ML20113A782
| ML20113A782 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 06/21/1996 |
| From: | Maynard O WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| WO-96-0102, WO-96-102, NUDOCS 9606250331 | |
| Download: ML20113A782 (13) | |
Text
-
o LF CREEK W@ NUCLEAR OPERATING
~
Otto L. Maynard dune 21* 1996 Vice President Plant Operations q
WO 96-0102 U.
S.
Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-137 Washington, D.
C.
20555
Reference:
Letter dated May 23, 1996, from J.
E.
- Dyer, NRC, to N.
S. Carns, WCNOC
Subject:
Docket No. 50-482: Responses to Violations 482/9609-01, 482/9609-02 and 482/9609-03 Gentlemen:
Attached is Wolf Creek Nuclear Operating Corporation's (WCNOC) reply to Notice of Violations 9609-01,
-02, and -03 that were documented in the referenced j
Resiccit Inspector's report. Violation 9609-01 concerned personnel failing to ensure all post-maintenance testing was completed prior to starting the B j
Motor-Driven Auxiliary Feedwater Pump.
Violation 9609-02 concerned an
)
inadequate procedure that failed to establish appropriate initial conditions for a surveillance test and resulted in the overspeed trip of the Auxiliary Feedwater Turbine.
Violation 9609-03 concerned inadequate operating procedures for the Turbine-Driven Auxiliary Feedwater Pump that did not require the turbine oil level to be maintained within the vendor approved range.
WCNOC's response to these violations is in the attachment to this letter.
If you have any questions regarding this response, please contact me at (316) 364-8831, extension 4450, or Mr. T. S. Morrill at extension 8707.
l Very truly yours, M
d 9606250331 960621
[/[/ 7 #[//'
PDR ADOCK 05000482 r
G PDR Otto L. Maynard OLM/jad Attachment cc:
L.
J.
Callan (NRC), w/a W. D.
Johnson (NRC), w/a J
I. Ringwald (NRC), w/a f
J.
C.
Stone (NRC), w/a 500.?f PO. Box 411/ Burlington, KS 66839 / Phone: (316) 364-8831 An Equal Opportunity Employer M/F/HC/ VET
b Attachment to WO 96-0102 Page 1 of 12 Reply to Notice of Violation 482/9609-01 violation 482/9609-01:
" Criterion V of Appendix B to 10 CFR Part 50 requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, and drawings appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Contrary to the above, on March 30,
- 1996, licensee procedures were inappropriate to the circumstances in that they failed to.contain a requirement for operators to ensure that all maintenance activities, including postmaintenance testing, be complete, prior to starting safety-related equipment for operational needs.
Consequently, on March 30, 1996, operators started and used. Motor-Driven Auxiliary Feedwater Pump B to fill steam generators prior to the completion of the postmaintenance retest and final packing adjustment."
This is a Severity Level IV violation (Supplement I).
ad=4seion of violation:
Wolf Creek Nuclear Operating Corporation (WCNOC) acknowledges and agrees that work control procedures were inadequate and did not prevent operators from starting and using the Motor-Driven Auxiliary Feedwater Pump (MDAFWP) prior to the completion of the post-maintenance retests and final packing adjustment.
Ranson for Violationt During Refueling Outage VIII. a major pump inspection was performed on the B MDAFWP. The work required that the system be out-of-service, drained and de-energized under a Clearance Order.
When work was completed on the pump, the Clearance Order was removed and the system filled and vented per procedure SYS AL-121, " Auxiliary Feedwater System Fill and' Vent."
The system was returned to operations without programmatic constraints in place to prevent Operations use of the system prior to completion of the post-maintenance retests (PMT),
j Work Package Tasks (WPT) 107850
-02,
-04, and. - 0 5, remained open:
Task 2 j
specified performance of procedure STS AL-212,
" Motor-Driven Auxiliary Feedwater Flow Path Verification and Inservice Check Valve Test," Task 4 j
specified a run-in test and shaft sleeve inspection, and Task 5 verified shaft seal leak rates.
On March 30, 1996, Control Room Operators were preparing to fill A and D Steam Generators using the Auxiliary Feedwater System.
Both MDAFWPs were in the standby condition.
The plant was in MODE 4 and the auxiliary feedwater pumps were not required to be operable per Technical Specifications.
There were no current Clearance Orders out for the MDAFWPs, so the Control Room determined it was acceptable to use either pump to fill the A and D steam generators.
The B MDAFWP was used because it feeds directly into Steam Generators A and D and did not require unlocking and opening the Auxiliary Feedwater System crosstie valves.
