ML20042D392

LER 89-011-01:on 890826,spurious Reactor Protection Sys Actuation Occurred.Definite Cause of Trip Not Determined. Brief Disturbance in Reactor Protection Sys Allowed Some Contactors to Trip.Procedure revised.W/900104 Ltr

ML20042D392
Person / Time
Site:	LaSalle
Issue date:	01/04/1990
From:	Diederich G, Klika J COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
References
LER-89-011, LER-89-11, NUDOCS 9001090077
Download: ML20042D392 (11)

Text

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'g . Director of Nuclear Reactor Regulation f

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Dear sirU

Licensee Event' Report #89-011-01,- Docket #050-374 is being..

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>- submitted to your office to supercede previously submitted <r s Licensee Event Report 89-011. .;

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LICENSEE EVENT REPORT (LER) Fo m Rev 2,0 Docket Neber (2) Pane Cl)

Facility Name (1). '

• 11e County Station Unit'2 015101010131714 1 of _1 0 Title (4)

• sourious Reactor Mection System Actuation Due to unknown Cause LER thaber (6) annart Date (7) Other Facilities Involved (8)

_. Event Date (5) Facility Names Year Docket ihmber(s)

Month Day Year Year. Sequential

/// lkaber "f// /// ekaber Revision Month Day U '/f/

01 51 01 01 01 I I el 9 s1 9 01111 01 1 011 01 4 91 0 01 51 01 01 01 1 I l -

Ol' e 21 6

" THIS REPORT IS SUBMITTED PURSUANT TO 1HE REQUIREMENTS OF 10CFR OPERATING (Check one or ,i re of the followine) (11) g g,) 20.405(c) 50.73(a)(2)(iv) 73.71(b)-

1 20.402(b) ,,_, .X_ _

20.405(a)(1)(l) 50.36(c)(1) 50.73(a)(2)(v) , 73.71(c)

PONER' ,,_ __,

50.36(c)(2) 50.73(a)(2)(vil) Other (Specify LEVEL' i i 20.405(a)(1)(ll) _ .,_ _

20.405(a)(1)(ill) 50.73(a)(2)(1) 50.73(a)(2)(vill)(A) in Abstract (10) 01 11 0 _,,, ,,,_ _

50.73(a)(2)f,li) 50.73(a)(2)(viii)(B) below and in

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50.73(a)(2)(lit) 50.73(a)(2)(x) Text)

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LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NUpWER-

Name AREA CODE W C. K1lka. Assistant Technical Staff Suoervisor, extension 2S33 8 l 1 15 315171-l6171611 C0WLETE ONE LlWE FOR EACH COWOWENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPOWENT MANUFAC- REPORTABLE CAUSE SYSTEM COMPOWENT MANUFAC- REPORTABLE TO NPRDS TURER TO NPRDS TURER X 3 l' C Rl Li Yl Gl01812 Y l l l l l l l l l l l l l l l l l l l l I 1 SUPPLE 14 ENTAL REPORT EXPECTED (14)

Expected Month l Day l Year Submission

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lyes (if wes. -:-s-lete EXPECTED SLBMISSION DATE) YlNO l l ll ABSTRACT (Limit to 1400 spaces, i.e, approximately fifteen single-space typewritten lines) (16)

On August 26,:1989, a controlled shutdown was in progress on Unit 2 . While conducting LOS-TG-SA2, " Turbine Valve Leak Tightness Surveillance," a Reactor Protection System (RPS) actuation occurred at 0414 hours0.00479 days <br />0.115 hours <br />6.845238e-4 weeks <br />1.57527e-4 months <br />. When the actuation signal was received, two of the four scram group lights of the RPS Bus A remained energized.

This prevented same of the rods from receiving the nomal automatic scram actuation. Rod motion appears to

- have initiated for these rods due to the Channel A backup scram actuation which occurred at tne same t me i as the initial event. The Control Room Operator manually initiated a nomal scram signal a few seconds later using the A2 and B2 scram pushbuttons. At this time all the remaining scram valves deenergized, indicating that the scram had occurred.

Before the turbine valve test was started, the Hathaway Sequence of Events alam typer was turned off due to its constant printing caused by alarm relay chattering. As a . result, the main source of infomation to be used in analyzing the reactor trip was not available. At the time of the trip, no plant parameters exceed 6d their trip setpoints.

