT BEEN SUCCESSFUL GL THE GENERIC GUIDELINES WILL RESULT IN WAITING FOR THE CORE EXIT THERMOCOUPLES TO INCREASE FROM 700F TO 1200F BEFORE INITIATING ADDITIONAL MITIGATING ACTIONS.
SIGNIFICANT DEGRADATION OF THE CORE CAN OCCUR DURING THIS HEATUP PHASE lb THE INVENTORY LOST BY STEAM RELIEF THROUGH THE PORVS WILL BE OFFSET BY THE INCREASE IN SAFETY INJECTION FLOW
-DUE TO THE REDUCTION IN RCS PRESSURE.
THE UHI ACCUMULATOR REPRESENTS AN ADDITIONAL SOURCE OF WATER WHICH IS NOT AVAILABLE IN THE GENERIC PLANT 0-THE DUKE APPROACH-IS INTENDED TO PREVENT PCTS FROM REACHING TEMPERATURES AT WHICH M-W REACTION WILL BE SIGNIFICANT.
THESE TEMPERATURES ARE WELL BELOW THE 2200F. LIMIT USED AS A LICENSING LIMIT OTHER COMMENTS S
600,000.LB/HR RELIEF CAPACITY THROUGH THE PORVS IS A VERY LARGE RELIEF CAPACITY.
DEPRESSURIZATION SHOULD BE SUCCESSFUL DOWN TO VERY LOW PRESSURES 0
CORE EXIT THERM 0 COUPLE TEMPERATURE DOES NOT REFLECT THE CLADDING TEMPERATURES IN THE HOTTER PARTS OF THE CORE
,.____,___.ic
._,.m._,_,_r.,
._,,,_,.m.,,
m..,.
m,,,,
..,...m.,
10 L
I DEVIATION 30 IN THE EPG FR-H.L RESPONSE TO LOSS OF. SECONDARY HEAT SINK,
~
FOLLOWING INITIATION OF FEED AND BLEED COOLING, RCS TEMPER-ATURE IS MONITORED TO ASSESS THE SUCCESS OF' CORE COOLING IN
' THIS MODE.
THE NEED FOR ADDITIONAL OR LESS FEED AND/0R BLEED CAPACITY IS DETERMINED.
THIS DEVIATION IS A. REFINE-MENT OF THE GENERIC GUIDANCE AND ENABLES BETTER CONTROL.0F THE PLANT DURING FEED AND BLEED.
f
=73 i
1 7
y
- = -
3,,.
m.
..y,,.,,.y.y,vy,,,,vwe,,ww-.r,e, w ee r.,mm,w,.w,,c-w_,...,
,.c m r e % _, _ e.v. s,,, -,,,. - -, _
11 DEVIATION 30 BASIS S
IN THE GENERIC GUIDELINES A REDUCTION IN THE FEED AND BLEED CAPACITY (NUMBER OF PORVS OPEN AND NUMBER OF SAFETY INJECTION PUMPS OPERATING) IS ONLY UNDERTAKEN FOLLOWING RESTORATION OF FEEDWATER TO THE STEAM GENERATORS.
IN THE BASIC ERGS THIS OCCURS SINCE ONE CANNOT PROCEED TO STEPS 22 AND 23 0F FR-H.1, RESPONSE TO LOSS OF SECONDARY HEAT SINK, WITHOUT MEETING THE CRITERION IN STEP 21 0
THE EPGS INCLUDE A REFINEMENT WHICH IS ADDED'TO STEP 17.
THIS ADDITION ALLOWS THE OPERATOR TO REDUCE OR INCREASE THE FEED AND BLEED CAPACITY DEPENDING ON THE C00LDOWN RATE.
- IF THE C00LDOWN RATE IS GREATER THAN 100F/HR AND THE CORE IS SUBC00 LED, THEN SI FLOW CAN BE REDUCED
- IF THE C00LDOWN RATE IS GREATER THAN 100F/HR AND THE CORE IS SATURATED, THEN ONE PORV CAN BE-CLOSED
- IF THE C00LDOWN RATE IS NOT ADEQUATE, THEN ADDITIONAL FEED AND BLEED CAPACITY IS ADDED e
THE GENERIC GUIDELINES FOR RECOVERING FROM FEED AND BLEED FOLLOWING RESTORATION OF A HEAT SINK ARE UNAFFECTED BY THIS DEVIATION e
FEED AND BLEED COOLING IS DEPENDENT ON A NUMBER OF FACTORS SOME OF WHICH CAN BE CONTROLLED AND WILL RESULT IN A LESS SEVERE PLANT RESPONSE. (I.E. LESS SEVERE C00LDOWN RATE) 1
=
'f
'~8 gp
- ~.
---i-.
--e-g-
e+wev-- - -e
- e'-
-y%*
gr
-*e-n+
e---
- - - ---N=-'--
- 87i&
W
---s---e
,v-y
.. s 12 J
DEVIATION 31 IN THE EPG, FR-I.3, RESPONSE TO VOIDS'IN REACTOR VESSEL, VENTING OF THE REACTOR VESSEL IS PERMITTED WITHOUT THE DETAILED PRECAUTIONS REQUIRED FOR HYDROGEN VENTING IF NO SYMPTOMS OF INADEQUATE CORE COOLING HAVE BEEN'0BSERVED.
~lF THE VOID MAY CONTAIN A SIGNIFICANT VOLUME OF HYDROGEN,
-THEN THE GENERIC VENTING PRECAUTIONS ARE FOLLOWED.
THE DISSOLVED HYDROGEN IN THE-RCS WOULD ONLY INCREASE THE VOLUMETRIC CONCENTRATION IN THE CONTAINMENT BY LESS THAN 0.1%,cIF.DIT WERE' CONTINUOUSLY VENTED.
IT IS THEREFORE
.NECESSARY FOR THE CORE TO UNDERGO METAL-WATER REACTION OF.THE CLADDING'FOR~A SIGNIFICANT VOLUME OF HYDROGEN TO
+
BE GENERATED.
IN-' ADDITION, THE SPDS WILL ALERT THE
- OPERATOR TO CONTAINMENT HYDROGEN CONCENTRATIONS GREATER
-THAN 0.5%.
FOR THESE REASONS, CONTINUOUSLY VENTING.
THROUGH THE REACTOR VESSEL-HEAD VENT IS' JUSTIFIED.
CONTINUOUS VENTING IS DESIRABLE AND ACHIEVABLE WITHOUT
. CONCERN FOR EXCESSIVE CONTAINMENT HYDROGEN CONCENTRATIONS.
F
?"# f ?
