ML20116J800
| ML20116J800 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 07/31/1996 |
| From: | WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML20116J585 | List:
|
| References | |
| SDG-1, NUDOCS 9608140078 | |
| Download: ML20116J800 (56) | |
Text
..
d
- o I
l BACKGROUND INFORMATION j
FOR 1
l AP600 i
SHUTDOWN i
EMERGENCY RESPONSE GUIDELINE SDG-1 AP600 RESPONSE TO LOSS OF RCS INVENTORY DURING SHUTDOWN Rev.2 July 31,1996 i
WESTINGHOUSE ELECTRIC CORPORATION ENERGY SYSTEMS BUSINESS UNIT ADVANCED TECHNOLOGY BUSINESS AREA P.O. BOX 355 PITFSBbt.'.GH, PENNSYLVANIA 15230 9608140078 960808 PDR ADOCK 05200003 F
PDR sDol a 3196 REVISloN: 2
TABLE OF CONTENTS Section Page
1.0 INTRODUCTION
1-1
2.0 DESCRIPTION
2-1 3.0 RECOVERY / RESTORATION TECHNIQUE 3-1 3.1 High-Level Action Summary 3-1 3.2 Key Utility Decision Points 3-3 4.0 DETAILED DESCRIPTION OF GUIDELINE 4-1 4.1 Detailed Description of Steps, Notes, and Cautions.
4-1 4.2 Step Sequence Requirements 4-46 O
l l
9 spol a 3196 i
REVISION: 2 1
1
1.0 INTRODUCTION
O Guideline SDG-1, RESPONSE TO LOSS OF RCS INVENTORY DURING SHUTDOWN, is a Shutdown Guideline (SDG) that provides procedural guidance to maintain core cooling and to protect the reactor core in the event that RCS inventory is lost during plant shutdown conditions.
There is only one explicit transition to guideline SDG-1. It is from the Shutdown Safety Status Tree, SDF-0.1, on an ORANGE priority when the operator determines that either PRZR level is less than the CMT actuation setpoint SL01, or if RCS hot leg level is less than the IRWST injection setpoint SLO 2 while the SLOl signal is blocked.
After all of the appmpriate actions in guideline SDG-1 are completed, the opentor is instructed to retum to the appropriate plant procedure after RNS is restored, or is instructed to evaluate p15nt status and retum to the appropriate plant procedure if RNS is not restored.
A I
i b)
D socia 3196 I.1 REVISION: 2
1 I
o
2.0 DESCRIPTION
U Guideline SDG-1, RESPONSE TO LOSS OF RCS INVENTORY DURING SHUTDOWN, provides actions to respond if RCS inventory is lost during Modes 5 and 6 plant shutdown conditions (i.e.,
when there is fuel in the reactor). This guideline is entered on an ORANGE priority from the Shutdown Safety Status Tme if the operator determines that either PRZR level is less than the CMT actuation setpoint SL01, or if RCS hot leg level is less than the IRWST injection setpoint SLO 2 while the SLOl signal is blocked. RCS inventory greater than SLO 2 is required to support RNS shutdown core cooling when required. Shutdown core cooling is needed at all times in Mode 5 and in Mode 6 when there is fuel in the vessel.
There are two plant conditions addressed in this guideline for a loss of RCS inventory during shutdown. These are: 1) with an open RCS, with an open RCS being defined as any opening in the RCS that cannot be readily closed from the control room, including an opened SG manway isolated from the RCS via the SG nozzle dams; and 2) a closed RCS, with a closed RCS being defined as an RCS secured (except for openings that can be closed from the control room) and filled (including the SG and PRHR tubes) to/above the low pressurizer level CMT actuation setpoint.
The response is different for each of these plant conditions; however, they all have the common goal of restoring RCS inventory and RNS cooling. The operator cannot exit this guideline without re-establishing RNS cooling.
Unless an attemate heat sink is established that directs reactor decay heat outside containment using either an SG or the spent fuel pit cooling system, decay heat is tmnsferred to the containment atmosphere by allowing the RCS/IRWST fluid to heatup and boil. Potential actions with control grade systems or components to cool the containment atmosphere include operation of the containment fan coolers which include operation of the Central Chilled Water System, Component Coohng System and Service Water System.
O socl#3196 2-1 REvlsloN: 2
3.0 RECOVERY / RESTORATION TECHNIQUE
%.)
The objective of the recovery / restoration technique incorporated into guideline SDG-1 is to provide actions for responding to a loss of RCS inventory and RNS cooling.
The following subsections provide a summary of the major action categories of operator actions and the key utility decision points for guideline SDG-1. RESPONSE TO LOSS OF RCS INVENTORY DURING SHUTDOWN.
3.1 High Level AcCon Summary A high level summary of the actions performed in SDG-1 is given on the following page in the form of major action categories. These are desenbed below in more detail.
Actions To Feed The RCS If The RCS Is Open An open RCS is defined as any opening in the RCS that cannot be readily closed from control room, including an opened SG manway isolated from the RCS via the SG nozzle dams. The RCS should also be considered open, or the actions for an open RCS should be taken, if the RCS (including the SG and PRHR heat exchanger tubes) is not filled to the pressurizer low level CMT actuation setpoint, m
i The first action taken under open RCS conditions is efilling the RCS inventory to greater than the RCS hot leg low level IRWST actuation setpoint (SLO 2). In addition to I
establishing / maintaining adequate RCS inventory, the actions taken include verifying ADS valves stages I to 3 are open and an attempt to restore RNS cooling. If RNS cooling cannot be established, then actions are initiated to protect personnel inside containment, establish containment closure and start available containment fan coolers.
Actions To Feed The RCS If The RCS Is Closed The RCS is considered closed if RCS conditions are other than those as defined above for an
\\
open RCS. The actions taken under closed RCS conditions include checking and maintaining RCS inventory greater than the pressurizer low level CMT actuation setpoint (SLOI) and.m attempt to mstore RNS cooling. If pressunzer level cannot be maintained greater that the low level CMT actuation setpoint (SLOl), then CMT injection valves are verified open, ADS actuation is verified when the CMTs drain to the appropriate setpoints and the IRWST level is checked to determine if the containment sump recirculation valves should be opened. If RNS cooling cannot be established, then actions are taken to establish an RCS heat sink using either the SGs or PRHR, and actions are also initiated to protect personnel inside containment, establish containment closure and start available containment fan coolers.
p)
L soci c 3196 3-1 REVISloN: 2
MAJOR ACTION CATEGORIES IN SDG-1 Actions To Feed The RCS If The RCS is Open
=
Actions To Feed The RCS If The RCS is Closed e
i e
sDol-on196 3-2 REVISION: 2
3.2 Key Utility Decision Points i
There is one key utility decision point in this guideline when the operator must initiate actions to protect personnel inside containment. In Steps 9 and 25, the operator is instructed to evacuate non-essential personnel inside containment. The operator will have to determine which personnel must be evacuated from containment at this time in the guideline.
