ML20059J933
| ML20059J933 | |
| Person / Time | |
|---|---|
| Site: | 05200002 |
| Issue date: | 11/05/1993 |
| From: | ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY, ASEA BROWN BOVERI, INC. |
| To: | |
| Shared Package | |
| ML20059J906 | List: |
| References | |
| PROC-931105-02, NUDOCS 9311150104 | |
| Download: ML20059J933 (90) | |
Text
{{#Wiki_filter:. . . . .- . SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT REC 0VERY q EMERGENCY OPERATIONS " " 1 GUIDELINES Page ' of- Revision k T 7
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.i EXCESS STEAM DEMAND' EVENT RECOVERY GUIDELINE i
l t i i ESDE' 931A150104 931105 [ 1 ABB CE SYSTEM 80+' PDR ADOCK 05200002 M A PDR ;j
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SYSTEM 80+" TITLE EXCESS STEAM DEMAND I EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 2 of Revision ""- PURPOSE ! This guideline provides the operator actions which should be accomplished in the event of an Excess Steam Demand Event (ESDE). The. actions in this' i guideline are necessary to ensure the plant is placed in' a safe, stable condition. The goal of the guideline is to safely establish the plant in a "c inut e m itu $$40T Y'Ybb"40T Se NT 50EY ' "U N' procedureef,Yofo enn mL ST^"DBY nr S"UTDD','N, if the break has been isolated. Radiological releases to the environment will be minimized and : adequate core cooling will be maintained by following this guideline. This i guideline provides technical information to be used by the~ utilities in i developing a plant specific procedure. l t ENTRY CONDITIONS
- 1. The Standard Post Trip Actions have been performed.
9C i All of the following conditions exist:
- a. Event initiated from [ Mode 3 or Mode 4]
- b. SIAS has NOT been blocked
- c. LTOP has NOT been initiated. f and
- 2. Plant conditions indicate that an Excess Steam Demand Event has ,
occurred. Any one or more 'of the following may be present:
- a. Loud noise indicative of a high energy steam line break.
- b. Decreasing RCS average temperature caused by the increased RCS heat removal.
- c. Increase in feedwater flow until main feedwater isolation valves-are closed on MSIS. -l
- d. Possible increase in containment temperature, pressure, humidity, j and Holdup Volume Tank level. - l l
ESDE 2 ABB CE SYSTEM 80+'
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' SYSTEM 80 +" TITLE - EXCESS STEAM DEMAND EVENT RECOVERY l
EMERGENCY OPERATIONS "
- - 1 GUIDELINES-Page 5 of Revision: ""
EXIT' CONDITIONS _ i
- 1. The diagnosis of an Excess Steam Demand Event is not confirmed.
E
- 2. Any of the Excess Steam Demand Event Safety Function Status Check acceptance criteria are not satisfied, f E
- 3. The Excess Steam Demand Event EOG has accomplished its purpose by i satisfying ALL of the following: -l
- a. All Safety function Status Check acceptance criteria are being satisfied. ,
- b. RCS conditions are being controlled and maintained in HOT STANDBY,- ;
HOT SHUTDOWN, or COLD SHUTDOWN.
- c. An appropriate, approved procedure to implement exists or has been approved, by the Plant Technical Support Center or the Plant-Operations Review Committee. .
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ESDE 3 ABB CE SYSTEM 80+*
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.P SYSTEM ~ 80 + " TITLE EXCESS:STEAMDEMAND;
-EVENT RECOVERY:
EMERGENCY OPERATIONS " GUIDELINES Page ' of ' Revision "" ;
-"r INSTRUCTIONS CONTINGENCY ACTIONS-
- 1. Confirm diagnosis of an Excess 1. Rediaonose event and exit to either:
Steam Demand Event by: appropriate Optimal Recovery l
- a. verifying Safety Function Guideline or the Functional Status Check acceptance Recovery Guideline. .;
criteria are satisfied, and !
' f.
- b. referring to the Break Identification Chart (Figure 7-2), .t j
and l
- c. sampling both steam generators for activity.
- 2. pressure, decreases 2. =H pressurizer pressure decreases H =w wp.c to pressurizegi or below {105spsdgpp+ Then ;
m,, to or below-{1825 p ia] and a SIAS verify an SIAS is actuated, has NOT been initiated-f automatically, Then manually. . initiate an SIAS. [ t
~*3. Ensure' maximum safety injection and 3. Jf safety injection and charging .
charging flow to the RCS (unless SI flow NOT maximized, Then do the termination criteria met) by the following as necessary: l following- ,
- a. . start idle SI pumps and verify a. ensure electrical power to ;
SI flow in accordance with valves and pumps, figure 7-3. .b. . ensure correct SI valve lineup, .
- c. ensure operation of necessary-auxiliary systems. !
-l
- Step Performed Continuously -
ESDE 4 'ABB CE SYSTEM 80+"
s SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY. EMERGENCY l OPERATIONS " of 5 Page Revision "" GUIDELINES
-1NSTRUCT10NS CONTINGENCY ACTIONS
'f
- 4. If pressurizer pressure decreases 4. Continue RCP operation to less than [1400 psia] following an SIAS, Then ensure two of four RCPs are tripped (in opposite loops). ,
*5. Verify RCP operating limits are 5. Trio the RCP(s) which do not satisfied. satisfy RCP operating limits.
- 6. Determine the affected SG (or most 6.
affected SG) by comparison of the
-i following:
- a. SG steam pressures,
- b. RCS cold leg temperatures, ,
- c. SG levels.
- 7. If Excess Steam Demand Event stopped 7. ,
due to MSIS, Then go to step 10. P 1 i
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i ESDE 5 ABB CE' SYSTEM 80+" -
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A c i SYSTEM 80+" TITLE EXCESS STEAM DEMAND > :i L EVENT REC 0VERY'
-EMERGENCY OPERATIONS -
GUIDELINES Page.' of "- Revision = ! l INSTRUCTIONS CONTINGENCY-ACTIONS *
- 8. Isolate the most affected steam 8.
generator by performing the following: ;
- a. close the MSIV, a. locally close MSIV, 'f
- b. verify closed, or close the b. locally close MSIV bypass v'alve, J ,
MSIV bypass valve,
- c. close, or verify closed the c. locally close ADV(s).
atmospheric dump valve (s),
- d. close the main feedwater d. locally close main feedwater- ,
isolation valve, isolation valve,
- e. close the startup and emergency e. locally close startup and emergency _
feedwater isolation valve, feedwater isolation valve -i
- f. close vents, drains, exhausts f. locally close vents, drains, and bleedoffs, exhausts, and bleedoffs.
g.-close the Turbine Driven EFW g. locally close the: Turbine Drive EFW pump steam admission valve. pump steam admission 1 valve. l* w r en If the co n orie d ed steam generator
- 9. Verify the correct steam generator 9. ,
p -- + hest - is isolated by checking the -was3 isolated, Then unisolate eet steam ' following: generator'and isolate'the most-affected .)
- a. SG steam pressures, steam generator per step 9.
- b. RCS cold leg temperatures,
- c. SG levels. f
*10. Maintain unisolated -steam generator 10.
level in the normal band using > main, startup or emergency ,
.feedwater.
a t
. ESDE 6 ABB CE SYSTEM 80+" .;
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SYSTEM 80 + " TITLE EXCESS STEAM DEMAND EVENT REC 0VERY: s- EMERDENCY OPERATIONS .. GUIDELINES Page 7
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INSTRUCTIONS CONTINGENCY ACTIONS.
*11. Stabilize RCS temperature by 11.
controlled steaming of the unisolated SG using the following (listed in preferred order):
- a. ttreMaa bypass system, s+cc -
- b. atmospheric dump valve (s).
*12. Jf SI pumps are operating, Then 12. Continue-SI' pump operation.
they may be throttled or stopped, one pump at a time, if ALL of the following are satisfied:
- a. RCS subcooled based on Repre-sentative CET temperature (Figure 7-1),
- b. pressurizer level is greater than [14.3%] and not -
decreasing,
- c. at least one steam generator is available for removing heat from the RCS (ability for feed and steam flow),
- d. the HJTC RVLMS indicates a minimum level at the top of the hot leg nozzles.
ESDE 7 ABB CE SYSTEM 80+"
' SYSTEM 80 + " TITLE- EXCESS STEAM DEMAND.
EVENT RECOVERY , EMERGENCY OPERATIONS " GUIDELINES Page 8 of Revision "" i INSTRUCTIONS . CONTINGENCY ACTIONS L
- 13. Jf criteria of step 12 cannot be 13.
maintained after SI pumps throttled f or stopped, Then appropriate SI pumps must be restarted and full SI .: flow restored. J
- 14. When pressurizer level is greater 14. Jf pressurizer level less than than or equal to [2%], Then ensure [2%), Then continue to operate the ;
charging and letdown', and the SI available charging pump and all' i (unless SI termination criteria available SI pumps for maximum met) are being operated to maintain available flow. pressurizer level [2% to 78%). ! i i
-h ESDE 8 ABB CE SYSTEM 80+"
SYSTEM ' 80 + " TITLE ~ EXCESS STEAM DEMANDt EVENT RECOVERY , EMERGENCY OPERATIONS. " GUIDELINES. Page ' of Revision "" .!
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i INSTRUCTIONS C_0NTINGENCY ACTIONS
*15. Maintain the RCS within the 15. H RCS'subcooling greater than P-T- j
< acceptable Post Accident Pressure limits or cooldown rate greater ~ ! L Temperature limits of Figure 7-1 by than [100*F/hr], Then do the the following. following as appropriate:
- a. pressurizer heaters and main or a. stop the cooldown, auxiliary spray, b. depressurize the RCS using.the i
.o_t Reactor Ccalant Gas Vent System j
- b. charging and letdown, orfmainorauxiliaryspray}to: {
or restore and maintain pres- !
- c. throttling of SI pumps. surizer pressure within the i limits of Figure 7-1,
- c. attempt to me ntain the plant in a. stable pressure-temper-ature configuration or con-tinue to cooldown within .the limits of Figure 7-1,
- d. H over-pressurization is due to SI/ charging flow, Then throttle or secure flow (refer to step 12) and manually con-trol-letdown to restore and-maintain pressurizer pressure within the limits of Figure 7-1.
i, ESDE 9 ABB CE SYSTEM 80+"
a SYSTEM 80 +" TITLE EXCESS STEAM DEMAND- ! EVENT RECOVERY j EMERGENCY OPERATIONS " GUIDELINES. Page '" .of Revision '"" Ih3TRUCTIONS CONTINGENCY ACTIONS
- 16. If containment pressure is greater- 16.
than or equal to [2.7 psig], Then ensure 'the following:
- a. containment isolation is a. Jf containment isolation does not occur [
actuated automatically from ESF automatically or all containment ' panel isolation valves are not in their and accident positions, Then manually ~ <
- b. all available containment re- initiate containment. isolation. [Planti l t
circulation fan coolers oper- specific method for manually isolating l ating containment will be provided in plant specific E0Ps]. -
- 17. If containment pressure is greater 17.
than or equal to [8.5 psig], Then . do the following: ' ensure containment spray system -! a. actuation, and
- b. place the hydrogen monitors in i
~+
service and continuously mon-itor containment hydrogen, l and
- c. ensure Annulus vent system fans .;
have started and pressure in i i the Annulus decreases to < [0"
+# w.gJ and i 4
s ESDE 10 ABB'CE SYSTEM 80+*- ! i
1 SYSTEM 80+" TITLE EXCESS STEAM DEMAND : EVENT RECOVERY EMERGENCY OPERATIONS
- GUIDELINES Page " of "'
Revision - INSTRUCTIONS CONTINGENCY-ACTIONS
- 17. (Continued)
- d. ensure adequate containment _t temperature-pressure control by ,
at least one containment spray , headerdeliveringatleas((5000 gpm], and
- e. take steps to have the H 2 recombiners made available and aligned for use.
- 18. If containment spray system is 18. Continue containment spray system operating and containment pressure' operation.
is less than [5.5 psig], Then ; containment spray may be ter-minated. Upon termination, the CSS :i must be aligned and reset for auto- : matic operation {or manual re-start}. t
*19. If the containment hydrogen 19.
concentration is greater than or ; equal to [0.5%], Then operate the ! hydrogen recombiners. ! I i i I l ESDE 11 AB8 CE SYSTEM 80+"
r : SYSTEM 80 +" TITLE . EXCESS STEAM' DEMAND a EVENT RECOVERY- j EMERGENCY OPERATIONS-GUIDELINES Page '2
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INSTRUCTIONS CONTINGENCY ACTIONS ! H containment hydrogen con- 20. -!
*20 .
centration is less than [0.5%], ! Then terminate operation of hydrogen recombiners. _
*21. H RCPs are NOT operating, Then 21.a. H RCP operation NOT desired, Then- :{
evaluate the need and desirability go to step 24. , of restarting RCPs. Consider the following: _o_t
- a. adequacy of RCS and core heat ,j removal using natural circu- b. H at'least one RCP is operating in lation, each loop, Then go -idstep 25. .
