ML20096E451
| ML20096E451 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 05/07/1992 |
| From: | Withers B WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC |
| Shared Package | |
| ML20096E425 | List: |
| References | |
| 92-0087, 92-87, NUDOCS 9205190197 | |
| Download: ML20096E451 (7) | |
Text
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LF CREEK W@ NUCLEAR OPERATING U
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May 7, 1992 cNet tietvii. on.cer Wi 92-0087 U. S. Nuclear Regulatory Cocenission ATTN Document Control Desk Mail Station P1-137 Vashington, D. C.
20555 Refertnces Letter dated April 9, 1992 from A. B. Beach, NRC to B. D. Withers, VCNOC
Subject:
Docket No. 50-482:
Response to Violation 482/9202-02 Gentlemen
/.t ached is Wolf Creek Nuclear Operating Corporation's (VCNOC) response to violation 482/9202-02 concerning three examples of failing to have appropriate procedures.
If you have any questions concerning this matter, please contact me or Mr. S. G. Wideman of my staff.
Very truly ours, rY-y art D. Withers President and Chief Executive Officer BDW/aem Attachment cci A. T. Howell (NRC). v/a R. D. Martin (NRC). w/a G. A.
Pick (NRC), w/a W. D. Reckley (NRC), w/a 9205190197 920515 PDR ADOCK 05000482
-hh PO Box 411 Buritngton, KS 66639 Phone. (316) 364-8831 An Eza opportunty Emp. oyer M F HC vtt
Attachment to WM 92-0087 Page 1 of 5 RE9LY TO A NOTICE OF VIOLATION Violation 482/9202-02:
Psilure To Have ADoroorlate Proceduget Findinal Technical Specification (TS) 6.8.1.a requires that written procedures be established, Lmplemented, and maintained covering the applicable procsdures recommended in Appendix A of Regulatory Guide (RG) 1.33 Revision 2,
February 1978.
10 CPR Part 50 Appendix B, Criterion V,
' Instructions, Procedures, and Drawings,' raquires, in part, that activities affecting quality shall be prescribed by procedures of a type approprjate to the circumstances.
Three examples of violation this requirement are stated belows 1.
RG 1.33, Appendix A, Item 8.b.
requires specific procedures for surveillance tests required by the TS.
This is accomplished, in part, by Surveillance Technical Specification Procedure STS BG-004, Revision 8, 'RCS Inservice Valve Test.'
Contrary to tl.e above, during the inspection period of January 26 through March 7,1992, STS BG-004 was determint:_ to be inappropriate to the circumstances because it did not provide precautions to indicate maximum system pressure while throttling the sesi injection throttle valves.
As a result, on January 10,
- 1992, the coolent charging positive displacement pump discharge piping was overpressurized during the performance of this test.
2.
Appendix A, Item 2.j, requires general operating procedures for going from Hot Standby to Cold Shutdown, Mode 3 to Mode 5 respectively.
This is accomplished by GEN 00-006, Revision 37,
' Hot Standby to Cold Shutdown'.
Contrary to the above, on February 23, 1992 with the plant in Mode 5 GEN 00-006 was determined to be !nappropriate to the circumstances because it did not provide adequate guidance for closing the safety injection cold leg injection valve, EM HV-8835.
As a result, approximately 12,000 gallons of water drained from the refueling water storaga tank to the reactor coolant system before the condition was detected and corrected by an operator.
3.
RG 1.33, Appendix A.
Item 7.c.(1),
requires procedures for the collection,
- storage, and discharge of gaseous vaste.
This is accomplished by Procedure SYS HA-200, Revision 8,
' Waste Gas System Startup and Shutdown.'
Contrary to the above, on March 3,
- 1992, SYS RA-200 was determined to be inappropriate to the circumstances because it did not provide adequate guldsnce for placing a gas decay tank on line.
As a result, an inadvertent releaJe of gaseous vaste occurred in the radwaste building.
Attachmsnt to VM 92-0087 Page 2 of 5 i
Reason For The Violations i
1.
On January 31,
- 1992, during a post-maintenance pressure test review by j
the tosponsible system engineer, it was identified that the charging header pressure had reached 2000 pounds per square-inch (psi) on January 10, 1992.
This value is 100 poi greater than the design pressure for this Class 2
- piping, but less than the 110 percent hydrostatic test pressure.
It was de t ermined that this event had occurred shortly before leakage was identidied on a weld of Positive Displacement Pump (PDP)
Relief Valve BG 811e.
