ML20006D486

LER 90-001-00:on 900105,unexpected Auxiliary Feedwater Automatic Startup Occurred During Periodic Cabinet Test. Caused by Procedure Deficiency.Procedures to Be Revised to Prevent recurrence.W/900207 Ltr

ML20006D486
Person / Time
Site:	Catawba
Issue date:	02/07/1990
From:	Glover R, Owen T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-001-01, LER-90-1-1, NUDOCS 9002130329
Download: ML20006D486 (6)

Text

@N 2 -

y  : .

Duke hwer Conga ~y (803) U I 3000 Catauha Nudrar Station PO Bra!% .

Cler, S C 29T10 i ,

DUKEPOWER February 7, 1990 l

Document Control Dcsk

~U. S. Nuc1 car Regulatory Commission Washington, D. C. 20555

l.

Subject:

Catawba Nuclear Station Docket No. 50-414 LER 414/90-01 i Gentlement Attached is Licensee Event Report 414/90-01, concerning AUXILIARY FEEDWATER AUTOMATIC START DUE TO AN INADEQUATE PERIODIC TEST

• PROCEDURE.

i This event was considered to bc of no significanco with respect to the health and safety of the public.

i very truly yours, f

'l l Tony B. Owen Station Manager

! keb\LER-NRC.TBO xct Mr. S. D. Ebneter American Nuclear Insurers

" Regional Administrator, Region 11 c/o Dottie Sherman, ANI Library U. S. Nuclear Regulator Commission The Exchange, Suite 245 101 Marietta Street, NW, Suite 2900 270 Farmington Avenue Atlanta, GA 30323 Farmington, CT 06032 Mr. K.,Jabbour M & M Nuclear Consultants 1221 Avenues of the Araericas U. S. Nuclear Regulatory Commission New York, NY 10020 Office of Nuclear Reactor Regulation Washington, D. C. 20555

.l

- INPO Records Center Suite 1500 Mr. W. T. Orders 1300 circle 75 Parkway NRC Resident inspector Atlanta, GA 30339 Catawba Nuclear Station l

9002130329 900207  % .

PDR ADOCK 05000414 pl

s PDC l

0

)

. s. . Nuc6t.m atout. Tom, co i io , l

/ . m.0vt D . 0 . .

. UCENSEE EVENT CEPORT (LER) 5 :a' ' ' '8' "

l

.aci6Tv Nam tu pocalT Nv= u m ini r m a.

C tawba Nuclear Station, Unit 2 o l6 l0 l0 l 0l4l1 l 4 1 loFl 015 h'* Auxiliary Feedwater Automatic Start Duc To An inadequate Periodic Test Procedure OTHim 8 &CiLITit$ INv0LytD 101 l

$ VENT Daf t (Si Lt m Nunett a (61 8ttPont DAf t 171 pocal1 Nuwaitmisi 40%TH Day vtAm vtan 5'['$ , , h ",'ly*y MONtu Day vtam ' ' Cit i yNavas 016l0l0l0i l l

~ ~

011 0l5 9 0 9l 0 0 l 0l 1 0l 0 0] 2 0l7 9l0 oistotoici l t I I

,,, gag g TMiG mtP0mf 18 SUDurTT40 PusituANT TO TMt atDuestutNTS 0810 Cpa 5 tenec. eae e, me,e e,,ae reae.,es s itti I

20 402(6I to 40tial X SO 73 42n i 73.71161

,, , u.,

= not i i

. 0. .. ,n ,,i,

. 0. . .n n.,

.0 .i.n ,,

= = i.n. ,

.0 , .n,n.,

. n.n.n..,

_ =; g.=,, , , ,

n .0.i.in n., u ni.nini, u n.nin..on.i - . ,

to 40lloillikel 6013.ntilat 60.?Stan211.shnti 30 e06laill ntl 60 73isillnant DO 73 eI(tilal 41CtN$18 CONT ACT som tHis Lim (1),

NiME TitlPHo%t NUMIitR I

• R4aCOD4 I R.M. Glover, Compliance Manager 8,0,3 8, 3 ,1 , , 3 ,2 , 3,6 COMPttf t DNS LINT 90m LAcw coher0NINT p altunt Dtscaisto sN fnis attomt its S

• j Civ88 Svsttu R f 0R,','g t CAvst sy st E M COMPQNtNT NI#O I,A LI COM*0NINT MANC l I i i I l i l 1 l l t i I I I I I I i 1 1 I I I I I

$UPPLEMENT AL MIP0fif t kPtCTIO (141 MON 1H DAv vlam sv.w,ssio,.

bto u, r.. ,e a u Y _ .c T <t . ~, ,, ,

. iweerro suewssioN o rei

<., . . . .,e,. . ... ., ,,,r..