-1
+-
F4 -re r*g+
=-er-
- FwdrF3-Nwi*
e
'a+w
+""*wnswra,a.w,-
t,e-eve.,--
ee--,ee-e- w w-w y,ev.we~*&a-9M**
w e ewve--usmat-m---@em 'w
- - -eMNe,-'
1 I
13 u;
DEVIATION 31 BASIS 0
THE CONCERN IS:THAT CONTINUOUS VENTING OF THE REACTOR VESSEL HEAD VENT MAY RESULT IN EXCESSIVE CONTAINMENT j
HYDROGEN CONCENTRATIONS.
0 CONTINUOUS VENTING'0F THE VESSEL HEAD IS ONLY USED 4
-IF THE HEAD VOID CANNOT CONTAIN A SIGNIFICANT VOLUME OF HYDROGEN H YDROG EN 0.A SOURCE OF-MYOR00EN MUST EXIST FOR HYDROGEN VENTING LTO BE-A CONCERN.
THE DISSOLVED HYDROGEN IN THE RCS IS TOO LITTLE TO BE A CONCERN (LESS THAN 0.1% IF VENTED TO THE CONTAINMENT) 0' ONLY IDENTIFIED SOURCE OF A LARGE VOLUME OF HYDROGEN IS A SEVERE' INADEQUATE' CORE COOLING EVENT WITH CLADDING TEMPERATURES WELL IN EXCESS OF 1000F
~0 THE EPGS PRECLUDE CONTINUOUS VESSEL HEAD VENTING IF
.ICC HAS.0CCURRED, ICC SYMPTOMS ARE CONTINUOUSLY-MONITORED LBY THE SPDS AND THE SHIFT TECHNICAL-ADVISOR AND WILL NOT GO UNDETECTED
-0 THE CONTAINMENT HYDROGEN CONCENTRATION IS CONTINUOUSLY-
' MONITORED BY-THE SPDS FOLLOWING AND LOCA EVENT.
AN ALARM IS GENERATED IF THE CONCENTR'ATION EXCEEDS 0.5%
0 CONTINUQUS VENTING IS DESIRED UNDER SOME CONDITIONS IN ORDER TO PROVIDE AN ADDITIONAL RCS ENERGY RELIEF PATH OR TO VENT A. STEAM VOID.
INTERRUPTION OF VENTING DUE TO NON-APPLICABLE. HYDROGEN CONCERNS IS AN UNNECESSARY
' RESTRICTION 0
GENERIC HYDROGEN VENTING GUIDELINES ARE USED IF THE ONLY REALISTIC SOURCE OF HYDROGEN, ICC, HAS OCCURRED
?
~
14
-II.
PLANT SPECIFIC DESIGN FEATURES e -UPPER HEAD INJECTION (UHI) ACCUMULATORS e
HYDR 0 GEN IGNITERS e
ANNULUS VENTILATION SYSTEM
. e CONTAINMENT AIR RETURN AND HYDROGEN SKIMMER FANS e
RHR AUXILIARY CONTAINMENT SPRAY
- s OTHER UHI/IC PLANT DIFFERENCES e
STANDBY SHUTDOWN FACILITY (SSF) e BORON INJECTION TANK (BIT) HAS BEEN REMOVED
?
-v
15 i
UHI
~
l SYSTEM DESCRIPTION 0.' PASSIVE-INJECTION TANK WITH PRESSURIZED NITROGEN COVER GAS S
BEGINS TO INJECT AT-APPROXIMATELY 1200 PSIG S ' AUTOMATICALLY ISOLATED ON LOW LEVEL TO PREVENT NITROGEN INJECTION 0
INCLUDED TO PROVIDE ACCEPTABLE PLANT RESPONSE TO LARGE BREAK LOCA FUNCTION ONE e ' VERIFY ISOLATION OF UHI IF INJECTION IS NOT DESIRABLE e
PERFORMED DURING INTENTIONAL DESPRESSURIZATIONS, AS IN A NORMAL SHUTDOWN 0-ISOLATED ONLY:IF RCS IS SUBC00 LED AND PRESSURE IS
<1900 PSIG e
CONTAINED IN THE FOLLOWING GUIDELINES:
- ES-0.2 NATURAL CIRCULATION C00LDOWN
- ES-1.2 POST-LOCA C00LDOWN AND DEPRESSURIZATION
- ES-2.1 SI TERMINATION FOLLOWING EXCESSIVE C00LDOWN-
~
- E-3 STEAM GENERATOR TUBE RUPTURE
- ECA-3.1 SGTR WITH CONTINUOUS RCS LEAKAGE:
SUBC00 LED-RECOVERY
- ECA-3.2 SGTR WITH CONTINUOUS RCS LEAKAGE:
SUBC00 LED RECOVERY
- ECA-3.3 SGTR WITHOUT PRESSURIZER PRESSURE' CONTROL
- FR-P.1 RESPONSE TO IMMINENT PRESSURIZED THERMAL STOCK CONDITIONS CHECK IF UHI SHOULD 'BE ISO-
- I.ATED -
- a. NC system subcooling >0*F
- a. IF either condition NOT
-AND-met, TIEN continue with NC system pressure < 1900 Step 10 while monitoring NC psig system pressure and sub-cooling. E these condi-tions are satisfied at any time, TIEN gag and isolate UHI accumulator isolation valves.
- b. Isolate and gag UHI accu-mulator isolation valves.
p 4
e-,--
-,~,.ne, n
,a--v--,,n-----
,.m,y, - - -,, - -
--,ww,,.,.nc
-w
<-.w.-
,er-..-
-16 s
-F, UNCTION'TWO
_ : VERIFY-ISOLATION OF'UHI AFTER IT~HAS DUMPED TO PREVENT
' NITROGEN INJECTION
'G - PERFORMED WHEN.UHI ISOLATION VALVES HAVE CLOSED'OR SHO.ULD HAVE' CLOSED
'S -CONTAINED IN THE FOLLOWING GUIDELINES:
- E-0 SAFETY INJECTION
- ECA-0 LOSS OF ALL AC POWER
'.ECA-1.1 LOSS OF EMERGENCY COOLANT RECIRCULATION-
- FR-C.1 RESPONSE TO INADEQUATE CORE COOLING FR-C.2 RESPONSE TO DEGRADED CORE COOLING ICHECK IF UNI ACCUMULATORS-SHOULD BE ISOLATED
'a.~NC system pressure
.a. GO TO Step 12.
WHEN
'<550 psig NC system pressure
<550 psig, THEN do Step 11b.
,b. Close'all UHI accumu-
- b. Vent an unisolated accu-lator isolation. valves.
mulator.