- b. existing RCS pressure and .;
temperatures,
- c. the need for main pressurizer I
spray capability,
- d. the duration of CCW inter- 1 ruption to RCPs,
- e. RCP seal staging pressures and temperatures. q
.T 1
o ESDE- 12 ABB CE SYSTEM 80+'" l
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i SYSTEM 80 + " TITLE EXCESS STEAM DEMAND EVENT REC 0VERY . EMERGENCY OPERATIONS- " GUIDELINES _ Page " of Revision "" : INSTRUCTIONS CONTINGENCY ACTIONS -
*22. Determine whether RCP restart 22. Go to step 24.
criteria are met by ALL of the' :; following:
- a. electrical power is available to the RCP,
- b. RCP auxiliaries (CCW) are ;
operating to maintain seal l cooling, bearing cooling, and , motor cooling, and there are no high temperature alarms on the , selected RCPs, ;
- c. the unisolated steam generator is available for removing heat from the RCS (ability for feed r and steam flow), ;
- d. pressurizer level is greater -
i than [33%] and not decreasing,
- e. RCS is subcooled based on ;
Representative CET temperature > (Figure 7-1),
- f. Other criteria satisfied per plant specific RCP operating f instructions. :
i u ESDE 13 ABB CE SYSTEM 80+'-
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~l SYSTEM 80 +" TITLE EXCESS. STEAM DEMAND-EVENT RECOVERY )
EMERGENCY OPERATIONS GUIDELINES- Page
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j INSTRUCTIONS CONTINGENCY ACTIONS :
*23. H RCP restart desired and restart 23. Go to step 24 .
criteria .atisfied, Then do the l following:
- a. start one RCP in each loop, -l
- b. ensure proper RCP aperation by monitoring RCP amperage and .
NPSH,
- c. operate charging and letdown (and SI) to maintain pres- [
surizer level {2% to 78%]. Operate SI pumps until SI . termination criteria met. (Refer to step 12). i
*24. H no RCPs are operating, Then 24. Ensure proper' control of steam verify natural circulation flow in generator feeding'and steaming at least one loop by ALL of the (refer to steps'10 and.11) and RCS following: inventory and pressure control
- a. loop AT (Ts - T,) less than (refer to steps.14 and 15). -
normal full power AT,
- b. hot and cold leg temperatures constant or decreasing. *
- c. RCS is subcooled based on Representative CET temperature ,
(Figure 7-1),
- d. no abnormal difference [ greater .[
than 10*F] between T gRTDs and representative CET temperature. t ESDE .14 ABB CE SYSTEM 80+*
SYSTEM 80+" TITLE . EXCESS STEAM DEMAND. _
-EVENT REC 0VERY-EMERGENCY' OPERATIONS "
- l Page " of Revision. 5" j GUIDELINES INSTRUCTIONS ' CONTINGENCY ACTTONS I
- 25. Evaluate the need for a plant 25. ;!
cooldown based on: .
- a. plant status, ;
- b. auxiliary systems availability, j o
- c. emergency feedwater inventory .j (refer to Figures 7-4 ' and 7-5) . l I
- 26. If a plant cooldown is desired, 26.a. Maintain the plant in a stabilized Then continue with the actions of condition, this guideline. and i
- b. Exit to appropriate procedure as j directed by (Plant Technical ;
, SupportCenter{. l
- 27.a. Borate the RCS to maintain shutdown 27.
margin in accordance with Technical Specifications. I and
- b. Prevent boron dilution by pres-surizer outsurge by the follow- 1 ing (listed in preferred order): -l i) borate to raise the entire RCS (including the mass in the pressurizer) to cold :
shutdown conditions, j E use main or auxiliary ' spray ii) i i to increase and maintain ! pressurizer borori concen-tration within 50 ppm of RCS - boron concentration. i ESDE 15 ABB CE SYSTEM 80+" j
n I i L SYSTEM 80+" TITLE ' EXCESS STEAM DEMAND ~ -. EVENT REC 0VERY 7 EMERGENCY OPERATIONS' " GUIDELINES P a g e of Revision "" . -i
~ INSTRUCTIONS CONTINGENCY' ACTIONS ,
- 28. Perform a controlled cooldown, 28. -*
using forced or natural circulation, in accordance with Technical Specifications. Reduce RCS temperatures by: [
- a. H the condenser is available, Then cooldown using the steam bypass system, O.E
- b. If the condenser or steam bypass system NOT available, Then cooldown using the unisolated SG ADV. j
*29. Control charging and letdown, and 29. H RCS subcooling can NOT be SI (unless SI termination criteria maintained, Then [78%) may be 1 met) to restore and maintain exceeded to restore RCS subcoc~ing.
pressurizer level [2% to 78%]. .
- a
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9 s ESDE 16 ABB CE SYSTEM 80+"
SYSTEM-80 + TITLE EXCESS STEAM DEMAND I '
-EVENT REC 0VERY EMERGENCY. OPERATIONS !
. GUIDELINES Page of "-
. Revision. "" j
'l INSTRUCTIONS -CONTINGENCY ACTIONS -
*30. Ensure RCS conditions are being -30. If RCS subcooling greater than P-T !
maintained within the limits of limits or cooldown rate greater l Figure 7-1 during cooldown by: than.[100*F/Hr.]1 Then do the ,
- a. manual operation of pressurizer following: '
heaters and spray, a. stop the cooldown,- : or b. depressurize the plant-using; ,
- b. operation of charging / letdown, Reactor Coolant Gas Vent System- '
%,4 or wn s.cc q.- f.
_o r orgestoreandmain in
- c. throttling of SI pumps (refer pressurizer pressure within the to step 12) Post Accident P-T limits of --
Figure 7-1, ,
- c. attempt to maintain the plantL in a stable pressure- l temperature configuration or !
continue to cooldown within the l limits of Figure 7-1,
- d. If overpressurization due to' SI/ charging flow,_ Then throttle or . secure flow (refer to step :
- 12) and manually control letdown to restore and maintain i pressurizer-pressure within the ;
limits of Figure 7-1. ij
*31. Maintain unisolated SG level in the 31. .i normal band throughout the cooldown !
using main, startup or emergency feedwater. ESDE 17 ABB CE SYSTEM 80+" l
E is .- 5 .. ' SYSTEM 80 +" TITLE EXCESSLSTEAM DEMAND l E EVENT REC 0VERY EMERGENCY OPERATIONS GUIDELINES Page " of " Revision
- j i
INSTRUCTIONS CONTINGENCY ACTIONS. ; i
*32. Ensure the available emergency 32.
feedwater inventory is adequate per : Figures 7-4 and 7-5. j
- 33. Bypass or lower the automatic 33. I initiation setpoints of.MSIS and f SIAS as the cooldown'and ]
depressurization proceed. l i
*34. When pressurizer pressure reaches 34. l
[740 psia], pre s reduce SIT I I pressure to [300 psia]. i
*35.
W M pressurizer pressure reaches 35. - [445 psia], Then vent, drain, or i isolate the SITS.
*36. finitiate low temperature 36. !
overpressurization protection (LTOP) at T., s [259'F]. i e f I i i. j, f ESDE 18 .ABB CE SYSTEM 80+" ;
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SYSTEM 80+" TITLE EXCESS STEAM DEMAND : EVENT RECOVERY , EMERGENCY OPERATIONS " L GUIDELINES Page- of Revision __ * ; INSTRUCTIONS CONTINGENCY ACTIONS' l i
*37. When the following SCS entry *37. H the RCS. fails to depressurize, ;
conditions are established: Then' a void should be suspected. ,
- a. pressurizer level > [14.3*/.] and a. Voiding the RCS may be ;
constant or increasing, indicated by any of the -j
- b. RCS subcooled following indications, i
- c. RCS pressure < [4S0 psia] parameter changes, or. trends:
- d. RCS nT s [400*F], i) letdown flow greater than !
charging flow, l Then exit this guideline and ii) pressurizer level increasing ; initiate SCS operation per plant significantly more than specific operating instructions, expected while ope' rating f pressurizer spray, iii) t'he RVLMS indicates that- i voiding is present in the' , reactor vessel, ) iv) HJTC unheated thermocouple ; temperature . indicates : saturated conditions in the 'I reactor vessel upperhead, !
- b. H voiding. inhibits RCS de-pressurization to SCS entry pressure, Then attempt to-
- l eliminate the voiding by: '
i) verify letdown is isolated, { and j ii) stop the depressurgization, { and
~
l i ESDE 19 ABB CE SYSTEM.80+" ; c .
n 4 SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY
] '
EMERGENCY OPERATIONS " GUIDELINES Page.2 of Revision "" a 1 INSTRUCTIONS CONTINGENCY ACTIONS , q
- 37. (Continued) iii) pressurize and-depresksurizel I the RCS within the limits of l i
Figure'7-1.by operating; _ pres-surizer heaters and spray or SI'and chargking. pumps. Monitor pressurizer level and the RVLMS for - trending of RCS inventory.. f
- c. Jf depressurization of the RCS l
to the SCS entry pressure is ; still not possible,'Then at . ; tempt to eliminate the voiding-by: i) operate the Reactor Coolant Gas Vent System to clear
- trapped non-condensible :
gases, l and , ii) monitor pressurizer. level and/or the RVLMS for i trending,of RCS. inventory.
- d. Continue attempts.to establish: j SCS entry condition, or exit this guideline and initiate an appropriate procedure.
q ESDE 20 ABB CE SYSTEM 80+" l l
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- SYSTEM 80 + " TITLE EXCESS STEAM DEMAND J EVENT RECOVERY EMERGENCY- OPERATIONS "
GUIDELINES Page 2' of Revision " 4 The Excess Steam Demand Event Recovery Guideline has accomplished-its purpose if all 'of the SFSC acceptance criteria being satisfied, RCS conditions are being controlled'in ' HOT STANDBY, HOT SHUTDOWN, or cold shutdown, and the entry conditions of an appropriate procedure are satisfied. EtLD
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t ESDE 21 ABB CE SYSTEM 80+* ; i
SYSTEM 80+ TITLE EXCESS STEAM DEMAND ! EVENT REC 0VERY j EMERGENCY OPERATIONS " : GUIDELINES Page 22
- of Revision ""
- SUPPLEMENTARY INFORMATION l This'section contains items which should be considered when implementing E0Gs and 'I preparing plant specific E0Ps. The items should be implemented as precautions, ,
cautions or notes or in the E0P training program. 3 Lengthy operation of the containment spray system may jeopardize the operation of equipment which would be desirable later in the event. Early consideration f should be given to termination of spray operation.
- 2. During all phases of cooldown, monitor RCS temperature and pressure to avoid exceeding a maximum cooldown rate greater than Technical Specification Limitations.
- 3. Do ~not place systems in " manual" unless misoperation in automatic is apparent. _ ;
Systems placed in " manual" must be checked frequently to ensure proper operation.
- 4. All available indications should be used to aid in diagnosing the event since the accident may cause irregularities in a particular instrument reading. ; Instrument ~
readings must be corroborated when one or more confirmatory indications are { available. (e.g., during rapid depressurization the indicated level in the ,. pressurizer may be too high). I v I
- 5. If the initial cooldown rate exceeds Technical Specification Limits, there may. be l a potential for pressurized thermal shock (PTS) of the reactor vessel.. Post Accident Pressure / Temperature Limits of Figure 7-1 should be maintained. ;
- 6. Solid water operation of the pressurizer should'be avoided unless subcooling cannot be maintained in the RCS (Figure 7-1). If the RCS is solid, closely ,
monitor any makeup or draining and any system heatup or cooldown to avoid any unfavorable rapid pressure excursions. i ESDE 22 ABB CE SYSTEM 80+"
i SYSTEM 80+ TITLE EXCESS STEAM DEMAND l EVENT RECOVERY- j EMERGENCY OPERATIONS 25 Page of
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GUIDELINES l l
- 7. Minimize the number of cycles of pressurizer auxiliary' spray 'whenever the j temperature ~ differential between the spray water and the pressurizer is greater ,
than 200*F in order to minimize the increase in the spray nozzle thermal stress l accumulation factor. , t
- 8. When a void exists in the reactor vessel, and RCPs are not operating, the-HJTC i RVLMS provides an accurate indication of reactor vessel liquid inventory. When a l void exists in the reactor. vessel, and RCPs are operating, it is not possible to obtain an accurate reactor vessel liquid level indication due to the effect'of..
the RCP induced pressure head on the HJTC RVLMS. -Tht ir.dic;ted level 21m !
.di-ffers for differe.d HJif RVLM5 designs under these cend;tTUDT' Information ,
concerning reactor vessel liquid inventory trending may still be discerned. j However, the operator is cautioned not to rely solely on the HJTC RVLMS- : indication when RCPs are operating and use other means of level indication if ( available. , The operator should continuously monitor for the presence of RCS voiding and take 9. steps to eliminate voiding any time voiding causes the heat removal or inventory j control safety functions to begin to be threatened. Void elimination should be started soon enough to ensure heat removal and inventory control are not lost.