As a result of the missing inforination, several scenarios were developed using available information in an attempt to deterinine the cause of the reactor trip. At this time a definite cause for the trip has not been detemined. The investigations have concluded that a very brief (less than 15 milliseconds) disturbance in the RPS system allowed same of the scram contactors to trip, but was not present long enough to ensure all the contactors tripped. The source of this spurious signal is unknown.

This event is reportable in accordance with 10CFR50.73(a)(2)(lv) due to the actuation of an Engineered Safety '

Feature System.

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• LMr ECT REPORT (LER)LTElti CONilNUAT10N' Fo m Rev 2.0  ;

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• NilecountyStationunit2 0 1 5 1 0 1 0 1 0 I al il 4 e19 - 01 11'I - 0 1: 1 ~01 2 0F 11 0 l":

-TEXT'  ; Energy ladustry identification System (Ells) codes are _ identified in the text as [XX] l N

• PIAlfi. AND SYSTEM 10ENTiflCAT10N:

y IGeneral' Electric.- Dolling Water Reactor l

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l Energy Industry identification System (Ells). codes are identified in the text as [XX)..

i A. COWITION PRIOR TO EVENT

'2 Event Date:- 8/26/09 Event Time: 0414 Hours

. Unit (s):

i 1 . Mode (s) Hame: Run Power Level (s): 105

)ReactorMode(s):'

k[ I. B DESCRIPT1001 0F EVENT:

I 10nAugust 26,.1999 a controlled shutdown'was'in progress on' unit 2 in preparation.for a maintenance outage to replace the seal on the 28 Reactor Recirculation (RR) [AD) pump. In accordance with the General Surveillance. schedule, LaSalle operating Survel11ance LOS-TG-SA1, " Turbine Semi-4nnual overspeed

. Survelliance," had just been completed satisfactorily. At 0336 hours0.00389 days <br />0.0933 hours <br />5.555556e-4 weeks <br />1.27848e-4 months <br />, LOS-1G-SA2,~ " Turbine Valve

' Tightness Test," was begun.

After. successful cogletion of the Turbine Control Valve leak tightness portion of LOS-TG-SA2 at s  : approximately 0412 hours0.00477 days <br />0.114 hours <br />6.812169e-4 weeks <br />1.56766e-4 months <br />, an Equipment Operator (EO) installed a jumper on the #2 Main Turbine Stop iValve (MSV 2) preany function board in the Electro-Hydraulic Control (EHC) [JG) cabinet. This causes

' the Main Turbine Stop Valves to go closed while maintaining the Turbine Control Valves open. This

! started the Turbine Stop Valve portion of the LOS-TG-SA2. o

' After the j'Juper was installed, MSV 2 began to drift closed as expected. When MSV 2 reached 905 open position, MSV 1, 3 and 4 closed reaching full closed at 0413 hours0.00478 days <br />0.115 hours <br />6.828704e-4 weeks <br />1.571465e-4 months <br />.

( Approximately 23 seconds after MSV i, 3 and 4 reached full closed, at least one subchannel in each of

' Reactor Protection System'(RPS) [JC) channels A and B tripped, with the respective channel trips occurring within 40 milliseconds of each other. - At this time only the "A" back-up scra channel ,

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p  : energized.;: (Refer to Attaciument A.)

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' After the automatic RPS actuation, the Control Room Operator (NSO, licensed Reactor Operator) perfoming the surveillance noticed that the A2/A3 rod scr m group lights were stl11 energized which indicated that the.A2'and A3 control rod scr m solenoids were still energized. He directed another NSO at the feedwater pump panel to manually scram the reactor. This NSO amed and depressed it.e A2 and 82 subchannel manual scram pushbuttons. This scr m occurred approximately 12 seconds after the automatic actuation. ' This action successfully deenergized the A2 and A3 scra solenoids (and red scrm group lights) and caused the B channel of the back-up scrm to energize (by deenergizing the "K14G" scrm icontactor). All rods were verified to be fully inserted within a minute of the initial signals, it is estimated that rod groups I and 4 were fully inserted 3 seconds after the initial actuation and all t

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• Liemt55 EVENT REPORT (LER)' TEXT CONTINUATION LER NUSER (6) Pace (3)

FACILITV NME (1) DOCKET NUSER (2)