FUNCTION THREE 9
VERIFY UHI' AVAILABILITY TO INJECT 4
PERFORMED.WHEN ADDITIONAL-INVENTORY IS OR MAY BE NEEDED e. CONTAINED'IN THE-SAME' GUIDELINES AS FOR FUNCTION TWO e
CHECK UHI AND COLD LEG ACCUMULATOR STATUS-
- a. UHI isolation valves.-
'a. Manually open valves OPEN unless closed after accumulator discharge.
- b. Cold leg accumulatior
- b. GO TO Step 5.
' pressure.>100 psig.
.c. Power available to cold
- c. Restore power-to valves.
leg accumulator isolation valves d.- Cold leg accumulator isola-
- d. Manually open valves.
? tion' valves - OPEN
17 HYDR 0 GEN IGNITERS ARRAYdFGLOWPLUGIGNITIONSOURCESDISTRIBUTEDTHROUGH-e OUT UPPER AND LOWER CONTAINMENT e
DESIGNED TO CONTINUOUSLY BURN OFF HYDR 0 GEN PRIOR TO ACCUMULATION -T4 SIGNIFICANT CONCENTRATIONS e
USED IN'ACCORDANCE WITH LICENSING COMMITMENTS, I.E.,
MANUALLY ENERGIZED AFTER SAFETY INJECTION AT THE FIRST SYMPTOMS OF A LOCA (IN E-1, HIGH ENERGY LINE BREAK INSIDE CONTAINMENT)-
e ENERGIZED IN FUNCTION RESTORATION GUIDELINES
- FR-C.-1 RESPONSE TO-INADEQUATE CORE COOLING
- FR-C.2 RESPONSE TO DEGRADED CORE COOLING
- FR-Z.1 RESPONSE TO HIGH CONTAINMENT PRESSURE ON HIGH. HYDROGEN CONCENTRATION Note: EHM system cannot be energized until Group 13 load sequencing
=n is permitted.
ENERGIZE HYDROGEN MITIGATION SYSTEM Dispatch on operator to locally energize Emergency Hydrogen Mitigation (EHM)
System.
18 t.
ANNULUS VENTILATION SYSTEM e ' REDUNDANT FILTER AND FAN SYSTEM AUTOMATICALLY ACTUATED 0N SAFETY INJECTION
-e FUNCTIONS T0 f1AINTAIN ANNULUS BETWEEN CONTAINMENT VESSEL AND REACTOR BUILDING WALL AT A NEGATIVE PRESSURE e
FILTERS AND RECIRCULATES AIR IN ANNULUS e
NEGATIVE PRESSURE, FILTERING, AND RECIRCULATION ACT TOGETHER TO REDUCE OFFSITE DOSES e
OPERATOR ACTION LIMITED TO VERIFICATION OF SYSTEM ACTUATION AND CORRECT OPERATION e
CONTAINED IN THE FOLLOWING GUIDELINES:
- E-0 SAFETY INJECTION
- E-1 HIGH ENERGY LINE BREAK INSIDE CONTAINMENT
- FR-Z.1 RESPONSE TO HIGH CONTAINMENT PRESSURE
- FR-Z.3 RESPONSE TO HIGH CONTAINMENT RADIATION VERIFY VE SYSTEM IN OPERATION
- Manually actuate VE system.
~
+.
- q. s 2
g l }g"..
'v
~
\\
47 n
\\
c i
8 CONTAINMENT.AIRRETURNfAN$
~
HYDROBEN SKIMMER, FANS:
e ; AIR RETURN FANS FUNCTION TO RECIRCULATE CONTAINMENT e
- ATMOSPHERE FROM UFPER T0 LOWER
- CONTAINMENT TO CONTINUE ENERGY REMOVAL VII:THE ICE. CONDENSER 9 e
HYDROGEN-SKIMMER FANS DRAW AIR"FROM ISOLATED REGIONS
{,t
.IN LOWER CONTAINMENT:AND DISCHARGE TO~ UPPER CONTAIN-m MENT NEAR THE RECOMBINERS TO PR0p.0TE MIXING AND PRE-c VENT HIGH LOCAL ltYDR0 GEN CONCENTRATIONS I y
e BOTH; SYSTEMS ARE REDUNDANT-AND ACTUATE ON HIGH-HIGH 3
CONTAINMENT-PRES 3URE FOLLOWING A TIME DELAY s.
e 0PERATOR ACTION LIMITED T0 VERIFICATION OF SYSTEM ACTUATION AND CCRRECT 0PERATION e
CONTAINED;IN~THE F0LLdWING GUIDELINES:
i s
E0 SAFETY INJECTION E
c>
E-1.,
HIGH ENERGY LINE BREAK ~-INSIDE CONTAINMENT '
V
- FR-Z.11 RESPONSE.TO HIGH. CONTAINMENT PRESSURE h
VERIFY VX SYSTEM OPTRATION
. a. '10. minute time de. lay chired.
.a. GO TO Step 8.
WdEN 10 3
minute time' delay expired, b-
. THEN do Steps'7b ind c.
~b. Containment air return
- b. Manually start fans.
fans --RUNNING
.c. Hydrogen skimmer fans -'-
- c. Manually start fans.
. RUNNING s
a,g l
\\
,y g
1.
I P
t
Tg 20
=
m m
RHR AUXILIARY CONTAINMENT SPRAY s
.e CAPABILITY TO SUPPLY ADDITIONAL FLOW FROM RHR HEAT EXCHANGER DISCHARGE TO CONTAINMENT SPRAY HEADERS
[n
- e -INCLUDED TO PROVIDE ACCEPTABLE RESPONSE TO DESIGN
- BASIS CONTAINMENT PRESSURE TRANSIENT FOLLOWING w
- ICE MELT
.s' :'USED IN ACCORDANCE WITH LICENSING COMMITTMENTS-
- ALIGNED'ONLY AFTER TRANSFER TO COLD LEG RECIR-2
- CULATION HAS BEEN MADE
- SUFFICIENT CORE: COOLING MUST-EE MAINTAINED DURING.
THE AUXILIARY SPRAY OPERATION e1 CONTAINED.IN THE FOLLOWING GUIDELINES:
- ES-1.3' TRANSFER TO COLD LEG RECIRCULATION
- FR-Z.1 RESPONSE 1TO HIGH CONTAINMENT PRESSURE
-ALIGN ND SYSTEM FOR AUXILIARY CONTAINMENT SPRAY-SY
- a. Containment pressure >1.2 psig a._GO TO Step 10.
- b. More than 50 minutes have elapsed -
- b. Continue with Step 10 since LOCA and MEN 50 minutes -
have elapsed since LOCA, THEN return to step 8a.