1 I
l l
l L.)
I i
1 v
l 1
soci.073196 3-3 REVislON: 2
4.0 DETAILED DESCRIPTION OF GUIDELINE This section provides a very detailed discussion of the generic guideline SDG-1 to facilitate procedure writing and training effons. By presenting guideline background information in greater l
detail through the use of a structured format (i.e., step description tables and step sequence tables),
applicability can be more easily determined. The separate and unique subsections containing this infonnation follow.
4.1 Detailed Description of Steps, Notes, and Cautions This section contains a one-page (or more) step description table for each separate guid:line step, note, and caution. Notes and cautions are always presented relative to the step they precede.
The Step Description Tables for the steps and associated notes and cautions of guideline SDG-1 are presented on the following pages.
1 sDoi.oni96 4-1 REVisloN; 2
l l
i STEP DESCRIITION TABLE FOR SDG 1 l
STEP 1 STEP:
Check if RNS Pumps Should Be Stopped PURPOSE:
To stop the RNS pumps if RCS level is not adequate to support pump operation or if the pumps are cavitating.
BASIS:
l Inadequate level in the RCS hot leg will result in pump cavitation and air ingestion. If air is ingested into the suction of the RNS pumps, the pumps are likely to stan cavitating. The s>Tnptoms l
of cavitation are typically erratic behavior of pump current (oscillations between high amperage l
values and low amperage values), erratic behavior of pump flow and excessive pump noise. Pump suction pressure in the MCR will also oscillate. If any plant personnel are in the immediate vicinity of the pumps, loud audible noises may be heard when air ingestion stans. If no actions are taken, damage to the pumps may occur due to vibration and the pumps may eventually seize and stop running. As soon as the operator is aware that cavitation is occurring, actions should be initiated to protect the RNS pumps. The operator should stop the RNS pumps until the proper operating conditions are reestablished.
ACTIONS:
Check if RNS pumps are nmning Determine if RCS hot leg level less than SLO 2 4
Determine if RNS pumps are cavitating Stop RNS pumps if cavitating Go to Step 2 if RNS pumps not cavitating
=
INSTRUMENTATION:
RCS hot leg level RNS pump operation status
=
CONTROL /EOUIPMENT:
Controls for RNS pumps KNOWLEDGE:
N/A ADDITIONAL INFORM ATION:
SLO 2 - Enter RCS low level IRWST actuation setpoint O
sDGl.073196 42 REVIsloN: 2
STEP DESCRifTION TABLE FOR SDG-1 O
STEP 2 STEP:
Verify RCS Drain Path Isolation PURPOSE:
To isolate RCS drain paths to prevent further loss of RCS inventory.
BASIS:
A possible cause for the loss of RCS inventory could be attributed to excessive draining of the RCS.
The two main paths that the operator can control from the main control room are the letdown path and the RNS IRWST retum path. To prevent further reduction in RCS inventory, the operator should verify both paths are isolated.
ACTIONS-Verify RNS IRWST retum line isolation Isolate RNS IRWST retum line Verify letdown isolation Isolate letdown INSTRUMENTATION:
RNS IRWST retum line status a
Letdown status CONTROL /EOUIPMENT:
Controls for RNS IRWST retum line
=
Controls for letdown KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A SDG1 073196 43 REVIsloN: 2 I
STEP DESCRIITION TABLE FOR SDG-1 STEP 3 - NOTE NOTE:
The RCS is considered open when an opening exists that cannot be closed from the control room such as a SG manway.
PURPOSE:
To remind the operator that the RCS is considered open if an opening exists that cannot for isolated from the control room.
BASIS:
An open RCS is defined as any opening in the RCS that cannot be readily closed from control room, including an opened SG manway isolated from the RCS via the SG nozzle dams.
ACTIONS:
N/A INSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
O N/A KNOWLEDGE:
N/A ADDITIONAL INFORM ATION:
N/A i
l 9
socim3196 4-4 REVisloN: 2
STEP DESCRIPTION TAELE FOR SDG-1
{w)
STEP 3
%J STEP:
Check RCS Status - OPEN PURPOSE:
To determine if the RCS is open BASIS:
An open RCS is defined as any opening in the RCS that cannot be readily closed from control room, including an opened SG manway isolated from the RCS via the SG nozzle dams. The RCS should also be considered open, or the actions for an open RCS should be taken, if the RCS (including the SG and PRHR heat exchanger tubes) is not filled to the pressurizer low level CMT actuation setpoint.
ACTIONS:
Determine if RCS is open INSTRUMENTATION:
N/A O
CONTROL /EOUIPMENT:
V N/A.
KNOWLEDGE:
The opemtor should understand what is meant by an open RCS.
ADDITIONAL INFORM ATION:
N/A O
SDolm3196 45 REVisloN: 2
STEP DESCRII" TION TABLE FOR SDG 1 STEP 4 STEP:
Verify Stage 1,2, and 3 ADS Valves - OPEN PURPOSE:
To ensure an adequate RCS vent path is open to containment BASIS:
In the April 10,1987 event at Diablo Canyon Unit 2, the RCS reached boiling in 30 to 45 minutes.
More importantly, this boiling caused RCS pressurization which was unanticipated. An RCS configuration can be postulated, with a blocked hot leg and a opening in the cold leg, which can result in the core being rapidly uncovered following initiation of boiling. Severe core damage can follow as soon as adiabatic heatup of the core reaches the point of rapid zirc-water chemical reaction.
By ensuring the Stage 1,2 and 3 ADS valves are open ensures an adequate RCS hot leg vent path (via the PRZR surge line) is provided to prevent RCS pressurization and possible core uncovery as described above.
ACTIONS:
Verify Stage 1,2, and 3 ADS valves are open Manually open valves
=
INSTRUMENTATION:
ADS valve position indication CONTROL /EOUIPMENT:
Manual ADS valve controls KNOWLEDGE:
If the Pmtection and Safety Monitoring System (PMS) is unsuccessful in opening the ADS valves, the operator should be aware that the Diverse Actuation System (DAS) has provisions for manually opening the ADS valves from the DAS panel.