Year /,/,/, Sequential /,/,/, Revision W/ thaber - W/ Nimber l o I 5 I o l'o l'o 1 31 71 4 sI9 - oI111 - 0I 1 ol 3 0F 11 o l

u u11'e Counts Station unit 2

-TEXT Energy industry identificatloc System (Ells) codes are identified in the text as [XX]

B. DESCRIPTION OF EVENT (Continued) control rods were fully inserted within 3 seconds of the manual scr m. Based on available indications,

'It was determined that all other expected automatic actions occurred as expected and a valid proces's scram signal had not occurred. This event is being reported in accordance with 10CFR50.73(1)(2)(lv) due to the actuation of an Engineered Safety Feature System.

Prior to performing the Turbine Valve lightness Test the turbine was tripped at 0306 and 0319 hours0.00369 days <br />0.0886 hours <br />5.274471e-4 weeks <br />1.213795e-4 months <br /> on August 26, 1989. The reactor did not scrm during either of these events because the 30E Turbine First Stage Pressure Trip Bypass was in effect at the time.

From approximately 2327 hours0.0269 days <br />0.646 hours <br />0.00385 weeks <br />8.854235e-4 months <br /> on August 25, 1999 to 0316 hours0.00366 days <br />0.0878 hours <br />5.224868e-4 weeks <br />1.20238e-4 months <br /> on August 26, 1989, the sequential memory of the sequence of events recorder (SER) was being saturated (filled) due to cycling inputs from the 8 Turbine Driven Feed Water Punp Seal injection Pressure switch, and the Off Gas Pre-Treatment Radiation

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Monitor Low Sanple Flow detector. Both of these alanns are " normal" for the shutdown condition, and were cycling rapidly.because the process signals were slowly passing through the al' arm setpoints.

At about 0338 hours0.00391 days <br />0.0939 hours <br />5.588624e-4 weeks <br />1.28609e-4 months <br /> the Hathaway Sequential Events Recorder (SER) alann printer was turned off because the typer was continuously printing messages caused by these nuisance alanns. This printing was distracting to the Operators who were performing the turbine valve surveillance in the inmediate vicinity of the typer. This had no effect on the operation of the visual or audible alarms in the Control Room.- Authorization to bypass these alanns had been initiated prior to when the printer was

. turned off and had just been obtained just prior to the event, but the associated bypass jimpers had not been installed.

As a result of not having the SER alann printer in operation at the time of the event, investigations into the cause of the event are very difficult. Therefore the primary sources of recorded data for this The event are the plant process computer (CX) [lD), the Startrec computer and Control Room charts.

process computer prints out certain digital inputs if they change state for at least I second (its digital point scan rate). It also printed a "NS$$ post trip log" which prints a historical log of 10 analog sensor readings (stored at 5 second intervals) retrieved from 5 minutes prior to its initiation.

This log was initiated by the receipt of the "A" backup scre signal which accompanied the initial automatic scram. The Startrec recording was initiated directly by the RPS actuation and records selected sigacis from .5 seconds before the trip to 1 minute after the trip. It has a scan rate of 20 milliseconds per scan.

C. APPARENT CAUSE OF EVENT To evaluate the cause of the scrm, a list of possible scrm signals was generated and available infonnation (including Control Room chart recorder data) was used to eliminate any parameters which it could be shown to have not exceeded their scrm setpoints (LSSS value) at any time. The results of this conparison concluded that there is no indication that any LSSS parameter actually reached a required scram setpoint. Therefore, any RPS channels which received trip signals were receiving only false trip indication, not reflective of the true process conditions.

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I LER NUSER (6) Pace (3)

FACILITY N M _(1)y DOCKET NUMER (2) y Year. SpentialfJ/ Revision .)

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TEX 1 > Energy Industry identification System (Ells) codes are identified in the text as [XX]

i 1 APPARENT CAUSE OF EVENT (Continued)-

J C.

=i LEstensive Operator interviews were conducted. The only significant infomation related to the cause of the event was the Operator' actions to verify that the visual annunciator system."first out" light ilt

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was' the " Turbine Stop Valves Not F-open" alam. This alam is espected during the associated test and would not necessarily reflect the cause of the scr e in this case. This contributed to the Operators' L

belief that the scre had been caused by a combination of the stop vs1ve closure (due to the test), and .

