ML20117P919
Text
1 January 19, 1989
- l MEMORANDUM FOR
William F. Kane, Director Division of Reactor Projects, Region I l
FROM:
Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of Operational Data
SUBJECT:
AEOD INPUT FOR THE VISIT OF C0MISSIONER CURTISS TO THE CALVERT CLIFFS SITE ON JANUARY 27, 1989 Per your staff's January 10, 1989 request, enclosed is the AEOD input to the briefing package for the commissioner's visit.
Our input consists of a summary analysis of operational experience at Calvert Cliffs Units I and 2 from October 1, 1987 to the present.
If you need any additional information, please contact Marc Harper (X24497) or John Crooks (X24425) of my staff.
Original signed by:
Ihomas M. Novak Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation of OperAtfonal Data
Enclosure:
As Stated cc: w/ enclosure D. Limroth, RI J. Clifford, DEDRO Distribution:
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1 Enclosure i
i Sumary of Operational Experience at Calvert Cliffs Units 1 and 2 from October 1,1987 to the Present I.
Overview 4
Of the Calvert Cliffs events reviewed during the period, two were categorized as potentially significant using the AE00 screening process (steam generator isolation check valve found to be incapabie of I
perfoming its safety function and various safety-related control valves could fail in an emergency situation). Each unit experienced four unplanned reactor scrams from power during (the period.
Calvert Cliffs 1 experienced four engineered safety feature ESF) actuations during the period (other than auxiliary feedwater actuations following reactor scrams), each a combination of safety injection signal and diesel generator start on one day in May 1988. Unit 2 experienced one ESF actuation during the period, an auxiliary feedwater actuation in 1987 i
H.
Abnomal Occurrences There have been no events classified, or considered, as Abnormal Occurrences (A0s) at the Calvert Cliffs units during the period.
III. Other Operational Data i
LER Reviews AE00 reviewed 22 LERs submitted by the licensee for Calvert Cliffs Units 1 (13 LERs) and 2 (9 LERs) for events occurring from October 1,1987 through the present. Of these LERs, none for Unit 1 and one for Unit 2 was considered potentially significant by the AE00 screening process.
This event is described below. An overall review of LERs indicates that the three major causes of events for both units during this period were administrative problems, maintenance errors, and equipment failures.
This was the case for both units.
The LER describing the event for Unit 2 judged potentially significant was:
Unit 2 LER 88-003, event date March 17, 1988. With the reactor in Mode 5, cold shutdown, a check valve in a line which supplies steam to the auxiliary feedwater pump turbines from Unit 2 nuder 2 steam generator (S/G) was disassembled for inspection. The check valve provides isolation of the number 2 S/G in the event of steam line break between the nud er 2 S/G and the main steam isolation valve. The disk was found to be severely bent, making the valve incapable of performing its design function. The comparable check valve for the nuder 1 S/G was also disassembled. Both valves showed signs of wear at the hinge pins and disk seat.
Subsecyent licensee analysis indicated that licensing basis steam line break analyses bounded the operating conditions with the valve damaged if existing conservatisms in the licensing basis analyses were considered.
(
l Containment design pressure would be exceeded but would be below the ultimate containment pressure capacity. The site boundary dose would not be exceeded.
Both the check valves were replaced with new check valves. The new valves contain stellite-faced disks and seat rings to aid in preventing i
steam cutting of the seating surfaces. The licensee stated that the new N
valves will be leak tested every refueling outage or one valve will be disassembled and inspected. If the inspected valve shows signs of wear, then the other valve will be disassembled also.
Additionally, one event judged significant for which no LER was submitted by the licensee should be mentioned. On April 14, 1988, the licensee reported that various control valves associated with safety injection, containment isolation, auxiliary feedwater and steam generator blowdown could fail in an emergency situation. The failure could occur if the I
pressure regulators for the instrument air system were to fail, allowing full instrument air pressure to pass to solenoids which vent the air supplies to the valves during an ESF actuation. Thus during an emergency, the full instrument air pressure could cause the solenoids to reverse position realigning the valves to a non-emergenc At-l l
the time Unit I was in Mode 5 and Unit 2 at full power. y position.
The licensee identified the cause of this problem as diaphragm material i
in certain regulators which could degrade in adverse environmental conditions both in normal service but more likely in post-accident conditions. The licensee estimates 20 valves in each unit were impacted.
The licensee concluded that the required safety function for these valves l
l could be fulfilled by means of compensatory actions.
In addition to the two significant events, one event of interest should be mentioned. This event is described in Unit 1 LER 88-011, discovery date October 28; 1988. It was discovered that the setpoint for one of i
two pressurizer code safety valves was 2648 psia. This setpoint pressure 1
is 58 psi higher than the maximum that technical specifications allow (2590 psia). The valve setpoint was reset to 2571 psia upon discovery.
l The licensee estimated that the plant operated in this condition for approximately 20 months.