ADDITIONAL INFORMATION:
N/A l
9 SDGI 073196 4-6 REVISION: 2
l STEP DESCRIPTION TABLE FOR SDG-t 1
i STEP 5 - CAUTION - 1
)
l CAUTION - 1:
Personnel working in containment should be warned before refilling the RCS to avoid inadvertent contamination of personnel working near RCS openings l
PURPOSE:
To avoid personnel contamination from potentially radioactive gases or steam I
vapor when filling an open RCS l
BASIS:
1 1
Refilling the RCS may purge out radioactive vapors or gases from any open RCS vents and I
contaminate personnel in the area. Th:refore personnel working in the vicinity of any RCS openings should clear the area prior to filling the RCS.
I ACTIONS:
N/A INSTRUMENTATION:
N/A CONTROL /EOUIPhENT:
N/A KNOWLEDGE:
The operator should be cognizant of RCS opening locations and any work going on in these areas ADDITIONAL INFORMATION:
N/A i
i l
i seat 0731%
47 RrvisioN: 2
1 i
STEP DESCRII"FION TABLE FOR SDG 1 i
i STEP 5 - CAUTION - 2 i
cal', l.ON - 2:
Only borated water should be added to the RCS to maintain adequate shutdown margt!!
PURPOSE:
To inform the operator that inadvertant dilution of the RCS, without RNS, may result in a loss of (localized) shutdown margin while adding RCS makeup BASIS:
Although the coolant boron should remain in the RCS (as opposed to transfe: Ting with the boiled-off steam) borated makeup should be added to the RCS to maintain localized shutdown margin since mixing in the RCS will be minimal under a loss of RNS conditions. The decay heat / boil-off rates i
during this time are low enough that boron precipitation is not a concem.
ACTIONS:
)
N/A 1NSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A l
ADDITIONAL INFORM ATION:
N/A i
1 l
9 sDG14Tl3196 48 REVistoN: 2
1 STEP DESCRIITION TABLE FOR SDG-1 i
STEP 5 - CAUTION - 3 i
CAUTION - 3:
If RCS hot leg level remains less than (SLO 2) for greater than 30 minutes, automatic alignment for IRWST injection should be verified.
PURPOSE:
To remind the operator that automatic alignment for IRWST injection will occur i
if RCS hot leg level remains less than (SLO 2) for greater than 30 minutes.
I I
BASIS:
l The IRWST will automatically align for injection to the RCS if RCS hot leg level remains less than
.j l
(SLO 2) for greater than 30 minutes. If this happens, the operator should verify the proper alignment for iRWST injection.
l l
l ACTIONS:
t N/A INSTRUMENTATION:
i i
RCS hot leg level indication i
IRWST injection alignment O
CONTROL /EOUIPMENT:
l Controls for IRWST injection path l
KNOWLEDGE:
I N/A 1
ADDITIONAL INFORMATION:
I SLO 2 - Enter RCS low level IRWST actuation setpoint I
i i
l i
l l
I i
i O
i I
i sDal.073196 49 REVisloN: 2 l
J
STEP DESCRIPTION TABLE FOR SDG 1 STEP 5 STEP:
Refill RCS PURPOSE:
To refill RCS hot leg level greater than the IRWST injection setpoint BASIS:
Refilling the RCS level to greater than SLO 2 prevents unnecessary automatic IRW iand pennits the restart of the RNS pumps. The preferred makeup source is CVS mai the CMTs and IRWST remain available for injection if needed.
ACTIONS:
Refill RCS hot leg level using CVS makeup pumps Refill RCS hot leg level using CMTs, gravity feed from IRWST to RNS suction, gravity feed
=
fmm IRWST INSTRUMENTATION:
RCS hot leg level indication CVS RCS makeup instmmentation IRWST injection via RNS suction instrumentation
=
IRWST injection instrumentation
=
CONTROL /EOUIPMENT:
Controls for:
CVS RCS makeup IRWST injection via RNS suction IRWST injection KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SLO 2 - Enter RCS low level IRWST actuation setpoint O
i j
socia 3196 4 10 REVislON: 2
. _. _. - - -. ~. - -.
i r
STEP DESCRIPTION TABLE FOR SDG-1 I
.i l
i STEP 6
\\
j.
STEP:
Identify And Isolate Any RCS Lestage i
PURPOSE:
To prevent RCS inventory loss due to RCS leakage or RCS interfacing systems j
t BASIS:
i.
)
}
To prevent RCS inventory loss due to RCS leakage or RCS interfacing systems.
i
- ACTIONS:
2
)
t 1
Identify / isolate any RCS leakage j
INSTRUMENTATION:
4
- l l
j N/A i
L CONTROL /EOUIPMENT:
4 I
?;
N/A KNOWLEDGE:
N/A y
ADDITIONAL INFORMATION:
i 1
N/A I
c I
1 ii 2
l i
i 4
4 k;
1 i
i 1
I sDG1 c 3196 4.I1 REVISION: 2 i
j
STEP DESCRII"FION TABLE FOR SDG 1 STEP 7 STEP:
Check RCS Hot Leg Level - GREATER THAN (SLO 2)
PURPOSE:
To determine if RCS hot leg level is greater than IRWST injection setpoint, SLO 2 BASIS:
The first action taken under open RCS conditions is checking and maintaining RCS inventory greater I
than the RCS hot leg low level IRWST actuation setpoint (SLO 2). If RCS hot leg level is less than i
SLO 2, then the operator should continue with subsequent steps while he tries to refill the RCS.
Adequate RCS hot leg level is required for RNS operation.
ACTIONS:
Determine if RCS hot leg level is greater than SLO 2 INSTRUMENTATION:
RCS hot leg level indication CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SLO 2 - Enter RCS low level IRWST actuation setpoint O
sDGI Um96 4-12 REVISION: 2
STEP DESCRIPTION TABLE FOR SDG 1 STEP 8 CAUTION CAUTION:
Starting an RNS pump may result in an RCS level decrease due to shrink or void collapse PURPOSE:
To wam the operator that an RCS level decrease, due to shrink or void collapse, may occur BASIS:
Since RCS boiling (voiding) was used for temporary core cooling, initiation of RNS cooling may cause a void collapse with a resulting RCS level decrease.
ACTIONS:
N/A INSTRUMENTATION:
RCS hot leg level indication CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORM ATION:
N/A I
O spal.073196 4 13 REVisloN: 2
STEP DESCRIITION TABLE FOR SDG 1 STEP 8 STEP:
Try To Restore RNS Flow PURPOSE:
To instruct the operator to attempt to restore RNS Flow BASIS:
A common concern, based on past plant designs, has been the loss of RNS because of inadequate water level above the RCS hot leg /RNS suction line interface. With an inadequate water level, air ingestion, caused by vonexing action, would cause the RNS pump to loose prime and therefore internipt the RNS cooling function. The AP600 design incorporates specific features to address this concem consisting of: 1) a stepped nozzle RCS hot leg /RNS suction line interface which limits entrained air to no greater than five percent,2) a sloped RNS suction line without any local highpoints to permit easy line refill after hot leg level is reestablished,3) RCS layout is such that draining the SG primary side can be accomplished with a higher hot leg level and 4) Hot leg level indication. Therefore, hot leg level is maintained greater than SLO 2 to provide adequate RNS suction.