-] 0

., . <. ,,,. . n.. ,. ., n e i 014 115 910 On Januqry 5, 1990, Unit 2 was in Mode 3. Hot Standby, in order to repair a Steam Generator Blowdown containment isolation valve actuator. During the performance of PT/2/A/4200/09A, Auxiliary Safeguards Test Cabinet Periodic Test, an unexpected Auxiliary Feedwater (CA) automatic start occurred coincident with the reset of the Diesel Generator (D/G) 2B sequencer at 2103:43 hours. The CA System was subsequently reset. After review of the test procedure and electrical elementaries did not reveal the cause, permission was obtained to repeat the test while personnel observed key relays. The loss of Main Feedwater (CF) Pumps relay was identified as the initiating relay in the second test.

Further review determined that the loss of CF Pumps relay is de-energized when the sequencer relays are actuated. Therefore the loss of CF Pumps relay is re-energized when the sequencer is reset if the CF Pumps are in a tripped condition. This problem is attributed to a procedure deficiency and procedures will be revised to prevent recurrence. This incident is reportable pursuant to 10CFR 50.73, Section (a)(2)(iv) and 10CFR 50.72, Section (b)(2)(ii),

g,cy . n.

y

{ *,

"w"* f*"" ""* '

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION vs wuctt. atout.,o.. cou..

maovto owe no so.co.

ExPints. $ '310

1. ace 6115 haast HI oocant Nuestam tri tin Nuusta ist Pa05 (31 4 "^a -

"2 2 "  ;'r7 C tawba Nuclear Station Unit 2 un u -. . - , = = mi o l6 l0 l0 l0 l4 l 114 910 -

Ol011 -

010 d2 oF 0 l5 q

h.7 BACKGROUND f2

• The Auxiliary Feedwater [EIIS:BA) (CA) System assures sufficient feedwater supply to the Steam Generators [E!!S:Hx] ($/Gs) for decay heat removal in the event of loss of Main Feedwater [EIIS:SJ] (CF). The CA System is independent g" for each Unit. Each Unit has two 100% capacity Motor Driven CA Pumps [EIIS:P]

and one 100% capacity Turbine Driven CA Pump (CAPT). The Motor Driven CA Pumps automatically start on loss of both CF Pumps or 2 of 4 low level indication on

- any one S/G. The Motor Driven CA Pumps are also automatically started in load '

[.

group 7 of the 0/G Load Sequencer [EIIS:EK] during a blackout and/or a LOCA.

A CA automatic start is an Engineered Safety Features [E!!S:JE] (ESF) Actuation and is reportable pursuant to 10CFR 50.73, Section (a)(2)(iv) and 50.72, Section ,

.. (b)(2)(ii). During a CA automatic start the Motor Driven CA Pumps start, the CA

..: discharge valves [EIIS:V) for each train fully open, the S/G Blowdown [EIIS:WI]

1 (BB) System isolates and the Nuclear Sampling (EIIS:KN] (NM) System from the h, S/Gs isolates.

The load sequencer functions to automatically energize the necessary blackout

. and/or LOCA required loads in a definite progressive sequence in such a manner J' -that the D/G [E!!S

EK] or Auxiliary transformer [EIIS:XFMR] is not momentarily overloaded. A loss of voltage at the 4.16 KV essential switchgear or a Safety o Injection Actuation Signal (Ss) from the Solid State Protection System [EIIS:JC]

(SSPS) will actuate the sequencer for each train.

PT/2/A/4200/09A, Auxiliary Safeguards Test Cabinet Periodic Test, tests the o operability of the final actuating device for nuclear safety related equipment while the Unit is in service without disturbing the operation of the Unit. ,

O- Section 12.42 verifies the logic of Train B Safety Injection Relay [EIIS:RLY]

K608. Components tested in this section include the 2B D/G Load Sequencer and Valves 2ND60, ND Hx 2B Outlet Control, IND61, ND Hx 28 Flow Control, and 2RN351, KC Hx 2B Outlet Throttle.

