ML20141D920
| ML20141D920 | |
| Person / Time | |
|---|---|
| Issue date: | 05/15/1997 |
| From: | Chaffee A NRC (Affiliation Not Assigned) |
| To: | Slosson M NRC (Affiliation Not Assigned) |
| References | |
| OREM-97-004, OREM-97-4, NUDOCS 9705200240 | |
| Download: ML20141D920 (17) | |
Text
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May 15, 1997 L
MEMORANDUM TO: Marylee M. Slosson. Acting Director j
Division of Reactor Program Management FROM:
Alfred E. Chaffee. Chief [ Original signed by)
Events Assessment and Generic Communications Branch Division of Reactor Program Management
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING MAY 7. 1997 - BRIEFING 97-04 On May 7.1997, we conducted an Operating Reactors Events Briefing (97-04) to inform senior managers from offices of the Commission. AE0D. NRR and regional offices of selected events that occurred since our last briefing on April 30, 1997. Attachment 1 lists the attendees. presents the significant elements of the discussed events. contains reactor scram statistics for the week ending May 4.
1997.
No significant events were identified for input into the NRC Performance Indicator Program.
i The statements contained in the attached briefing slides represent the best information currently available to the NRC.
Future followup could produce new information that may alter the NRC's current view of the events discussed.
Attachments: As stated (3) cc w/atts:
See next page i
CONTACT:
Kathy Gray. NRR (301) 415-1166 DISTRIBUTION:
(w/atts) q q, go Central Files PUBLIC 1Kilgore SECY l
PECB R/F KGray WBurton
-DOCUMENT NAME: G:\\KAG\\0RTRANS Ta receive a copy of this document. Indicate in the boa: "C" = Copy without attachment / enclosure "E* = Copy with attachment / enclosure "N* = No copy OFflCE PECB lE PF.CB l,
PECB l
C/PECB l N NAME KGray:JkdKW WBurton{f 7/.
EGoodwm C AChaffee M
j DATE 05/ G /97 5
05/ p /97 05/ J ) /96 N) 05/ f(197 QtFICIAL Mt'GORJ COPY 2000"l3 MBC Hl.E CEi4TER CBPV Cfe'-G " Y 9705200240 970515 PDR ORG NRRA PDR
cc:
S. Collins. NRR (0-12G18)
F. Miraglia. NRR (0-12G18)
R. Hernan. NRR (014B21)
F. Gillespie. NRR (0-12G18)
F. Hebdon. NRR (014B21)
R. Zimmerman. NRR (0-12G18)
R. Capra. NRR (013D1)
T. Martin. NRR (0-12G18)
C. Shiraki. NRR (013D1)
B. Sheron. NRR (0-12G18)
S. Varga. NRR (0-14E4)
J. Zwolinski. NRR (0-14H3)
J. Roe. NRR (0-13E4)
E. Adensam NRR (0-13E4)
G. Lainas. NRR (0-7D26)
G. Holahan. NRR (0-8E2)
D. O'Neal. NRR (0-10E4)
B. Boger. NRR (0-9E4)
M. Markley. ACRS (T-2E26)
D. Ross. AEOC (T-4018)
C. Rossi. AEOD (T-4A9)
F. Congel. AEOD (T-4028) 1 R. Barrett. AEOD (T-4A43)
S. Rubin. AE00 (T-4D28)
M. Harper. AE00 (T-4A9)
W. Leschek. AE00 (T-4A9)
V. McCree. EDO (0-17G21)
J. Gilliland PA (0-2G4) t i
D. Morrison. RES (T-10F12)
W. Hill. SECY (0-16G15)
H. Miller, Region I i
C. Hehl, Region I L. Reyes Region II J. Johnson Region II S. Vias. Region II A. Beach. Region III J. Caldwell. Region III E. Mershoff. Region IV P. Gwynn Region IV l
K. Perkins. Region IV/WCF0 l
G. Fader. INPO l
J. Zimmer. DOE a
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UNITED STATES S
NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. 20555-0001
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May 15, 1997 MEMORANDUM T0:
Marylee M. Slosson. Acting Director Division of Reactor Program Management FROM:
Alfred E. Chaffee. Chief OlM Events Assessment and Generic Communications Branch Division of Reactor Program Management
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING MAY 7, 1997 - BRIEFING 97-04 On May 7.1997, we conducted an Operating Reactors Events Brie'fing (97-04) to inform senior managers from offices of the Commission. AE0D. NRR and regional offices of selected events that occurred since our last briefing on April 30.
