ML060660075
| ML060660075 | |
| Person / Time | |
|---|---|
| Site: | Salem, Hope Creek  |
| Issue date: | 03/21/2003 |
| From: | Harvin K - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2005-0194 | |
| Download: ML060660075 (23) | |
Text
03/21/2003 05:28:27 SCOTT MAIER (NUSZM)
NOTIFICATION
SUMMARY
[VERIFY CURRENT REQUIREMENTS CONTAINED IN NC.WM-AP.ZZ-OOOO(Q)
"NOTIFICATION PROCESS"]:
- 1) DESCRIBE THE ACTUAL CONDITION?
(Do not use individual's name(s); you may use computer ID's or badge numbers)
During the Turbine Rollup on 3/21 it was noticed that the
- 2 & #3 bypass valve response was more erratic than was observed on previous turbine rolls.
As the main turbine came up to rated speed it was noticed that the bypass valve signals and actual positions swinging as much as 40% initially which calmed to 25% (on the controlling valve) as things became steady state at a slightly higher power level.
- 2) HOW DOES THIS ISSUE IMPACT PLANT OR PERSONNEL SAFETY?
Preventing turbine roll and power ascension
- Bypass valve response not as desired for normal operation
- 4) WHAT CAUSED THE CONDITION?
- not sure if control or valve problem
- 5) WHAT ACTIONS, IF ANY, HAVE BEEN TAKEN TO CORRECT THE CONDITION?
- notification written, CRS
- notified, Generator synch and power ascension placed on hold
- 6) RECOMMENDED ACTION/CORRECTIVE ACTION AND WORK CENTER RESPONSIBLE FOR CORRECTING CONDITION.
(Use Title/Position, not name)
TS&R the cause of the Erratic response
- 7) ANY OTHER RELEVANT INFORMATION?(WHO, WHEN, WHERE, WHY, REFERENCES, ESTIMATED COST, EMIS TAG, ECT)
- 8) HOW WAS THE ISSUE IDENTIFIED?
Normal observation on turbine rollup
- = NA FOR SIGNIFICANCE LEVEL X NOTIFICATIONS 03/21/2003 06:00:00 DANIEL FROST (NUD2F)
It is expected that the bypass valves will perform their design function during a turbine trip.
Power is currently not above 25% and the Bypass valves are not required to be operable.
A Tracking LCO is currently open against the bypass valves.
LCO #03-145.
03/21/2003 13:18:34 RICHARD CUMMINS (NUR2C)
Condition was corrected when load-set was set down further from indicated zero.
R11 OMAP-3 submitted.
03/21/2003 13:49:03 RICHARD CUMMINS (NUR2C)
Engineering to provide additional input as to likely failure cause.
The load set was causing control valves to cycle slightly, causing a responsive cycling of bypass valves.
03/21/2003 16:34:32 JOHN THOMPSON (NUJRT)
Engineering obtained GETARS traces of EHC system parameters while the BPVs were oscillating.
The following was observed:
- 1. BPV Demand (PID 138) was oscillating from 21.3% to 24.3% in a sine wave with a 6-7 second period.
A step change reduction of 0.6% was seen just after each peak.
- 2. CV Flow Demand (PID 136) was oscillating from 2.6% to 3.7% in a sine wave with a 6-7 second period.
A step change increase of 0.13% was seen
just after each low point at 2.87%.
The CV Flow Demand increase preceded the BPV Demand increases.
- 3. Sensed pressure (PID 145) was oscillating from 928.4 psig to 929.0 psig in a sine wave with a 6-7 second period.
- 4. Load Set (PID 148) was at 3.48%
and steady.
- 5. Main Turbine Speed (PID 140) was varying 0.6 rpm around 1810 rpm with same period.
Speed increased after the CV Flow Demand increase.
- 6. CV#1 Position (PID-128) was oscillating from 1.3% to 1.9% with the same period.
Position followed the CV Flow Demand.
The following was recorded after the Load Set was reduced.
- 1. All parameters listed above were steady except BPV Flow Demand which
was varying about 0.8% randomly.
Load Set was at 2.5%, CV#1 position 1.6%,
BPV Demand 19%,
CV Flow Demand 2.5%.
