ML072110433
| ML072110433 | |
| Person / Time | |
|---|---|
| Site: | Cooper, River Bend, Waterford, South Texas, San Onofre, Fort Calhoun  |
| Issue date: | 07/25/2007 |
| From: | - No Known Affiliation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2007-0180 | |
| Download: ML072110433 (4) | |
Text
p Question 1:
During normal steady-state power operations at River Bend Station, licensed operators observed a sudden increase on the offgas pretreatment monitor, indicating a major fuel cladding rupture.
Operators began to shut down the plant.
- However, a sticking feedwater regulating valve made controlling reactor pressure vessel water level difficult.
Operators tripped the reactor and cooled the plant to cold shutdown.
Following the shutdown, the licensee determined that the feedwater control valve had stuck open because of an original manufacturing defect.
The licensee also determined that the fuel failure had been caused by foreign material introduced into the system during the last refueling outage.
At the time of the reactor shutdown, a diesel generator had been out of service to rework a failed fuel injection pump.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
L Minor O
Screened as green
[]
Go to Phase 2 o
Transfer to:
(Other SDP Process)
Question 2:
During a local leak rate test of the component cooling water loop containment isolation valves at South Texas Project Unit 1, the valve failed to hold pressure, making quantification of its leak rate impossible to determine.
Licensed operators took the technical specification required actions.
Maintenance personnel later determined that the inboard valve had previously been assembled wrong during a maintenance evolution.
This caused the valve to stick in the midposition about half the time.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
[]
Minor 0 Screened as green 0] Go to Phase 2 0]
Transfer to:
(Other SDP Process)
Question 3:
At Cooper Nuclear Station, the service water system is the ultimate heat sink for the reactor.
Technical Specification 3.4.3, provides an allowed outage time for a single pump of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Two days after its last surveillance
- test, during a normal pump swap, Pump 1A failed to provide flow to the Division I header.
The licensee determined that station operators had inadvertently locked the manual pump discharge valve in the closed position, rather than locking it open as required by procedure.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
U Minor Q Screened as green 3 Go to Phase 2 U Transfer to:
(Other SDP Process)
Question 4:
At San Onofre Unit 3, during a high head safety injection system pump test, the pump only developed 3900 gpm, as opposed to the 4000 gpm required by the IST procedure.
This value placed the pump in the ASME Alert range.
The licensee identified that during the last refueling outage, the pump had been overhauled and inappropriate materials had been used when licensee mechanics had refurbished the impeller.
The technical specifications require that the pump develop 3500 gpm at 1500 psig.
Licensee engineers determined that the pump could continue to perform its intended function.
The surveillance interval was decreased to monthly from quarterly, but no further action was taken.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
O Minor U Screened as green U
Go to Phase 2 0]
Transfer to:
(Other SDP Process)
Question 5:
At Fort Calhoun, licensed operators tripped the reactor because of low instrument air pressure.
Operators are required to continue into lower modes because the loss of air began affecting condenser vacuum.
When attempting to place the plant in cold shutdown, vessel level began to decrease.
Operators identified that a drain valve between the shutdown cooling isolation valves was locked open instead of locked closed.
This resulted in the reactor coolant system being drained to the containment floor drain sump.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
o Minor 0 Screened as green 0
Go to Phase 2 o
Transfer to:
(Other SDP Process)
Question 6:
The Entergy load dispatcher at The Woodlands (near Houston) distribution center called the Waterford 3 control room and informed the control room supervisor that if the Waterford 3 unit were to trip offline, that the offsite power feed to the Waterford 3 switchyard would not meet system minimum frequency and voltage requirements.
Waterford Units 1 and 2 were offline for maintenance.
The control room supervisor ordered that the emergency diesel generators be started and loaded on the grid.
No technical specification entries were made.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
" Minor
" Screened as green 3 Go to Phase 2 0 Transfer to:
(Other SDP Process)
Question 7:
At ANO Unit 1, the 'A' low pressure injection pump was placed in service for shutdown cooling at the start of a refueling outage.
The unit was in Mode 3 at the time.
After 5 minutes of operation, valid high temperature alarms on the pump inboard and outboard bearings were received.
Operators trended the bearing temperatures and noted that the temperature rise did not exceed annunciator response procedure requirement to secure the pump and appeared to be stable.
A condition report was initiated.
Further review during the refueling outage identified that the incorrect bearings had been installed during the previous maintenance outage.
The low pressure injection pump is required to be operable for shutdown cooling and low pressure injection purposes.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
Q Minor U Screened as green U
Go to Phase 2 U Transfer to:
(Other SDP Process)
Question 8:
Mechanics repaired the seat of a high pressure safety injection valve during a recent refueling outage at Wolf Creek.
Following plant heatup to Mode 3, operators performing a reactor coolant system inspection identified a significant body-to-bonnet leak.
The licensee quantified the leakage at approximately 15 gpm.
Technical Specifications requires that identified reactor coolant system leakage be no greater than 10 gpm in Modes 1 through 4.
The plant was cooled back to cold shutdown to repair the valve.
Mechanics determined that a low temperature gasket material had been used in reassembling the valve, and the material had failed because of high system temperatures.
State the Performance Deficiency:
Determine if this performance deficiency should be characterized as minor.
If more than minor, determine the best disposition for the finding out of the following list:
U Minor o2 Screened as green Ul Go to Phase 2 U Transfer to:
(Other SDP Process)