The licensee believes that the cause of the out-of-limits setpoint was differences in temperature profiles at the off site testing facility where this valve was adjusted and the actual temperature profile of the l
safety valves on the pressurizer. The conclusion will be verified using a new method of setting safety valve lift setpoints at the actual installed temperature profiles.
Licensee analyses indicates that vessel pressure would not have exceeded 2750 psia in the event of the worst-case pressure transient.
l Unplanned Reactor Scrams from Power i
Calvert Cliffs 1 experienced four unplanned reactor scrams from power i
during the period, all but one automatic. Two were caused by equipment problems, one in the feedwater system and one in the main generator
L 1
l system. One was caused by lightning causing a transformer to short, and l
the last one was caused by a procedural deficiency.
Calvert Cliffs 2 experienced four unplanned reactor scrams during the 1
period, all but one automatic. Two were caused by personnel errors by technicians, one by equipment problems in the main generator system, and one by an unknown cause in the feedwater system.
ESF Actuations Calvert Cliffs 1 experienced four ESF actuations during the period, other than auxiliary feedwater actuations following reactor scrams. Each was a combination of a safety iniection signal (no injection) and a diesel 9enerator start within two hours on one day during a refueling outage in May 1988. The actudtions were caused by equipment problems and procedural deficiencies.
Calvert Cliffs 2 reported one ESF actuation during the period, other than auxiliary feedwater actuations following reactor scrams. The event was an auxiliary feedwater actuation (no scram) at 100 percent power in 1987 caused by a deficient procedure.
IV. Performance Indicator Data Performance Indicator (PI) data extending through September 1988 are attached. NOTE: The PI data does not include manual scrams. The PI safety system actuations are a specific subset of all ESF actuations -
energency core cooling system (ECCS) actuations and emergency power I
(diesel generator) actuations in response to a dead bus.
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pyrggfqngt nouat 4.is CALVERT CLFFS 1
Legend:
oioer eioni Averose M Irdcolor Critical Hours 86-4 to 88-3 4 ou rier Moring Averoge t Automatic Scrcyris WNe Cnted
- 2. Sofety System Actuotons rsoo 23eo
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FIGURE 4.16 P
D NEONAI-CALVERT CLIFFS 1: Trends Performance Indicators Declined improved
- 1. Automotie Se oms WNie Critied (2 Otr. Avg end 88-3) -
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- 2. Sofety System Actuations (2 Otr. Avg end 88-3).
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- 3. Significont Events (2 Otr. Avg end 88-3).
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- 4. Sofety System Failures (2 Otr. Avg end 88-3).
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- 5. Forced Outoge Rote (2 Otr. Avg end 88-3) -
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- 6. Equpment Forced tg/
oR Crit Hr
-2.5-iO-i5 -iO-5.5 0h 03 IO E5 20 2.5 Devotions from Previous 4 Otr. Plont Meons (Meosured in Standard Devictions) 1 CALVERT CLIFFS 1: Deviations from Older Plant Means Performance Indicators Bei w Avg. Perf. Above Avg. Perf.
- 1. Automotic Scroms While Critied t
(4 Otr. Avg end 88-3) -
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- 2. Sofety System Actuations (4 Otr. Avg end 88-3).
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- 3. Significant Events (4 Otr. Avg end 88-3)-
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- 4. Sofety System Failures (4 Otr. Avg end 88-3).
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- 5. Forced Outoge Rote (4 Otr. Avg end 88-3)-
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- 6. Equpment Forced tg/
Crit Hr
-2.5-10-i5 -t'o-0.5 O!O Oh io i5 2'02.5 Deviations from 06du Plant Meons (Measured in Standard Deviations) 1 45
TABLE 10.16 CALVERT CLIFFS 1
'Pgp$Q PI EVENTS FOR 97-4 SCPAM 11/11/87 LERs 31787015 50.728: 10656 POWER: 100 DEW
- 1GNTNING SNOW STORM CAUSED OUTPUT TRANSFORMER TO $NORT CAUSING TURRINE TRIP RX PI EVENTS FOR 88-1 NONE PI IVENTS FOR 88-2 SE 04/16/88 LERs 50.728: 12013 POWER: 0 DESC: Alt SYSTEM REGULATORS CGJLD FAIL OVERPRESSURIZING $0LEW010 OPERATED PILOT VALV SAFETT RELATED AIR OPERATED VALVES TO NOT FAIL SAFE SCA 05/02/88 LERf 31788002 50.728: 12180 POWER: 0 DESC FOUR (6) SI'S, WHEN WORKING IN ESFAS CA31 NET. SI IN PULL TO LOCK. DG DID START.