- c. Check.for flow from at least
- c. E both ND trains avail-g_ :
one NI pump AND one NV pump.
able, THEN GO TO Step 8d.
IF NOT, THEN GO TO Step 10.
Td.: Close ND cold leg injection-
- valve on one ND train.
,e. Open ND auxiliary containment' spray valve on that ND train.
99
-1 J
SECURE ND AUXILIARY ~CONTAIN-MENT-SPRAY 4
-a. Check containment pressure
- a. Continue to monitor con-
~
<1.2 psig.
tainment pressure.
MEN
- c pressure <1.2 psig, THEN s
complete Step 9.
b'. Close the open ND auxiliary containment spray valve.
'c. Open ND cold leg injection valve on-that train.
q 21 r
g
- 0THER UHI/IC PLANT DIFFERENCES
'e: LOWER POST-ACCIDENT CONTAINMENT PRESSURES e-ADDITIONAL SUMP INVENTORY DUE TO MELTED ICE
-o; LOWER CONTAINMENT SPRAY ACTUATION SETPOINTS
'e ~ LOWER. COLD LEG ~ ACCUMULATOR PRESSURE SETPOINTS e
C0tlTAINMENT PRESSURE CONTROL SYSTEM m
u
-k 4
re--
,.-,-am--,,
iy9 igg,,,,,,.,,--y i,, pop--
,w.ywyw,-w-yw r,ww,me-,weg
-3,
-emg,%
y-e-
-s-ye
22 m
1 STANDBY SHUTDOWN FACILITY (SSF) e PROVIDES ALTERNATE RCP' SEAL INJECTION CAPABILITY AND
- LIMITED ALTERNATE. PLANT CONTROL CAPABILITY e' POWERED BY: SEPARATE DIESEL GENERATOR
= e-EMERGENCY PROCEDURE USE LIMITED TO TAKING CREDIT FOR SEAL INJECTION DURING LOSS OF ALL AC POWER 4
- st IF ALTERNATE-SEAL INJECTION FLOW VERIFIED AND NO
- SYMPTOMS OF ANY 0THER LOSS OF RCS INVENTORY OBSERVED,
- C00LDOWNlAND.DEPRESSURIZATION SEQUENCE IN ERGS (REV. 0-
- STEPS 14 AND 15) IS BYPASSED e -IF EITHER CONDITION IS NOT MET, C00LDOWN AND DEPRES-SURIZATION IS PERFORMED AS IN GENERIC GUIDELINES.
AS INDICATED BY A DECREASING PRESSURIZER LEVEL OR I
gvi1S ZNDIC A T10N t
,e
,-,,,.-4
..e
~- -,, - -
v,
..r..-,
-,.mm..m,rn-,
-m,,,-
a-
~
n.,n--,
1 23
SUMMARY
e : PLANT SPECIFIC DESIGN FEATURES ARE USED IN ACCORDANCE
~
- WITH FSAR OR LICENSING COMMITMENTS e. PERFORMANCE OF PLANT SPECIFIC FEATURES IS COMPLEMENTARY
~
TO GENERIC SYSTEMS
~-
e OPERATOR ACTIONS CONCERNING PLANT SPECIFIC FEATURES
- ARE LIMITED T0:
VERIFICATION OF ACTUATION AND OPERATION OF AUTOMATIC SYSTEMS-t
-- PERFORMANCE-0F LIMITED MANUAL ACTIONS BASED o0N SPECIFIC CRITERIA
~
J A
e d
i m..
mv w
-w-
,-v y,en-r,-.
.,..-+-, -,,,
-,.y
,e 7
..,-n4,.
s.,-..-_+.--g
-ny..
e
24
-III.- RVLIS UTILIZATION 8
SYSTEM DESCRIPTION TWO' TRAINS
- THREE RANGES S
RVLIS LOWER RANGE
- VALID WITH ALL RCPS OFF
- USED TO MONITOR CORE UNC0VERY 0 'RVLIS UPPER RANGE'
- VALID WITH'ALL RCPS 0FF
+-
- USED TO MONITOR VOID IN VESSEL HEAD AND TO CONTROL HEAD VENTING 0
RVLIS DYNAMIC HEAD RANGE 4
---VALID WITH ONE OR MORE RCPS ON
- USED~TO MONITOR RCS INVENTORY (VOID FRACTION)
NRC CONCERN-THE RVLIS UPPER RANGE IS NOT USED IF ANY REACTOR COOLANT PUMPS ARE RUNNING, ALTHOUGH SOME CAPABILITY TO DO SO EXISTS.
/
-,.,,--.--m-
,...-,,,-.w c,.,,,,. -.=-... +, - -.,,.
,--,--m------.m
,m-a.e
-, -.,. ~. -
.----uav.-~n,..-
ame.,
4 -
25 l
Spare Head Penetration AP 6P UPPER RANGE a
Outlet Outlet h
V t-DYNAMIC HEAD x
/
P APb Movable D:tector Conduit h
rain A Train 8 Figure 4.9-1. RVLIS System O
e a
9 4,-.,
-e-
,m.,..-3
.-,,-._-,,--.w-w
,n,-,,-~,,
v.-,,%,-._w,,,-,-,-,---.,-,w-.--r,-e.,,-----,--, - - - - -, -
s
^
a
'L 26 p
- .s M f
+-
..IN ;THE LOOP WITH THE RVLIS TAP
-~ CHANNEL A NOT VALID IF RCP A.IS ON CHANNEL 1B NOTJVALID IF RCP C.IS ON
~
L8.THE--UR' INDICATION VARIES DEPENDING ON THE NUMBER OF
- ^
?RCPS~ RUNNING-AND:TO SOME EXTENT ON THE COMBINATION
-+
OF PUMPS RUNNING Si THE DEPENDENCY OF,.THE RVLIS INDICATION ON THE'RCP STATUS
'SIGNIFICANTLY COMPLICATES ~THE USE.OF IT, IN PARTICULAR
'IN TERMS 10F HUMAN FACTORS.
THE USE OF THE RVLIS DHR ALSO DEPENDS ON THE RCP STATUS - HOWEVER ITS USE IN THAT
. MODE IS NECESSARY FOR ICC MITIGATION. (SEE NEXT.PAGE) 0 - IT-IS UNLIKELY THAT~A' PLANT TRANSIENT WILL EVOLVE INTO THE CONDITIONS OF CONCERN, I.E. RCPS. RUNNING WITH A' LARGE.NONCONDENSIBLE VOID.
THIS'WOULD ONLY OCCUR DUE JTO-AN'ICC' EVENT.
THE-EPGS WILL NOT RESTART A' REACTOR ICO'0LANT PUMP IF:A VESSEL: HEAD VOID IS NONCONDENSIBLE.
