ML20059C214
| ML20059C214 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/17/1993 |
| From: | Chaffee A Office of Nuclear Reactor Regulation |
| To: | Grimes B Office of Nuclear Reactor Regulation |
| References | |
| OREM-93-047, OREM-93-47, NUDOCS 9401050019 | |
| Download: ML20059C214 (14) | |
Text
_
a December 17,1993 l
MEMORANDUM FOR:
Brian K. Grimes, Director Division of Operating Reactor Support
{
FROM:
Alfred E.
Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support l
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING l
DECEMBER 15, 1993 - BRIEFING 93-47 On December 15, 1993, we conducted _an Operating. Reactors. Events Briefing (93-47) to inform senior managers from offices of the Chairman, OEDO, ACRS, RES, NRR, AEOD, and regional offices of i
selected events that occurred since our-last briefing on December 8, 1993. lists the attendees.
presents the significant elements of the discussed events. contains reactor scram statistics for the week ending December 12, 1993.
One significant event was identified for input into the NRC Performance Indicator Program (Enclosure 4).
ORIGINAL SIGNED BY:
Alfred E.
Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support
Enclosures:
As stated cc w/ enclosures:
See next page DISTRIBUTION:
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W. Beckner (PDIV-4-1)
F. Gillespie, NRR (12G18)
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Callan, NRR (12G18) l S. Varga, NRR (14E4)
J.
Calvo, NRR (14A4)
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Lainas, NRR (14H3) f J. Roe, NRR (13E4)
J.
Zwolinski, NRR (13H24)
E. Adensam, NRR (13E4) i W.
Russell, NRR (12G18)
J. Wiggins, NRR (7D26) l A.
Thadani, NRR (8E2) 1 S.
Rosenberg, NRR (10E4)
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Rossi, NRR (9A2) i B. Boger, NRR (10H3)
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Congel, NRR (10E2)
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Crutchfield, NRR (11H21) i W.
Travers, NRR (11B19) l D.
Coe, ACRS (P-315)
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Jordan, AEOD (MN-3701)
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Holahan, AEOD (MN-9112) j L.
Spessard, AEOD (MN-3701)
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Brockman, AEOD (MN-3206)
S. Rubin, AEOD (MN-5219)
M. Harper, AEOD (MN-9112)
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Grant, EDO (17G21) 9 R.
Newlin, GPA (2GS)
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Bates, SECY (16G15)
T. Martin, Region I W.
Kane, Region I R.
Cooper,. Region I S.
Ebneter, Region II E. Merschoff, Region II S.
Vias, Region II J. Martin, Region III E. Greenman, Region III J.
Milhoan, Region IV B.
Beach, Region IV B.
Faulkenberry, Region V K. Perkins, Region V bec:
Mr. Sam Newton, Manager Events Analysis Department Institute of Nuclear Power Operations 4
700 Galleria Parkway Atlanta, GA 30339-5957
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December 17, 1993 l
MEMORANDUM FOR:
Brian K. Grimes, Director Division of Operating Reactor Support FROM:
Alfred E. Chaffee, Chief Events Assessment Branch I
Division of Operating Reactor Support
SUBJECT:
OPERATING REACTORS EVENTS BRIEFING DECEMBER 15, 1993 - BRIEFING 93-47 On December 15, 1993, we conducted an Operating Reactors Events Briefing (93-47) to inform senior managers from offices of the Chairman, OEDO, ACRS, RES, NRR, AEOD, and regional offices of selected events that occurred since our last briefing on December 8, 1993. lists the attendees.
presents the significant elements of the discussed events. contains reactor scram statistics for the week ending December 12, 1993.
One significant event was identified for input into the NRC Performance Indicator Program (Enclosure 4).
hj f
Alfred E.
Chaffee, Chief Events Assessment Branch Division of Operating Reactor Support
Enclosures:
As stated 1
cc w/ enclosures:
See next page
ENCLOSURE 1 LIST OF ATTENDEES OPERATING REACTORS EVENTS FULL BRIEFING (93-47)
DECEMBER 15, 1993 NAME OFFICE NAME OFFICE A.