SSA 05/02/88 LERf 31788002 50.728: 12180 POWER: 0 DESC: FOUR (4) SI'S, WNEN WCRKlWG IN ESFAS CASINET. $1 IN PULL TO LOCK. DG DID START.
SSA 05/02/88 Leas 31780002 50.728: 12180 POWER: 0 DESC: FCMt (4) SI's, WHEN WORKING IN ESFAS CASINET. $1 IN PULL TO LOCK. DG DID START.
SSA 05/02/88 Leas 31788002 50.728: 12180 POWER: 0 DESC FGJR (4) SI'S, WHEN WORKING IN ESFAS CASINET. $1 IN PULL TO LOCK. DC D!D START.
PI EVENTS FOR 88-3 SCRAM 07/15/88 Leks 31788006 5 0. 72s: 12835 POWER: 89 DESC: NIGN FEEDWATER NEATER LI! VEL CAUSED TURBINE TRIP DUE TO UNCLEAR PROCEDURE.
SCRAM 08/24/88 LERf 31788009 50.728: 13278 POWER: 100 DESC: FITTING ON Alt LINE TO FRY FAILED DUE TO Y!8 RATION CAUSING FRV TO Fall OPEN CAUSING NIGN 36
I nGURE 4.17 P
NAL I
CALVERT CLFFS 2
Legend:
Older Plant Average Indscotor x
Critical Hours l
86-4 to 88-3 l
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t Automate Scrorns WNie Critied l
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- 2. Sofety System Actuatons i
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year - Quarter I
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- 4. Sofety System Falures l
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es-et-i e7-2 si-3 si-4 ei-o seLa es's esL svis si-a ei-s e7L es'-i esLa es-s Year - Ourter Year - Quarter
- 5. Forces Outage Rote (s)
- 6. Equi Forced Outoges/
Crated Hours no a
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o esL4 si-i ai-si-a e7' 4 es-t an'- ee'-3 Year - Oterter esLe s7'- si-2 e7'-3 s/-4 ei-i seLa asks Year - Quarter 46 l
rouac 4.i7 PJE t1 CALVERT CLIFFS 2: Trends Performance Indicators oectired mproved t Automatic Scroms While Critical (2 Otr. Avg end 88-3) -
0.7 s
- 2. Sofety System Actuations (2 Otr. Avg end 88-3).
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- 3. Sigraficant Events (2 Otr. Aq end 88-3).
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- 4. Sofety System railures (2 Otr. Avg end 88-3).
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- 5. Forced Outoge Rote (2 Otr. Avg end 88-3).
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- 6. Equipment Forced gtg/
Crit Hr t
-2.5-2.0-i.5 -I.0 -0.5 0 0 0.'5 to i5 2 0 2.5 Devotions from Previous 4 Otr. Phant Means (Meosured in Standard Deviations) l s
CALVERT CLIFFS 2: Deviations from Older Plant Means Performance Indicators Below Avg. Perf. Above Avg. Perf.
t Automatic Scroms While Critical I
(4 Otr. Avg end 88-3) -
-o sS
- 2. Sofety System Actuations (4 Ott. Avg end 88-3).
os3
- 3. Sigenficant Events (4 Otr. Avg end 88-3).
. css 1
- 4. Sofety System foilwes (4 Otr. Avg end 88-3) -
us
- 5. Forced Outoge Rote (4 Otr. Avg m> 88-3).
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- 6. Eqvpment Forced ig/1000 Crit. Hrs.
Avg end 88-3) -
0
-2.5 ~b' 0 -i.S -I0 -d.5 0'0 0'5 t'0 t'5 2'0 2.5 iotsons from 06 der Plant Means (Meosured in Standwd Deviations) i 47
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TABLE 10.17 l
CALVERT CLIFF 8 2 P
M l
PI EVENTS FOR 87-4 SCRAM 12/21/87 LERs 318870U9 50.728: 11039 POWER: 100 DESC: TURBINE / GENERATOR TRIP - CAUSE WAS THE N!SALIGNMENT OF TNE STATOR FRANE.
i PI EVENTS FOR 88-1 l
l SCRAM 01/22/88 LER8 31888002 50.728: 1129C POWER: 100 DESC: ELECTRICIAN TRIPPED A BREAKER CAUSINC A LOSS OF AN INSTRUNENT SUS AND A PI EVENTS FOR 88-2 l
SE 04/16/86 LERf 50.728: 12013 POWER:
0 DESC: AIR SYSTEM REGAATORS CGAD FAIL OVERPRESSURIZING $0LEN010 OPERATED PILCT VALVES SAFETY RELATED AIR OPERATED VALVES 70 NOT FAIL SAFE SCRAM 06/27/88 LERS 31888004 50.728 12130 POWER: 100 DESC: MFP TRIPPED FOR UNENOWN REASON CAUSING LOW SG LEVEL RX TRIP.
i PI EVENTS FOR 88-3 NONE i
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