- 10. Reducing containment temperature will reduce hydrogen production from corrosion f due to the reaction of containment building metal (especially aluminum and zinc) and boric acid (containment spray). This is a temperature dependent reaction. !
11 -. Any cautions provided by the hydrogen recombiner vendor concerning operation of [ the recombiner with a degraded containment environment should be inserted here. ! l'
- 12. Operation of any equipment in the containment building when containment hydrogen concentration 2 [4!',] should consider the possibility of hydrogen ignition
.-{fie r e rem.c ~.y. Consideration should be given to the following: ]
i i ESDE 23 ABB CE. SYSTEM 80+" 1 1
t > .i SYSTEM- 80 + " TITLE -EXCESS STEAM DEMAND l EVENT RECOVERY-EMERGENCY OPERATIONS " GUIDELINES Page 2' of Revision "
- a. The importance to safety of eauipment operation
- b. The urgency of equipment operation
- c. The use of alternative equipment located outside containment
- d. The current hydrogen level and the anticipated time to reduce H2 s [4%]..
- 13. Measured containment hydrogen typically represents a value of hydrogen in units' of percent by volume of dry air. The measured hydrogen will typically indicate.
higher than the actual containment hydrogen for a steam / air mixture inside containment. The indicated value should, therefore, be corrected to account for any steam / air mixture inside containment.
- 14. If there is a conflict between maintaining adequate core cooling and complying; with the pressure / temperature limits of Figure 7.], then maintaining adequate core cooling will be given the higher priority. Subcooling has precedence over PTS considerations.
- 15. 'The loss of one AC or DC safety division bus will not prevent the operators from performing the actions of this guideline. However, it is desirable to have a complete complement of electrical equipment to mitigate and recover from an event. Therefore, the operators should attempt to restore electrical power to all AC or DC safety divisions.
- 16. If there _is a conflict between isolating a SG and maintaining adequate heat removal, then maintain RCS heat removal via the least affected SG. At-least one ,
SG should always be available for heat removal, if at all possible. ESDE. 24 ABB CE SYSTEM 80+"
;e-SYSTEM 80+" TITLE -- EXC'ESS STEAM DEMAND EVENT REC 0VERY.
EMERGENCY OPEPATIONS-of :*
~
GUIDELINES Page " Revision "" Figure 7-1 TYPICAL POST ACCIDENT PRESSURE-TEMPERATURE LIMITS' (TO BE DEVELOPED DURING DETAILED ENGINEERING) ESDE 25 ABB CE SYSTEM 80+"
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 2' of Revision '" i Figure 7-2 BP.EAK IDENilFICATION CHART s a PRin&ARY BREAK 04 SECONDA$tY BREAK SUSPECTED e emm someocuwe
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. 1 ESDE 26 ABB CE SYSTEM 80+" !
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SYSTEM 80+" TITLE - EXCESS STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 2' of Revision "" Figure 7-3 : TYPICAL ACCEPTABLE SI FLOW VS RCS PRESSURE i i i E2 N N . N s
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ESDE 27 ABB CE SYSTEM 80+" :
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A i SYSTEM 80+" TITLE EXCESS STEAM DEMAND -i EVENT REC 0VERY EMERGENCY OPERATIONS " GUIDELINES Page 28 of Revision = ., Figure 7-4 t TYPICAL FEEDWATER CAPACITY VS TIME UNTIL SHUTDOWN COOLING REQUIRED l
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Secondary Pressure = 1100 psia
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/ reedwater Temperature = 1200F- ,
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- i 1-O 0 2 4 6 8 to 12 14 -16 at 20 22 24 26 28 30 32 TTME ctoers) from start of Feedwater-i 3
i ESDE 28 ABB CE SYSTEM 80+* l i
SYSTEM 80+" TITLE EXCESS STEAM DEMAND ; EVENT RECOVERY' 1 EMERGENCY OPERATIONS Page " of " Revision o= GUIDELINES : l t Figure 7-5 TYPICAL FEEDWATER REQUIRED FOR. SENSIBLE HEAT REMOVAL Tcoto (Required) vs eT oto (Initial) (TO BE DEVELOPED DURING DETAILED ENGINEERING)
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ESDE 29 ABB CE SYSTEM 80+" + l
SYSTEM 80 + " TITLE EXCESS STEAM DEMAND-EVENT RECOVERY EMERGENCY OPERATIONS " ~ GUIDELINES Page 3 of Rev..ision "" SAFETY FUNCTION STATUS CHECK .. t SAFETY FUNCTION ACCEPTANCE CRITERIA r
- 1. Reactivity Control 1. a. Reactor power-decreasing- [
and l
- b. Negative Startup Rate and
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- c. Maximum of one CEA'NOT fully in- !
serted or borated per Tech. Specs. f
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- 2. Maintenance of Vital Auxiliaries (AC 2. a. Safety Load Division I AC' Buses .[
and DC Power) energized E Safety Load Division II AC Buses energized I
'and !
- b. .,afety Load Division I'DC Buses j energized, j E !
Safety Load Division II DC Buses energized, i { i i I l
- t
- ; ~ q 1 ESDE 30 ABB CE SYSTEM 80+" v
p SYSTEM P,0 +" TITLE. EXCESS STEAM DEMAND i' EVENT RECOVERY EMERGENCY OPERATIONS "- GUIDELINES. Page 3' of Revision " SAFETY FUNCTION ACCEPTANCE CRITERIA
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- 3. RCS Inventory Control 3. a. H pressurizer level is-[2% to 78%],Then:
i) charging.and letdown,.and SIL (unless SI termination criteria met);are maintaining.or restor-ing pressurizer l level and ii) the RCS is subcooled-and-iii) the'HJTC RVLMS indicates the level is.above the hot leg nozzles., 9L
- b. H pressurizer level-is less than
[2%),Then:
- 1) available charging pump' is operating and the SI pump (s)'
are injecting water into the RCS per Figure 7-3. and ii) the HJTC RVLMO indicates the core is covered. ESDE 31 ABB CE SYSTEM 80+"
1 SYSTEM 80+" TITLE EXCESS STEAM DEMAND i EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 32 of Revision "" j i SAFETY FUNCTION' ACCEPTANCE CRITERIA ~
- 4. RCS Pressure Control 4. a. - Pressurizer heaters- and spray, or . .
charging and letdown, or SI-pumps-(unless SI termination criteria ! met) are maintaining ~or restoring _ pressurizer pressure within the: limits of Figure 7-1. : E-
- b. available charging pump is operating and the SI pump (s) are injecting water into the_RCS~per -!
Figure 7-3 (unless SI termination [ criteria are met). !
-i
- 5. Core Heat Removal 5. a. -Ta RTD and representative Core _ Exit Thermocouple temperatures less than ,
[626*F].
.and
- b. The RCS is subcooled.
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< 1 i
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-ESDE 32 .ABB CE SYSTEM 80+"
,q
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND ! EVENT REC 0VERY EMERGENCY OPERATIONS GUIDELINES Page " of "' Revision "" SAFFTY FUNCTION , ACCEPTANCE CRITERIA >
- 6. RCS Heat Removal 6. a. The..unisolated steam generator has level:
i) . within the~ normal level band with feedwater available to - , maintain level ~ or > ii) being restored by feedwater flow with increasing SG. level and-
- b. RCS T,,,is less than [567'F].
- 7. Containment Isolation 7. a. i) Containment pressure less than
[2.7 psig] or . ii) CIAS present or manually initiated. ; and-
- b. No containment area radiation monitors are alarming. l and
- c. No steam plant radiation monitors- -
are alarming , and
~d. No nuclear annex alarms. >
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ESDE- 33 ABB CE SYSTEM 80+" 1
u SYSTEM. 80 + " TITLE EXCESS STEAM D'EMAND [ EVENT RECOVERY t EMERGENCY OPERATIONS j of Page 3' "' Revision GUIDELINES 1 SAFETY FUNCTION ACCEPTANCE CRITERIA
- 8. Containment Temperature'and Pressure 8. a. 1) Containment temperature less:
Control than [236*F] and .j
- 11) Containment. pressure less than - l
[8.5 psig] I O_f -!
- b. The containment cooling system.is operating:
- i) Annulus. Fans.are energized and' 'j Annulus pressure.is <-[0 indes-- '!
w.g.] l and -; ii) At least one containment spray-
' header delivering at least. .i
[5000 gpm] I I j i j ESDE 34 ABB CE SYSTEM 80+" l
i SYSTEM 80 + " TITLE EXCESS STEAM' DEMAND-EVENT RECOVERY' EMERGENCY OPERATIONS GUIDELINES . Page " of " Revision "^"
-t SAFETY FUNCTION ACCEPTANCE CRITERIA :
h
- 9. Containment Combustible Gas Control 9. a. Containment sprays have NOT been ;
actuated-g
- b. 1)' Annulus fans are energized .and Annulus pressure is < [0 incho-w.g.]. :
and ii) Hydrogen concentration less .j than [0.5%). E -l
- c. i) all available hydrogen recombiners are energized' !
and.
.41) Igniter: have been initiated- -
and fii) hydrogen concentration is less than [4%)'. l l I i 1 1 4 . 1 ESDE 35 ABB CE SYSTEM 80+" l 1 l J
o SYSTEM 80 +" TITLE EXCESS STEAM DEMAND l EVENT REC 0VERY~ j i EMERGENCY OPERATIONS " GUIDELINES Page " of Rev..ision = l t 4 BASES i
.+
The bases section of the Excess Steam Demand Event (ESDE) Recovery Guideline describes I the ESDE transient in relation to the actions which the operator takes during an ESDE. The purpose of the bases section is to provide the operators with information which f will enable them to understand the reasons for, and the consequences of,- the actions - ; they take during an ESDE. i i Characterization of ar, ESDE ! I An Excess Steam Demand Event (ESDE) is any event which leads to an unexpected, rapid ; increase in steam generator steam flow or loss of steam generator inventory that requires and/or results in a reactor trip or exceeds the control capability of the.
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reactor regulating system, pressurizer pressure control system and/or pressurizer level > control system. Some of the possible causes include: l i a) Rupture or break in a main steam line. ; b) Rupture or break of a main, startup or emergency feedwater line downstream -j of the last check valve (break upstream of the last check valve in a- .! I feedwater line is considered a loss of feedwater event). c) Inadvertent opening of main steam system valve (s) (e.g., atmospheric dumps, i steam bypass, etc.). j d} Stuck open steam generator safety valve. ; i The following parameters usually characterize an ESDE: I a) Increased steam flow from the-steam generators. -l b) Decreasing steam generator pressure and water level (initially, there may f be level swell). j c) Decreasing RCS average temperature causing a decrease in pressurizer j pressure and water level, i ESDE 36 ABB CE SYSTEM 80+" q
1 i SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY l EMERGENCY OPERATIONS " GUIDELINES Page 37 of Revision = l d) Reactor trip caused by the high core power, low steam generator water i level, low pressurizer pressure, low steam generator pressure, or high l containment pressure depending on the size and location of the bre'ak. l e) SIAS may be generated from low pressurizer pressure or high containment j pressure (if ESDE within the containment). i f) A CIAS, CSAS, and MSIS may be generated on high containment pressure (if. , ESDE within the containment). ; g) Possible increase in containment pressure, temperature, humidity, and/or Holdup Volume Tank. ! h) Possible increase in containment hydrogen concentration due to corrosion of , zinc and aluminum by the containment spray system. I t Safety Functions Affected i i An Excess Steam Demand Event, depending on the cc.use, will primarily affect the safety- j functions reactivity control, RCS heat removal, and containment temperature and pressure control (for events inside containment). However, all safety functions should 7 be monitored to assure public safety, or to detect failures which might lead to unsafe < conditions. A significantly large ESDE usually results in excess steam flow on the secondary side -l which will lead to a reactor trip. This decrease in react'or heat input (due to reactor
-l trip), combined with the increase in steam generator heat removal due to the excess 1 steam flow, rapidly reduces RCS temperature. A reduction in RCS temperature causes an apparent inventory decrease due to volume contraction, a system pressure decrease, and ;
possible RCS voiding. The inventory shrinkage will usually cause an SIAS if the j pressurizer empties. This shrinkage will be reversed by subsequent RCS heatup (if heat -; removal is not established with the intact SG) and/or the safety injection system and l the charging pump. If ne break can be isolated, either manually or. automatically, ! then the ESDE is essentially over. For the situation where the break cannot be isolated, the operators lose control of the affected steam generator and must -isolate feedwater to that steam generator, allowing it -to boil dry. ESDE 37 ABB CE SYSTEM 80+* '
l a 1 i SYSTEM 80+ TITLE EXCESS STEAM DEMAND , EVENT RECOVERY l EMERGENCY OPERATIONS " GUIDELINES Page 38 of Revision "" ! l l It is important to establish heat removal capability via the unaffected SG prior to the ; affected SG boiling dry. The unaffected SG must be used to stabilize RCS temperature ! 1 and if RCPs have been tripped, it will take a few minutes to establish the' thermal i driving head for natural circulation in the unisolated loop. { If a significant ESDE occurs inside containment, the steam flow will result in an increase in containment pressure and temperature. There are several success paths for ; Containment Isolation and Containment Temperature and Pressure Control. If containment pressure reaches [2.7 psig], this will result in a CIAS. The CIAS isolates all non-essential containment penetrations. If containment pressure reaches [8.5 psig], a CSAS will be initiated. The CSAS causes containment spray to actuate and the Annulus ' Ventilation System (AVS) to draw a vacuum in the Annulus. The'AVS will minimize uncontrolled radioactive leaking from the containment. 1 Some hydrogen may be generated in the containment due to the reaction of boric acid (from the spray system) with the containment metals (especially aluminum and zine). ! This reaction will produce hydrogen at a rate which increases with containment . temperature. If detectable hydrogen is generated ([> 0.5%]), the hydrogen recombiners .I and igniters are run to remove the hydrogen. ' Hydrogen generation by metal and boric , acid reaction is not expected to produce enough hydrogen'to exceed {4%). Therefore, if' ! the containment hydrogen concentration exceeds [4%), the operators should exit the-ESDE- l . ORG and implement the Functional Recovery Guideline. . As steam generator pressure decreases due to the energy loss, an MSIS will occur and isolate the steam generators except for emergency feedwater to the intact' steam. , generator. If the event is occurring downstream of the MSIVs, then the break will be. l isolated. - I
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l ESDE 38 ABB CE SYSTEM 80+* i
-i -- - e __.m__m.b
y 4
. SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY-E EMERGENCY OPERATIONS GUIDELINES Page'" of " Rev.ision "*"
i i Trendina of Key Parameters-Reactor' Power (Figure 7-6) , In response to the reduction in moderator temperature, reactor power will initially ! increase until an RPS setpoint is reached by one of the following: CPC, low steam ; generator pressure, high containment pressure, low steam generator water level, or low! pressurizer pressure. As the steam generator blowdown continues to reduce moderator. I temperature, there exists a possibility of a return to criticality. l RCS Temperature. (Figures 7-7 and 7-8) Prior to the reactor trip, RCS. temperature will decrease because heat' removed by the.- 'l ESDE and the steam exceeds heat produced by the core. After the reactor has tripped, 'j heat removal by the ESDE will exceed decay heat, causing further cooling of the RCS.