Attachment to WO 96-0102 Page 2 of 12 The pump operated for approximately two minutes when the local Operator reported to the Control Room that steam was coming from th, inboard packing and the outboard packing was hot.
The pump was immediately secured and an action request written.
Subsequent discussions with Maintenance and System Engineering personnel revealed that the B MDAFWP was not intended to be operated until both groups could be present to perform a packing run-in.
They planned to monitor the packing and adjust the packing follower.
This information was not known by the Control Room Operators on either the offgoing shift from that morning or by the operators on duty; Investigation and interviews determined the root cause of this event was inadequate procedural controls.
Work controls procedure, AP 16C-002, " Work controls," did not provide programmatic constraints necessary to prevent the pump from being returned unconditionally to Operations before all post-maintenance tests were complete.
Corrective Steps That Have Been Taken and the Results Achieved!
As an immediate corrective
- action, representatives from Maintenance, Integrated Plant Scheduling, System Engineering. and Operations held a series of meetings to determine the root cause and what programmatic changes were necessary to prevent recurrence.
The results achieved from these meetings l
provided an immediate solution to be followed by more detailed procedural changes.
The corrective actions are as follows:
- A Team Leader (during non-refueling operations) or an Outage Window Manager (during refueling outages), will be assigned.to safety-related pumps that are removed from service.
The designated individual will verify that all PMTs are complete prior to returning the system unconditionally to operations.
The designated individual will utilize existing plant processea to accomplish this task, including but not limited to:
- 1) signing on the clearance Order that provides the boundary for the maintenance activity;
- 2) creating a separate Clearance Order that keeps the point of control in the possession of that person; or,
- 3) utilizing an Information Tag at the point of control for the equipment.
The Shift Supervisor will review the scope of work and open activities with the Team Leader or Outage Window Manager on a periodic basis.
" Work Controls" procedure, AP 16C-002, was revised to identify the tasks of the Team Leader and the Outage Window Manager.
The revision was implemented on June 5, 1996.
4 Attachment to WO 96-0102 Page 3 of 12 On June 18, 1996, the procedure revision was placed in Essential Reading for Team Leaders, Shift Supervisors, and Shift Engineers.
Outage Window Managers will receive Pre-outage training prior performing the required tasks.
System Engineers and Maintenance Planners attended Continuing Training sessions to review the new requirements. This corrective action was completed on June 18, 1996.
Corrective Stens That Will Be Taken and the Date when Full Consoliance Will Be the Results Achieved.
I Full compliance has been achieved and no further corrective actions are required.
i i
Attachment to WO 96-0102 Page 4 of 12 Reply to Notice of Violation 482/9609-02 Violation 482/9609-02
" Criterion V of Appendix B to 10 CFR Part 50 requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, and drawings appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Contrary to the above, on March 31, 1996, Surveillance Test Procedure STS RP-
- 004,
" Auxiliary Shutdown Panel Control Switch Test,"
Revision 7,
was inappropriate to the circumstances, in
- that, it failed to establish appropriate initial conditions for the test, and thereby caused an inadvertent everspeed of the auxiliary feedwater turbine when it opened the trip and throttle valve with the auxiliary steam supply isolation valve open."
This is a Severity Level IV violation (Supplement I).
Admission of violation Wolf Creek Nuclear Operating Corporation (WCNOC) acknowledges and agrees that the surveillence procedure did not establish appropriate initial conditions for the test, and thereby resulted in an inadvertent overspeed of the Auxiliary Feedwater Turbine.
Reason for the Violation Procedure STS RP-004, section 8.10 opens FC HV-312, " Turbine-driven Auxiliary Feedwater Pump Trip and Throttle Valve."
There was not a precaution statement directing the operator to verify that the steam supply to the valve was closed, and when section 8.10 was performed, steam was admitted to the Turbine and the Turbine experienced an overspeed condition.
The root cause of this event was an inadequa'e surveillance procedure that t
omitted relevant information in that procedure. STS RP-004 did not require verification that the steam supplies to the TDAFWP were closed.
A contributing cause was that the dayshift did not have a proper questioning attitude prior to commencing STS RP-004 on March 31, 1996.
Corrective Steps That Have Been Taken and the Results Achieved Operations personnel have evaluated safety related equipment having multiple energy sources and determined that only the TDAFWP is affected.
Procedure STS RP-004 was revised on May 9, 1996, to require verification that steam supplies are closed prior to stroking valve FC HV-312 open.
Procedure STN FC-002 was reviewed and found to contain the necessary steps to preclude operation with more than one steam source.