LTHELVOID'IN THAT CASE WOULD BE VENTED. PRIOR TO RCP RESTART.
.0' FOLLOWING AN ICC EVENT THE HEAD VOID.WOULD NOT BE VENTED
.WITHOUT: CONCURRENCE FROM THE TSC.
UTILIZATION OF~THE UR WITH RCPS ON COULD BE CONSIDERED AT THAT. TIME g
tow; O PgtA fbt ' CONFZ b64CE e
4777tg ott2ArzoNAL.
6xP6R EENCC W.rL L BE GA1yg.b ZW TH6 hM' GAS 0F ZN TGRG ST
~0
. YHE EXI.S TENC-s1&TNob reovrb6s M RGA bY FOR A L6VGL og vozb FRACTZON ' TNbZCA TION t,tNp6til ANY
- f:
00Nbr Tron 4
/
E 27 J
CATAWBA NUCLEAR STATION
- ~
b EMERGENCY PROCEDURE GUIDELINES REVISION 1 DATE 06-26-84 i
STEP ACTION / EXPECTED RESPONSE RESPONSE NOT OBTAINED 6
CHECK RVLIS INDICATION
- a. At least one NC pump -
- a. GO TO Step 6e.
RUNNING
~
setpoint from table below not increasinr. THEN GO TO Step 7.
Otherwise wait until DHR RVLIS indication greater than the appro-priate setpoint for the number of NC pumps running, and THEN return to guideline in effect.
Number of Channel A Channel B 3C Pumps with NC Pump A with NC Pump C Running Running NOT Running Running NOT Running 4
>80%
>80%
3
>60%
>35%
>60%
>35%
2
>45%
>23%
>45%
>23%
1
>35%
>15%
>35%
>15%
- c. ',0 TO Step 7.
- d. Return to guideline in effect.
- e. LR RVLIS indication >>p%.
- c. IF LR RVLIS indication SF not increasing, THEN GO TO Step 7.
Other-se wait until LR RVLIS S % and THEN return to guideline in effect.
- f. LR RVLIS indication - NOT DECREASING
- f. GO TO Step 7.
- g. Return to guideline in effect.
7 CHECK NC PUMP SUPPORT SYSTEMS -
AVAILABLE Establish conditions per Try to establish support OP/1/A/6150/02A, REACTOR system availability.
COOLANT PUMP OPERATION FR-C.1 Page 3 of 10
V 28 IV.SETPOINTS e
CORE EXIT THERM 0 COUPLES l"
e RCS T-AVE
- e T-COLD
- e T-HOT e
RCS PRESSURE e
PRESSURIZER PRESSURE e
PRESSURIZER LEVEL e
RVLIS i
e-STEAM LINE PRESSURE e
STEAM GENERATOR LEVEL
-- e AUXILIARY FEEDWATER FLOWRATE e
CONTAINMENT PRESSURE o
HYDROGEN CONCENTRATION' e
REFUELING WATER STORAGE TANK LEVEL s
CONTAINMENT SUMP LEVEL e
MISCELLANE0US e
SUBC00 LING MARGIN m
',A
__.,_,_.__,,...-..._..,_..-,,,._y,-,_...._,-...
,_.,,_ _ ___ m _,,.-.m
..m___-...---
4
e,,
29 M..
h CORE EXIT THERM 0 COUPLES-SEIEDINI MSE BASIS DEVIATION 350 ICC TEMPERATURE CRITERION ERG NO 476 SGTn C00LDOWN TARGET ERG NO
- 488 SGTR C00LDOWNLTARGET' ERG NO 500-SGTR. RAPID COOLDOWN TARGET DUKE YES*
. 502-SGTR C00LDOWN TARGET ERG NO
- 514 SGTR C00LDOWN TARGET ERG NO
^
526 SGTR C00LDOWN TARGET ERG NO 537
.SGTR COOLDOWN TARGET ERG NO 1
700-ICC. TEMPERATURE CRITERION ERG NO
-1200
,ICC TEMPERATURE _ CRITERION ERG NO
- A TEMPERATURE OF 500*F WAS SELECTED TO PROVIDE AMPLE RCS SUB-COOLING WHEN PRESSURE WAS DECREASED TO BELOW THE STEAM LINE SAFETY VALVE LIFT SETPOINTS.
THIS VALUE IS COMPARABLE TO THE ERG TARGET OF 507'F (No-LOAD TEMPERATURE - 50*F).
Y p
I
_.-,,-..,..w---.
c.~,-*w.ww-e
++-ve--e'r'e-v-*w=""Tww"-*"
n-30 1.:.
~
RCS LOOP TEMPERATURES SETPOINT llSf BASIS DEVIATION T-AVE
~
557J NO-LOAD RCS T-AVE ERG NO 564-LOW T-AVE FEEDWATER ISOLATION ERG NO.
T-COLD 250 STATUS TREE PTS CRITERION DUKE YES*
300 COLD OVERPRESSURE CRITERION ERG N0 300 LOW TEMPERATURC. CRITICALITY ERG NO
--350 LOW TEMPERATURE ECCS LOCK OUT ERG NO
. 400 EXCESSIVE C00LDOWN CRITERION DUKE N/A ~
457-STATUS TREE PTS CRITERION DUKE YES**
T-H0T 200-INDICATION OF COLD SHUTDOWN ERG NO 350 RHR INITIAION ERG NO "550 P-ll BLOCKING TARGET ERG No 557
.HIGH SAFETY VALVE T-SAT ERG NO
- ADDITIONAL MARGIN PROVIDED TO ACCOUNT FOR INABILITY TO MEASURE DOWNCOMER FLUID TEMPERATURE
- ADDITIONAL MARGIN PROVIDED TO GIVE WARNING OF ENTRY INTO OVER-COOLING TRANSIENT m B)A yog GRG-itG V L, con s,z s,7CMr WETH R6V o
W 31 RCS PRESSURES
~
.SETPOINT~
HEE BASIS DEVIATION L100 CLA LOW PRESSURE' ISOLATION UHI/IC NO
. 150 LOW PRESSURE ECCS ISOLATION DUKE N/A 1951 RHR-PUMP-SHUT 0FF PRESSURE ERG NO
'385-RHR INITIATION PRESSURE ERG NO 1400 PORV LOW SETPOINT' ERG NO j550 CLA' SHUT 0FF PRESSURE UHI/IC NO 550 UHI LOW PRESSURE-ISOLATION-UHI/IC N/A f
1000
'CLA MAXIMUM ISOLATION PRESSURE UHI/IC NO
'1500-CHARGING /SI MINIFLOW CLOSURE DUKE N/A
.1500-
.UHI SHUT 0FF PRESSURE UHI/IC N/A
- 1520 SI PUMP SHUT 0FF PRESSURE ERG NO 1900-UHI MAXIMUM ISOLATION PRESSURE UHI/IC N/A 2000 CHARGING /SI MINIFLOW OPENING DUKE N/A
/
32 PRESSURIZER PRESSURE SETPOINT MEE BASIS DEVIATION 1845 LOW PRESSURE REACTOR TRIP ERG NO 1900 P-ll BLOCKING TARGET ERG NO 1955 P-11 SETPOINT ERG NO 2135' PORY SETPOINT IN FR-S.1 ERG NO
'2135 UPPER LIMIT FOR REPRESSURIZATION DUKE
'YES*
2235 488HE NO-LOAD PRESSURE ERG NO 2260 SPRAY ACTUATION SETPOINT ERG NO 2315 PORV RESEAT PRESSURE ERG NO 2335 PORV LIFT PRESSURE ERG NO 2400 FAILURE OF PRESSURE CONTROL DUKE N/A 2400 HIGH PRESSURE MINIFLOW ISOLATION DUKE N/A
- NO ADVERSE EFFECTS WILL RESULT FROM A REPRESSURIZATION TO NEAR NORMAL OPERATING PRESSURE. THIS SETPOINT PROVIDES MARGIN TO LIMIT
' THE REPRESSURIZATION TO BELOW THIS VALUE.