CHAFFEE NRR B.
LEFAVE NRR N. HUNEMULLER NRR K.
CONNAUGHTON NRR R.
DENNIG NRR J.
THOMAS NRR R. GOODWIN NRR M. VIRGILIO NRR S.
ROSENBERG NRR E.
ROSSI NRR T.
YAMADA NRR J.
MINNERS RES G.
MARCUS NRR J.
MITCHELL OEDO T.
SCARBROUGH NRR V.
BENAROYA AEOD M.
CARUSO NRR-J.
IBARRA OCM G.
ZECH NRR TELEPHONE ATTENDANCE (AT ROLL CALL)
Rections Resident Inspectors Region I E.
Collins (Cooper)
Region II l
Region III Region IV Region V IIT/AIT Team Leaders Misc.
't l
ENCLOSURE 2 1
1 OPERATING REACTORS EVENTS BRIEFING 93-47 LOCATION:
10 B11, WHITE FLINT WEDNESDAY, DECEMBER 15, 1993 11:00 A.M.
COOPER SHUTDOWN C0OLING SUCTION ISOLATION VALVES LEAKING PRESENTED BY:
EVENTS ASSESSMENT BRANCH DIVISION OF OPERATING REACTOR SUPPORT, NRR I
l 93-47 l
COOPER SHUTDOWN COOLING SUCTION ISOLATION VALVES LEAKING l
MAY 1992 TO MARCH 1993 PROBLEM FOR 11 MONTHS, COOPER OPERATED WITH LEAKAGE THROUGH BOTH l
CONTAINMENT ISOLATION VALVES IN THE RHR SHUTDOWN COOLING SUCTION LINE.
CAUSE THE LEAKAGE WAS CAUSED BY CRACKS IN THE SEATS AND DISKS OF
)
THE VALVES.
SAFETY SIGNIFICANCE POTENTIAL UNIS0LABLE INTERFACING SYSTEMS LOCA (ISLOCA)
RESULTING IN SIGNIFICANT RELEASES OF RADI0 ACTIVE MATERIAL THAT WOULD BYPASS PRIMARY CONTAINMENT.
THE POSTULATED ISLOCA COULD ALSO DEGRADE THE EFFECTIVENESS OF SECONDARY CONTAINMENT.
DISCUSSION 1
o DURING AN INSPECTION IN MARCH-MAY, 1993, NRC INSPECTORS NOTED A MAINTENANCE ITEM TO DISASSEMBLE THE VALVES AND REVIEWED THE LICENSEE'S OPERABILITY DETERMINATION.
CONTACT:
N. HUNEMULLER, NRR/ DORS AIT:
NO
REFERENCES:
I.R. 50-298/93-17 SIGEVENT:
YES
COOPER 93-47 o
ON MAY 1, 1992, WHILE THE PLANT WAS OPERATING, THE HIGH PRESSURE ALARM FOR THE RHR SUCTION PIPING ACTUATED.
THE LICENSEE ESTABLISHED A VENT PATH TO THE ECCS KEEP-FILL SYSTEM, AND CONTINUED PLANT OPERATION.
o LEAKAGE THROUGH THE INB0ARD VALVE WAS APPR0XIMATELY 0.4 GPM, BUT LEAKAGE THROUGH THE OUTB0ARD VALVE COULD NOT BE DETERMINED.
THE LICENSEE CONSIDERED THE VALVES OPERABLE BECAUSE THE LEAKAGE DID NOT EXCEED THE 5 GPM T
IC C F CA N
H S
0 EV LU N
F THE CONTAINMENT ISOLATION FUNCTION.
o ON MARCH 29, 1993, THE INB0ARD VALVE FAILED A LOCAL LEAK RATE TEST.
THESE VALVES ARE ANCHOR / DARLING FLEX-WEDGE GATE VALVES.