Performance Improvement Request (PIR) 96-1043 was initiated to address the root cause and corrective actions, and placed in Operations Required Reading on May 21, 1996, to reinforce the importance of good communication during turnover.
Attachment to WO 96-0102 Page 5 of 12 This event was discussed during Control Room crew turnovers, and operators were counseled on the importance of having a questioning attitude and awareness of potential conflicting activities.
Corrective Steps That Will Be Taken and the Date When Full Comoliance Will Be the Results Achieved:
Full compliance has been achieved and no further corrective actions are required.
Attachment to WO 96-0102 Page 6 of 12 Additional Information Requested in Response to Violation 9609-02
Background:
On March 30, 1996, the Control Room dayshift crew began performance of procedure STS RP-004,
" Auxiliary Shutdown Panel control Switch Test."
Procedure STS RP-004 verifies the operation of the component controls located on the auxiliary shutdown panel.
The test was not completed during the dayshift.
At 1900 CST, the nightshift crew assumed the watch and was directed to start procedure STN FC-002, " Auxiliary Feedwater Turbine Overspeed Test."
The nightshift Supervising Operator signed onto STN FC-002 and sent the original to the support crew for performance of the test.
He instructed the support crew not to perform STS RP-004 and STN FC-002 concurrently due to conflicts with the Auxiliary Feedwater Turbine. The support crew commenced STN FC-002 and proceeded to the step where valve FCV-004, " Auxiliary Steam Supply to the Turbine Driven Auxiliary Feedwater Pump Isolation Valve," was opened. At 0453 CST, on March 31, 1996, the support crew stopped the procedure because the Auxiliary Boiler was unavailable. The Auxiliary Boiler was still unavailable at turnover time, but was expected to be restarted soon.
The nightshift believed that STN FC-002 would be completed once the boiler was restarted and prior to other testing being done.
Procedure STN FC-002 was listed on the Shift Supervisor Relief Checklist under Significant Testing / Restoration In Progress, and on the Control Room Turnover Checklist as Testing in Progress /Pending. After turnover, the dayshift crew decided to continue with the performance of STS RP-004.
1.
"There was poor coordination of the suspended procedure STN FC-002 with procedure STS RP-004."
j Contributing to this event was that valve FC-V004 was not closed when procedure STN FC-002 could not be completed. Auxiliary steam was available when the procedure was started, but the Auxiliary Boiler failed and a steam supply was not available.
The test was suspended with the intent of completing it when auxiliary steam was restored.
It is not always advisable to restore from a surveillance when it is suspended.
However, in this instance it would have been prudent, since the surveillance was extending into the next shift.
Procedure STN FC-002 was listed under Testing in Progress /Pending on the Control Room Turnover Checklist.
The dayshift Supervising Operator interpreted that to mean the procedure would be started on the next shift, not that the test was in progress. The word "pending" created confusion as to whether the test was in progress or waiting to be done, and was not challenged by the operators.
2.
"There was a weak turnover, in that, few oncoming watchstanders knew that valve FCV-004 remained open, and operators apparently did not question the status of suspended procedure STN FC-002."
-- ~ _ -.
I I
Attachment to WO 96-0102
~
Page 7 of 12 Inadequate communication and lack of a questioning attitude contributed to the event. The nightshift and dayshift Reactor Operators discussed STN FC-002, but a clear communication of the status of the procedure between the two operators did not occur.
This miscommunication was escalated by the fact that a copy of the procedure was used in the Control Room and not the signed original which showed which steps were complete.
3.
"There were weak programmatic administrative requirements for surveillance test suspension.
Administrative Procedure AP 29B-003,
' Surveillance Testing,' Section 6.6, provided four steps associated with the suspension of surveillance testing.
None of these four steps required the test
)
performers to restore the system lineup to any particular configuration l
and, therefore, permitted the suspension of Procedure STN FC-002 with valve i
FC-V004 open."
Programmatic administrative requirements for surveillances are located in Administrative Procedure AP 29B-003, " Surveillance Testing," Section 6.4,
" Pre-Test Activities."
Verification of system lineup when attempting to initiate a test is more appropriate than when suspending a test, and should have precluded this event had the steps been used effectively.
After a j
test is started, it is not always possible to return to the original line-up.
Accordingly, step 6.4.7 states that when Shift Supervisor / Supervising operator authorization is
- required, the Shift Supervisor / Supervising operator shall perform the following:
- 1. Determine if plant conditions allow performance
- 2. Achieve proper plant conditions for the test, if practical
- 3. Discuss the subject test with the test performer to determine its affect on plant status
- 4. Assure that performance of the test will not place the plant in an unsafe condition.