The RNS has redundant equipment. If a failure in one train occurs, the other train can be placed in service. The RNS pumps are automatically loaded onto the standby diesel generators if they were operating at the time of loss of nonnal power. The operator may have to manually load the RNS pumps onto the standby diesel generators if the automatic loading feature fails. The following supporting systems are also required to provide prompt restoration of RNS cooling: SWS, CCS and PLS. After RNS is restored, the desired cooldown rate is established and the operator transitions to the appropriate plant procedure.
ACTIONS:
Start an RNS pump Maintain RCS hot leg level greater than SLO 2 Detennine if RNS cooling has been restored Establish desired RCS cooldown rate Go to appropriate plant procedure INSTRUNENTATION:
RNS cooling performance status indication Hot leg level indication CONTROL /EOUIPhENT:
RNS controls required for RCS cooling Controls for RNS support systems KNOWLEDGE:
N/A sDol.073196 4 14 REVisloN: 2
. -...... - ~..... - -... - -, _.. - ~ -.
.. - ~. - ~.
-. ~
... - _ ~
a i
I STEP DESCRIFFION TABLE FOR SDG.I.
I t
t l
ADDITIONAL INFORMATION:
P i
i SLO 2 - Enter RCS low level IRWST actuation setpoint i
i 1
i i
1 i
i i
4 l
I i
i a
i s
i l
4 l
2 i
i 1
i 1
ab' I
1 4
1 I
i i
1 1
1 4
I I,j 1
i sDol e 3196 4 15 REVISION: 2
i STEP DESCRII" TION TABLE FOR SDG 1 1
STEP 9 l
STEP:
Check if Fourth Stage ADS Should Be Actuated PURPOSE:
To determine if Fourth Stage ADS should be actuated BASIS:
1 Founh stage ADS actuation is required if CMT level cannot be maintained above the CMT founh stage ADS actuation setpoint or if RCS hot leg level is low. Following ADS actuation, the operational procedure is to start the normal residual heat remo' al system. The nonnal residual heat j
v removal system provides injection into the RCS from the IRWST at about 100 psig. This injection stops the CMT injection and prevents the fourth stage ADS valves from being actuated. Founh stage ADS will be required and actuated if there is a normal residual heat removal system equipment or operator failure. On fourth stage ADS actuation, the founh stage ADS isolation valves and the IRWST injection isolation valves open and allow gravity draining injection to the RCS from the IRWST.
ACTIONS:
i 1
1 Determine if fourth stage ADS should be actuated Detennine if CMT level is less than SLOS
}
Determine if RCS hot leg level decreases to less than SLO 4 Manually actuate founh stage ADS i
Verify founh stage ADS isolation valves open Manually open founh stage ADS valves Verify IRWST injection isolation valves open Manually open IRWST injection isolation valves INSTRUMENTATION:
Indication for CMT level
=
RCS hot leg level ADS founh stage isolation valve position ADS fourth stage valve position IRWST injection isolation valve position indication CONTROL /EOUIPMENT:
Controls for ADS founh stage isolation valves ADS fourth stage valves IRWST injection isolation valves O
soal.073196 4-16 REVisloN: 2
STEP DESCRIPTION TABLE FOR SDG 1 KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SLO 4 RCS hot leg level greater than bottom of hot legs SLOS CMT fourth stage ADS actuation setpoint u
O 4
1 l
1 O
sooten96 REVISION: 2 i
STEP DESCRII' TION ABLE FOR SDG 1 STEP 10 STEP:
Check IRWST Level PURPOSE:
To verify the containment sump recirculation valves are automatically opened to align the plant in the recirculation mode BASIS:
On low level in the IRWST, the containment sump recirculation valves are automatically opened to align the plant in the recirculation mode. In this mode, water is recirculated from the containment sump through the containment sump recirculation lines into the reactor vessel under either gravitational force or by using the nonnal residual heat removal system. This step verifies that the containment sump recirculation valves are open.
ACTIONS:
Determine if IRWST is less than SLO 6 Verify containment sump recirculation valves are open Manually align valves as necessary INSTRUMENTATION:
Indication for i
IRWST level
=
Containment sump recirculation valve position
=
i CONTROL /EOUIPMENT:
Containment sump recirullation valve controls KNOWLEDGE:
i 1
N/A ADDITIONAL INFORMATION:
SLO 6 IRWST level for transfering RNS to contaiment sump 9
stxn-073196 4 18 REvlstoN: 2
STEP DESCRIITION TABLE FOR SDG 1 STEP 11 STEP:
Initiate Actions To Protect Personnel Working In Containment PURPOSE:
To ensure personnel inside containment are protected from a potential adverse radiological environment BASIS:
When the core starts boiling, steam and/or gases may be released into containment through vents in the RCS. The release of steam into containment can create a habitability (temperature) concem for operators who may be in the area to perform recovery actions. The potential exists for release of radioactive materials from the RCS into containment ccusing a personnel contamination problem.
Any non essential personnel inside containment should be evacuated. As an additional precautionary measure, essential personnel entering containment may need to take additional protective measures l
such as respirators, breathing air or special protective clothing. Containment radiation should be periodically monitored and at some point, it may be necessary to evacuate essential personnel from containment.
ACTIONS:
Initiate actions to protect personnel working in containment O
INSTRUMENTATION:
Containment radiation monitoring i
CONTROL /EOUIPMENT:
i N/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A i
I i
O soola3196 4 19 Revision: 2
l STEP DESCRIITION TABLE FOR SDG 1 i
STEP 12 STEP:
Initiate Actions To Establish Containment Closure PURPOSE:
To establish a boundary to prevent the release of fission products I
BASIS:
Since RNS cooling has been lost, and initial attempts to restore RNS cooling have been unsuccessful, actions must be taken to address the possibility of core uncovery and subsequent fuel damage due to RCS inventory loss. Since two of the three radiological barriers may be open (the RCS and containment), actions must be taken to close containment and pmvide a barrier to the release of radioactive materials should the event proceed to core damage. Containment closure must be accomplished before the onset of core damage. Once containment closure is initiated, closure should continue until controlled and stable decay heat removal has been restored (either RNS cooling j
or stable heat removal via the secondary plant) and the RCS is retumed to a controlled and stable condition.