L
^
- r; 33 PRESSURIZER LEVEL SETPOINT-
_MSE BASIS DEVIATION 5
.LEVELLON SCALE LOW ERG NO-18 LOW LEVEL LETDOWN ISOLATION ERG NO 20 NATURAL CIRCULATION LOW TARGET ERG-NO 25-
'NO-LOAD SETPOINT ERG N0 30 NATURAL CIRCULATION HIGH TARGET ERG N0 40 VOID COLLAPSE LOW TARGET ERG NO 50
' VOID-COLLAPSE COMPENSATION DUKE YES*
-60 VOID COLLAPSE HIGH TARGET ERG NO 90 NATURAL CIRCULATION HIGH TARGET ERG NO 92 HIGH LEVEL REACTOR TRIP
. ERG NO 95' LEVEL ON SCALE HIGH ERG NO~
- A DIFFERENT VALUE WAS USED AFTER A PLANT SPECIFIC CALCULATION o
.(
34 L
RVLIS-SETPOINT.
- lfd; BASIS DEVIATION LOWER-RANGE
'O ArbbCG OF CORG - PLtls ERROR' blix6 Y6 S H58 !
TOP OF CORE PLUS ERRORS ERG N0*
UPPER RANGE
- 72 ~
TOP OF HOT LEG PLUS ERRORS ERG NO-97.
UPPER RANGE FULL MINUS_ ERRORS ERG NO DYNAMIC HEAD RANGE 15-INACTIVE'l PUMP SETPOINT-DUKE YES**
23L INACTIVE: 2 PUMP SETPOINTL DUKE YES**
'35 INACTIVE 3 PUMP SETPOINT DUKE YES**
35-ACTIVE 1TPUMP SETPOINT-DUKE YES**
45:
ACTIVE 2 PUMP SETPOINT-DUKE YES**
60 ACTIVE 3 PUMP SETPOINT DUKE YES**
80
. ACTIVE-4 PUMP SETPOINT DUKE YES**
- WESTINGHOUSE USES TWO SETPOINTS, 12~FT AND 3% FT.
DUKE USES ONLYL12LFT-TO VERIFY AN ADEQUATELY COVERED CORE.
- DUKE SETPOINTS ARE ADJUSTED TO APPROXIMATELY 25% void FRACTION TO PROVIDE ADDITIONAL. INVENTORY IF RCP'S ARE TRIPPED
0
- r 35 STEAM LINE PRESSURE SETPOINT USE BASIS DEVIATION 2
'100
'LOWPRESSURE[hTDAFWPUMP DUKE N/A 385 RHR COOLING FOR RUPTURED SG DUKE N/A 500 TARGET FOR LOSS OF ALL AC C00LDOWN UHI/IC N/A 7252 LOW STEAM PRESSURE SI SETPOINT ERG NO 1125 STEAM LINE PORY LIFT SETPOINT ERG NO 1175 LOWEST STEAM LINE SAFETY SETPOINT ERG NO
~
'1230 HIGHEST STEAM LINE SAFETY SETPOINT ERG' NO m
t
I 36 1
f I
STEAM GENERATOR LEVEL
'SETPOINT.
USE BASIS DEVIATION NARROW RANGE 5
LEVEL.ON SCALE LOW ERG NO 15 UPPER BAND FOR SGTR CONTROL DUKE N/A 38 NO-LOAD SETPOINT ERG NO 70 UPPER LIMIT FOR BACKFILL DUKE YES*
82.4 P-14 HIGH LEVEL SETPOINT ERG NO 95 LEVEL ON SCALE HIGH ERG NO WIDE RANGE 3
MINIMUM USABLE HEAT SINK DUKE N/A INDICATION
- USED RESULT OF CALCULATION BASED ON PLANT-SPECIFIC INSTRUMENT ERRORS RATHER THAN AN ARBITRARY NUMBER.
f b
[
sp--
2-e c
+2
-.---,,--,-+.,y%
,w, r,w-..-w-,.,,,,
,,v,~.
+.w,+~wwcy,evsw-,g.., -,. --wd=
- y,
-.a..
a...
- .\\ '>
.:n
~
37 y ) 8' -
,~
l-l
(.
i AUXILIARY FEEDWATER FLOWRATE SETPOINT HSli BASIS DEVIATION so 's 25 MAXIMUM FLOW FOR ALL GV4 ERG NO DEPRESSURIZED 100 MAXIMUM FLOW TO DRY SG ERG NO
'450 MINIMUM FLOW FOR HEAT REMOVAL ERG NO e
1
38
, ; 4. -
CONTAINMENT PRESSURE SETPOINT USEL BASIS DEVIATION 0.3-CPCS INTERLOCK SETPOINT UHI/IC N/A 1.2 HIGH PRESSURE SETPOINT UHI/IC N/A 3
HIGH-HIGH PRESSURE SETPOINT UHI/IC.
N/A 10 IrlDICATION OF ICE MELT UHI/IC N/A 15 CONTAINMENT DESIGN PRESSURE ERG NO Y
3g c:...