Operttions personnei reviewed activities that occurred on January 10, 1092 which could have created an overpressure condition.
It was concluded t o. i t th*
event had occurred during the performance of surveillance procedure STS S3 004, Revision 1,
'CVCS Seal Injection and Return Flow Balance'.
The purpose of surveillance procedure STS BG-004 is to adjust the seal injection throttle valves to limit total seal injection flow to approximately 80 gallons per minute (gpm) during safety injection with one centrifugal charging pump operating at runout flow.
During the January 10, 1992 performance of surveillance procedure STS BG-004, Operations personnel determined that too much flow was present through the reactor coolant pump (RCP) seals and began adjusting the seal injection throttle valves.
The seal injection throttle valves were adjusted to establish approximately 8 gpm to each RCP seal.
As this was the only charging path that existed and because the PDP epeed was in manual flow control at 49 gpm, charging system pressure quickly rose abovw the PDP relief valve setpoint.
The remaining flow output of the PDP (appertimately 17 gpm) was flowing through the PDP relief valve.
This remaining flow output was not evident, as indicated charging flow and seal injection flow were matched.
The Reacter Operato.
observed an increase in charging system pressure but did not realize that the relief pressure had been exceeded.
When the charging pressure gauge began oscillating, the Reactor Operator directed station operators to open the seal injoction throttle valves to the point that system parameters stabilized.
At that time, the surveillance test was suspended.
Seal injection flow vas now at approximately 42 to 44 gpm, flow through the PDP relief valve was approximately 5 to 7 gpm and charging system pressure was approximately 2900 psi.
The charging system remained in this condition for several hours untal which time the Auxiliary Building Operator noted a weld leak on the PDP telief valve.
A review of surveillance procedure STS BG-004 revealed that information specified by vendor design documentation had not been properly incorporated into the procedure.
The procedure's initial conditions specified that the charging and letdown flow be balanced during procedure performance while the vendor design documentation specified that the charging system be aligned with charging and letdown in its normal mode of operation.
This is significant in that the procedure's initial conditions were being met.
- Also, the vendor design documentation specifies that the seal injection throttle valves should be adjusted with the RCS at normal operating pressure and normal operating ta=perature.
Surveillance procedure STS BG-004 specified that the plant should be in Mode 1, Power Operation.
Mode 2.
Startup, or Mode 3 Hot Standby however, while the plant is in Mode 3.
it is not always at normal operating pressure and temperature.
Attachm nt to WM 92-0087 Page 5 of 5 Surveillance procedure STS BG-004 provides directions for adjusting seal injection flow ta a given value for the measured differential pressure between the charging system and RCS: however, it did not provide directions to establish or maintain a differential pressure for the desired seal flow.
Additionally, a contributing cause is the failure of the Operations persennel to realize that the indicated high pressures were beyond the setpoint of the PDP relief valve.
2.
On February 23, 1992, during normal Control Room watchstation rounds, it was discovered that the Refueling Water Storage Tank (RWST) level was decreasing and that approximately 12,000 gallons had drained from the RWST to the RCS.
At that time, the unit was in Mode 5 Cold Shutdown, with the KCS temperature at 122 degrees f ahrenheit and pressure at 0 psi.
Control Room Operators were draining the RCS to accommodate repairs on a leaking core exit thermocouple penetration conoseal.
Procedure GEN 00-006,
' Hot Standby to Cold Shutdown,' had just been completed and procedure GEN 00 007,
'RCS Drain Down ' had been commenced.
Operations personnel determined that there were two possible flowpaths that would have allowed the inadvertent draining of the RVST.
The two flowpaths were through the Spent Fuel Pool Cleanup to Recycle Holdup Tank Isolation
- Valve, EC V081, or through the Safety Injection Pumps.
Safety Injection Cold Leg Isolation Valve EH EV8835 was discovered to be open and isolation valve EC V081 was verified as closed.
RWST level stopped decreasing upon closure of isolation valve EH EV8835.
The root cause of this event was determined to be a failure of procedure GEN 00 007 to ensure that isolation valve EH HV8835 ws closed during depressurization of the RCS prior to the RCS pressure decreasing below 100 psi.
3.
On March 3,
- 1992, in preparation for sampling Vaste Gas Decay Tank 12 the Radwaste Operator began switching waste gas decay tanks in accordance with system procedure SYS HA-200,
' Waste Gas System Startup and Shutdown.'
The gas analyzer rack was subsequently placed in stand 5y which lines the gas analyzer rack vent to the Radvaste Building Heating, Ventilation and Air Conditioning (EVAC) System.