-i Pressurizer Pressure (Figure 7-9)
Pressurizer pressure will decrease after the.ESDE due to the decrease in RCS ] temperature and the corresponding RCS volume contraction. Pressure may decrease to hot' _; leg temperature saturation pressure depending on the magnitude of the RCS cooldown. l i Pressurizer Level (Figure 7-10) l q s Pressurizer level will decrease due to lower RCS temperature after the reactor trip. For large excess steam demands the pressurizer may empty completely before invent'ory
. ]
control can be regained. ] 1
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_ l l ESDE 39 ABB CE SYSTEM 80+" .- _ _ _ a
1 e SYSTEM 80 +" TITLE EXCESS' STEAM DEMAND 'j EVENT RECOVERY ! EMERGENCY OPERATIONS " "" GUIDELINES Page '" .of Revision ,
-Reactor Vessel level (Figure 7-11)
Void formation can occur in the RVUH for ESDE or other overcooling events.which are. large enough to cause the pressurizer to empty. When the pressurizer empties, voids- ; begin forming in the RVUH. The RCS pressure decreases until it equals the saturation [ pressure associated with the hottest point in the RCS (which is the RVUH). Saturated j liquid in the RVUH will continue to flash to steam until the affected steam generator. l experiences dryout and RCS repressurization is established. For the'most severe. excess -! steam demand events the rate of RCS cooldown can be great enough so that RVUH voids are: formed before the pressurizer empties. l 3 Steam Generator Pressure (Figures 7-12 and 7-13) ! Following an ESDE, the pressure in the affected steam generator will decrease due to the decrease in resistance caused by the break. The pressure in the unaffected steam l generator will initially increase after the MSIS and then decrease as RCS temperature ; decreases. If the cause of the ESDE is located downstreain of the MSIVs, the pressure f in both steam generators will equalize after an MSIS. Steam Generator level (Figures 7-14 and 7-15) ] Following an ESDE, the level in both the affected and unaffected-steam generators will 5 initially increase due to swell and then decrease 's a the-feedwater level control system. j will not be able to keep up with steam flow. Following an MSIS the level-in both steam generators will increase if the ESDE occurred downstream of the MSIV. .If the-ESDE - occurred upstream of the MSIV, the level in the affecte'd'_ steam generator' will continue to decrease while the level in the unaffected steam generator increases. If the event.- is a feedwater line break, steam generato'r water level decreases in;the affected steam. generator without an initial swell [until the feedring is uncovered) while the' unaffected steam generator level will usually remain relatively' constant.- l ESDE 40 ABB CE SYSTEM 80+* l q
SYSTEM 80 +" TITLE EXCESS, STEAM DEMAND'
' EVENT RECOVERY :
EMERGENCY OPERATIONS Page " of " Rev.is ion "" GUIDELINES l E Figure 7-6 : REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM 0F MSIV CORE POWER l (T0 BE DEVELOPED DURING DETAILED ENGINEERING) ,
'a 4
9
'! )
e i i m > ESDE 41 ABB CE SYSTEM 80+"
SYSTEM 80 + " TITLE EXCESS STEAM DEMAND EVENT RECOVERY. : EMERGENCY OPERATIONS " GUIDELINES Page '2 of Revision "" - ! L l i
'i I
Figure 7-7 l REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM OF MSIV UNAFFECTED LOOP RCS WIDE RANGE TEMPERATURES-o
'h '
(T0 BE DEVELOPED DURING DETAILED ENGINEERING) i P t 5 b ESDE 42 ABB CE SYSTEM 80+* ; r
SYSTEM 80 +" TITLE- EXCESS STEAM DEMAND ~ L EVENT REC 0VERY- , EMERGENCY OPERATIONS " Page '5 - of Revision "" GUIDELINES , I i Figure 7-8 , REPRESENTATIVE MSLB OUTSIDE CONTAINMENT-UPSTREAM 0F MSIV AFFECTED LOOP RCS WIDE RANGE TEMPERATURES l (T0 BE DEVELOPED DURING DETAILED ENGINEERING) 1 r
.l
- I i
P ESDE 43 ABB CE' SYSTEM.80+" a
SYSTEM 80 + " TITLE EXCESS: STEAM DEMAND
. EVENT REC 0VERY ,
EMERGENCY OPERATIONS - GUIDELINES Page " of Revision "" i i l rh i i Figure 7-9 . REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM OF MSIV PZR WIDE RANGE PRESSURE. d (To BE DEVELOPED DURING DETAILED ENGINEERING) i ll
- p i
.i i
ESDE 44 ABB CE SYSTEM 80+*
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L:: , i b SYSTEM '80 + " TITLE EXCESS STEAM DEMAND , , EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 'S of Revision ""-
.i a
l ll r E Figure 7-10 REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM OF MSIV , PZR LEVEL r a (T0 BE DEVELOPED DURING DETAILED ENGINEERING) ! I i
; i l
- -j ESDE 45 ABB CE SYSTEM'80+* ;
i
1 SYSTEM 80+" TITLE EXCESS STEAM DEMAND-EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page " of Revision "" I Figure 7-Il REPRESENTATIVE EXCESS STEAM DEMAND EVENT REACTOR VESSEL LIQUID VOLUME vs TIME (T0 BE DEVELOPED DURING DETAILED ENGINEERING) ESDE 46 ABB CE SYSTEM 80+"
'l SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY
' EMERGENCY OPERATIONS "
GUIDELINES Page '7 of Revision "" Figure 7-12 REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM 0F MSIV UNAFFECTED STEAM GENERATOR PRESSURE-(T0 BE DEVELOPED DURING DETAILED ENGINEERING) ESDE~ 47 ABB CE SYSTEM 80+" _
4 SYSTEM 80 +" TITLE . ' EXCESS' STEAM DEMAND EVENT RECOVERY ~ EMERGENCY OPERATIONS "- GUIDELINES - Page '8 of Revision "" Figure:7-13. REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM OF MSIV AFFECTED STEAM GENERATOR PRESSURE (TO_BE DEVELOPED DURING DETAILED ENGINEERING) i ESDE ~ 4B ABB_CE SYSTEM 80+"
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY
-EMERGENCY OPERATIONS "
GUIDELINES
. Page " of Revision ""
i Figure 7-14 REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM 0F MSIV UNAFFECTED STEAM GENERATOR WIDE RANGE LEVEL (T0 BE DEVELOPED DURING DETAILED ENGINEERING) _j f f f s i ESDE _. 49 ABB CE SYSTEM 80+"
SYSTEM 80+" TITLE EXCESS STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS " I GUIDELINES Page " of Revision "" i i k i Figure 7-15 REPRESENTATIVE MSLB OUTSIDE CONTAINMENT UPSTREAM OF MSIV AFFECTED STEAM GENERATOR WIDE RANGE LEVEL (T0 BE DEVELOPED DURING DETAILED ENGINEERING) t ESDE' 50 ABB CE SYSTEM.80+*1
3 9 SYSTEM 80+" TITLE EXCESS STEAM DEMAND' EVENT RECOVERY- .
.. t EMERGENCY OPERATIONS GUIDELINES Page 5' of "
Revision " l
+
Guideline Strateav and Information Flow . 1 Figure 7-16 provides a- summary of the ESDE Recovery Guideline's strategy. Prior to j implementing the actions provided in the ESDE Recovery Guideline, the operator would j have diagnosed the event. The first actions in the ESDE Recovery Guideline require a . verification that these actions have taken place and require the operator to use the- f Safety Function- Status Check to confirm that the plant is recovering. The.nextl steps l provide instructions on establishing those conditions necessary for effectively :! recovering from an ESDE. The strategy can be broken into five major recovery actions. { The five major recover actions carry the plant to the SCS entry conditions. The first- ] ' major action consists of stopping the uncontrolled cooldown o' the RCS. If-the ESDE is' upstream of the MSIVs, this is accomplished by isolation the affected steam generator. l Feedwater is supplied only to the intact steam generator since feeding the broken steam i generator will continue to depressurize the RCS. This action also reduces the risk of l radioactive release from the plant. The second major action is to stabilize the RCS l pressure and temperature. It may not be necessary to cool the plant down if ~it can be : maintained in a stable condition while the break is repaired. The third action is to I evaluate the necessity of a plant cooldown. The factors affecting this decision f include the amount of emergency feedwater available, the status'and availability of , auxiliary systems and the extent of the damage and time required for repair. If the - .l j plant 'can be maintained at a stable condition, then the fourth action is to do just that. While the plant' is in this condition it is necessary to keep evaluating and.be i prepared for a cooldown if conditions warrant. The fifth major action consists of _; cooling the plant on either forced circulation or on natural circul'ationfin the RCS,- l all the way to SCS entry conditions. This cooldown is performed using the unaffected I steam generator if the break is upstream of the MSIVs' or both steam generators and the 1
'ADVs if the break is downstream of the MSIVs. 1
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A more detailed chart . illustrates.the recovery guideline strategy and lists the guideline steps which correspond to each strategy objective. Refer to Figure'7-18. j 1
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ESDE 51 ABB CE SYSTEM 80t" I
w i. SYSTEM 80 +" TITLE EXCESS' STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS GUIDELINES Page 52 of_." Revision "" Figure 7-16 EXCESS STEAM DEMAND EVENT RECOVERY STRATEGY CHART (T0 BE DEVELOPED DURING DETAILED ENGINEERING)
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l 4 SYSTEM 80+" TITLE EXCESS STEAM DEMAND
~'
EVENT REC 0VERY'- EMERGENCY OPERATIONS a Page " of
- GUIDELINES Revision "
Bases for Operator Actions
- The operator actions are directed toward determining the cause of the Excess Steam ,
Demand Event (ESDE), isolating that part of the system, and retucMag the plant to a safe, stable, and controlled condition. :
- 1. The diagnosis of an Excess Steam Demand Event should be confirmed using the Break' 3 Identification Chart (Figure 7-2) and by comparing control board parameters'to the acceptance criteria in the Safety Function Status Check to ensure that all safety functions are being satisfied. In particular, the operator should note the status of RCS subcooling and containment and steam plant' activity. These-parameters provide a means of discriminating between ESDEs and LOCAs/SGTRs. For d ESDEs, neither steam plant or containment activity monitors should be alarming.
ESDEs which occur in plants with existing SG tube leakage may result in increases in steam plant radiation or containment activity. For LOCAs, containment activity monitors may be alarming but steam plant activity' monitors should not be. alarming. For a SGTR, steam plant activity monitors may be alarming but containment activity monitors should not be alarming. Sampling both steam generators for activity will assist in confirming the diagnosis. These actions : ensure the proper guideline is being used'to mitigate the effects of an ESDE. [ If the initial diagnosis of an ESDE is confirmed, then the operator continues- ' with the actions of this guideline. However, if the operator determines that a ! SGTR or a LOCA has occurred, then the ESDE Recovery Guideline is exited and, the actions of ths: proper guideline'are implemented. This allows the operator to switch to the proper guideline for those events similar_ t'o ESDE which may be
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occurring. LOCAs, ESDEs, and SGTRs h. ave similar initial symptoms _ and could_ be_ ; confused early in the event.