==
Conclusions:==
The notch changes seen in CV and BPV Flow Demand indicate some type of switching action.
There is a voltage comparator switch shown as VCP004 on drawing PM003-T1-0036 that functions to switch the CV Flow Demand signal from the speed/load control into the BPV Amplifier A60 when the signal increases above 0.00 vdc (0%
demand) and switches back out at #0.10 vdc (negative demand).
If this comparator setpoint was high and switched at 2.87 vdc instead of 0.0 vdc, an effective pressure setpoint change would occur because the CV Flow demand would not be subtracted from the BPV Demand per design until
it had already increased to 2.87%.
- However, the BPV Demand should have been reduced by 11.51 and this did not occur (0.6%).
The oscillations began when turbine speed was increasing through about 1500 rpm.
This indicates the problem was likely to be coming from the speed control section.
CV oscillations are not normal for speed control and would cause BPV oscillations due the BPV Demand summer that subtracts CV Flow from Total Flow from pressure control.
The Load Set output is not the likely cause because it indicated steady both before and after the oscillations and the oscillations should have been seen before 1500 rpm also.
BPV-2 indicated a slower response during the BPV time response test performed prior to startup.
This can be ruled out as a cause because the oscillations occurred when BPV-3 was operating.
Another possibility is the PMG power supplies.
These power supplies are energized around 1200 -
1500 rpm and could take over the 30 and #22 vdc buses.
The power buses can affect system setpoints if varied. The power supply outputs were observed to be normal and not in control after the unit synchronized.
This is considered unlikely.
The cause of the oscillation is unknown at this time.
The impact on plant operation was actually minimal as reactor pressure varied only about 0.5 psig.
Speed control is switched out by Pressure Control for normal operations.
Recommendations for R11:
- 1. Verify the calibration of VCP004 FLOC H1CH
-1CHXS-C363A15.
- 2. Perform a speed control simulation at the Load Set values listed above and monitor the system for unusual behavior.
This would consist of connecting frequency sources to the speed inputs (see HC.IC-CC.AC-0001), simulating main steam
- pressure, selecting 1800 rpm and observing the CV Demand signal.
03/25/2003 07:56:27 RICHARD CUMMINS (NUR2C) 03/25/2003 14:27:18 MARC CHASTAIN (NUM3C)
WMSC Data Planning Group -
099 Main Work Center M-PMX Maint Act Type -
PL Priority -
4 Start Date -
4/20/03
Planning Level -
3 Outage Requirement -
Y Performance Indicators -
NONE FEG -
Notes -
OMAP-3 SUBMITTED (CUMMINS) -
SEE ABOVE 03/26/2003 12:38:26 JOHN POWELL (NUJYP)
03/18/2 003 08:13:06 JOHN THOMPSON (NUJRT)
- 1. Description of condition:
Hope Creek main turbine bypass valves selected on the bypass valve selector switch opens to approximately 15%
when the selector switch is rotated to select a single bypass valve.
- 2. Impact on Plant/Personnel Safety:
Affects operation of BPV test and will cause BPV-1 to stay 15% open during normal operation.
- 3. Requirement not met:
BPV-1 should remain at zero with the BPV Jack at zero
- 4. What caused the condition to occur:
Unknown
- 5. Actions taken to correct condition:
Testing performed on 03/17/03 at approx. 2000:
Rotated the BPV selector switch from BPV #1 thru
- 9. When the selector switch was placed on BPV
- 1, the valve was observed to open approximately 15%.
As the selector switch was rotated from BPV #1 to #2, BPV
- 1 remained open, and BPV #2 was observed to open approximately 15%. As the BPV selector switch was rotated from BPV #2 to BPV #3, BPV #2 was observed to close and BPV #3 was observed to open approximately 15%.
As the selector switch was rotated from
- 3 thru #9, the previous valve would close.
Only BPV #1 remained open when not selected.
Main steam line pressure was 0 psig and EHC pressure setpoint was 150 psig (at minimum) during the testing.
At 2230 BPV #1 closed when EHC pumps were removed from service to
support trouble shooting for BPV#2.
Demand signal remained slightly positive, and the same as at the end of the 2000 testing.