UPON DISASSEMBLY FOR REPAIR AND INSPECTION, CRACKS WERE FOUND IN THE INB0ARD VALVE'S OUTB0ARD SEAT AND DISK AND IN THE OUTB0ARD VALVE'S OUTB0ARD DISK FACING.
FOLLOW UP o
THE LICENSEE'S ROOT CAUSE ANALYSIS CONSULTANT DETERMINED THAT THE VALVE CRACKING WAS DUE TO EITHER THERMAL BINDING, TRAPPED BONNET WATER THERMAL EXPANSION, THERMAL CYCLING, OR FABRICATION DEFECTS.
o REGION IV SUBMITTED THIS ITEM AS A P0TENTIALLY RISK SIGNIFICANT EVENT NOT REPORTED IN Ah LER.0R A PROMPT NOTIFICATION.
COOPER 93-47 o
THIS ITEM WAS INCLUDED AS ONE OF FOUR IN A LEVEL III VIOLATION WITH A $75K CIVIL PENALTY FOR FAILURE TO PROMPTLY IDENTIFY AND CORRECT A CONDITION ADVERSE TO QUALITY.
e.
NUREG/CR-5124 AND NUREG/CR-5928 ESTIMATED THAT ISLOCA THROUGH THE SHUTDOWN COOLING SUCTION LINES WOULD CONTRIBUTE ABOUT 3E-8/ YEAR TO THE CORE DAMAGE FREQUENCY BASED UPON VALVE FAILURE RATES OF ABOUT 1E-7/ HOUR.
o THE ACTUAL PROBABILITY OF GROSS FAILURE OF THE VALVES AT COOPER COULD NOT BE DETERMINED.
IF GROSS FAILURE OCCURRED THE CORE DAMAGE PROBABILITY WOULD BE ON THE ORDER OF 1E-2.
NUREG/CR-5124 PROVIDED AN ESTIMATE OF 2.65E-2 THAT PRESSURIZATION OF THE RHR SUCTION LINE TO NORMAL REACTOR OPERATING PRESSURE WOULD CAUSE GROSS RUPTURE AND A LARGE LOCA.
A LARGE LOCA BETWEEN THE '17' AND '15' VALVES WOULD e
BE UNIS0LABLE AND WAS ASSUMED TO DAMAGE THE LOW PRESSURE ECCS EQUIPMENT NEEDED TO MITIGATE THE LOCA, DUE TO THE EFFECTS OF THE HARSH LOCA ENVIRONMENT IN THE REACTOR BUILDING.
IT IS POSSIBLE THAT CONTINUED INJECTION BY THE CONDENSATE SYSTEM AND LATER INJECTION FROM RHRSW COULD PREVENT CORE DAMAGE.
TO ESTABLISH RHRSW WOULD REQUIRE LOCAL ACTION IN THE CONTROL BUILDING, AND THIS ACTION IS DIRECTED BY THE E0Ps.
l
P COOPER T4-
.93-47 VARYING THE OPERATOR FAILURE RATES BETWEEN VALUES REFLECTING THAT RECOVERY WAS-1) NOT POSSIBLE, TO
- 2) LOCAL RECOVERY WAS POSSIBLE,.RESULTED IN ESTIMATED CORE DAMAGE PROBABILITIES OF 3E-2 TO l
9E-3, GIVEN GROSS FAILURE OF THE-SUCTION VALVES.
- y o
NRC IS EVALUATING THE NEED FOR AN INFORMATION NOTICE.