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'an unexpected loss of the scrm bypass function which operates off of the-turbine first stage pressure.

l l} . Subsequent indications of.the turbine first stage pressure. led to the conclusion that this was not

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.likely to be'the cause of the scr m signal.

Further investigations indicate that the scrm signal could be due to a spurious pulse (not caused by an h

actual process variable transient) on one of the sensing lines which is shared by an "A" and a "B" RPS E subchannel. All shared sensing lines were identified using plant drawings.

i Extensive tests of the RPS system was undertaken in an attempt to detect anomalies in the following' areas:

1) proper subchannel wiring'(i.e., that the correct contactors respond to trip and reset

-actuations,

2) Inadvertent or failed rest / seal-in paths,

3) loose connections, E 4)- -foreign materials inside the contactors or houslogs,

5) response timing between paired contactors and between contacts on the see contactor,

6) logic inputs (station scre functional survelliances perfomed),

7) Radio - frequency interference, and

8) mechanically induced trips due to striking conmon sensing lines.

All of these tests demonstrated proper operation in all "A" and "8" RPS channels.

' The failure of the A2 and A3 Reactor Protection System channels to drop out indicates that the K14E and K14G scr e contactors did not trip. Scr m contactors K14E and K14G were removed from the plant to be tested. Prior to removal the following was perfomed:

1) Visual checks for discoloration

2) Drop out timing tests

3) Response times

4) Coll and contact resistance

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I LP_""' EVENT L"lRT (GR) TEXT CONTINUATION - Fom Rev 2.0 DOCKET NupeER (2) ER MurunER (6) Pane (3)

, FACILITY NNE (1) 4 Year Sequential Revision 3 g//

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% 11e t- M y Station Unit 2 015101010131114 8l9 - 0l111 - 0l 1 015 0F 11 0 l' i

. TEXT Energy Industry identification System (Ells) codes are identified in the text as (KXJ 1

3 E C.,' APPARENT CAUSE OF EVENT-(Continued) 3

5) Varlstor current check

6) Coil shorted turns test

. 7) Temperature rise test P Early evaluations indicated that the pulse which initiated the trip signal was sufficiently short and b

the reaction time of the contactor(s) was slow enough to prevent drop 4ut and seal-out of one contactor in a logic pair.

H Extensive testing was done by System Operational Analysis Department (SOAD), with vendor and NRC observers to look for abnomalltles in the removed K14E and K14G contactors and in a new contactor.

This testing has found no identifiable problem with the K14E or K14G contactor.' However the testing demonstrated a repeatable condition where narrow pulse actuations (between 8 and 12 ellliseconds) will l< occasionally result in one contactor in the pair dropping out and the other remaining energized. ,

The initiation of the event could not have been a valid scem signal. The studies done show that the observed operation of the RPS system was not the result of mechanical binding but could be mimicked by 1 applying trip signals for short (8 to 12 milliseconds) latervals. Such signals were observed to cause l only one of the two relays in the RPS automatic scram channel to actuate (de-energize and stay de-energized).'.

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The most plausible explanation of this event is that it was initiated by a spurious. signal having a duration of 8 to 12 ell 11 seconds. Because not all plant monitering 'quipment was available at the time, i

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the exact source of this spurious signal cannot be detemined.

The manual scram was a valid scram signal and perfonned as expected and designed.

D. SAFETY ANALYSIS OF EVENT Initiation of the event was not due to an actual transient on a parameter which is monitored to protect the reactor. All systems, when required to operate, functioned as designed. l l-The delay in the operation of these contactors caused the insertion delay of two groups of rods.

Insertion of two rod groups is sufficient to ensure the reactor is subcritical in hot shutdown.

l Reviews of the conputer scan of rod positions which was requested at the time of the scrm indicated that all rods were being inserted. This shows that the actuations of the "A" backup scram channel was sufficient to cause the scran air header to bleed down enough to open the scram valves of the last two groups of rods and cause them to begin moving before the Operator manually .scramed the reactor.

This event is not expected to have been worse at higher power levels since no actual plant transient occurred during the event.

Due to tne redundancy of the Reactor Protection System components and the satisfactory response of required support systems, ti.e safety consequences of this event are minimal.