1997.
Attachment I lists the attendees. presents the significant elements of the discussed events. contains reactor scram statistics for the week ending May 4, 1997.
No significant events were identified for input into the NRC Performance Indicator Program.
The statements contained in the attached briefing slides represent the best information currently available to the NRC.
Future followup could produce new information that may alter the NRC's current view of the events discussed.
Attachments:
As stated (3) cc w/atts:
See next page CONTACT:
Kathy Gray NRR (301) 415-1166 t
~ ~ ' ~ ~ ~ ~
i
LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING (97-04)
MAY 7, 1997 NAME OFFICE NAME OFFICE t
A. Chaffee NRR L. Rossbach NRR W. Burton NRR J. Beall OCM-EM E. Goodwin NRR C. Rossi AE00 V. Hodge NRR B. Holian OCM-SJ M. Slosson NRR R. Eckenrode NRR J. Roe NRR F. Hebdon NRR A. Cubbage NRR C. Jackson NRR W. Lyon NRR R. Wessman NRR C. Shiraki NRR R. Hernan NRR K. Gray NRR TELEPHONE ATTENDANCE (AT ROLL CALL)
Reaions Resident Insoectors Region II Sequoyah Regior: III Zion Regiori IV Misc-ATTACHMENT 1 i
-l
J d
l OPERATING REACTORS EVENTS BRIEFING 97-04 i
l LOCATION:
0-10811, WHITE FLINT
)
WEDNESDAY, MAY 7, 1997 11:00 A.M.
i 4
SEQUOYAH, UNIT 1 INADVERTENT DRAINDOWN ZION, UNIT 2 GAS ACCUMULATION IN VESSEL HEAD i
l i
PRESENTED BY:
i i
EVENTS ASSESSMENT AND GENERIC COMMUNICATIONS BRANCH L
DIVISION OF REACTOR PROGRAM MANAGEMENT, NRR ATTACHMENT 2 i
1
^
i 97-04 i
SEQUOYAH, UNIT 1 j
INADVERTENT DRAINDOWN
[
MARCH 24, 1997 PROBLEM j
PARTIAL DRAINDOWN IN MODE 5 DUE TO ERR 0NE0US LEVEL INDICATION.
j SAFETY SIGNIFICANCE CONTINUED LOSS OF REACTOR COOLANT SYSTEM (RCS) INVENTORY l
COULD RESULT IN INTERRUPTION OF CORE COOLING.
SEQUENCE OF EVENTS INITIAL CONDITIONS UNIT 1 - MODE 5.
PREPARING TO REDUCE PRESSURIZER (PZR)
LEVEL FROM SOLID TO 25%.
3/23 DRAINDOWN INITIATED.
2300 3/24 INTERRUPTED DRAINDOWN FOR DIESEL GENERATOR TEST.
0230 PZR COLD CALIBRATED LEVEL INSTRUMENT (CC) READING 56%, PZR HOT CALIBRATED (HC) LEVEL INSTRUMENT READING 25%.
0630 ONCOMING SHIFT WALKED DOWN BOARDS.
0658 DRAINDOWNdFPZRRESUMED;TOATARGETLEVELOF25%
ON CC..
CONTACT:
W. BURTON, NRR/DRPM/PECB AIT: HD
REFERENCE:
MORNING REPORT #2-97-0018 SIGEVENT: TJD
SEQUOYAH, UNIT 1 97-04 0700 ONCOMING SHIFT (30 MINUTES) CREW MEETING OUTSIDE MAIN CONTROL ROOM.
0711 PZR LOW LEVEL ALARM RECEIVED (HC 17%).
0735 DAY SHIFT ASSUMES DUTY.
CC 44%, HC 0%.
CC MARKED WITH GREASE PENCIL.
0745 CC 38% STEADY AND IDENTIFIED AS NOT CHANGING.
HC 0%. DRAINDOWN SECURED.