HYDROGEN CONCENTRATION
-SETPOINT USE BASIS DEVIATION 0.5 HYDROGEN MITIGATION LOW SETPOINT ERG NO 31 MAXIMUM VENTING CONCENTRATION ERG N0 3.5
' MINIMUM PURGE CONCENTRATION FSAR' N/A 6
HYDROGEN MITIGATION HIGH ERG NO SETPOINT 6
MAXIMUM RECOMBINER CONCENTRATION ERG NO 3
14 0 REFUELING WATER STORAGE TANK LLVEL-SETPOINT
.USE BASIS DEVIATION l
FEED-AND-BLEED SWAP OF HIGH-DUKE N/A HEAD PUMPS 11 LOW-LOW LEVEL SETPOINT ERG NO
.20 MINIMUM FEED-AND-BLEED INVENTORY DUKE N/A 37 LOW-LEVEL SETPOINT ERG NO
.50 MAXIMUM FEED-AND-BLEED INVENTORY DUKE N/A L.
41' CONTAINMENT' SUMP LEVEL
- SETPOINT HEE BASIS DEVIATION
- 1.5 LOW FLOW AIR ENTRAINMENT LIMIT DUKE N/A 2,5 HIGH FLOW AIR ENTRAINMENT LIMIT DUKE N/A i-13 HIGH SUMP-LEVEL-DUKE YES*
- PRELIMINARY LEVEL SELECTED TO AVOID FLOODING OF STEAM GENERATOR LEVEL TRANSMITTERS). FINAL LEVEL STILL UNDER EVALUATION 4-1 ti
~'
42
+:
- j. --
i sr MICELLANE0US SETPOINTL USE' BASIS DEVIATION 5% FP SUBCRITICALITY STATUS TREE ERG NO
. 10-10 AMPS P-6 SETPOINT ERG HO 100 PPM BORON MARGIN FOR NATURAL DUKE N/A CIRCULATION 150 PPM BORON MARGIN FOR STUCK ROD ERG NO p
150 PPM BORON: MARGIN FOR BACKFILL DUKE N/A 75$h'r MINIMUM EMERGENCY BORATION FLOW DUKE N/A
+
- 50*F/HR NATURAL CIRCULATION C00LDOWN
-ERG NO RATE
.100*F/HR MAXIMUM C00LDOWN RATE ERG NO
-0.2 DPM
.SUBCRITICALITY STATUS TREE ERG NO
'6"
.HOTWELL LOW-LOW LEVEL' ERG NO
-2FT SPENT FUEL P00L' LOW LEVEL ERG NO 60*F BAT LOW TEMPERATURE ALARM ERG NO Y
h
+
43 y.x
- V-
-SUBC00 LING MARGIN
, UTILIZATION OF SUBC00 LING MARGIN SETPOINTS S
ENSURE RCS INVENTORY IS MAINTAINED IN A SUBC00 LED STATE INCLUDING. INSTRUMENT ERRORS
~ VERIFIES ADEQUATE CORE COOLING ENSURES THAT HEAT TRANSFER IS INDICATED BY TEMPERATURE CHANGE' S
AVOID EXCESSIVE SUBC00 LING WHICH CAN AGGRAVATE A
-PRESSURIZED THERMAL SHOCK EVENT 0
ENABLE EQUALIZATION OF RCS-AND STEAM GENERATOR PRESSURE
.TO.STOP LEAKAGE THROUGH A SGTR.
O REDUCE INVENTORY LOSS FROM THE RCS S
ESTABLISH A MARGIN TO REACHING SATURATION C,0NDITIONS PRIOR TO~A DEPRESSURIZING ACTION
. NATURAL CIRCULATION C00LDOWN RCP RESTART WITH A VESSEL HEAD VOID SAFETY INJECTION FLOW REDUCTION 4
/
t h
w
'4'.
- 1
,,r-.,,,---.-,..,,.v..--~_m,..-_,
[
.qq o+:
~
SUBC00 LING MARGIN SETP0lNTS s
"O*F'- USED AS THE MINIMUM MARGIN;THAN ENSURES RCS SUBC00 LING ANs - ro VEREFY AccMMUL A7en: ' rNJG C7. tom my MeuzitG.h t
1 0-5*F - USED AS A TARGET OPERATING BAND FOR MINIMIZING SUBC00 LING o
20*F:- USED TO CONTROL SAFETY INJECTION FLOW REDUCTION l
,i'30*F - USED TO LIMIT'RCS PRESSURE FOLLCWING A SGTR WITHOUT
-PRESSURIZER PRESSURE CONTROL
- 6. -
1 50*F - USED AS A COMFORTABLE MARGIN TO SATURATION s
i 100*F - USED AS A TARGET AND UPPER LIMIT FOLLOWING AN OVERCOOLING'(PTS) EVENT l200*F-USEDASANUPPERLIMITDURINGTHEC00LDOWNFOLLOWING j.
AN OVERC00 LING (PTS) EVENT a
11 5 1~
. 3. g '
fa -:
f
(
k l
DEVIATION BASES l
o e
50*F~(RATHER THAN 0*F) IS-USED AN NN SI TERMINATION CRITERION FOR GUIDELINES IN WHICH RCS'REPRESSURIZATION'IS EXPECTED AND i
ACCEPTABLE.
THIS SIMPLY REQUIRES THAT A MORE C0fiFORTABLE
[
MARGIN IS' ESTABLISHED.
i e
100*F (RATHER THAN 10*F) IS USED AS AN RC's DEPRESSURIZATION j
TARGET FOR. PTS EVENTS.
THIS VALVE'WILL AVOID POTENTIAL VOIDING IN THE RCS.
THE RATHER SEVERE GENERIC GUIDANCE IS-i UNNECESSARY FOR THE CATAWBA VESSELS DUE TO GOOD WELD CHEMISTRY.
1 e
r l
i L
f b.
+
w o-0 Dose Comparison The NRC concern with the absence of a blowdown guideline was the loss of a potential method for reducing doses. The blowdown guideline will not result in lower doses than the backfill guideline since, for backfill, all reactor coolant inventory is contained and processed within the normal Chemical and Volume Control System.
In contrast, the blowdown guideline would introduc.
contaminated reactor coolant into the balance-of-plant, with the potential for more difficulty in containing the contamination. Duke Power does not intend to include a cooldown guideline using blowdown.
Design Blowdown Capacity Two options exist at Catawba for draining a steam generator through the blow-down system. First, the steam generator drain tanks and pump, while being properly shielded and having sufficient capacity,are only designed for 150'F and 200 psig. Therefore this system cannot be used for cooldown of a ruptured steam generator at elevated temperatures and pressures. Second, the normal blowdown path, while designed for full operating temperatures and pressures, is of IJnited storage capacity since it fur.ctions in a recirculation mode.