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/ Nueer V/ Nueer tasatie County Station unit 2 oI5IoIoIo 1 31 71'4 e19 - ol111 - ol 1 016 oF- 11 o l-4 TEXT = Energy Industry identification System (Ells) codes are identified in the text as [KK1 E. . CORRECTIVE ACTIONS The Operating Department generated procedure guidance to prevent the deactivation of key recording ,

l devices whlie major evolutions are in progress and delay the start of major evolutions until these H

? recording devices were operable. LaSalle Aeninistrative Procedure LAP-1600-2, " Conduct of Operations," j has been revised with the following guidance:

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1) . The SER alam typer wlil not be turned off during evolutions that have a high potential for an  :!

unexpected translent, j 2); Provide options which can be used to deal with nuisance alams. -

-In addition, the.laportance of the SER in post event evolutions has been included in Operator training.  !

. Options for improving the availability of the SER will be pursued tracked by Action item Record (AIR) l s 374-200 4 9-03701. ':

E- Response time " tests were conducted on these scram contactors in an attempt _ to identify faulty contactor l l ,and/or quantify the magnitude of their response times. During the test equipment hookup to the A1 j L subchannel, the partial scr a condition appeared.to be repeated only once in many attempts, where the A2 I L

~and A3 lights did not deenergize as quickly as did the Al and A4 lights. This trip signal'was generated.

While setting up the monitoring instruments and, though it was observed by personnel in the Control Room, was not recorded. , Subsequent attempts to repeat the event at varying times failed to repeat the unusual dropout behavior of the suspected "E" contactor or identify its cause. Because of this second

- observation of slallar behavior as the initial scran and the repeated successful tests on the "G" contactor, the "E" contactor was considered to be suspect. As a conservative measure, both the K14E and K14G contactors have been replaced. The two removed contactors have been sent to Commonwealth Edison's l System Operational Analysis Department (SOAD) to be analyzed for potential failure mechanisms.  ;

lI The SOAD testing and inspection of the removed contactors consisted of 4 phases. These were:

1. Detailed inspection of "as found" conditions prior to removal.

• 2. Preliminary non-destructive response time characteristics testing of the contactor and associated varistor (voltage spike suppressor).

3. Disassembly and inspection with vendor and NRC observation.

4. Reassenbly and testing of response times under varied trip demand conditions.

Phase 1 discovered the presence of fire retardant cable packing which had vibrated out of the conduit entering the top of the contactor housing. This was not considered to be related to the problem under evaluation.

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DOCKET NueER (2) LER INMBER (6) P m (3)

FACILITY INuE (1)-

' Year /// Sequential // Revision fff

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TEXT Energy Industry identification System (Ells) codes tre identified in the text as [XX)

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E. .. CORRECTIVE ACTIONS (Continued)-

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Phase 2 demonstrated that it was possible to deeerrgize a single contactor in a pair if the demand

" pulse" is short enough, between 8 and 12 milli',econds. t y

Phase 3 discovered no unusual conditions ip',lde the contactor moving assembly or contacts. All movable

surfaces were free of foreign material wh'ch could cause binding or sticking, and no physical distortion j of any parts was found. The above mentioned packing material was present inside the ccntactor body, in small quantitles. This dry, soft material was not seen to potentially interfere with contactor movement. No contact welding was indicated, t-l ;. y> i Miase 4 involved detailed simulation of the plant logic chain. Oropout tests of the parallel contactors f'

was perforined using the same relay contact configuration as the plant. (Phase 1 tests had used a solid state switching device to drop out the contactors.) -In this way, ranoom portions of the AC waveforin would be interrupted by the driving relay contacts, and the possible effect of contact bounce could be t

-simulated. This testing showed that narrow pulses to the logic chain which result in. interruption of AC power to scram contactor for intervals of 8 to 15 milliseconds would result in a single contactor dropping out approximately once in 70 to 80 demands. The width of this interval is consistent with all observed inforination to date.

On September 8,1989 following the perforinance of LaSalle Instrument Surveillance LIS-#R-402, "Interinediate Range Monitor Pod Block and Reactor Scram Functional Test" on the D Interinediate Range Monitor (IRM) [lG), the D 1RM function switch was moved from OPERATE to TRIP TEST and back to OPERATE with the IN0P INHIBIT button depressed. (This bypasses the inoperative scr m signal.) This was done to i.