0838 BEGA!
REFILL OF PZR.
0916 PZR LEVEL STABILIZED AT 26% ON HC.
DISCUSSIDH e
MINIMUM LEVEL 12 FEET AB0VE RCS HOT LEG.
e 3300 GALLONS NEEDED TO REFILL THE RCS.
UNEXPECTED DRAINDOWN DUE T0:
(1) ERR 0NE0US LEVEL INDICATION DUE TO LOSS OF REFERENCE LEG.
(2) LACK OF UNDERSTANDING 0F RELATIONSHIP BETWEEN LEVEL INSTRUMENTS.
REFERENCE LEG VOIDING - OCCURRED WHEN NONCONDENSABLES GASES IN REFERENCE LEG DURING PZR DEPRESSURIZATION CAME OUT OF SOLUTION.
IDENTIFIED EROBLEMS:
- 1. 182" DISPLACED FROM CC REFERENCE LEG PROBABLY DUE TO SYSTEM DEPRESSURIZATION.
SEQUOYAH, UNIT 1 97-04 l
- 2. BOTH CREWS RETURNING AFTER 3 DAYS OFF.
i f
- 3. NEITHER CREW QUESTIONED LEVEL INDICATIONS.
- 4. MANAGEMENT NOT ATTENTIVE TO DRAINDOWN OPERATION.
l
- 5. INADEQUATE LOGKEEPING.
l
- 6. INADEQUATE TRAINING.
- 7. PROCEDURAL MODIFICATIONS AS RESULT OF '93 EVENT INCOMPLETE.
FOLLOWUP e
TERMINATED DRAINDOWN AND REFILLED PZR TO HC 26%.
e OPERATIONS SUPERINTENDENT BRIEFED ALL CREWS.
REFERENCE LEG BACKFILLED, SYSTEM INSPECTED.
PROCEDURES REVISED.
PREVIOUS EVENTS j
MARCH 6-7, 1997 - PRAIRIE ISLAND 2 COLD SHUTDOWN.
DRAINED ~7500 GALLONS FROM RCS (EXPECTED TO DRAIN ONLY ~3000) DUE TO OPERATOR ERROR.
FEBRUAR.Y 1, 1997 - OCONEE 3
]
SHUTDOWN.
DRAINED ~4000 GALLONS FROM RCS DUE TO MISALIGNED VALVE DURING LEAK TEST.
BRIEFED 2/12/97.
4 SEQUOYAH, UNIT 1 97-04 j
l NOVEMBER, 1995 - HATCH 2 COLD SHUTDOWN.
DRAINED ~12,000 GALLONS IN ~ 1 MINUTE i
DUE TO INADEQUATE MODIFICATION, MAINTENANCE, AND TESTING CONTROL WITH RESPECT TO THE REMOTE SHUTDOWN PANEL AND RELATED EQUIPMENT.
{
SEPTEMBER 13, 1995 - SURRY 1 COLD SHUYDOWN.
DRAINED ~4500 GALLONS OVER ~5 HOURS DUE TO INADVERTENT ISOLATION OF REACTOR HEAD VENT.
i SEPTEMBER 17, 1994 - WOLF CREEK HOT SHUTDOWN.
DRAINED ~9000 GALLONS IN ~ 1 MINUTE TO l
REFUELING WATER STORAGE TANK DUE TO OVERLAPPING i
OPERATIONS AND MAINTENANCE ACTIVITIES.
BRIEFED 9/28/94 l
AND UPDATED 3/1/95.
APRIL 9, 1993 - SEQUOYAH 1 DRAINED ~10,000 GALLONS FROM RCS DUE TO FAILURE OF PRESSURIZER COLD CALIBRATION LEVEL CHANNEL.
REFERENCE LEG HAD BECOME PARTIALLY DRAINED DUE TO LEAKAGE PAST AN INSTRUMENT VENT VALVE.
RELATED GENERIC COMMUNICATIONS e
INFORMATION NOTICE (IN) 96-37
" INACCURATE REACTOR WATER LEVEL INDICATION AND INADVERTENT DRAINDOWN DURING l
SHUTDOWN" (DESCRIBES SURRY 1 EVENT).