At 2300, main condenser vacuum was broken.
At 2345, Operations checked the BPV#1 demand and reported the demand is now slightly below zero (a change from slightly positive).
This indicates the BPV Jack output changed slightly and is producing the expected demand signal.
Loss of main condenser vacuum removes the output of the BPV amplifier to the 9 BPV#s.
The slightly negative demand is normal for BPV#1 since it is the first BPV to respond.
Voltage readings taken on the BPV amplifier indicate the BPV Jack motor drive is either not driving far enough to achieve
0.00 vdc or the potentiometer is bad.
- 6. Recommended actions and work center:
Troubleshoot and repair.
Recommended work center:
Maintenance
- 7. Other relevant information Initiated by:
John Thompson, Reliability Engineering; x3656
- 8. How was the issue identified?
During troubleshooting activities related to the BPV-2 sticking open.
03/20/2003 13:42:18 MARGARET THOMAS (NUMAT)
CRRC NOTE:
UPGRADED TO SL-2 AT THE SM MEETING ON 03/20/03.
SEE Ni 20136007.
03/14/2003 23:07:22 PETER SCARPATI (NUPSS)
- 1) DESCRIBE THE ACTUAL CONDITION?
(Do not use individual's name(s); you may use computer ID's or badge numbers)
Following the sychronization of the Main Generator to the grid, the operator applied the load to the generator, which closes the bypass valves.
The #2 BPV did not stroke closed.
The indication is that the valve is 37-40% open and on CRIDS the valve is shown NOT CLOSED and the BPV position is 7% open.
Local observation is that the valve is approximately 3/8" open.
All other parameters are normal.
- 2) HOW DOES THIS ISSUE IMPACT PLANT OR PERSONNEL SAFETY?
Plant can not run
> 25% with bypass system inoperable.
REQUIREMENT NOT MET?
- Bypass system INOP
- 4) WHAT CAUSED THE CONDITION?
- Unknown
- 5) WHAT ACTIONS, IF ANY, HAVE BEEN TAKEN TO CORRECT THE CONDITION?
- Performed visual observation of the valve.
A conference call between Operations, Maintenance and Engineering will discuss the issue.
Power ascension has been stopped.
- 6) RECOMMENDED ACTION/CORRECTIVE ACTION AND WORK CENTER RESPONSIBLE FOR CORRECTING CONDITION.
(Use Title/Position, not name)
TS&R, recommence power ascension.
- 7) ANY OTHER RELEVANT INFORMATION? (WHO, WHEN, WHERE, WHY, REFERENCES, ESTIMATED COST, EMIS TAG, ECT)
- 8) HOW WAS THE ISSUE IDENTIFIED?
During the synchronization of the main generator to the grid.
- = NA FOR SIGNIFICANCE LEVEL X NOTIFICATIONS 03/16/2003 00:58:26 GLENN FIGUEROA (NUGOF)
Troubleshooter was performed per instructions in sh.op-ap.zz-0008q with the following results:
- 1) #2 bypass valve was found approx 48% open with -64mA.
- 2) Ops placed selector switch to #2 bypass valve.
Valve did not appear move was 44% open with -56 mA.
- 3) Ops depressed and held test button to #2 bypass valve.
valve stroked full open smoothly. Valve stroked.522 with no noise. stopped smoothly.
- 4) Removed amphenol connector to #2 bypass valve. No valve movement, no noise, no
EHC porting pitch audible changes.
100% open 0 mA
- 5) Ops released test pushbutton -
no change to valve in field.
- 6) resistance readings on servo valve coil pin a
& b and c & d a-b 130.1 c-d 103.3
- 7) Cleaned and inspected amphenol connector.
No dirt or deficiencies discovered.
- 8) Reconnected amphenol. Valve closed fast.
Heard EHC port.
Heard loud solid stop (metal to metal).
Valve travelled.517
(.005 less than open). 45%
open with -64mA.
Plant responded as expected.
Valve stem was visually inspected with no scoring, stem appeared to be aligned with packing gland.
No external FME issues observed which may prevent valve from operating properly.
Linkage and LVDT rod ends were inspected sat. No binding or excessive wear.