! verify proper operations but was not part of LIS-41R-402. During this actiore the RPS subchannel was reset (which is not the case during the normal Lis). When the mode switch was noved from TRIP TEST to CPERATE,'a HI-H1 signal was generated for a short period. RPS rod grocps B2 and 83 were dropped but 81 i and 84 did not trip. Investigations did not find any specific problems with tie system.

During the investigation it was learned that the channel C and D Turbine First Stage Pressure switches This did were found to be out of tolerance in the non-conservative direction due to instrument drift.

not affect the sequence of events. Deviation report (1-2-89-039) has been generated on these switches and they have since been recalibrated.

Corrective actions have been taken to correct specific equipment operational problems. These have been done under LaSalle Work Requests, and were reviewed in accordance with a special On-Site Review for plant startup.

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! The RPS specific corrective actions are as follows:

1. Scram contactors K14E and Kl4G were replaced.

2. The turbine valve leak tightness testing was satisfactorily perforined on Unit 2 statup to verify that the event is not repeated as a result of testing.

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' Energy Industry Identificction System'(Ells) codes are identified in the text as [XX]:

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.EA 00RRECTIVE ACTIONS'(Continued)

,: .3. RecordinginstroentationwasIinstalledtomonitortheRPSchannelsduringthe'subsequentstartup

'of Unit 2, until the next refuel.

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= F .' PREVIOUS EVENTS tiene.

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' 6. -- COWONENT FAILURE DATA -

Manufacturer- tienenc1'ature . Model ihmber MFG Part thster .

General Electric Scr a contactor CR-105 CR105002 -j CR105X100E l'

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• TEXT _ :' . Energy Industry Identification System (Ell 5) codes are identified in the text-as [XX]_

ATTACHMENT A-h REACICR PROTECTION SYSTEt1 RPS CHAMMEL A RPS CHANNEL B

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i "45-G1 R05S "55'55il0DS "4 -G5'R0DS' "U'~G4 RO55

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l lL. .

[' ==D ==H ==F -- B

==B

==F ==H' I L

O O h T"'

v ScRaa AIR b]69:11]:j:] Header l\ , . .

I KQ A C  :

F H BACKUP SCRAM: -

Backup "A" .g -Energize to actuate

-oriven by Auto scram E. Backup "B' B D -scrams all rod' E G O O L. 12s voC 12s voc y

I I

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' ~ ~ ~ ^^ ~ ^^~ ~ ~' ' ' ~

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• Fore Rev 2.0 L c""r EVENT REPORT (LER) TEXT CONTimlAT10ll i DOCKET NupWER (2)' LER IL T : (6) Paae (3)

FACll,lTY NIWE (1)

' * ' Year //,/ Sequential ///, Revision W/ thaber -f

~

W/ thaber-8 A lle County Station Unit'2' 0 1 5 l'0 1 0 1 0 1 31 71 4 ei9 - 011l1 - 01 1 11 0 0F 11 0 l1' TEXT Energy Industry Identification System (Ells) codes are identified in the text as (XX)

ATTACHMENT B-r RPS LOGIC EXAMPLE  ;

LaSalle' .

SUBCHANNEL IKil 2 ,

128 URC 0 Bupass O I

-TRIP Turb. Stop Ulv Not .Open Cont Ulv Fast Close

=

=

.4

7=

=

= Turb ist

'StgPress u S/D == RESET u

M" Mode SU. ""

= i Scran Disch Volume Hi

=\=='B/P sw MSIVs not Full Open n u\= ='Rx Mode..,e::!.d. " " '_ . " " -

Switch -

t

==

HI D/H Pressure == - ' \ a gAJ HI Rx. Pressure u SCRAM n reqd "

LO Rx, Hater Lvl MSL HI Rad n HI Neutron Flux , ,

L ( IRH/ RPRM -RUN )

H '*

l Manual Scran - n -- - - - .

Contactor K14R  !

r- QK1,4E  ;) '

(Ks o 4

' r-

6. ,s g ,. y d --

5

.)

T I d

l T i x X15 X19 MANUAL SCRAN SCRAM RESET SCRAM RESET LOGIC l'

SU. Reset Resets B/U Position Relay Contactor Lockout K19A (

Gi+ G+

K19B K19C ( gy G2+G3 X19D 1H

,