" UNEXPECTED PLANT PERFORMANCE.DURING PERFORMANCE OF NEW SURVEILLANCE TESTS" (DESCRIBES HATCH 2 EVENT).
l
(
I.
l.'
SEQUOYAH, UNIT 1 97-04 IN 95-03
" LOSS OF REACTOR COOLANT INVENTORY AND POTENTIAL LOSS OF EMERGENCY MITIGATION FUNCTIONS WHILE IN A SHUTDOWN CONDITION" (DESCRIBES WOLF CREEK EVENT).
e BULLETIN 93-03
" RESOLUTION ~0F ISSUES RELATED TO l
REACTOR-VESSEL WATER LEVEL INSTRUMENTATION IN BWRs" (REQUESTS ADDRESSEES TO IMPLEMENT ACTIONS TO ENSURE THAT POTENTIAL LEVEL ERRORS CAUSED BY GAS IN REFERENCE
[
LEGS DO NOT RESULT IN IMPROPER SYSTEM RESPONSE OR OPERATOR ACTIONS.)
i e
" LEVEL INSTRUMENTATION INACCURACIES OBSERVED DURING NORMAL PLANT DEPRESSURIZATION" (JANUARY 21, 1993, WNP-2).
DURING PLANT C00LDOWN FOLLOWING REACTOR SCRAM, " NOTCHING" (MOMENTARY INCREASE IN INDICATED LEVEL) OBSERVED IN LEVEL INDICATION DUE TO GAS BUBBLE MOVING THRU VERTICAL PORTION OF REFERENCE LEG.
" LEVEL INSTRUMENTATION INACCURACIES CAUSED BY RAPID DEPRESSURIZATION" (MILLSTONE UNITS 1 AND 3).
DISCUSSES INACCURACIES IN LEVEL INDICATION DUE TO SLOPING INSTRUMENT LINES AND RAPID SYSTEM DEPRESSURIZATION.
l.
i 97-04 ZION, UNIT 2 GAS ACCUMULATION IN VESSEL HEAD MARCH 7, 1997 PROBLEM l
UNDETECTED GAS ACCUMui.ATION IN THE REACTOR VESSEL.
1 l
SAFETY SIGNIFICANCE VOID IN VESSEL COULD IMPACT DECAY HEAT REMOVAL.
1 BACKGROUND 9/1/96 3RADUAL DECREASE IN THE UNIT 1 REACTOR VESSEL l
LEVEL, VENTING REVEALED A VOID IN THE HEAD, i
~1028 GALLONS TO REFILL.
1 12/14/96 OPERATIONS MANAGER (0M) POSTPONED IMPLEMENTATION OF UNIT 1 CORRECTIVE ACTIONS j
UNTIL AFTER UNIT 2 REFUELING OUTAGE.
i SEQUENCE OF EVENTS INITIAL CONDITIONS UNIT 2 -
COLD SHUTDOWN, DEPRESSURIZED i.
2/16 UNIT 2 DEPRESSURIZED.
2/20 REACTOR VESSEL VENTED.
3/7/97 UNIT 2 OPERATOR QUESTIONED COMPUTER TREND PLOT FOR PRESSURIZER LEVEL AND VOLUME CONTROL TANK (VCT).
i i
CONTACT:
W. BURTON, NRR/DRPM/PECB AIT: HQ
REFERENCE:
REGIONAL CALL SIGEVENT: TBD
i ZION, UNIT 2 97-04 3/8/97 UNIT 2 REACTOR VESSEL HEAD VENTED AND REACTOR VESSEL LEVEL INDICATING SYSTEM (RVLIS) PLACED IN-SERVICE.
LOWEST VESSEL LEVEL WAS 3.5 FEET AB0VE THE POINT WHERE RHR WOULD BE AFFECTED.
6900 GALLONS TO REFILL THE REACTOR HEAD.
1 4/4/97 TEAM ESTABLISHED TO REVIEW UNIT 1 AND UNIT 2 VOIDING AND GAS ACCUMULATION.
4/6/97 GAS VENTED FROM UNIT 2 SAMPLED.