EVENT DESCRIPTION On January 5, 1990, Unit 2 was in Mode 3, Hot Standby, in order to repair the actuator on 2BB19A, S/G 2B Blowdown Containment Isolation Valve. Other maintenance and testing activities requiring Mode 3 status were also being performed. These activities included shaft realignment of CF Pumps 2A and 28.

The CF Pumps were tripped and the S/G levels were being maintained by CA Pumps 2A and 28. The Control Room Operators (CR0s) were manually controlling the S/G 1evels with the CA Control Valves. The CA System was in standby readiness since Reactor Coolant [EIIS:AB] System pressure was above 1955 psig.

l gym... .....m.i,....,,...-

t

+

io=

u s. =vetian mmvoav ca i une m.a maovio ow =o meio.

UCENSEE EVENT REPORT (LER) TEXT CONTINU ATION iness amo 5 ,

lt, , ggg gyggggg gg, pggg gg, DOCEll NURADt h (4)

IAC4kITV DIAABL 4H

's*a " WP." "?A*.T;

)'

Catawba Nuclear Station, Unit 2 o ls j o l 0 l 0 l4 l 1l 4 9 l0 -

0l0l1 -

0 10 013 of 0l5

}

itxt a . m =ac e anwim f-- At 2103:43 hours, an unexpected Train B CA Automatic Start occurred coincident with the reset of the 2B D/G Sequencer per PT/2/A/4200/09A, Section 12.42.

Since CA Pumps 2A and 2B were already in operation, the Valve isolation.

Control Train B reset status light going dark, and Train B B the CA Control Valves to prevent overfill of the S/Gs and realigned NM and BB.

Additional Performance personnel were contacted inprocedure order to determine the reason Review of the test and for the unexpected CA automatic start.

electrical Therefore, elementaries did not reveal the wascause of the CA automatic star the Shift Supervisors permission obtained to repeat Section 12.42 of PT/2/A/4200/09A while personnel were stationed to observe the operation of key relays.

At 0300:57 hours, on January 6, a second CA automatic start occurred coincident with the reset of the D/G 2B sequencer while personnel observed the associated relays. The loss of CF Pumps relay was identified as the initiating relay in the second test. By 0302 hours0.0035 days <br />0.0839 hours <br />4.993386e-4 weeks <br />1.14911e-4 months <br />, the CR0s had realigned from the Trai automatic start.

the negative leg of the loss of CF Pump relay is opened During when the sequen relays are actuated.

the sequencer is reset if both CF Pumps are in a tripped condition.

previous performance of this test, this sequence of events pressure.

CONCLUSION This incident has been attributed to inadequate procedural precautions.

PT/2/A/4200/09A allowed Section 12.42 to be completed in Mode 3 with CA automatic start enabled and bothPT/1(2)/A/4200/09A CF pumps trippedalong without withcompensating other test measures to prevent a CA automatic start. procedures that involve testing of the D prevent the recurrence of thisInproblem. Nuclear Station were contacted to re addition, Design Engineering is elementaries for a similar problem. investigating the circuitry for appropriate s operation, Review of the OEP database yields three previous LER events414/88-05,involving Unexpected ESF actuations due to p mcedural deficiencies in the past two years.

Auxiliary F0edwater Autostart Occurs During Testing Due to Unknown Cause and lack of Proredural Precautions, involved the CA, CF, Turbine Interlocks Periodic Test procedure which did not ensure that the CA The automatic CA automatic startstartlogic was in a reset shtus prior to removing the autostart414/85-05 defeat. in that the "CA Valve described in this report differs from LERControl Train A(B)" reset status Feedwater Isolation on Hi Hi S/G Level Ouring sequencer. LER 414/89-013,

