ML20059M441
| ML20059M441 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 09/11/1990 |
| From: | Lyster M CENTERIOR ENERGY |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9010040180 | |
| Download: ML20059M441 (4) | |
Text
D CENTRg PERRY NUCLEAR POWER PLANT Mail Adatess:
10 CENTER ROAD -
P.O. BOX 97 Michael D. L veter PERRY, OHIO 44081 PERRY OHIO 44081 Vice Pres:delt - Nuclear (216)259 3737
. rR10R11y 9001 September 11, 1990 PY-CEI/01E-0327 L h-l e,=
['CL f ou Mr. A. Bert Davis
- S9 L
Regions) Administrator, Region III
-- gnt M U.S. Nr lear Regulatory Commission i
799 Robaev:lt Road l
Glen Ellyn, Illinois 60137 Perry Nuclear Power Plant Docket No. 50-440 i
Main Steam Isolation-Valve and Motor 7eed Pump l
Problems - Sept. 7, 1990
Dear Mr. Davis:
During shutdown of the Perry Nuclear Power-Plant, Unit-1 on September 7, 19)fi.,
operational problems were experienced with two of eight Main Steam Isolation Valves, as well as the Motor Driven Feedwater Pump.
.~
N Based on discussions held with members of your staff cn September 7,;1990,;we are providing the enclosed information. Attachment 1 provides a brief description of the failure-characteristics, current condition *, and preliminary troubleshooting plan for the Main Steam Isolation Valves.
Similar j
information for the Motor Driven Feedwater Pump is provided in' Attachment 2.
This letter eiso confirms our previous verbal commitment.to take actions necessary to preserve evidence of "as-found" conditions for the MSIVs, and to' obtain Region III concurrence with proposed troubleshooting plans.
j If t e re are any further questions regarding these matters, please do not i
hesitat.. to call.
- !q Since ly,.
//
4, s
Michael D. Ly tur
' i MDL:MLE:nje i
cc: NRR Project Manager Sr. Resident Inspector SEP 14 O 0Di09 Operating Units:
\\(
. cleveland Electric muminahng Toledo Edison 9010040180 900911 PM M W W OO M gd/'
S PDCL l
gn j
6 PY-CEI/0IE-0372 L Failure of Main Steam Isolation Valves 1B21-F022C and 1B21-F028B September 7, 1990-Description of Failure On September-7, 1990, shutdown of.the Perry Nuclear Power Plant, Unit 1 was commenced in preparation for the second refueling outage.
During the-t cooldown, operators vere' directed to close the Main Steam Isolation Vcives to
~
maintain control of the reactor cooldown rate.
i On 09/07/90.at 0626,.1B21-F028B (outboard MSIV, B Main Steam Line) was slov closed successfully.
The control switch was then placed in the closed
-1 position and,the valve drifted open.. Operators then attempted to faat close the valve unsuccessfully.
The control switch was left in the closed position.
and the valve subsequently closed on its own (fast closed _in ~3 seconds) on 09/0,'/90' at 0640 hours0.00741 days <br />0.178 hours <br />0.00106 weeks <br />2.4352e-4 months <br />. At 0625 hours0.00723 days <br />0.174 hours <br />0.00103 weeks <br />2.378125e-4 months <br /> Operators slow closed IB21-F022C (inboard MSIV, C Main Steam Line) successfully; however, when its control switch was placed in the closed position, the valve drif ted open also.:
Operators attempted to fast close the valve but were unsuccessful.~_Its control switch was also left in the closed position and-the valve closed-on its own on 09/08/90 sometime between 1500 and 1913 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.278965e-4 months <br />.- The last time-these valves were satisfactorily fast closed was for surveillance activities on 01/08/90.
Current Status Currently, the plant is in Operational Condition 4, Cold Shutdown, with temperature being maintained by the shutdown cooling mcde-of the Residual Heat Removal system._ All eight MSIVs remain closed, and. provision have been made to ensure no work is performed on the valves,.or their associated electrical and pneumatic control systems.
L Dryvell and steam tunnel entries have been made and a. visual-inspection has-l been performed on 1B21-F022C and F028B (both valves were alosedLat the time of inspection), which identified no mechanical problems.
No evidence'of steam-l leakage in the vicinity of the air packs were noted.
Troubleshooting and Repair Activities l
The main steam isolation valves are to remain closed until completion of Local Leak-Rate Testing (LLRT), currently scheduled to-begin on' September _15, 1990.
No exercising, testing or maintenance vill be performed on the pneumatic controls for the MSIVs until these LLRTs'are complete. Vith regard to' further j
troubleshooting activities, the following requirements vill be established.
1.
Actions vill be taken as necessary to ensure that complete documentary-
~
evidence of the "as found" condition of equipment being inspected is 1
maintained.
l l
l 1.
1.
PY-CEI/0IE-0372 L Page 2 of 2 1
L 2.. A step by step troubleshooting program vill be developed and used to 1
establish the root cause of the HSIVs failure to meet acceptable 1
t performance criteria.
3.
Actions which'vould disturb any components that offer a potential for being the root cause, including'pover sources,= switches, solenoids,and the air system directly feeding the MSIVs vill not be commenced until arrangements are made for NRC oversight, as necessary.
s 4.
A Licensee Event Report vill be submitted to the NRC, disclosing the findings and conclu-ions of these efforte._ If necessary,. supplements vill be provided.
t CODED /NJC/V3799 i
1
'1 g
4 Attach =nt 2 PLCEI/01E-0372L Page 1 of 1-Failure of Motor Driven Feedvater Pump.
September 6, 1990 Description of Failure During a planned reactor shutdown on September 6, 1990, the Motor Driven Feedvater Pump (MDPP) was started, in anticipation of low power operations.
No problems were indicated until approximately twenty minutes later, at which' time local indication for pump vibration was indicating off scale tigh. An engineer then proceeded to the pump and observed seal water coming out of the drain vents for each pump seal.
He also observed seal water temperature at 200'F and-heard a screeching noise coming from the pump. The control room was informed of the situation and operators secured the pump.
The situation was discussed between engineering and operations personnel.
Based on preliminary indications, it'vas considered that the vibration problem-and seal leakage condition vould not have precluded use of the pump for the 1
remainder of the controlled shutdown.
After evaluation, the decision was made i
to restart the pump.
Prior to restarting the pump, additional vibration monitoring instrumentation was connected and.upon restart of the pump,.both' seal leakage and motor current were closely scrutinized.
Pump vibration was high and the screeching noise was heard again.
Motor current was slso high just prior to securing the pump. The pump vas secured and its condition documented.
l Current Status currently, the plant is in Operation Condition 4, Cold shutdown, vith temperature being maintained by the shutdown cooling mode of the Residual Heat-l Removal system. The MDFP coupling has been removed, the motor meggered, and phase to phase resistance checked.
Preparation are in progress for an uncoupled run of the motor.
A visual inspection of the pump seals-revealed mushroomed metal in the seal area and it was also noted that the pump shaft can "i
be turned by hand.
Troubleshooting and Repair Activities The following activities are planned in response to the MDFP failure.
1.
Perform an uncoupled motor run to obtain running current, bearing temperatures, and vibration analysis.
2.
Disassemble, visually inspect, and measure clearances on pump bearings and seals.
3.
Remove the rotating element, perform visual inspection and check internal' clearances, and perform a runout check to determine if pump shaft is bent.
l 4.
Reassemble and test HDFP.
Modifications to operating or test instructions will be implemented if l
. necessary, as determined by the results of troubleshooting activities.
NJC/ CODED /3805 a
-