ACTIONS:
Initiate actions to establish containment closure INSTRUMENTATION:
1 N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
Means to establish containment closure ADDITIONAL INFORMATION:
Specific guidelines for establishing containment closure during typical shutdown conditions.
Containment closure as discussed in this step includes establishing the desired position of available containment isolation valves to minimize release outside containment.
O sDol.073196 4 20 REVISloN 2
I
-STEP DESCRIPTION TABLE FOR SDG-1 i
STEP 13 l
STEP:
Start Available Containment Fan Coolers i
PURPOSE:
To ensure all available containment fan coolers are runnmg to remove containment heat BASIS:
The intent of this step is to remove heat fmm containment resulting fmm coolant boiling off in the f
RCS. Note that steam vented off via ADS stages 1,2 and 3 will be condensed and captured via the i
ADS spargers in the IRWST. Therefore, until the IRWST starts steaming, the heat load on the contamment fan coolers should be minimal.
ACTIONS:
Start available containment fan coolers i
d INSTRUMENTATION:
Contamment fan cooler instrumentation CONTROLEOUIPMENT Controls for containment fan ' coolers KNOWLEDGE:
N/A-ADDITIONAL INFORMATION:
N/A O
soot-on196 4-21 REVISloN: 2
STEP DESCR1FilON TABLE FOR SDG-1 STEP 14 STEP:
Retum to Step 3 PURPOSE:
To re-evaluate RCS opened / closed status and transition to appropriate procedure actions as required BASIS:
To continue attempts to restore RNS cooling.
ACTIONS:
Return to Step 3 INSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A O
snai.073196 4-22 REVISION: 2
STEP DESCRIPTION TABLE FOR SDG-1 r~N iv)
STEP 15 STEP:
Check If CMTs Should Be Actuated PURPOSE:
To determine if CMT injection is necessary to replenish RCS inventory BASIS:
CMT actuation based on low level in the pressurizer (SL01) is available in mode 5 except when it is blocked for reduced inventory operations. Actions for reduced inventory operation are addressed in steps 3 through 12. The RCS should be filled and pressurizer level expected to be nonnal when this step is performed. If RCS inventory is being lost such that pressurizer level drops to less than SL01, the operator should verify that the automatic CMT actuation has occurred.
ACTIONS:
Detennine if pressurizer level is greater than SLO 2 Verify that CMT injection valves are open Manually open CMT valves i
INSTRUMENTATION:
PRZR level indication n
( )
CMT injection valve position indication l
CONTROL /EOUIPMENT:
Controls for CMT injection valves KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SL01 - Enter PRZR level CMT actuation setpoint during shutdown
%)
sDol.073196 4-23 REV!sloN: 2
STEP DESCRIITION TABLE FOR SDG 1 l
STEP 16 STEP:
Verify PRHR Actuated PURPOSE:
To ensure that PRHR is aligned to cool to reactor core BASIS:
PRHR is automatically actuated on CMT actuation. The operator should verify that the PRHR isolation valves are open for cooling the reactor core.
ACTIONS:
Verify that PRHR isolation valves are open Manually open PRHR isolation valves
=
INSTRUMENTATION:
PRHR isolation valve position indication CONTROL /EOUIPMENT:
Controls for PRHR isolation valves KNOWLEDGE:
N/A i
ADDITIONAL INFORMATION:
N/A O
SDGl@3196 4-24 REVISION: 2
l STEP DESCRllTION TABLE FOR SDG 1 f)
STEP 17
'm; STEP:
Check If ADS Should Be Actuated PURPOSE:
To determine if ADS should be actuated based on prevailing plant conditions 1
BASIS:
The automatic depressurization system (ADS) actuation is required if core makeup tank (CMT) level cannot be maintained above the first stage ADS actuation setpoint or if RCS hot leg level is low, if i
ADS actuation is required, then the operator verifies that the first three ADS stages have operated successfully. The second and third stage ADS are actuated after a time delay.
If ADS is actuated, (or if CMT level is approaching the first stage ADS setpoint) the operator is j
directed to align the normal residual heat removal system to inject the in-containment refueling water storage tank (IRWST) to the RCS to prevent the need for fourth stage ADS actuation. The normal i
residual heat removal system provides injection into the RCS from the IRWST at about 100 psig.
This injection stops the CMT injection and prevents the fourth stage ADS valves from being actuated.
l ACTIONS:
Detemine if ADS should be actuated Determine if CMT level is less than SLO 3 Determine if RCS hot leg level is greater than Slot Determine if (ST01) seconds have elapsed from first stage ADS signal j
=
Determine if (ST02) seconds have elapsed from second stage ADS signal Verify actuation of first three ADS stages Manually open first,second and third stage ADS valves Align normal residual heat removal system to inject into RCS INSTRUMENTATION:
Indication for CMT level RCS hot leg level
=
ADS actuation ADS valve position
=
ADS isolation valve position Normal residual heat removal system suction valve position Normal residual heat removal system discharge valve position
=
Normal residual heat removal system pump status indication
=
q spot.073196 4-25 REVISION: 2
STEP DESCRIPTION TABLE FOR SDG I CONTROL /EOUIPMENT:
Controls for ADS valves ADS isolation valves Normal residual heat removal system suction valve Normal residual heat removal system discharge valve Normal residual heat removal system pump KNOWLEDGE:
Aligning RNS to inject into the RCS does not require the closing of the RNS suction valves from i
the RCS ADDITIONAL INFORMATION-SLO 3 CMT low level ADS actuation SLG4 RCS hot leg level greater than bottom of hot legs
{
ST01 Time delay for second stage ADS actuation ST02 Time delay for third stage ADS actuation O
O sDc14r/3196 4 26 REVISlos: 2
STEP DESCRIITION TABLE FOR SDG-1 STEP 18 STEP:
Check If Fourth Stage ADS Should Be Actuated PURPOSE:
To determine if Founh Stage ADS should be actuated based on CMT level BASIS:
Founh stage ADS actuation is required if CMT level cannot be maintained above the CMT fourth stage ADS actuation setpoint or if RCS hot leg level is low. Following ADS actuation, the operational procedure is to start the normal residual heat removal system. The normal residual heat removal system provides injection into the RCS from the IRWST at about 100 psig. This injection stops the CMT injection and prevents the fourth stage ADS valves from being actuated. Founh stage ADS will be required and actuated if there is a normal residual heat removal system equipment or operator failure. On fourth stage ADS actuation, the fourth stage ADS isolation valves and the IRWST injection isolation valves open and allow gravity draining injection to the RCS from the IRWST.