Beyond the blowdown blowoff tank (3000 gallons) and the excess hotwell capa-city (5000 gallons) leakage would be dumped to the turbine building sump.
This is undesirable from a dose standpoint. Even if the available hotwell liquid volume was increased to create extra storage capacity, the volume of one steam generator above the U-tubes is over 30,000 gallons. This volume may have to be drained several times in the blowdown tooldown guideline.
Therefore, Duke Power concludes that the. Catawba plant design is not compat-ible with the steam generator tube rupture alternate cooldown approach using blowdown.
1 l
y
^
3 F
uy
,'l
]O.
f i
[
..y e.
JS The Catawba' Emergency Procedure Guidelines-lower rpnge RVLIS-ICC setpoints differ jfrom:the generic'setpoints in two places only.
g l 1.' 7The Catawba Core Cooling Critical S'afecy Function -(CSF) Status _ Tree RVLIS setpoints with all reactor coolant pumps off are 43%. ;This is derived
.by:taking:the. indication for 6.ieet of collapsed liquid level', 39%,;and adding ~ a - 4% error allowance. -
2.
The RVLIS setpoint, corresponding to ERG FR-C.1 Step 6 and FR-C.2 Step 7,
[
-in'the_ Catawba. Emergency, Procedure GpidelineNis equivalent to a collapsed
- liquid. level.at-theLtop of.the cord,154%, plus the 4% error. allowance.
The correspon'ing-Westinghouse' ERG setpoint in-each case is 3 feet-above the d
bottom of the core plus errors." ' The NRC concerns to be resolved are (1) whether earlier entry into or exit from the-core. cooling + guidelines because of'the
. higher;setpoint will cause the. operator to postpone lor omit necessary actions to. respond _to lower priority CSF Status Tree alarms and, (2) why the higher
.setpoints are con'servative.
-Omission.or Postponement of Lower Priority Actions
$Thellower priority lCSFs,'in order are Heat.. Sink, Reactor Coolant System Integrity,-
J
. Containment Integrity, and Reactor; Coolant Sy' stem Inventory. Responses to each
(
- function'during'an inadequate: core' cooling scenario are discussed separately.
~
LHeat. Sink': Theinadequatedorecooling(ICC):guidelinNsprovidethenecessary guidance on the use of'the' steam generators to mitigate the-ICC condition. In Teffect, the Heat l Sink CSF.is addressed within the ICC guidelines during.ICC con-p g
9_,
ditions.-:
, f(
i Reactor: Coolant System Integrity: 'ICC requires saturated core conditions. Pres-
~
lsurized thermal ~ shock. which.is-the safety concern in this status tree, does/not Jwarrant concern when ICCl symptoms. exist. RCS pressure _is alraady_ minimized to
~
~
l the: extent achievable,. and the-need to restore core cocling' far outweighs the effect of additional cooling of the reactor vessel.~ - In _ addition. PTS is only a Lainimal safety concern at Catawba'due to the excellent weld chemistry ~of the t
_; vessel.
b a
~..
-w
_ Containment. Integrity: Alliimpor' tant means.of maintaining containment-integrity.
In addition..t e operator verifies the actuation h
^
- fare' automatically, actuated.
Tand' operation'of these automatic,nystems.~in the entry guideline,lE-0, Reactor Trip'or Safety _ Injection,;priof to transferring to any"ICC guideline.
1
+
y w.
j?
n; y
~. -
3
'l y
t
+
+
y
+
t, A
f s
a r
[ '{
e
- ' ~
=
e------,-<----m,
,,-l,,
e..
_,, ;,l,
0
.. L o -
Inventory: Jmaly low priority alarms exist on this status tree. All are to be fresponded to at the operator's discretion and never require prompt attention.
- Therefore,'the1 Inventory CSF is not affected or impacted by the Core Cooling
- Status: Tree.
g
.The Catawba: Safety Parameter. Display System (SPDS) a'nd Status Trees keep the Loperator: continuously aware of the alarm states of all critical safety functions.
t =
The operating philosophy is to concurrently implement the actions of lower pri-1.ority Function, Restoration Guidelines which do not hinder or conflict with.the "P#
actions ofithe higher priority guideline in effect.
In the context of core
~
cooling. this'~would mean that if the RVLIS indication were exhibiting a sus-tained increase, as in reflood,the operator, while technically remaining in
~
- the
- ICC guideline; untfl; the top of the core setpoint was reached, would be free to also do anylother actions (which would not hinder restoration of core cooling) to address other< problems of which he was aware.
In summary, based
.on-this, approach.andithe above justification, no important operator actions Lwill be postponed:or omitted due to using a more conservative Core Cooling Status Tree setpoint'.-
Conservative Nature Of The Higher Setpoints The 6 feet setpoint (compared to the 3 feet setpoint) provides_for an increased
- likelihood that core mixture level, swelled by steam voids below the surface, is SV at or above,the top of the core. Earlier diagnosis of core uncovery. based on (the higher'setpoint will reduce the likelihood that a sustained partial-core
'uncovery will'go undete'ted.. It is possible that-the RVLIS increase during
\\#
e reflood could slow when the vessel mixture level exceeded the upper tar level
..of;the~ instrument. If there.were significant voiding-below the mixture level, this.might delay exitifrom~the ICC guideline. However, as mentioned in the preceeding section, the operator.can address other' problems in other guidelines while' awaiting the completion.of reflood. Also,.this situation is not unique to
- the Catawba
- guidelines since the Westinghouse ERGS, in all pumps-off.RVLIS exits 17
,-except the.onesiin' question, also require a top of core collapsed level before-leaving.
~
?Th'e top:of the core setpoint, as mentioned above, is consistent with the.other
~
-exit. points in theLgeneric ICC guidelines and ensures that any core recovery, Jinitiated by1the. restoration of' safety injection systems in the preceeding steps,
- \\,
williresult.in complete'reflooding'of the core prior'to exiting the guideline.
- fi An example of.the conservatism of this approach is demonstrated by the following
- scenario. Having identified symptoms of ICC,.the operator is successful in p
partiallyLreflooding the' core by unisolating the UHI accumulator.
Should UHI-S sT!
- delivery result in reflooding the core to a-level-in excess of-3 feet, the-Fgeneric guidelines would allow the operator to exit. However, a sustained re-
[
?cov'eryffrom.ICC.is not ensured.since the core remains substantially uncovered and-there-is no' sustained delivery of injection water. ICC symptoms will even-
.tually recur. -The Catawba guidelines require the operator to continue ICC mit-5:e rigation~ actions untilJthe core is completely reflooded. This approach better
}gg lindicatesEthat a sustained core cooling condition has been achieved.
- v a
~
1 A