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RHR SYSTEM FIGURE 2 COR002-23 REV. 7 CIA 02036
I ENCLOSURE 3 REACTOR SCRAM Reporting Period: 12/06/93 to 12/12/93
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YTD YTD ABOVE BELOW YTD 3
PLANT & UNIT P0ufR TJP1 CAUSE COMPL ICATIONJ E
12/06/93 FT CALHOUN 1 100 SA Equipment Failure NO 2
0 2
12/06/93 CLINTON 1 5
SM Equipment failure NO 0
1 1
12/07/93 HATCH 1 100 SA Equipment Falture NO 4
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Octo: Year Tc Oate (YTD) Totals include Events Within The Calendar Year Indicated By The Erd Date of The Specified Reporting Period 115 10 Pose:1
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12/15/93 l
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COMPARI$0N OF WEEKLY SCRAM STATISTICS WITH INDUSTRY AVERAGES f*ERIOD ENDING 12/12/93 i
NUMBER 1993 1992 1991*
1990*
1989*
OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCRAM CAUSE SCRAMS AVfRAGE AVE RAGE AVERAGE AVERAGE AVERAGE t
(YTD)
POWER GRE ATER THAN OR EQUAL TO 15%
i EQUIPMENT F ALLURE
- 2 1.9 2.6 2.9 3.4 3.1 DESIGN /1NSTALLATION ERRCa*
0 0.0 OPERAtlkG ERROR
- 0 0.3 0.2 0.6 0.5 1.0 MAINTENANCE ERROR
- 0 0.5 0.4 l
EXTERNAL
- OTHER*
0 0.1 0
0.0 0.2 0.1 Subtetal 2
2.8 3.4 3.5 3.9 4.2 POWER LESS THAN 15%
EQUlPMENT FAILURE
- 1 0.4 0.4 0.3 0.4 0.3 CESIGN/lkSTALLATION ERROR
- 0 0.0 OPERATING ERROR
- 0 0.1 0.1 0.2 0.1 0.3 MAINTENANCE ERROR
- O 0.0 0.1 EXTERNAL
- O 0.0
+
OTHER*
O 0.0 0.1 Subtetal 1
0.5 0.7 0.5 0.5 0.6 1
TOTAL 3
3,3 4,3 4,g 4,4 4,g l
i j
1993 1992 1991 1990 1989 NO. OF WEEKLY WEEKLY WEEKLY WEEKLY WEEKLY SCRAM TYPE SCRAMS AVE R AGE AVERAGE AVERAGE AVERAGE AVERAGE (YTD)
TOTAL AUTOMATIC SCRAMS 2
2.4 3.1 3.3 3.2 3.9 j
TOTAL MANUAL SCRAMS 1
1.0 1.0 0.7 1.2 0.9 TOT ALS k8Y DIFFER BECAUSE OF ROUNOING OFF I
- Detailed breakdown not in database for 1991 and eartler
- EXTERNAL casse included in EQUIPMENT F ALLURE
- MAINTENANCE ERROR and DESIGN / INSTALLATION ERROR causes included in OPERATING ERROR
- OTHER cause included in EQUIPMENT EA1 LURE 1991 and 1990 ETS 14 Page: 1 12/15/93
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.
OEAB SCRAM DATA iManual and Automatic Scrams for 1987 ------------------ 435 j
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 --(YTD 12/12/93)-- 168 f
i l
1
ENCLOSURE 4 OPERATING REACTOR PLANTS BIGNIFICANT EVENTS 6
SORT > Event Date OUERY> Event Type SIG & Close Out Date >= 11/10/93 & Event Type = "SIGa PL ANT & l' NIT N
M9 R DESCRIPfl04 0F EVENT SIGNIFICANCE 3
FING PRESENTER COOPER 1 05/01/92 0
DURING PLANT OPERATION IN MAY 1992, THE STATION Reactor Coolant Pressure Boundary 93-47 HUNEMULLER N.
INFORMAL EXPERIENCED PRIMARY COOLANT LEAKAGE THROUGH TWO SHUIDOWN COOLING SUCTION ISOLAilON VALVES INTO THE LOW PRESSURE SUCTION PIPING OF THE RHR SYSTEM. DURING THE REFUELING OUTAGE IN 3/93, THE LICENSEE DISASSEMBLED THE VALVES AND FOUND CRACKS IN THE SEATS AND DISCS. THIS WAS FIRST DISASSEMBLY SINCE BEGINNING OPS IN 1974. LEAKAGE COULD BE VIEWED AS PRECURSOR TO LOCA CUTSIDE CONTAINMENT THAT WOULD DISABLE BOTH RHR TRAINS.
ETS-11 Page:1 12/15/93
.