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If the diagnosis of one event cannot be made~ then. l the operation is directed to exit the ESDE guideline and to_ implement the j Functional Recovery Guideline. The Functional Recovery Guideline is safety ; function based and will ensure that all safety functions are addressed regardless ; of what event (s) is occurring. - l ESDE 53 ABB CE SYSTEM 80+* i,
1
' SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT REC 0VERY EMERGENCY OPERATIONS "
GUIDELINES Page 5' of Revision = l
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- 2. If the Excess Steam Demand Event is large enough to decrease pressurizer pressure- f to or below the SIAS setpoint of [1825 psia], then.an SIAS should be~ initiated' ;
automatically. If this does not occur when pressure decreases to [1825 psia], . ! then the operator should manually initiate an SIAS. _j
- 3. An ESDE may reduce RCS temperature by as much as [250*F]'due to increased RCS heat removal. Due to the effects of the moderator temperature coefficient, this !
cooldown adds positive reactivity to the core and can possibly result in a return to criticality subsequent to the reactor trip. To ensure that the core remains 4 subcritical, it is necessary to maximize RCS boration during the initial stages ' l, of severe ESDEs. The charging and safety injection systems should accomplish 'f this automatically because significant ESDEs will result in the actuation of l
- safety injection. If an SIAS is actuated, then all available charging and SI ;
pump (s) should be operating and injecting water into the RCS. The SI and ; charging flowrates should be checked and maximized (Figure 7-3 provides _ information which can be utilized to verify adequate SI flow is occurring) for RCS boration and inventory replenishment. The charging pump may have to be ; manually restarted if an interruption of electrical power to the charging pump i bus has occurred. The following guidance will assist in ensuring maximum ; injection of water into the RCS: *
- a. idle SI pumps should be started
- b. system flow should be verified to be within the limits of Figure 7-3, i
If any SI pump that should be operating won't start, the charging pump is not available, or SI flow is not in accordance with Figure 7-3, then the following ; guidance is provided: )
- a. the operator should verify that electrical power is available to valves and pumps necessary for inventory control
- b. the SI valve lineup; should t,e verified to be correct in the control room !
- c. auxiliary systems necessary for SI or charging operation should be checked. j ESDE 54 ABB CE SYSTEM 80+"
SYS TEM '80 + " TITLE EXCESS-STEAM DEMAND , EVENT REC 0VERY EMERGENCY OPERATIONS " " GUIDELINES Paga 55 of Revision It must be noted, however, that the maximization of charging and safety injection can result in excess RCS inventory, possible filling of the pressurizer to a solid condition, and a PTS concern upon RCS heat up. fluid expansion, and I subsequent RCS pressure excursion. Operators must be aware of these concern's and terminate or t90ttle SI pumps when the criteria are met and establish-unaffected l SG heat remova, to stabilize RCS temperature as the affected (isolated) SG boils dry. -j r
- 4. Steps 4 and 5 contain guidance regarding the RCP operating strategy for a ESDE (Figure 7-17). A generic RCP trip strategy has been developed which. results in :
the tripping of all four RCPs for depressurization events where RCS is not subcooled, but allow the continued operation of two RCPs (in opposite loops) for , depressurization events where RCS is subcooled. For undiagnosed events, where , the Functional Recovery Guideline is implemented, the RCP trip strategy is identical to that followed in the LOCA guideline. Steps 4 and 5 detail the two significant operational aspects regarding the RCP trip strategy for a ESDE. j i The first operational strategy results in the operator tripping two RCPs (in ' opposite loops) if pressurizer pressure decreases to less the [1400 psia] following a SIAS and RCS is subcooled. This action may occur in the Standard Post Trip Actions and, in this case, the operator would simply verify that two RCPs (in opposite loops) have been tripped. The operator trips all four RCPs if pressurizer pressure decreases to less than [1400 psia] following a SIAS and RCS is not subcooled. If the operator cannot confirm that a ESDE has occurred, and , the Functional Recovery Guideline is implemented, the RCP-. trip strategy is j identical to that followed in the LOCA guideline. If the depressurization event ! can be diagnosed and is determined to be other than LOCA (i.e., ESDE or SGTR), i then only two RCPs (in opposite loops) are tripped. The other two RCPs remain l operational until one or more of the RCP operating requirements (e.g., NPSH, temperatures _ seal flow, oil pressures, motor amperage, vibration) are no longer > satisfied, then, any pump which does not satisfy these requirements should be tripped. This gives the operator maximum flexibility in plant control because a ! ESDE 55 ABB CE SYSTEM 80+" :
)
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND _ EVENT REC 0VERY , EMERGENCY OPERATIONS " GUIDELINES Page " of Revision " r normal plant cooldown can be performed while still ensuring a conservative approach to event recovery.
- 5. The second aspect of the RCP operating strategy concerns the verification that ,
RCP operating limits are satisfied. The RCPs may be operating in a j pressure-reduced RCS and degraded containment conditions' are also passible. This-could result in the loss of vital RCP auxiliaries (e.g., [CCW)). The operator must continuously monitor RCP operating limits (e.g., temperatures, seal _ flow, oil pressures, NPSH, motor amperage, vibration) and trip any RCPs which do not - satisfy RCP operating limits. Plant specific RCP operating limits should appear in the plant specific E0Ps, either directly or by referencing the applicable - I operating instructions.
- 6. The most affected steam generator should be determined by comparison of steam ;
pressures, cold leg temperature differences, and steam generator levels. If the ESDE is not isolable (e.g., a break inside containment will still be producing -i steam flow after the MSIVs are shut), the steam generator with the reduced loop ; Tc, lower steam pressure, and lower steam generator level is the affected steam , generator. These differences between affected and unaffected steam _ generators. will be more pronounced after MSIS actuation. If the ESDE is downstream of the MSIVs and the MSIS occurs, both steam generators' pressures and loop temperatures should approach approximately the same values and then start to increase following MSIV closure.
- 7. If the shutting of MSIVs (MSIS) stops the ESDE, then neither SG is the affected SG. The operator should go to step 10 and skip the guidance provided for isolating the most affected SG. If the MSIS does not stop the ESDE, then continue with step 8.
4 ESDE 56 ABB CE SYSTEM 80+*-
I 1 SYSTEM 80 +" TITLE ' EXCESS ~ STEAM DEMAND EVENT REC 0VERY , EMERGENCY OPERATIONS " Page " of Revision "" GUIDELINES , i t 1 Figure 7-17a RCP TRIP STRATEGY FOR ESDE i T (FLOW AND STRATEGY CHARTS WILL REFLECT THE DETAILED STEPS IN THE GUIDELINE.)'
.{
i e h
' ESDE- 57 -ABB CE SYSTEM BD+"
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND - EVENT RECOVERY EMERGENCY OPERATIONS - Page 48- of " Revision ""- GUIDELINES. , t Figure 7-17b ESDE RECOVERY GUIDELINE' a (FLOW AND STRATEGY CHARTS WILL REFLECT THE DETAILED STEPS IN THE GUIDELINE.)
.j 6
h 5 s a ESDE 58 ABB CE SYSTEM 80+" b
o SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY l EMERGENCY OPERATIONS 1 GUIDELINES Page 5' of ' Revision " t
- 8. The most affected steam generator should be isolated to stop the' uncontrolled ;
plant cooldown and to stabilize the plant. If both steam generators are found.to i be affected, then isolate the steam generator with the worse ESDE, if it can be . determined, and attempt to maintain RCS heat removal capability via one steam l generator. This action is designed to mitigate the uncontrolled cooldown and ; ready the plant for event recovery. The most affected steam generator is isolated as follows: i
- a. The main steam isolation valve is closed. '
- b. The main steam isolation valve bypass valve is verified closed, or closed. !
- c. The atmospheric steam dump valve (s) is verified closed. -
- d. The main feedwater isolation valve is closed. l
- e. The startup and emergency feedwater isolation valves are closed. !
- f. Vents, drains, exhaust, and bleedoffs are closed, .
i
- g. The Turbine Driven Emergency Feedwater Pump Steam admission valve is '
closed. { l
- 9. Once the steam generator has been isolated, isolation of the correct (affected) '!
steam generator should be verified by checking steam generator pressures, RCS i cold leg temperatures, and steam generator levels. This provides feedback that 1 i the correct steam generator has been isolated. If the wrong steam generator has been isolated then it should be unisolated and the affected steam generator f should be isolated per step 8. l
- 10. The unisolated steam generator's level (or both SGs if neither is the affected ]
SG) is maintained or restored to the normal band using main, startup or emergency ) feedwater. This ensures that a heat sink is available for removing heat from the-- l RCS. I l
- 11. When the isolated steam generator dries out, RCS temperatures will begin to j increase unless a means of controlled steaming has been established. If a method l of heat removal is not established, the RCS heatup will, when taken in !
ESDE 59 ABB CE SYSTEM 80+'~ .
i SYSTEM 80+" TITLE EXCESS STEAM' DEMAND l EVENT RECOVERY l EMERGENCY- OPERATIONS ! GUIDELINES Page " of' " Revision "" l I l conjunction with the inventory added to the RCS from'SI and charging pump. l operation, cause the plant to go solid and have the potential of creating a PTS } condition. A controlled heat removal method should be established before this f dry out condition occurs. The preferred method of heat removal-is via the steam d bypass system (if the steam bypass system and condenser are available) with the ;j atmospheric dump valves as a backup method of heat removal. If the break is downstream of the MSIVs, then the atmospheric dump valve (s) should be used for , RCS heat removal. This action establishes control of RCS and core heat removal .f in order to preclude heatup and repressurization of the RCS for PTS ! considerations. !
- 12. If the SI pumps are operating, then they must continue to operate at full ;
capacity until Si termination criteria are met. Termination of SI should be , sequenced by stopping one pump at a time while observing the termination '{ criteria. Throttling of SI flow is also permissible if all of the following SI l termination criteria are satisfied: ; a) RCS is subcooled based on Representative CET temperature (Figure 7-1). . Establishing subcooling ensures the fluid surrounding the core is subcooled. Voids may exist in some parts of the RCS (e.g., reactor vessel { head as determined by the HJTC RVLMS), but these are permissible as long as core heat removal is maintained. l b) Pressurizer level is greater than [14.3%] and not decreasing. A l pressurizer level greater than [14.3%] and not decreasing, in con.iunction I with criterion a) above, is an indication that RCS inventory control has' been established. l c) The unisolated steam generator is available for removing heat from the RCS. ; A steam generator having the ability for feed flow and steam flow is j available for removing heat from the RCS. . d) The HJTC HJTC RVLMS indicates a minimum level at the top of the hot leg 'l nozzles. This prov< ides an extra margin of core coverage and, taken in , conjunction with the above, serves -as an additional indication that adequate RCS inventory control has been established. ESDE 60 ABB CE SYSTEM 80+' i
i i SYSTEM 80 +" TITLE EXCESS STEAM DEMAND j EVENT RECOVERY .! EMERGENCY OPERATIONS Page " of " Rev..ision "
- GUIDELINES If all of the SI termination criteria are met, then the operator may either stop l, or throttle the SI pumps. The operator may decide to throttle, rather than terminate the flow, if the SI is to be used to control pressurizer level or plant ' f pressure. :
- 13. If the criteria of step 12 cannot be maintained after the SI pumps are throttled ;
or stopped, then the appropriate SI pumps should be restarted and full. SI flow restored.
- 14. Once pressurizer level has been restored to greater than or equal to [2%), then r level should be maintained [2% to 78%] by control of charging and letdown j (preferentially) as necessary, and the SI flow. If SI termination criteria are ,
met, then SI pumps may be throttled or stopped. When pressurizer level is being controlled at [2%] or greater, then if the charging pump is available, it may be : operated as necessary to maintain level. If the charging pump is not available, then SI pump (s) operation must continue to maintain level. 'If pressurizer level is not restored to [2%), then all available charging and SI pumps should be operated for maximum flow. j A pressurizer level of [2% to 78%) with a saturated bubble in the pressurizer should be established if possible, as the means of RCS pressure control. If ! pressurizer level drops below the top of the pressurizer heaters, the pressurizer heaters may burn out if they have not been interlocked off. It may be necessary to exceed [78%] pressurizer level if the operator is attempting to restore RCS ; subcooling since pressurizer heaters may be unavailable and solid water operation ; may be necessary to restore subcooling.