ACTIONS:
Doermine if fourth stage ADS should be actuated Detennine if CMT level is less than SLOS Determine if RCS hot leg level decreases to less than SLO 4 (VO Manually actuate fourth stage ADS
=
Verify founh stage ADS isolation valves open e
l Manually open founh stage ADS valves Verify IRWST injection isolation valves open Manually open IRWST injection isolation valves
(
INSTRUMENTATION:
Indication for CMT level l
RCS hot leg level
=
l l
ADS fourth stage isolation valve position j
ADS fourth stage valve position IRWST injection isolation valve position indication CONTROL /EOUIPMENT:
)
Controls for ADS fourth stage isolation valves ADS fourth stage valves IRWST injection isolation valves
[U snal-073196 4-27 RIVIsloN: 2
i l
STEP DESCRIITION TABLE FOR SDG 1 l
KNOWLEDGE:
N/A l
ADDITIONAL INFORMATION:
SLG4 RCS hot leg level greater than bottom of hot legs SLOS CMT fourth stage ADS actuation setpoint O
O socia 3196 4-28 REVISION: 2
l
~
1 STEP DESCRif'rION TABLE FOR SDG-1 l
l
\\
STEP 19 i
STEP:
Check IRWST Level l
PURPOSE:
To verify the contauunent sump recirculation valves are automatically opened to
}
align the plant in the meirculation mode l
l BASIS:
On low level in the IRWST, the containment sump recirculation valves are automatically opened to align the plant in the recitrulation mode. In this mode, water is recirculated from the containment i
sump through the containment sump recirculation lines into the reactor vessel under either gravitational force or by using the normal residual heat removal system. This step verifies that the containment sump recirculation valves are open.
\\
i ACTIONS:
l l
Determine ifIRWST is less than SLO 6 Vesify containment sump recirculation valves are open Manually align valves as necessary j
INSTRUMENTATION:
r l O Indication for
!D IRWST level i
Contamment sump recirculation valve position i
I CONTROL /EOUIPMENT:
l l
Contamment sump recirculation valve controls KNOWLEDGE:
N/A l '
ADDITIONAL INFORMATION:
l SLO 6 IRWST level for transfering RNS to contaiment sump l
i I
socim3196 4 29 REvlsloN: 2 l
l l
STEP DESCRITTION TABLE FOR SDG 1 1
STEP 20 STEP:
Evaluate Long Term Plant Status PURPOSE:
To detennine long tenn plant status and future recovery actions BASIS:
The equipment used to establish long tenn core cooling and inventory control is the same equipment that is used to recover from design basis LOCAs and is designed to function in the long term so that plant recovery is possible. This allows the plant staff to evaluate the event and develop recovery procedures so that the plant can be repaired and brought back to senice.
ACTIONS:
N/A INSTRUMENTATION:
N/A CO!(i~rtOL/EOUIPMENT:
F1/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A 1
r O
l suoi m 3196 4 30 REVISloN: 2
i STEP DESCRIITION TABLE FOR SDG 1 l
STEP 21 STEP:
Go To Appropriate Plant Procedure PURPOSE:
To direct the operator to the proper procedure following completion of the steps in this guideline l'
BASIS:
Now that the guideline steps have been completed, the operator should continue plant operation and/or recovery going to the appropriate normal plant pmcedure or abnonnal plant procedure.
1 ACTIONS:
Go to appropriate plant procedure i
INSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
N/A
.O l
KNOWLEDGE:
i N/A ADDITIONAL INFORMATION:
i i
i y
l a
O SDoi 073196 4-31 REVislON: 2
STEP DESCRIPTION TABLE FOR SDG 1 STEP 22 - CAUTION - 1 CAUTION -1:
Personnel working in containment should be wamed before refilling the RCS to avoid inadvenant contamination of personnel working near RCS openings PURPOSE:
To avoid personnel contamination from potentially radioactive gases or vapors when filling an open RCS BASIS:
Refilling the RCS may purge out radioactive vapors or gases from any open RCS vents and contaminate personnel in the area. Therefore personnel working in the vicinity of any RCS openings should clear the area prior to filling the RCS.
ACTIONS:
N/A INSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
The operator should be cognizant of RCS opening locations and any work going on in these areas ADDITIONAL INFORMATION:
N/A O
sDal a 3196 4-32 REVISION: 2
7-STEP DESCRIPTION TABLE FOR SDG-1 O
STEP 22 CAUTION - 2 CAUTION - 2:
Only borated water should be added to the RCS to maintain adequate shutdown margin PURPOSE:
To inform the operator that inadvertant dilution of the RCS, without RNS, may result in a loss of (localized) shutdown margin while adding RCS makeup BASIS:
Although the coolant boron should remain 1:4 the RCS (as opposed to transferring with the boiled-off steam) borated makeup should be added to the RCS to maintain localized shutdown margin since mixing in the RCS will be minimal under these loss of RNS conditions. The decay heat / boil-off rates during this time are low enough that boron precipitation is not a concern.
ACTIONS:
N/A INSTRUMENTATION:
N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A O
sDolm31%
4-33 REvlsioN: 2
STEP DESCRIITION TABLE FOR SbG-1 STEP 22 STEP:
Maintain PRZR Level - GREATER THAN (SLOI)
PURPOSE:
To maintain pressurizer level greater than the CMT actuation setpoint during shutdown BASIS:
The preferred makeup source is CVS makeup so that the CMTs and IRWST remain available for injection if needed. Maintaining pressurizer level greater than SLOl prevents unnecessary automatic CMT actuation.
ACTIONS:
Maintain pressurizer level using CVS makeup pumps Maintain pressurizer level using CMTs, gravity feed from IRWST, gravity feed from IRWST to RNS suction INSTRUMENTATION:
Pressurizer level indication CVS RCS makeup instrumentation IRWST injection instrumentation IRWST injection via RNS suction instrumentation CONTROL /EOUIPMENT:
Controls for:
CVS RCS makeup IRWST injection IRWST injection vie RNS suction j
KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SLO! PRZR level CMT actuation setpoint during shutdowTi O
l sDol e 3196 4 34 REVislON: 2
STEP DESCRIPTION TABLE FOR SDG.I O
STEP 23 STEP:
Check If CMT Injection Should Be Isolated PURPOSE:
To isolate CMT injection if it is not needed BASIS:
If pressurizer level is above the CMT actuation setpoint, then CMT injection into the RCS is not necessary and can be stopped.