1 4.
"The inspector noted that system operating procedures established an initial condition to ensure that the system was lined up in accordance with the applicable system lineup checklist procedure.
However, surveillance test procedures had no similar requirement.
As a result, the program relied on the individual surveillance procedure and the Shift Supervisor to ensure that appropriate initial conditions supported the performance of the test."
The procedural matrix is as follows.
The checklist is intended to place a system in a known configuration allowing operating procedures to be performed. Often~several checklists need to be performed simultaneously to ensure not only that the system being started is correctly lined up, but that required support systems are available.
Surveillance procedures are written based on certain operating conditions.
Some surveillances are run for out-of-service components while others are run for operating systems.
)
This results in a significantly greater number of potential variables for the surveillance procedures compared to operating procedures.
During an outage, until the specific point in time at which the test is to be initiated, there is no effective way to anticipate all possible variables.
That is why the surveillance Pre-Test Activities referenced in item #3
l Attachment to WO 96-0102 l
Page 8 of 12 l
l above were included.
Some surveillances are expected to be run simultaneously and others are mutually exclusive.
Multiple unrelated surveillances are performed on a regular basis.
Control Room personnel l
were aware that these two specific surveillances could not be run together.
l There was not clear communication during turnover as to the status of procedure STN FC-002.
Procedure STS RP-004, has been revised to include checking the steam supplies are closed.
This will ensure that positive control of the Turbine drive is maintained.
i Corrective Stens That Have Been Taken and the Results Achieved l
Corrective action applicable to the four NRC concerns:
Performance Improvement Request (PIR) 96-1043 was initiated to address the root cause and corrective actions, and placed in Operations Required Reading on May 21, 1996, to reinforce the importance of good communication during turnover.
Additional corrective action specifically in response to concern #1:
"Pending" was removed from the Control Room Turnover Checklist heading of Testing in Progress /Pending on May 10, 1996.
Tests that are to be completed I
on the next shift can be listed under the comments section of the turnover I
sheet.
l Additional corrective action specifically in response to concerns #3 and #4:
l Operations personnel have evaluated safety related equipment having multiple energy sources and determined that only the TDAFWP is affected.
Procedure STS l
RP-004 was revised to verify all steam sources were isolated prior to stroking FC HV-312, TDAFWP Trip and Throttle Valve.
Procedure STN FC-002 was reviewed and found to contain the necessary steps to preclude operation with more than l
one steam source.
I Corrective Stans That Will Be Taken and the Date when Full Caneliance Will Be the Results Achieved Full compliance has been achieved and no further corrective actions are required.
t
Attachment to WO 96-0102 Page 9 of 12 Reply to Notice of Violation 482/9609-03 violation 482/9609-03
" Criterion V of Appendix B to 10 CFR Part 50 requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, and drawings appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Contrary to the above, between October 24, 1995, and May 4, 1996, operating
. procedures for the turbine-driven auxiliary feedwater pump did not require the turbine oil level to be maintained within the operating range prescribed by the vendor.
During this period, an engineering evaluation of the guidance had been completed, but did not justify operation contrary to the vendor guidance.
On March 31, 1996, an NRC inspector noted that turbine lube oil level was below the low-level mark as operators were preparing to start the turbine."
This is a Severity Level IV violation (Supplement I).
m 4ssion of violations Wolf Creek Nuclear Operating Corporation (WCNOC) acknowledges that operating procedures for the Turbine-Driven Auxiliary Feedwater Pump (TDAFWP) did not require the turbine oil level to be maintained within the operating range prescribed by the vendor.
Reason for the violations NRC inspectors performing a Terry Turbine Auxiliary Feedwater Pump Assessment on August 15 and 16, 1995, initially raised a question on the oil level.
A Performance Improvement Request (PIR 95-2222) documented the concerns.
Engineering promptly requested additional information from the TDAFWP Turbine vendor, Dresser-Rand.
On August 30, 1995, a fax was received by WCNOC from Dresser-Rand detailing the proper oil level for the TDAFWP Turbine.
It provided limits for lubrication, including a statement that stated, "Do not allow oil level to exceed these limits," in reference to the 3/8 inch band on the oil level gauge.
The same fax also included a sketch showing the oil ring in relation to the oil level.
On_ September 29, 1995, another fax was received by WCNOC from Dresser-Rand providing further clarification.
The fax stated, "The proper oil level per the gauge insures the optimum performance of the oil ring lubrication and operating outside this range is not recommended.
Your turbine also has a saddle pump lube system.
As long as you can see oil in the site gauge there is sufficient oil for the pump to operate and properly lubricate the turbine and the governor.