Because of pressure reductions through the hydrogen recombiner, the vaste gas compressor cannot maintain high pressures in the low pressure line-up and therefore the system must be placed in high pressure line-up.
However, when the Radwaste Operator switched to Vaste Gas Decay Tank #2, the system was in the low pressure line-up and the tank was at a pressure which required a bigh pressure line-up.
Vaste Gas Compressor
'A' was started and had operated for approximately 30 to 45 seconds before flow and pressure indications made the Radwaste Operator aware that the system should have been in the high pressure lir.e -u p.
During compressor operation, system pressure had increased above the 50 pound setpoint of the i
system relief valve which caused it to lift and vent the vaste gas to the Radwaste Building HVAC.
i l
The root cause of this event was determined to be a failure of system procedure SYS HA 200 to state that prior to switching waste gas decay tanks.
ensure the system is in sSa proper operational line-up for the pressures contained in the oncoming Vaste Gas Decay Tank, i
L. _.
Attachment.
VM 92-0087 ra{g 4 oi 5 k
,s.tgi live Steps That Have Been Taken And Results Achieved:
1.
Upon identification of the leak, Centrol Room perscnnel started the
'A' centrifugal charging pump and secured the PDP.
Charging system pressure was a
reduced and stabilized below the PDP relie. e51v6 setpoint at approximately 2620 psi.
A corrective work request was initiated to determine the cause and to repair the leak.
Repair and testing of the valve was completed on February 6, 1992.
Procedure STS BG-004 is being revised to provide initial plant conditions consistent with the vendor design documentation.
The revisions to STS BC-006 will be completed by Hay 29, 1992.
This event has been discussed in licensed operator initial training.
Additionally, this event has been added to the lesson plan on plant and industry events for the current licensed and non-licensed operator requalification training cycle.
This training will increase the operating crew's awareness of the potential to overpressurize the PDP discharge piping.
2.
Procedure GFJ' 00 006 was revised to include a step that closes injection valve EM HV8835 to prevent RWST inventory from flowing to the RCS during RCS depressurization.
- Also, procedure GEN 00-0J7 was revised to include a step that ensures isolation valve EH HV8835 was closed prior to RCS pressure decreasing below 100 psi.
- 3. Because the vaste gas decay tanx had not been sampled prior to the event, the Control Room notified Chemistry personnel in accordance with the Offsite Dose Calculation Manual.
Chemistry personnel sampled the contents of the tank.
The estimated exposure to the whole body was 0.25 mrem with a limit of 500 mremlyr and to the skin was 1.16 mrem with a limit of 3000 mremlyr.
System procedure SYS IIA-200 was revised to include a step to ensure the system is in the proper operational line-up for the pressures contained in the oncoming Vaste Gas Decay Tank.
Corrective Stet. That Vill Be Taken To Avoid Further Violations:
Tha following discussion addresses measures to be taken to preclude the 1
occurrence of events abnilar to the three examples cited in the violation.
Wolf Creek Nuclear Operating Corporation (WCNOC) is aggressively eddressing improvements in procedural guidance through the efforts of the Management Action Plan (MAP).
which was presented to the Nuclear Regulatory Commission on April 17, 1992.
The Operations Department is developing a plan to perform a complete review of all Operations procedures.
Encompassed by the plan is the development of a procedure review group.
The group will be tasked with creating a guidance document for procedure format and content.
Following completion of the guidance document, the group will connence a reviev of the procedures and coordinate necessary changes.
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Attachmont to kh 92 0087 Page 5 of 5 Operations Management is also addressing improvement in the proper use of procedures.
Discussions have been held with the Shift Supervisors and operating crews.
Operations Management has and continues to emphasize the importance of verbatim compliance with procedures and the importance of understanding what the procedure is to accomplish.
Additionally, management stresses the necessity for reading and understanding the procedure prior to coecencing its performance.
The discussed efforts are not related to the operations Department alone, improvements in procedural guidance to enhance procedure usability and compliance are being implemented in othar departu.onts as well.
VCNOC has identified a negative trend in the areas of personnel performance and procedural adequacy and have initiated efforts to reverse this trend.
MAP Issue V addresses the improvements in procedural guidance and ensures that it receives continuing ettention.
Date When Full Conliance Vill Pe Achieved:
Full compliance will be achieved on June 26,
- 1992, with the completion of the current licensed and non-licensed operator requalification training cycle which will cover the overpressurization of the PDP discharge piping event.
Long term enhancements are being addressed by those actions being performed as part of the MAP.
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