- )5. Maintaining RCS conditions within the acceptable limits of Figure 7-1 ensures that the [100*F/Hr] cooldown rate is not exceeded, that the core is covered by i subcooled fluid, and minimizes the concern for pressurized thermal- shock by ;
maintaining less than thei200*F subcooling limit is minimized. This is - accomplished using pressurizer heaters and main (preferred) or auxiliary spray, . i i ESDE 61 ABB CE SYSTEM 80+"
SYSTEM 80 +" TITLE EXCESS STEAM. DEMAND.- l EVENT REC 0VERY EMERGENCY OPERATIONS-GUIDELINES Page " .of " . Revision " j operation.of charging and letdown, or throttling of SI pumps to control. ; pressurizer pressure within the limits of Figure 7-1. . If subcooling or cooldown limits are being violated, then the operators should' l take actions to restore the RCS to within the P-T limits. Depending on;the f situation, the operator should perform the following actions as appropriate: ! t
- a. Stop the cooldown. .
- b. Operate the Reactor Coolant Gas Vent System or main or auxiliary spray as ;
necessary to restore pressurizer pressure to within the P-T limits of- 'l Figure 7-1. :
- c. Attempt to maintain the plant in a stable pressure-temperature ,
configuration. The cooldown may be continued, if desired, within- the j limits of Figure 7-l. ,
- d. If an overpressure situation exists and is caused.by SI pumps and/or :
charging flow, then throttle or stop SI (refer to step 12)_ or the charging . pump and manually control letdown to restore and maintain pressure within .- the' Post Accident P-T limits of Figure 7-1.
- 16. If containment pressure is greater than or equal to [2.7 psig], then the operator l- l ensures the following:
3 i-
- a. The operator verifies that containment isolation occurs at the appropriate automatic setpoint. If containment isolation does not occur automatically ;
or all containment isolation valves are not in their accident positions, ( then the operator should manually initiate containment isolation. The purpose of this step is to prevent direct communication-between the containment atmosphere and the environrant. Operators should be alert to the loss of auxiliaries to the containment ([in' particular component cooling water]) which may occur with containment isolation. Re-establishing letdown should also be. considered if it is available. This .i will enable the operator to better <ontrol RCS inventory during a possible-ESDE 62 ABB CE-SYSTEM 80+"
SYSTEM 80+" TITLE EXCESS STEAM DEMAND EVENT RECOVERY :
- EMERGENCY OPERATIONS " - .. 1 GUIDELINES Page '5 of Revision " ;
1 RCS heatup and subsequent fluid expansion. This action can minimize the possibility of PTS. ,
- b. High pressure in the containment may pose a threat to containment integrity. Furthermore, high containment temperature adversely impacts the !
accuracy of instruments whose transmitters are located inside containment l (e.g., pressurizer level and pressure, steam generator pressure and level,- RCS loop RTDs) and may impact the continued availability of equipment located in containment. The effect of temperature on hydrogen generation l (by corrosion reactions) is described in the bases of step 18. To minimize- l the temperature in containment, the containment recirculation. fan coolers -l should be operated if they are available.
- 17. The containment spray system is automatically actuated at a containment pressure l of [8.5 psig) or greater. If containment pressure reaches [8.5 psig], then.the ;
operator should ensure containment spray actuation, the annulus vent system fans have started and place the hydrogen monitors in service because conditions will now exist for the generation of hydrogen in containment. In order to maintain i containment pressure below design pressure, one containment spray header l delivering [5000 gpm] is sufficient to remove decay heat. i When containment sprays are actuated, the conditions created in the containment may generate detectable hydrogen concentrations. Hydrogen may be generated by' the reaction of boric acid (from containment spray flow) and metals in the containment. Aluminum and zinc are two metals which are reactive with boric acid. The reaction rates of boric acid and aluminum and zinc are a function of- ! temperature. Therefore, if the containment m ay system has been spraying boric acid onto zinc and aluminum surfaces in a high temperature environment, conditions exist for the generation of hydrogen in the containment. l The appropriate personnel should be directed to make the recombiners available , and aligned for use. User of the recombiners may be required by subsequent steps in order to satisfy the combustible gas control safety function. ESDE- 63 ABB CE SYSTEM 80+" j
i l SYSTEM 80 +" TITLE EXCESS STEAM DEMAND l [ I EVENT RECOVERY e EMERGENCY OPERATIONS " ^^"' GUIDELINES Page " of Revision
*18. Containment spray system operation may be terminated when containment pressure- f has been reduced to an acceptable level. Continued operation of the sprays after l pressure has been reduced to an acceptable level increases the possibility of
( wetting electrical connectors which may result in electrical grounds, shorts and j other malfunctions. Therefore, if containment sprays have actuated and j containment pressure is reduced below [5.5 psig], then containment spray may be terminated. After terminating containment spray, the containment spray system f should be realigned for automatic or manual operation in case containment j pressure again increases to the actuation setpoint. The annulus vent system can [ also be secured at this time. l t
*19. Hydrogen recombiners should be energized when hydrogen is detected in containment i (2: [0.5%]). This action is performed to keep the containment hydrogen l concentration as low as possible throughout the event. The recombiners take j
-approximately [1 hour] to reach operating temperature so no decrease in' measured .i hydrogen concentration should be expected before this. time. l t
i
*20. Although hydrogen is not flammable until it reaches a concentration of at least !
[4%], it is prudent to reduce ' hydrogen to as low a concente ati n as possible _ f (i.e., less than the minimum detectable hydrogen concentration of 0.5%). Such I action minimizes the possibility of reaching the flammability limit and of i forming pockets of high concentration hydrogen. Therefore, the hydrogen recombincrs should be run until hydrogen concentration is reduced to less than f [0.5%). l i
*21. Plant conditions should be carefully assessed before any RCPs are restarted. The ;
need for forced circulation operation should be balanced against the risk of l damage to the RCP seals. f i The need for operation of the RCPs should be evaluated based on: l i
- 1. the adequacy of the RCS and core heat removal under the existing natural ;
circulation conditions, ; ESDE 64 ABB CE SYSTEM 80+' : l v e a
SYSTEM 80 +" ' TITLE EXCESS STEAM DEMAND-EVENT REC 0VERY [ EMERGENCY OPERATIONS GUIDELINES Page " of " - Revision " 1
- 2. the existing RCS pressure and temperatures, :
- 3. the need for main' pressurizer spray capability.
If the existing natural circulation is providing satisfactory RCS and core heat removal, a transfer for forced circulation operation may not be necessary. This { would be particularly true if the RCS had already been cooled and depressurized to SCS entry conditions. If the RCS pressure and temperatures are closer to HOT-STANDBY conditions, it may be desirable to restart the RCPs in order to allow a normal forced circulation cooldown. Consideration should also be given to the necessity of having main pressurizer spray capability if auxiliary spray.is not providing the desired depressurization rate. ! i The potential for RCP seal degradation should be evaluated based on: !
- 1. how long CCW to the RCPs was interrupted, :
- 2. RCP seal staging pressures and temperatures.
The possibility of seal degradation increases if the CCW has been interrupted for longer than [10 minutes). The seal staging pressures provide an indication of degraded seal stages (a low pressure drop across a stage indicates a problem). t Restart of an RCP with one or more degraded seal stages should be avoided if possible.
- 22. If all RCPs have been stopped, then operation 'of two RCPs (in opposite loops) !
should be attempted, if RCP restart criteria are met. This will ensure continued i forced circulation of coolant through the core, cooling of the RV head region, l provide the capability for the normal mode of pressurizer spray, condense RCS ; steam voids, and remove non-condensible gases from the SG tube bundle. Furthermore, this action enhances' the strategy to obtain an uncomplicated cooldown, since a forced circulation cooldown is preferred to a natural ! circulation cooldown whenever possible during a recovery from an ESDE. However, : only one reactor coolant pump in each loop should be operated to minimize heatI { input to the RCS. ESDE 65 ABB CE SYSTEM 80+*
SYSTEM 80+" TITLE EXCESS STEAM DEMAND EVENT REC 0VERY EMERGENCY OPERATIONS GUIDELINES: Page " of' " Revision "" ,
.i Determine whether RCP restart criteria are met by the following:
- a. Electrical power available to the RCP. I
- b. RCP auxiliaries, component cooling water to' maintain seal cooling, bearing .
cooling, and motor cooling should be operating- in. order to prevent damage- . to the pump and/or motor. Following automatic or operator initiated [ containment isolation, reinstatement of component cooling water should be considered to ensure adequate RCP cooling. There should be no high temperature alarms on the RCPs to be operated.
- c. The unisolated steam generator is available for removing heat from the RCS.
A steam generator having the ability for feed flow and steam flow is available for removing heat from the RCS. :
- d. Pressurizer level is greater than [33%] and not decreast g. A pressurizer [
1evel above 33% provides the operator with a margin for maintaining plant- l control during an ESDE. ,
- e. The RCS is subcooled based on representative CET temperature. A subcooled' ]
condition, taken in conjunction with (b) above, indicates that adequate i inventory control has been established. l
- f. [All plant specific RCP operating criteria should be satisfied before the- :
RCPs are restarted to prevent damage to RCPs resulting from abnormal operating conditions]. l Upon restarting two RCPs in opposite loops, pressurizer level and pressure may.
*23.
decrease 6 to loop shrinkage and/or steam void condensation. It is possible- : that this action will drain the pressurizer. Steam voids present in.the reactor 4 vessel will condense upon restarting RCPs. The HJTC RVLMS should be monitored-for the trending of reactor vessel liquid level. This trending information may. be correlated to pressurizer level decrease. RCP operation with a drained : pressurizer may continue provided'certain actions are taken and certain criteria -l are' satisfied. The following constitute the actions to be taken,.and the criteria to be ; satisfied, when restarting RCPs: ;
~!
ESDE 66 ABB CE SYSTEM 80+"- l t
. . . . . . ._ . ~ { y i SYSTEM 80 +" TITLE EXCESS STEAM DEMAND l EVENT RECGVERY' ; EMERGENCY OPERATIONS " i Page " of Revision "" GUIDELINES r
- a. Start one RCP in each loop-
- b. Ensure proper RCP operation by monitoring RCP amperage and pump NPSH. NPSH- i is determined by pressurizer pressure and corresponding T, on Figure 7-1. j
- c. Operate charging (and SI) pumps, and letdown to restore and maintain :
pressurizer level [2% to 78%]. If HPSI pumps are operating, continue:their I operation until SI termination criteria are met-(refer to step 12). This action will ensure that pressurizer heaters remain covered but will : minimize the amount of water added to the RCS. _j i e
*24. If all RCP operation is terminated and inventory and pressure are controlled, i then natural circulation is monitored by heat removal via at least one steam generator. Natural circulation flow should occur within [5-15 minutes] after the a RCPs were tripped. l The operator has adequate instrumentation to monitor natural circulation for the' j single phase liquid natural circulation process. The RCS temperature l instrumentation, namely loop 4T, can be used along with other information to -l confirm that the single phase natural circulation process is effective. The RCS temperature response during natural circulation will be slow [5-15 minutes) as .
compared to a normal forced flow system response time of 6-12 seconds, since the coolant loop cycle time will be significantly larger. When single phase natural circulation flow is established in at least one loop, . + the RCS should indicate the following conditions:
- a. Loop 6T (Tg - T,) less than normal full power AT,
- b. Hot and cold leg temperatures constant or decreasing, ;
1
- c. The RCS is subcocied based on Representative CET temperature
- d. No abnormal differences between Tn RTDs and core exit thermocouples. Hot leg RTD temperature should be consistent with the core exit thermocouples. 1 Adequate natural citculation flow ensures that core exit thermocouple l temperatures will be approximately ' equal to the hot leg RTDs temperature i
ESDE 67 ABB CE SYSTEM 80+" :
v SYSTEM 80+" TITLE EXCESS STEAM DEMAND EVENT RECOVERY , EMERGENCY OPERATIONS " GUIDELINES Page of Revision "" f i within the bounds of the instrument's inaccuracies. An abnormal difference between Tn and the CETs is greater than [10*F). j; Natural circulation is governed by decay heat, component elevations, primary to secondary heat transfer, loop flow resistance, and voiding. Component elevations ! on C-E plant are such that satisfactory natural circulation decay heat removal is .; obtained by fluid density differences between the core region and the steam l generator tube sheet. ]1 As a contingency, if the criteria listed are not met, then natural circulation in -; the RCS is not effectively transferring heat from the core to the . steam generators. Both RCS and Core Heat Removal Safety functions may become -l jeopardized if any of the above criteria continue to be violated. Operators l L should ensure that RCS pressure and inventory, and SG steaming and feeding, are being controlled properly to prevent violation of a safety function. t
- 25. At this point in the recovery, the operators should decide if a cooldown to shutdown cooling entry conditions is necessary. One of the factors to be considered is existing plant status. If the continued availability of any systems required for maintenance of HOT STANDBY is in doubt, a cooldown should be l
performed before the ability to cooldown is lost. For example,- if the available emergency feedwater inventory is marginally adequate (as determined by using-l Figures 7-4 and 7-5), a cooldown should be commenced immediately to avoid running _ > out of emergency feedwater before the shutdown cooling system can be placed into [ operation. Similarly, consideration should be given to the availability of j compressed air and cooling water systems as well as the continued availability of l electrical power. A cooldown may also be required before any necessary repairs j can be made.