..... m . u,. m .... -

f a'oa m

~

m esec Poem sena v3. esuctsA: Raou6; tony coMamessoas

{, / LICENSEE EVENT REPORT (LER) TEXT CCNTINUATION waoven oMe m mo-m4 IN DOCK &T ItVMD6 A Ltl gg H R WMDE R @

i "*a "#Lli. Mif,'O C:t wba Nuclear Station. Unit 2 ol6l0l0l0l4l1l4 910 -

Ol011 -

0 l4 oF l 0 l0 0 l5 4

swu==.~e <. ww smann 1 4

] Testing Due to Inadequate Procedure Precautions, also involves the CA, CF, Turbine Interlocks test. The procedural deficiency identified in LER 414/89-013 involved the operational interaction of the systems and components being tested whereas the procedure deficiency in this incident involves misinterpretation of '

design drawings. LER 413/89-019 Two Unplanned Automatic Alignments of the Nuclear Service Water System To The Standby Nuclear Service Water Pond, involves procedural deficiencies associated with a Maintenance and a modification procedure used for the first time. The above incidents meet the Duke Power Nuclear Safety Assurance definition of a recurring problem. The corrective J action prescribed in the previous incidents would not have prevented the incident described in this report. Due to the complexity of the design of the circuit and the number of conditions that had to be met to cause the CA automatic start, it is doubtful that procedure review would have prevented this  :

type of incident. Therefore, no other corrective actions are recommended at 1

- this time, other than the revision of the procedures that apply to the CA j J automatic start circuit when the D/G sequencer is placed in test.

l The review of the OEP database also identified five CA automatic starts over the past two years (LER 414/89-015,414/88-032,414/88-024,414/88-014,414/88-05).

LER 414/88-05, as described in the above paragraph, involves a procedural 4 deficiency, therefore, this incident also meets the Duke Power Nuclear Safety  :

Assurance definition of a Recurring Event. The remaining CA automatic starts were caused by equipment malfunction or inappropriate action. For the reasons stated in the preceding paragraph, a generic procedure review is not being recommended at this time.

Station Management will meet to review these events to determine whether any further corrective actions are warranted to address the recurring problem of procedure deficiencies.

CORRECTIVE ACTION IMMEDIATE

1) The CR0s reset CA and throttled the CA control valves to maintain S/G level, and realigned affected BB and NM valves.

SUBSEQUENT

1) Performance repeated Section 12.42 of PT/2/A/4200/09A to determine .

I cause of the CA automatic start.

2) Performance determined that the CA automatic start was caused by the

- re-initiation of the CF pump trip caused by the D/G sequencer reset. l

3) Performance alerted McGuire Nuclear Station (MNS) performance of the i problem so that applicability to MNS could be investigated.

.v.s. m , no,-m m m a hcfuma

? 1

. .2 ucui. ...ve, , . 0, -  !

(f.

',* LICENSEE EVENT REPORT (LE] TEXT CONTINUATION A>.aovio ous =o ma-oio.

ex ints num 9holkftv geA.48 HD DOCh.T NutdDlh (3) LlR NUMDER 86) PAot (31

.... = =  ;

Catawba Nuclear Stationt Unit 2 0 l5 l0 l0 l0 l4 l ll 4 910 -

0l 0l1 -

010 Ol 5 0F 0l5 van v - . < e w .,nn

{

6 4) Performance determined which other periodic test involving testing of f the 0/G sequencer relays that will require revision to prevent an unexpected CA autostart.

. 1 i PLANNED )

- I

1) PT/1(2)/A/4200/09A and other applicable periodic test procedures 1 involving testing of the D/G sequencer relays will be revised to

, prevent unexpected CA automatic starts during testing.

2) The need for changes to IP/1(2)/3670/01A(01B), Load Sequencer limer L Calibration, to prevent unexpected CA automatic starts will be investigated.

p). 3) The CA automatic start circuitry will be investigated for appropriate

> system response during all modes of operation and the possibilities and consequences of a " relay race" during sequencer reset if CA has already been reset will be evaluated.

, 4) A meeting will be held between the management of Performance,

Operations, Maintenance Engineering Services and the Catawba Safety Review Group to determine whether further corrective action can be taken to prevent further ESF actuations due to procedure deficiencies.

5) This report will be revised to reflect any additional corrective r actions identified. .

[ SAFETY ANALYSIS ,

' This incident occurred during testing with Unit 2 in Mode 3 with both Motor Driven CA Pumps in operation to maintain S/G level. The Auxiliary Safeguards test caused the B Train CA automatic start due to re-initiation of the loss of CF Pumps relay when the D/G 2B sequencer was reset. The Train B components .

responded as designed to the Train B automatic start signal and the CR0s properly responded by resetting the CA System and throttling the CA control valves to maintain the proper S/G levels. The CA System maintained its safety function to provide decay heat removal for the Reactor Coolant System.

Therefore, the health and safety of the public were unaffected by this incident.

+

.....m.i.......,,,,m, rg =