DISCUSSION VOID WOULD HAVE CONTINUED TO GROW UNTIL RESIDUAL HEAT REMOVAL SUCTION AFFECTED.
PRESSURIZER LEVEL WOULD NOT HAVE PROVIDED DIRECT INDICATION.
GAS ACCUMULATED IN STEAM GENERATORS.
CAUSE e
GAS INTRUSION FROM NITROGEN BLANKET IN VCT.
SEVERAL ITEMS CONTRIBUTED TO EVENT:
(1)
UNTIMELY CORRECTIVE ACTIONS FOR PREVIOUS EVENT (2)
POOR IMPLEMENTATION OF OPERATING EXPERIENCE INFORMATION (3)
INADEQUATE PROCEDURES (4)
LACK 0F KNOWLEDGE OF RVLIS BY OPERATIONS AND ENGINEERING STAFFS
L[.
i-i ZION, UNIT-2 97-04 (5)
FAILURE TO REPORT EVENT FOLLOWUP l
e REDUCED NITROGEN OVERPRESSURE IN UNIT 2 VCT i'
l e
INITIATED DAILY VENTING 0F VESSEL HEAD l
e TROUBLESHOOTING PLAN WAS INITIATED NEW PROCEDURE DEVELOPED FOR EXTENDED OPERATION IN l
i MODE 5 TEAM ESTABLISHED TO REVIEW EVENTS e
o ENFORCEMENT-ACTION BEING CONSIDERED PREVIOUS EVENTS AUGUST 28, 1996 - HADDAM NECK COLD SHUTDOWN.
TEMPORARY VENT' HEADER INSTALLED.
NITROGEN FROM VCT LEAKED THROUGH SEVERAL CHEMICAL AND VOLUME CONTROL SYSTEM VALVES INTO VESSEL.
NITROGEN LEAKED INTO SYSTEM FASTER THAN VENT SYSTEM REMOVED IT.
RESULTED IN INCREASED PRESSURIZER LEVEL WITH DECREASE IN VESSEL LEVEL.
LATER, NITROGEN WAS ISOLATED DUE TO CONCERNS OF EXCESSIVE USE.
NITROGEN REMOVED FROM VENT HEADER REDUCED NITROGEN IN SYSTEM AND REQUIRED ~5000 GALLONS TO REFILL.
I' j
ZION, UNIT 2 97-04 l
{
SEPTEMBER 13, 1995 - SURRY 1 l
COLD SHUTDOWN.
DRAINED ~4500 GALLONS OVER ~5 HOURS DUE i
TO VOID FORMATION AND WITH INADVERTENT ISOLATION OF j
HEAD VENT.
WHEN SYSTEM PRESSURE WAS REDUCED, BUBBLE EXPANDED.
OPERATOR SAW INCREASE IN STANDPIPE LEVEL AND
[
INCREASED LETDOWN.
(INFORMATION NOTICE 96-37) l SEPT. - DEC, 1993 - SEQUOYAH 1 l
GAS ACCUMULATION IN RCS DUE TO LOWER THAN NORMAL i
TEMPERATURE IN VCT.
MORE DISSOLVED GAS DUE TO LOWER TEMPERATURE.
GAS RELEASED WHEN WATER TRANSFERRED T0
[
RCS.
8,300 GALLONS TO REFILL.