1 ACTIONS:
Detennine if pressurizer level is greater than SLOl Close CMT injection valves INSTRUMENTATION:
Indication for Pressurizer level CMT injection valve position indication CONTROL /EOUIPMENT:
Controls for CMT injection valves KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
SL01 PRZR level CMT actuation setpoint during shutdow11 O
sDol.073196 4-35 REVislON: 2
~
STEP DESCRIITION TABLE FOR SDG 1 STEP 24 - CAUTION CAUTION:
Starting an RNS pump may result in an RCS level decrease due to shrink or void collapse PURPOSE:
To wam the operator that a PRZR level decrease, due to shrink or void collapse, may occur BASIS:
Since RCS boiling may occur as a result of losing RNS cooling and without any other RCS heat 3
sunk, re-initiation of RNS cooling may cause a void collapse with a resulting PRZR level decrease.
ACTIONS:
N/A INSTRUMENTATION:
PRZR level indication i
CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
l l
N/A l
i l
9 soci.073196 4-36 REVlsloN: 2
STEP DESCRIPTION TABLE FOR SDG-1 i
STEP 24 V
STEP:
Try To Restore RNS Flow PURPOSE:
To instruct the opemtor to attempt to restore RNS Flow BASIS:
A common concem, based on past plant designs, has been the loss of RNS because ofinadequate water level above the RCS hot leg /RNS suction line interface. With an inadequate water level, air ingestion, caused by voitenng action, would cause the RNS pump to loose prime and therefore interrupt the RNS cooling function. The AP600 design incorporates specific features to address this concem conristing of: 1) a stepped nozzle RCS hot leg /RNS suction line interface which limits entrained air to no greater than five percent,2) a sloped RNS suction line without any local highpoints to pennit easy line refill after hot leg level is reestablished. 3) RCS layout is such that draining the SG primary side can be accomplished with a higher hot leg level and 4) Hot leg level indication. Therefore, hot leg level is maintained greater than SLO 2 to provide adequate RNS suction.
' The RNS has redundant equipment. If a failure in one train occurs, the other train can be placed in service. The RNS pumps are automatically loaded onto the EDGs if they were operating at the time of loss of nonnal power. The operator may have to manually load the RNS pumps onto the EDGs if the automatic loading feature fails. The following supporting systems are also required to provide O
prompt restoration of RNS cooling: SWS, CCS and PLS. After RNS is restored, the desired cooldown rate is established and the operator transitions to the appropriate plant procedure.
ACTIONS:
)
Start an RNS pump Maintain RCS hot leg level greater than SLO 2 Determine if RNS cooling has been restored Establish desired RCS enoldowTi rate Go to appropriate plant procedure INSTRUMENTATION:
RNS cooling performance status indication PRZR level indication CONTROL /EOUIPhENT.
RNS controls required for RCS cooling Coritrols for RNS support systems KNOWLEDGE:
p N/A sDGl@3196 4 37 REVtsloN: 2
STEP DESCRII' TION TABLE FOR SDG 1
(
ADDITIONAL INFORMATION:
l SLOl - Enter PRZR level CMT actuation setpoint during shutdown O
l l
l O:
soal m 3196 4 38 REVISION: 2
STEP DESCRII'rION TABLE FOR SDG-1 i
[]
STEP 25 Q.)
l STEP:
Establish RCS Heat Sink Using SGs PURPOSE:
To provide an RCS heat sink using available SG(s)
BASIS:
1 The plant condition required for this step is a " closed" RCS, wl.ich has already been determined. By definition, a closed RCS requires that the RCS (including the SG tubes) be filled to at least the PRZR CMT actuation level setpoint (SL01). In addition to a closed RCS, an SG must be available.
An SG is available if the secondary side of a non-ruptured, non-faulted SG is filled to approximately normal level, and atmospheric steam release capability via the SG power operated relief valves (PORVs) is operable (with the plant shutdown, steam dump to the condenser would not be available).
The ADS valves remain in the position they were in at the time this step is reached. Subcooled core cooling will take place until the RCS and SGs reach saturation based on SG secondary side atmospheric pressure. With the ADS valves and RCS closed, the RCS will slightly pressurize above atmospheric pressure to an equilibrium value required to remove core decay heat. This plant configuration will permit RCS/SG natural circulation to transfer core decay heat to the SGs, The SGs remain at atmospheric pressure with steam release to the atmosphere. Since SG pressure will g
be maintained at atmospheric pressure via the open SG PORVs, saturated core cooling will take
(]
place at approximately 212'F. RCS inventory will be monitored and controlled via Step 15. SG feedwater will be required, as necessary, depending on the length of time RNS cooling is lost to maintain secondary inventory.
If the ADS valves remain open, this method of saturated core cooling will not be effective since no temperature gradient will develop to promote natural circulation. Very little, if any, temperature gradient between the RCS and SG will exist because both the RCS and SG(s) will remain at atmospheric pressure when the ADS valves and SG PORVS are open.
ACTIONS:
Detennine if any SGs are available Try to restore SGs to service Feed SGs to establish and maintain SG level Open respective SG PORVs INSTRUMENTATION:
SG level indication f
SFW operation instrumentation RCS hot leg, cold leg and SG temperature indication SG PORV position indication ADS valve position indication
(~N Hot leg level indication v) t spot.073196 4-39 REvlsloN: 2
STEP DESCRIITION TABLE FOR SDG-1 CONTROL /EOUIPMENT:
Controls for:
SFW operation SG PORV operation K.NOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A O'
i l
i O
sDol m 3196 4-40 REVISION: 2
STEP DESCRIITION TABLE FOR SDG-1 p
STEP 26 b
i i
STEP:
Establish RCS Heat Sink Using PRHR 1
PURPOSE:
To provide an RCS heat sink using the PRHR heat exchanger BASIS:
The passive residual heat removal system (PRHRS) is designed to cool the RCS using natural circulation from the RCS thmugh the PRHR heat exchanger (PRHRHX) during the initial cooldown phase (of plant shutdown) before RNS cooling is initiated. The PRHR heat exchanger uses the IRWST as a heat sink normally maintained at containment ambient temperature. Aligning the PRHRS to cool the RCS will provide a heat sink for the RCS although it may not be very efflective until the RCS heats up. If PRHR cooling can not be placed in service; at an RCS temperature of (ST03) F, the operator is instructed to open all ADS valves to initiate a feed and bleed mode of cooling for the RCS and to prevent funher pressurization of the RCS.
j ACTIONS:
Detennine if PRHR is available Align PRHR to cool RCS Open all ADS valves if PRHR is not available and RCS temperature reaches (ST03) F INSTRUMENTATION:
Instrumentation for:
PRHR operability status PRZR level indication CONTROL /EOUIPMENT:
i Controls for:
PRHR operation ADS valves KNOWLEDGE:
i The operator should be aware of IRWST cooling capabilities provided by RNS, SFS and containment fan coolers. If PMS is unsuccessful in opening / closing the ADS valves or actuating PRHR, the operator should be aware that the Diverse Actuation System (DAS) has provisions for manually opening / closing the ADS valves or actuating PRHR from the DAS panel.