However, continuous operation outside the correct range will result in a higher frequency of various bearing related problems and required maintenance."
The evaluation for PIR 95-2222 used the above faxed information along with information from telephone conversations with Dresser-Rand and concluded that
Attachment to WO 96-0102 Page 10 of 12 the current turbine oil level was adequate to ensure availability of the TDAFWP.
As stated in the PIR, the TDAFWP turbine has an oil sump and a shaft-driven pump that feeds both bearings and the governor valve actuator.
Because the turbine oil system is interconnected, the oil level is the same throughout the system.
The optimum oil level is not lower than 0.25 inches above the bottom dead center of the oil rings to a maximum of 0.375 inches above the minimum.
Operating within this ranges maximizes the bearing life.
- However, as long as the top of the oil level is visible in the site glass, when the turbine is in a standby condition, the bearings will receive adequate lubrication.
The turbine is able to operate within this large range because of the forced circulation provided by the shaft-driven oil pump.
The oil rings primarily provide lubrication to the bearings at start-up and coast down if the oil pump fails.
Because the turbine has an oil pump that provides forced circulation, the oil rings only provide a secondary way to lubricate the bearings.
The installed site glass initially only had a center line mark.
While this was adequate, a mark identitying the optimum oil level range was preferred by WCNOC personnel.
No corrective actions were taken for PIR 95-2222.
Enhancements identified, but not completed at that time included, marking the site glass with high and low marks and obtaining better copies of the faxed material for incorporation into the Technical Manual.
On March 31, 1996, an NRC inspector noted, using the newly installed marks on the site glass, that the oil level was below the low-level mark, as the Operators prepared to start the turbine.
Procedure CKL ZL-004,
" Turbine Building Reading Sheets," defined the turbine oil level as satisfactory when greater than one-eighth of the height of the sight glass.
The inspector noted that CKL ZL-004 did not direct Operators to maintain the turbine oil level within the range specified by Dresser-Rand.
The engineering evaluation addressed acceptable operation, but did not address long term optimal performance.
More details describing the type of lubricating system and associated effects of high and low oil level with a forced lubrication system would have further clarified the issue.
The root cause of this event is an incomplete procedure that did not contain up-to-date vendor information.
Corrective Steps That Have Been Taken and the Results AchieveA Based on additional information received from Dresser-Rand, new oil levels have been established (reference diagram on page 12).
There is an optimal band as defined above, and an acceptable band of greater than 1 inch above the high mark, or 1 inch below the low mark.
When the oil level is discovered to be outside the optimal range but within the acceptable range, an action request is required to be initiated to restore level to within the optimal range.
When the level is outside the acceptable range, the equipment status is questionable, and the Shift Supervisor and System Engineer should be contacted immediately to determine operability.
i Attachment to WO 96-0102 Page 11 of 12
" Turbine Building Reading Sheets," procedure, CKL ZL-004, was changed to incorporate the vendor recommendations on May 7,
1996.
The oil sight glass marks were previously added per Work Package Task 106536-1, on March 18, 1996.
On Operator's Aid, OA 96-08, a placard, was placed near the sight glass to r
visually define the optimum and acceptable ranges as described above.
Additionally, the placard specifies actions to be taken upon indication of a oil level outside the specified ranges (reference diagram on page 12).
All applicable correspondence from Dresser-Rand has been added to the Technical Manual.
i System Engineers have been counseled on the need for timely corrective action i
and follow-up actions, particularly as they relate to newly discovered information.
Corrective Stens That Will Be Taken and the Date When Full C - liance Will Be the Results Achieved:
Full compliance has been achieved and no further corrective actions are required.
i a
-+
t Attachment to Wo 96-0102 Page 12 of 12 Diagram for 9609-03 Operator's Aid 96-08 1
Placard on the Auxiliary Feedwater Turbine TERRY TURBINE OIL LEVEL IF oil level INCREASES to 1" Above HI mark, THEN Immediately notify the Shift Supervisor and System Engineer to determine operability IF oillevelis Greater Than HI mark, THEN submit an Action Request to restore Hi - -
level to within marks.
LOW -
4 IF oillevel is Less Than LOW mark, THEN submit an Action Request to restore level to within marks (see note 1).
i IF oil level DECREASES to 1" Below LOW mark, THEN Immediately notify the Shift Supervisor and System Engineer to determine operability Note (1): Oil level may decrease approximately 3/8" after the TDAFWP is started. This is normal and operation slightly below the low mark is satisfactory since oil level will gradually return to Commitment n rmal when pump is secured.
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RCMS96-110 4