(INFORMATION NOTICE 94-36) i l
i l
i 4
J i
REACTOR SCRAM Reporting Period: 04/28/97 to 05/04/97 YTD YtD ABOVE BELOW YTD Ell [
PLANT & UN,11 POWER 11P[
CAUSE COMPLICAtt0NS 15%
15%
TOTAL 04/29/97 SURRY 1 1
SM Equipment Failure NO 1
1 2
04/30/97 SOUTH TEXAS P 100 SM Equipment Failure NO 3
0 3
05/04/97 OAVIS BESSE 1 100 SA Equipment Failure NO 1
0 1
I 4
i l
l l
i ATTACHMENT 3 Note: Year To Date (tTD) Totals Include Events Within The' Calendar Year Indicated By The End Date Of the Specified Reporting Period ETS 10 Page:1 05/08/97
e COMPAR!s0N OF WEEKLY SCRAM STATISTICS WITH INDUSTRY AVERAGES PER100 ENDING 05/04/97 NUM8ER 1997 1996 1995 1994 1993 0F WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCRAM CAUSE SCRAMS AVERAGE
.AVERACE AVERACE tVERAGE AVERAGE (YTD)
POWER GREATER THAN OR EQUAL TO 15%
EQUIPMENT FAILURE 2
0.79 1.52 1.83 1.52 1.83 DEslGN/ INSTALLATION ERROR 0
0.23 0.10 0.12 0.08 0.04 OPERATING ERROR 0
0.11 0.08 0.15 0.21 0.27 MAINTENANCE ERROR 0
0.28 0.50 0.38 0.54 0.52 EXTERNAL 0
0.06 0.13 0.21 0.17 0.13 OTHER 0
0.06 0.10 0.06 0.02 Subtotal 2
1.53 2.43
- 2. 75 2.52 2.81 e
POWER LESS THAN 15%
EQUIPMENT FAILURE 1
0.23 0.23 0.10 0.27 0.38 0.02 CESIGN/lWSTALLATION ERROR 0
0.00 OPERATING ERROR 0
0.00 0.10 0.13 0.08 0.13 MAINTENANCE ERROR-0 0.06 0.06 0.08 0.02 EXTERNAL 0
0.00 0.04 OTHER 0
0.00 i
Subtota' 1
0.29 0.39 0.31 0.37 0.57 TOTAL 3
1.82 2.82 3.06 2.89 3.38 1997 1996 1995 1994 1993 NO OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCR AM TYPE SCRAMS AVERAGE AVERAGE AVERAGE AVERAGE AVERACE (YTD)
TOTAL AUTOMATIC SCRAMS 1
1.13 1.71 1.92 2.19 2.44 TOTAL MANUAL SCRAMS 2
0.68 1.10 1.13 0.69 0.94 TOTALS MAY DIFFER SECAUSE OF ROUNDING OFF 1
i ETS 14 Page: 1 05/08/97
-]
...... -,. ~.. -
~ - - -.
7
- NOTES 1.
PLANT SPECIFIC DATA BASED ON INITIAL REVIEW OF 50.72 REPORTS FOR THE WEEK OF INTEREST.
PERIOD IS MIDNIGHT SUNDAY THROUGH MIDNIGHT SUNDAY.
SCRAMS ARE DEFINED AS REACTOR PROTECTIVE ACTUATIONS WHICH RESULT IN ROD MOTION, AND EXCLUDE PLANNED TESTS OR SCRAMS AS PART OF PLANNED SHUTDOWN IN ACCORDANCE WITH A PLANT PROCEDURE.
THERE ARE 111 REACTORS HOLDING AN
. OPERATING LICENSE.
2..
PERSONNEL RELATED PROBLEMS INCLUDE HUMAN ERROR,. PROCEDURAL DEFICIENCIES, AND MANUAL STEAM GENERATOR LEVEL CONTROL PROBLEMS.
3.
' COMPLICATIONS: RECOVERY COMPLICATED BY EQUIPMENT FAILURES OR PERSONNEL ERRORS UNRELATED TO CAUSE OF SCRAM.
4.
"OTHER". INCLUDES AUTOMATIC SCRAMS ATTRIBUTED TO ENVIRONMENTAL CAUSES (LIGHTNING), SYSTEM. DESIGN, OR UNKNOWN CAUSE.
,O_EAB SCRAM DATA l
Manual and Automatic Scraras for 1987 ------------------ 435 Manual and Automatic Scrams for 1988 ------------------ 291 Manual and Automatic Scrams for 1989 ------------------ 252 Manual and Automatic Scrams for 1990 ------------------ 226 Manual and Automatic Scrams for 1991 ------------------ 206
. Manual and Automatic Scrams for 1992 ------------------ 212 Manual and Automatic Scrams for 1993 ------------------ 175 Manual and Automatic Scrams for 1994 ------------------ 150 Manual and Automatic Scrams for 1995 ------------------ 159 Manual and Automatic Scrams for 1996 146 Manual and Automatic Scrams for 1997 --(YTD 05/04/97)-- 32 1
1 r
.