ADDITIONAL INFORMATION:
'p ST03 - Enter normal RNS cut-in temperature f
l sDolm3196 4-4I REVisloN: 2 i
1 1
STEP DESCRIPTION TABLE FOR SDG 1 STEP 27 STEP:
Initiate Actions To Protect Personnel Working in Containment PURPOSE:
To ensure personnel inside containment are protected from a potential adverse radiological environment BASIS:
When the core /lRWST starts boiling, steam and/or gases may be released into containment through j
vents in the IRWST. The release of steam into containment can create a habitability (temperature) concem for operators who may be in the area to perform recovery actions. The potential exists for release of radioactive materials from the RCS/lRWST into containment causing a personnel contamination problem.
Any non essential personnel inside containment should be evacuated. As an additional precautionary measure, essential personnel entering containment may need to take additional protective measures such as respirators, breathing air or special protective clothing. Containment radiation should be periodically monitored and at some point, it may be necessary to evacuate essential personnel from containment.
ACTIONS:
Initiate actions to protect personnel working in containment INSTRUMENTATION:
Containment Temperature indication
=
Containment radiation monitoring CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
N/A ADDITIONAL INFORM ATION:
N/A O
sDalm31%
4 42 REVislON: 2
STEP DESCRIITION TABLE FOR SDG 1
(
STEP 28
(
STEP:
Initiate Actions To Establish Containment Closure PURPOSE:
To establish a boundary to prevent the release of fission products BASIS:
Since RNS cooling has been lost, and initial attempts to restore RNS cooling have been unsuccessful, actions must be taken to address the possibility of core uncovery and subsequent fuel damage due to RCS inventory loss. Since two of the three radiological barriers may be open (the RCS and containment), actions must be taken to close containment and provide a barrier to the release of radioactive materials should the event proceed to core damage. Containment closure must be accomplished before the onset of core damage. Once containment closure is initiated, closure should continue until controlled and stable decay heat removal has been restored (either RNS cooling or stable heat removal via the secondary plant) and the RCS is retumed to a controlled and stable condition.
ACTIONS:
Initiate actions to establish containment closure
=
INSTRUMENTATION:
f3 N/A CONTROL /EOUIPMENT:
N/A KNOWLEDGE:
Means to establish containment closure ADDITIONAL INFORMATION:
Specific guidelines for establishing containment closure during shutdown conditions and using the passive core cooling systems (i.e., PXS/PRHR and PCC). Containment closure as discussed in this step includes establishing the desired position of available containment isolation valves to minimize release outside containment.
rN k
spol-073196 4-43 REVisloN: 2
STEP DESCRIPTION TABLE FOR SDG 1 l
STEP 29 i
STEP:
Start Available Containment Fan Coolers PURPOSE:
To ensure all available containment fan coolers are running to remove
{
containment heat BASIS:
j The intent of this step is to remove heat from containment resulting from the IRWST boiling off to containment. Note that subcooled PRHR cooling will occur, and steam vented off via ADS stages 1, 2 and 3 will be condensed and captured via the ADS spargers in the IRWST. Therefore, until the IRWST starts steaming, the heat load on the containment fan coolers should be minimal.
ACTIONS:
Start available containment fan coolers INSTRUMENTATION:
Containment fan cooler instrumentation CONTROL /EOUIPMENT:
Controls for containment fan coolers KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A O
sDGl@3196 4 44 REVistoN: 2
~ -..
f L
STEP DESCRIPTION TABLE FOR SDG 1 t
4 1
STEP 30 f
i STEP:
Retum To Step 15 I
PURPOSE:
To retum to the initial procedure step that addresses recovery with a closed RCS l
BASIS:
Steps 15 to 29 fonn a loop of recovery actions with closed RCS conditions. Since RNS cooling has not been re-established, as evaluated in Step 24, the operator is sent back to the beginning of this
)
, loop to re-evaluate the status of RCS cooling and restoration of RNS cooling of the RCS.
ACTIONS:
Retum to Step 15 1
1 INSTRUMENTATION:
)
i N/A CONTROL /EOUIPMENT:
-1 N/A
)
KNOWLEDGE:
N/A ADDITIONAL INFORMATION:
N/A 1
O SDGIG3196 4-45 RhVIslON: 2
4.2 Step Sequence Requirements This section consists of a table which presents the existing guideline sequence and identifies the interchangeability of guideline steps for the benefit of the procedure writer.
The Step Sequence Table for SDG-1 is pmvided on the following page. The interchangeability of guideline steps is identified by the numbers in the column to the right of each guideline step.
O l
l O
SDol-0731%
4 46 REVis10N: 2
)
A
.: MiA-gW C "
STEP SEQUENCE FOR SDG-1 STEP SEOUENCE 1.
Check If RNS Pumps Should Be Stopped 1
I 2.
Verify RCS Drain Path Isolation 2
1 3.
Check RCS Status - OPEN 3
4.
Verify Stage 1,2 and 3 ADS Valves - OPEN 4
5.
Refill RCS 5
i 6.
Identify And Isolate Any RCS Leakage 6
i 7.
Check RCS Hot Leg Level - GREATER THAN (SLO 2))
7 8.
Try To Restore RNS Flow 8
9.
Check If Founh Stage ADS Should Be Actuated 9
- 10. Check 1RWST Level 10
- 11. Initiate Actions To Protect Personnel ' Working In Containment 11 s
- 12. Initiate Actions To Establish Containment Closure 11
- 13. Start Available Containment Fan Coolers 11 14.
Return To Step 3 12
- 15. Check If CMTs Should Be Actuated 13
- 16. Verify PRHR Actuated 14
- 17. Check if ADS Should Be Actuated 15
- 18. Check If Fourth Stage ADS Should Be Acttated 16 1
- 19. Check 1RWST Level 17 sDol m 3196 4-47 REVIsloN: 2 l
20.
Evaluate Long Term Plant Status 18 21.
Go To Appropriate Plant Procedure 19
- 22. Maintain PRZR Level - GREATER THAN (SLO 2) 20 23.
Check If CMT Injection Should Be Isolated 21 24.
Try To Restore RNS Flow 22
Establish RCS Heat Sink Using PRHR 24
- 27. Initiate Actions To Protect Personnel Working in Containment 24
- 28. Initiate Actions To Establish Containment Closure 24
- 29. Stan Available Containment Fan Coolens 24
- 30. Retum To Step 15 25
)
i e
i sDol m 3196 4-48 REVIsloN: 2 i