)
- 26. The following steps of the ESDE guideline provide the operator instructions for i performing a cooldown to shutdown cooling entry conditions. If it is decided i
'l that a cooldown is not necessary, the plant should be maintained in a stable- l l
ESDE 68 ABB CE SYSTEM 80+" ; l t
1 SYSTEM 80 +" TITLE EXCESS STEAM DEMAND ! EVENT. RECOVERY-
. EMERGENCY OPERATIONS GUIDELINES Page a of' " : Revision "" l condition until the Plant Technical Support Center provides an appropriate - '
procedure.to implement and directs the operators to exit the ESDE ORG. i
*27. The plant should be borated per Technical Specification limits for reactivity control purposes. If letdown is not available, it may not be possible to borate- !
the RCS to the cold shutdown RCS boron concentration prior to commencing'the I cooldown if there is limited makeup space available in the pressurizer. If this , is the case, the operator should borate the RCS to the minimum shutdown margin' i corresponding to T, (per Technical Specifications). During the cooldown, as RCS j shrinkage provides more space in the pressurizer, the operator should-borate'to f maintain the minimum shutdown margin until the cold shutdown boron concentration ; is achieved. Note that if a 75*F/hr. cooldown rate is maintained, charging capacity will not be able to keep pressurizer level constant during the initial j stages of the cooldown. Therefore, pressurizer level will lower and additional' i space will be available in the RCS for boration. I
- 28. An orderly cooldown to an SCS entry conditions, using forced or natural- [
circulation, is performed in accordance with Technical Specifications. One of , the following methods should be utilized to reduce RCS temperature: ! a) The preferred method for cooling the RCS is by discharging steam using the steam bypass system. This method can only be implemented if the condenser-is available. If the condenser or steam bypass system is not available, an RCS cooldown b) ; should be performed by dumping steam using the atmospheric steam dump valves. l
*29. Pressurizer level should be restored and maintained at [2% to 78%] by control of charging and letdown (preferentially).as.necessary, and SI pumps. If SI ,
termination criteria are met, then SI pumps may be throttled or stopped. _A pressurizer level of [2% to 78%] should be restored'and maintained to avoid j losing pressure control with the saturated bubble in the pressurizer. If the l pressurizer level drops below the top of the pressurizer heaters,. pressurizer j l ESDE 69 ABB CE SYSTEM 80+" ! l i
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND j EVENT-RECOVERY '! EMERGENCY OPERATIONS " 1 GUIDELINES Page 78 of . Revision "" ! I heater operation will be interlocked off for heater protection. It may be !
+
necessary to exceed {78%] pressurizer level if the operator is attempting to - + t restore RCS subcooling, and solid water operation may be necessary to restore l subcooling. i
*30. The operator should control RC5 conditions throughout the cooldown to ensure that - -
pressure is being maintained within the P-T limits of Figure 7-1. The preferred l method of RCS pressure control is by manual operation of pressurizer heaters and j spray. If necessary, charging and letdown, or the throttling of SI pumps can be-l utilized to control pressurizer pressure. l
?
If subcooling or cooldown limits of Figure 7-1 are being violated, then the f operators should take actions to restore the RCS to within the P-T limits. ; Depending on the situation, the operator should perform the following actions as
.l appropriate: .!
l
- a. Stop the cooldown f
- b. Operate the Reactor Coolant Gas Vent System or the main or auxiliary spray !
as necessary to restore pressurizer pressure to within the P-T limits of j Figure 7-1. ;
- c. Attempt to maintain the plant in a stable pressure-temperature ,
configuration. The cooldown may be continued, if desired,- within the { limits of Figure 7-1.
- d. If an overpressure situation exists and is caused by SI and/or charging flow, then throttle or stop SI pump (refer to step 12) or the charging pump and manually control letdown to restore and maintain pressure within I the Post Accident P-T limits of Figure 7-1. d
*31. The unisolated steam. generator's water level is to be maintained in the normal i band using main, startup or emergency feedwater. This ensures that a heat sink l is available for RCS heati removal.
ESDE 70 ABB CE SYSTEM 80+" ;
?
SYSTEM 80+" TITLE EXCESS STEAM DEMANDI 4 EVENT RECOVERY , EMERGENCY OPERATIONS Page " of- " Revision " : GUIDELINES i e
*32. The emergency feedwater inventory should be monitored and replenished from .
available sources as necessary to continually provide a source for a secondary ? heat sink. Examples of alternate sources of emergency feedwater are non-seismic tanks, fire mains, lake water supplies, potable tanks, etc. Plant-specific l r alternate sources of feedwater should be identified and cited in the plant -l i specific procedure. The amount of emergency feedwater required to either ~i maintain the plant at HOT STANDBY conditions or to cooldown may be determined , from Figures 7-4 and 7-5.
- 33. During a controlled cooldown and depressurization,- the automatic operation of ;
certain safeguard systems is undesirable. Therefore, the setpoints of MSIS and SIAS should be manually reset (lowered) as the cooldown progresses to ensure that j automatic engineered safeguards protection remains available until the RCS-is ! 4 cooled down and depressurized. j f
*34. If pressurizer pressure reaches [740 psia], the safety injection tanks (SITS) ,
must be vented, drained, or their discharge valves shut to prevent the nitrogen j cover gas from being discharged into the RCS when RCS pressure is reduced below i the SIT's pressure during a controlled cooldown. The max SIT pressure is [640 psia] and the value of [740 psia] is 100 psi greater than the maximum SIT- - pressure.
*35. If the pressurizer pressure reaches [445 psia], the isolation valves on the SITS l may be closed to prevent unnecessar, SIT discharge. The value of [445 psia] is j the SIT outlet valve interlock setpoint. ;
i
*36. Low temperature overpressurization protection (LTOP) is instituted at T,2:
[259'F] to protect against subjecting the RCS pressure boundary to low l temperature brittle fracture. l l
*37. The cooldown and depressu'r ization should continue until shutdown cooling system ,
entry conditions are established - i ESDE 71 ABB CE SYSTEM 80+" i I
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EVENT RECOVERY
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EMERGENCY OPERATIONS " 1 GUIDELINES Page 72 of Revision = 3 l
- a. pressurizer level control should be established and verified by a level greater than [14.3%] and' constant or increasing,
- b. 'the RCS is subcooled, [
- c. RCS pressure should be at or below the shutdown cooling system entry--
pressure of [450 psia], j
- d. RCS hot leg temperature should be at or below the sh'utdown cooling system entry temperature of [400*F],
When these criteria ares established, the ESDE ORG should be exited and SCS l operation initiated per [ operating instructions]. ! If the RCS cannot be depressurized to SCS entry pressure, then a_ void should.be suspected. Any time it is found that voiding inhibits RCS depressurization to- '! SCS entry pressure, when SCS operation is desired, then an attempt at elimination of the voiding should be made. j
- a. The operator should continuously monitor for the presence of voids. l Voiding in the RCS may be' indicated by any of the following indications', ;
parameter changes, or trends: .i a i) letdown flow greater than charging flow, ii) pressurizer level increasing significantly greater than expected while operating pressurizer spray,- f iii) the HJTC RVLMS indicates that voiding is present in the reactor. i vessel, iv) HJTC unheated thermocouple temperature indicates saturated conditions j in the reactor vessel upper head]. ! i i
- b. If voiding should be eliminated, then proceed as follows:
i i) Letdown is isolated or verified to be isolated to minimize further inventory loss,_ - I ESDE 72 ABB CE SYSTEM 80+* a
SYSTEM 80+" TITLE EXCESS' STEAM DEMAND EVENT RECOVERY ; EMERGENCY OPERATIONS " GUIDELINES Page " of Revision "" ,
?
ii) The depressurization is stopped 'to prevent further growth of the l void, Pressurizing and depressurizing the RCS within the limits of Figure ! iii) 7-1 may condense-the void. Pressurizing has the effect of filling the voided portion of the RCS with cooler fluid which will remove heat from the region. Subsequeat depressurization and a repeating of-this process several times will cool and condense the steam void. In -l the case of a void in the reactor vessel, the pressurization / i depressurization cycle will produce a fill and drain of the reactor 1 vessel. The pressurization /depressurization cycle may be l accomplished using pressurizer heaters and spray (preferred method) or the SI/ charging system (alternative method). Monitor pressurizer j level and the HJTC RVLMS for trending of RCS inventory. This.will j assist the operator in assessing the effectiveness of void elimination. j
- c. If indications of unacceptable RCS voiding continue, then voiding may be caused by non-condensible gases. Operate the Reactor Coolant Gas Vent System to clear trapped non-condensible gases. Monitor pressurizer level and/or the HJTC RVLMS for trending of RCS inventory. This will assist the operator in assessing the effectiveness of' void elimination.
When SCS entry conditions a e established, the ESDE guideline should be exited and shutdown cooling initiated per plant specific operating instructions. If l significant voiding is present in the loop with the isolated steam generator, the ; SCS should be aligned to the other loop. This step will place the plant in an operational mode where a complete cooldown and depressurization of the plant can take place. !
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- I ESDE 73 ABB CE SYSTEM 80+" ;
j a
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT REC 0VERY- ' EMERGENCY OPERATIONS " l GUIDELINES Page 7' of Revision " Safety Function Status Check : The Safety Function Status Check (SFSC) is used to continually verify the status of_ l safety functions. The safety function ' acceptance criteria are-selected from best-estimate analysis to reflect the range for each parameter which would be expected , following an Excess Steam Demand Event. If all SFSC acceptance criteria are being' satisfied, then the adequacy of this guideline for mitigating the event in progress is confirmed and the health and safety of the public is ensured. ! i l l
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t h f i i , ESDE 74 ABB CE SYSTEM'80+"
' SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS GUIDELINES Page " of " Revision "" j i
SAFETY FUNCTION STATUS CHECK BASES EXCESS STEAM DEMAND EVENT i The safety functions and their respective acceptance cr;teria listed below are those - .; used to confirm the adequacy of the ESDE Guideline in mitigating the event. i
- j SAFETY FUNCTION ACCEPTANCE CRITERIA BASES
- 1. Reactivity Control a. Reactor Power Decreasing .For all emergency events, and the reactor must be
- b. Negative Startup Rate shutdown. Reactor power .;
and decreasing, in conjunction
- c. Not more than 1 CEA bottom -with negative startup' rate, -
light not lit or borated per is a positive indication: Tech. Specs. that reactivity control is- l established The crit'erion :I that no more than one CEA be. stuck out or the RCS borated observes' typical i Technical Specification y requirements. I I i. l 1 k ABB CE SYSTEN 80+" ESDE 75
SYSTEM 80 + = TITLE EXCESS STEAM DEMAND EVENT RECOVERY. EMERGENCY OPERATIONS " Page
- of Revision ""
GUIDELINES SAFETY FUNCTION -ACCEPTANCE CRITERIA BASES
- 2. Maintenance of a. Safety Load Division I AC One division of AC power is :
Vital Auxiliaries Buses energized required'for equipment. (AC and DC Power) or necessary to maintain ! Safety Load Division II control of all other ' safety AC buses energized functions. 'One division.of.- , and DC power is required as a
- b. Safety Load Division I DC minimum to provide Buses energized monitoring and~ limited i
o_t control of the other safety Safety Load Division 11 function. DC Buses energized. j i r I a ESDE 76 ABB CE SYSTEM 80+* i
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY EMERGENCY OPERATIONS' " GUIDELINES-Page " of : Revision "" BASES' l SAFETY FUNCTION ACCEPTANCE CRITERIA'
- 3. RCS Inventory a. H pressurizer level is. A value of [2%] was' chosen Control [2% to 78%), Then: as the lower limit to I i) charging and let- prevent draining the-down, and SI (un- pressurizer. The value.of:
less SI termi- [78%) was chosen as an nation criteria upper limit for pressurizer met) are main- level to ensure an operable taining or re- steam bubble exists -in the e storing pres- pressurizer, but can be surizer level exceeded if solid operation and is required to restore : 9 ii) the RCS is sub- subcooling. cooled i and Subcooling coexisting with'. iii) the HJTC RVLMS a pressurizer level of [2% , indicates the RCS to.78%) indicates-adequate-level'is above the RCS inventory control via a
-hot leg nozzles. saturated bubble in the ,
or pressurizer. Repre-
- b. H pressurizer level is sentative CET temperature i less than [2%], T_he!!: is to be used during.
- i) the available natural circulation flow .
charging pump is conditions and Tg RTDs are operating and the to be used during: forced SI pumps (s) are ' circulation flow injecting water conditions. i into the RCS per j Figure 7-3.