Roll notification to order to continue necessary trouble shooting.
Ops depressed and held test pushbotton to #2 bypass valve 03/18/2003 07:05:19 MARGARET THOMAS (NUMAT)
CRRC NOTE:
VALIDATED AS SL-2 AT THE SM MEETING ON 03/17/03.
NOTF# 20136006 03/18/2003 16:22:57 CHRISTOPHER SERATA (NUCLS)
- 1. DESCRIPTION During plant shutdown on March 17, the bypass valve response when controlled by the BYPASS VALVE JACK was erratic. At one point with EHC PRESSURE SET in control, 2 bypass valves fully open, and the BYPASS VALVE JACK demand just below the PRESSURE SET demand, a tap on the BYPASS VALVE JACK INCREASE pushbutton resulted in the #3 bypass valve pulsing from 0% to 75%
open.
This condition caused a 50# drop in reactor pressure in one minute.
The drop in pressure caused a lowering in coolant temperature adding positive reactivity and a rise in power.
The power rise approached the the APRM upscale SCRAM of 15% and caused the RO to have to range up on 4
IRMs within a
minute.
It also resulted in a lowering of level from 33" to 25" requiring manual control to maintain level between the low level SCRAM and the high level RFP trip setpoints.
- 2. IMMEDIATE ACTIONS TAKEN The plant was stabilized and the IPTE terminated.
After evaluating plant
- response, a
meeting was convening.
Those present included the IPTE Test Manager and Test
- Engineer, the Shift Manager and Control Room
Supervisor, the immediate
Response
Team
- manger, and a d d i t i o n a 1 representatives from the OCC Team.
After an evaluation of the conditions and development of a
concensus
- approach, r
e a
c t
o r
depressurization was continued using EHC PRESSURE SET.
No additional anomalies were noted.
- 4. ADDITIONAL ACTIONS TAKEN Initiated this notification.
Discussed the performance of the BYPASS VALVE JACK with the EHC Specialist (NUJRT).
The specialist referred to the BYPASS VALVE JACK performance as
- erratic, and a
notification to replace the BYPASS V A L V E J A C K potentiometer was initiated.
- 5.
RECOMMENDED CORRECTIVE ACTIONS Evaluate equipment
- response, procedure
- guidance, and crew performance.
The recommended evaluation manager for this issue is the Hope Creek Operations
'E' Shift Manager (NUCLS).
03/18/2003 23:15:01 BERNARD LITKETT (NUBXL) 03/19/2003 12:34:16 MARGARET THOMAS (NUMAT)
CRRC NOTE: VALIDATED AS SL-2 AT THE SM MEETING ON 03/19/03.
03/19/2003 16:32:15 JAMES STAVELY (NUJ2S)
Additional Information
- 1) Core Thermal Power (CTP) stayed below 25%
RTP so there are no issues involving thermal limit compliance or effects (T/S 3.2.1 through 3.2.4). Similarly, the License Limit on CTP was not approached.
- 2)
Since the APRMs stayed below the scram setpoint, there are no issues involving the:
RPS system response.
- 3)
Control rod insertions were consistent with the Shutdown Sequence so there are no issues involving control rod movement.
- 4)
The CTP increase portion of this event was similar to an increase in Total Core Flow (i.e.
a global effect) and thus violated the 1i RTP/hr limitation for the f a i 1 e d f u e 1 reliability rules.
Although this event potentially could cause a
further degradation of the fuel defect, there are currently no indications of s i g n i f i c a n t degradation and no corrective actions are pratical (consistent with Appendx B of the Cycle Management Report for post fuel reliability rule v i o 1 a t i o n s ).
Increased monitoring of the fuel defect is already in place for the startup due to cesium increases following both recent scrams.
The changes in cesium response can not be directly linked to this event since it
also occurred on the previous scram.
03/19/2003 20:22:24 DANIEL BOYLE (NUD3B)
This orders' evaluation and corrective actions are required to be presented to SORC upon completion. NUD3B 03/21/2003 13:41:45 MARGARET THOMAS (NUMAT)
CRRC NOTE: UPGRADED TO SL-1 AND ASSIGNED TO NUKXK AT THE SM MEETING ON 03/21/03.