; and- )
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ESDE ~ 77 ABB CE SYSTEM 80+" l R
i ~ SYSTEM 80 +" TITLE EXCESS STEAM DEMAND EVENT RECOVERY . EMERGENCY OPERATIONS " GUIDELINES Page 7" of ~ Revision " ,; SAFETY FUNCTION ACCEPTANCE CRITERIA EASES
- 3. RCS Inventory ^ii) the HJTC RVLMS }AnHJTCRVLMSindication i
' Control (Continued) indicates the core that the hot-leg is is covered. covered, taken'in >
conjunction with' .; subcooling, is an additional indication that RCS inventory' control has - beenestablishedi. , r For cases where RCS .i inventory has badly degraded, the SI operation i provides implicit assurance that control is being:
. regained. RVLMS indicating the core is covered ensures. ;
a subcooled medium;for heat' , transfer surrounds.the Core. P s ESDE 78 ABB CE SYSTEM 80+"
=;
v ; SYSTEM 80+" TITLE- EXCESS STEAM DEMAND- I EVENT REC 0VERY EMERGENCY OPERATIONS " GUIDELINES Page " of Revision ."" SAFETY FUNCTION- ' ACCEPTANCE CRITERIA BASES F '4. RCS Pressure a. Pressurizer heaters and Following the initial Control spray are maintaining or transient, and once plant restoring pressurizer- . control is reestablished, . pressure within the operation of the-limits of Figure 7-1. pressurizer heaters and' o_t sprays should be sufficient
- b. The available charging to control the RCS pump is operating and the pressure. While RCS SI pump (s) are injecting pressure control is badly-water into the RCS per degraded, the'SI operation Figure 7-3 (unless SI provides. implicit" assurance termination criteria are that control.is being met). regained.
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ESDE 79' ABB CE SYSTEM 80+"
is SYSTEM 80+" TITLE ~ EXCESS STEAM DEMAND. li EVENT. RECOVERY EMERGENCY OPERATIONS 3 GUIDELINES Page , of. . Rev..ision ' m : l
- SAFETY FUNCTION ACCEPTANCE CRITERIA- BASES .:
r Ts RTD and representative- The basis ~for'the
- 5. Core Heat Removal a.
Core Exit Thermocouple temperature limit during temperatures less than - the use.of optimal recovery. [626*F]. ' procedures other than LOCA; and is the indication that the
- b. The RCS is subcooled, event specific recovery .
strategy is not effective in core heat removal. For-the optimal. recovery guidelines other than LOCA, heat is normally removed from the RCS by the steam generators. -The value of -i the CET temperature will be governed by steam generator conditions (i.e., pressure ~ and temperature). 'In , general T, mTsc .and CET temperature will be T, + core 4T. Normally -this' core AT.is expected to'be : approximately [59'F] during single phase natural-circulation conditions. For forced RCS flow conditions Tso a T, a Tai i CET temperature. , 1 I i The secondary system design
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pressure is [1200 psia).
.ESDE 80 ABB CE SYSTEM 80+*- _,
o SYSTEM 80 +" TITLE EXCESS STEAM.0EMAND EVENT RECOVERY- . EMERGENCY OPERATIONS-- " GUIDELINES. Page 8' of Revision ^^". SAFETY FUNCTION ACCEPTANCE CRITERIA BASES
- 5. Core Heat Removal The corresponding satur- j (Continued) ation temperature is- ;
l [567.2*F]. By, adding f [59'F] to account for j thermocouple inaccuracy and : AT between T, and CET, the i value of [626*F] is - reached. The subcooling is' based on keeping the core. covered with subcooled fluid and thus ensuring adequate core' , cooling.
- 6. RCS Heat Removal a. The unisolated SG has Adequate RCS heat removal -
1 level: - will be maintained if at' . i) within the normal least one steam generator ': level band with is available for removing
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feedwater avail- heat (capable of steam flow , able to maintain and feed flow). j the level -
.o_C In this case, feedwater ,
ii) being restored by levels restoring or in.the , feedwater flow normal band with feed flow- ; with level in- capability satisfies the ! creasing RCS heat removal safety i and function. 4 b.i RCS T,,, is < [567'F] . : i a ESDE 81 ABB CE SYSTEM 80+* l
-i SYSTEM 80 +" TITLE EXCESS STEAM DEMAND:
EVENT RECOVERY EMERGENCY OPERATIONS " GUIDELINES Page 82 of Revision ""- ! SAFETY FUNCTION ACCEPTANCE CRITERIA BASES , ~
- 7. Containment a. i) Containment [2.7 psig], is the CIAS :
Isolation pressure less than setpoint. If pressure [2.7 psig) increases-to [2.7 psig],-
-l or then containment isolation- >
ii) CIAS present or valves go to their accident' a t positions (CIAS). - If.this - manually l initiated, does not occur auto- .I and matically, the operator [
- b. No containment area must manually initiate a q '
radiation monitors CIAS. lDuring ESDEs, it is-al arming. not expected that there j and will be radiation inside' f
- c. No steam plant radiation containment, in the steam--
monitors alarming. plant, or in the nuclear ; and annex. These' monitors. -
- d. No nuclear annex alarms should not- be alarming.
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i t ESDE 82 ~ ABB CE SYSTEN 80+"' ;
- SYSTEM 80+" TITLE ' EXCESS STEAM DEMAND
. EVENT RECOVERY EMERGENCY OPERATIONS "
GUIDELINES Page - of Revision " -l SAFETY FUNCTION ACCEPTANCE CRITERIA BASES ' :
- 8. Containment Temper- a. i) Containment tem- [236*F] corresponds to the ature and Pressure perature less than saturation. temperature for Control [236*F]- [8.5 psig]. [8.5 psig]:is :
^
and . based CSAS.setpoint.- ii) Containment pres- Containment'.. temperature and I sure less than pressure may exceed the ; [8.5 psig]- above limits dering inside L , or containment ESDE events.
- b. The containment cooling If this happens', the system is operating in containment cooling systems one of the following con- should be operating to- E minimize the temperature-
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figurations: ; i) At least 1 Annulus and pressure. Ateleast 1
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Fan is energized Annulus Fan should be. > and Annuluscpres- operating to reduce Annulus sure is less than pressure to less-than [0 in , [0 ht w.g.] w .g.). The fan coolers or
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and containment sprays will-ii) All fan-coolers in remove 100% of theEdesign_ + operating basis . heat- load 'should be' - f or specified as the acceptable
. iii) One containment operating configurations.
spray header' ! delivering at .; 1 east [5000.gpm] I
- e 4
83 ABB CE SYSTEM 80+" ESDE f f
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i SYSTEM 80+" TITLE EXCESS STEAM DEMAND ~ EVENT RECOVERYz EMERGENCY OPERATIONS " GUIDELINES Page 8' of Revision "" q
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$AFETY FUNCTION ACCEPTANCE CRITERIA BASES ;
- 9. . Containment Combus- a. Containment sprays have Hydrogen may be generated tible Gas Control NOT been actuated by corrosion reactions j o_t .between the spray. solution q
- b. i) . At least 1 Annulus and some metals inside con 2 fan is energized tainment. If the sprays' ]
and have not been actuated,.no-ii) Annulus pressure . mechanism for generating is less than [0 in14 hydrogen inside containment. I w.g.] . exists, and combustible gas: , and control will not be a con- LI iii) Hydrogen concen- cern. If containment spray. tration less than 'has actuated,-but hydrogen [0,5%]. concentration is less than or the minimum detectable con-
- c. 1) all available centration ([0.5%]), then hydrogen recom- the Containment Combustible. .
biners are ener- Gas Control' Safety Function. l gized, is satisfied if the- Annulus . l and Ventilation System is re - q ii) Igniters have been moving air inLthe Annulus. : initiated. For most ESDE events, even. , and steam line breaks inside si lii) hydrogen concen- containment, no hydrogen- .; tration is:less generation is expected. If than [4%]. detectable hydrogen is gen- j
. erated (2: [0.5%I]),then l[
the hydrogen recombiners-and igniters should-be ; i operated-to lower this con- { centration of hydrogen'in q l containment. ,
.ESDE 34 ABB CE SYSTEM 80+*
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i SYSTEM 80+" TITLE EXCESS STEAM DEMAND' EVENT RECOVERY- - EMERGENCY OPERATIONS " Page 85 of - Rev..ision ' " GUIDELINES l ACCEPTANCE CRITERIA BASES' i SAFETY FUNCTION
- 9. Containment Combus- Hydrogen concentration 2 l tible Gas Control flammable limit ([4%)) .-!
(Continued) indicates that this guideline is not adequately.. ! mit_igating the event (s) in , progress and a transfer to i the FRG is appropriate. , l
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f R: J
-ESDE 85 ABB CE SYSTEM 80+"
1 q
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1 SYSTEM 80 +" TITLE EXCESS STEAM DEMAND l EVENT RECOVERY G D i ES Page 8' of " . Revision "" fypnt Strateav . This section contains the detailed ESDE recovery actions strategy flow chart Figure l t 7-19. The flow chart pictorially depicts the strategy around which the' ESDE guideline , t is built. It is intended to assist the procedure writer in understanding the intent of i the guideline and for use in training. - Operators should understand the major - , objectives of the guideline in order to facilitate their progress toward the guideline ! l goals. i The strategy flow chart shows the recovery guideline strategy in detail'and lists.the ' guideline steps which corresplad to each. strategy objective. Some steps in the - >,
' guideline may be performed at any time during the course of an event.' Those-steps are indicated by an asterisk next to the step number.
1 i i i 3 l i _ ESDE 86 ABB CE SYSTEM 80+" ' '!
SYSTEM 80 +" TITLE EXCESS STEAM DEMAND y EVENT REC 0VERY , EMERGENCY OPERATIONS " GUIDELINES Page 87 of Rev..ision ""^" ! i Figure 7-18a l EXCESS STEAM DEMAND EVENT STRATEGY CHART STPAs PERPORMED ,
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DI AG N OSTic ) A CTIO NS q, ESDE ORG ; ENSURE SPTAs i PERFORMED STEP # 1 YES ( NO
# 2*
iP ' j II SIS IN ET R U CTS O NS EVENT , DI A G N O SE D? , ETEP #3*,4* , STEP #1* ' iP 1P 4P R CP INST R UCTIO NS GO TO F 8 T RG GO TO FRG '{ STE P #3*.4* STEP #2* STEP #1* i
,r .
IDENTIFY AFFECTED SG 1 STEP #7 1r -i 1 i V ~l i ESDE 87 ABB CE SYSTEM 80+"
SYSTEM 80 +"- TITLE
~
EXCESS STEAM DEMAND EVENT REC 0VERY-EMERGENCY- OPERATIONS - Revision " - Page ** of " GUIDELINES Figure 7-18b EXCESS STEAM DEMAND EVENT STRATEGY CHART 1 .
\
YES O STO PPE D FTER WP .. 1 P 150 LATE AF FECTED SG
, & VERIFY CORRECT STEP #S,10 .
i i F E E D /sT E AM ! UNISO LATED SG - ' TEMP CONTROL : ST E P #p-11 *,12* ) 1 P 'j - RCE INVENTDRY CON-TRO L HPSI, LPSI TE RMS-' ) N ATION & REETART -i ST EP #13*,14*,15*,15* ' -l RCS PR ESSURE CO NTRO L '
- 0
, 1 STEP #17* -
i Te . T Rd"W(ifr! L, H2l G UID %'th
- R ADCONTRO L '
h. A N CE, sT E P # 1 s+,1 s *,20*,21 *,22*,23* -l ir i
.2 !
~ V l 4 1 d ESDE- 88 ABB CE' SYSTEM 80+* lj
SYSTEM 80 +" TITLE - EXCESS STEAM DEMAND [ EVENT RECOVERY ~ 1 EMERGENCY OPERATIONS GUIDELINES P a g e of
- Revision ""
-t Figure 7-18c j EXCESS STEAM DEMAND EVENT STRATEGY CHART
't 5
i 3 t
'II *"
REST A RT P #24'
.,,/d.pk .. .-
CRIT E .l A "E " ./ TEP W26* I 4 ,, nestanT RcP. "9M"fR"" ; I sver = =- ;; I sT =P m-ves coaIoEwm ao . L L
........... .:qgg.g:.. ;
1.T.P.,.. m. . 3 PERPORM COOLCO*N , j Ff EP Wat
- t
""*c '"JI."If"' ;
, sTrP #22*
t RCS PRIESURE CONTROL f [ STEP #23 D l ;
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i ESDE 89 ABB CE SYSTEM 80+'" -
SYSTEM 80+" TITLE EXCESS STEAM DEMAND - EVENT RECOVERY EMERGENCY OPERATIONS " a GUIDELINES Page " . of Revision "" ; Figure 7-18d. EXCESS STEAM DEMAND EVENT STRATEGY CHART e i 3
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IP 50 FEEDING & CONDENSATE INVENTORY STEP #sa*,3s - , 1P SYPA15 ESF AS SETPOINTS ; STEP #38' ISOLATE VENT OR DRAIM SITS STEP #37' 1P
. INITIATE LTOP j O STEP #38' .,
SCS CD TlONS MER qp STEP #38* , p , I MONITOR FOR VotDS fMtfth CS D STEP #39' STEP #39' < 1 r ELIMINATE VOLDS
- i STEP #39' J
. .I ESDE 90 ABB CE SYSTEM 80+* ,
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