ML20086J527
| ML20086J527 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 07/13/1995 |
| From: | Jackie Cook ILLINOIS POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| JGC-289-95, L42-95(07-13)LP, L42-95(7-13)LP, NUDOCS 9507190101 | |
| Download: ML20086J527 (10) | |
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Illinois Power Company Chnton Power Station P.o. Box 678 Chnton, IL 61727 Tel 217 935-5623 Fax 217 935-4632 John G. Cook Vice President ILLIN9BS u-r,o2*s P(w M R u2 95c 07-13 >tp 1A.120 JGC-289-95 July 13, 1995 Docket No. 50-461 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
Response to Notices of Violation Contained in Inspection Repon 50-461/95003 (DRS)
Dear Sir:
The attachments to this letter contain the Illinois Power (IP) response to the two violations of Nuclear Regulatory Commission (NRC) requirements documented in NRC inspection report 50-461/95003 (DRS). IP admits that both violations occurred. The first violation lists two examples of failure to take timely and effective corrective action to ensure conditions adverse to quality are corrected. These two examples were answered separately because the reason for the lack of prompt and effective corrective action was different for each example described in the violation. The second violation describes the failure of safety-related heat exchanger test results to be properly evaluated by the engineering staff.
Attachment A of this letter contains the response to the timeliness and effectiveness of corrective action issue and Attachment B contains the response to the heat exchanger test results evaluation issue. IP is confident that these responses address the concerns identified in these violations.
Sincerely yours, J.G. Cook Vice President MRS/csm Attachments cc:
NRC Clinton Licensing Project Manager f
NRC Resident Office, V-690 C(
g}f" Regional Administrator, Region III, USNRC Illinois Depanment of Nuclear Safety n j
- v si t 9507190101 950713
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PDR ADDCK 05000461 0
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Attachment A to U-602468 Page1of6 i
Response to Notice of Violation 50-461/95003-01a(DRS) i The Notice of Violation states in part:
"10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action," states, in part,
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" Measures shall be established to assure that conditions adverse to quality such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected."
Contrary to the above, the licensee failed to effectively correct a steadily increasing oil leak from the HPCS diesel generator inboard bearing from 1988 until March 31,1995 when the leakage, combined with the licensee's misunderstanding of the indication for l
proper oil level, resulted in the failure of the bearing assembly due to inadequate quantity i
of the lubricatir 'il."
Background and Reason for Violation l
The oil leak on the High Pressure Core Spray (HPCS) diesel generator inboard bearing was originally identified on Maintenance Work Request (MWR) D03216 on December 28, l
1988. The MWR was not scheduled for work at the time since the leak was considered minor, and it required a major diesel generator outage to repair. Oil was being added to the one gallon reservoir at the rate of about one pint every three months. In April 1993, preparations were being made to replace faulty spaceheaters in the HPCS generator. This I
would require a major HPCS generator outage. The bearing oil leak severity was reviewed and the equipment vendor provided information that potentially no improvement i
in the leak rate may be achieved through repair efforts. In an effort to minimize HPCS unavailability time, engineering recommended, and management agreed, that the bearing oil leak would not be repaired. No formal evaluation was prepared and no formal trending i
method was established for continued monitoring of the severity of the oil leak.
i On March 31,1995, in the twentieth hour of a twenty-four hour surveillance test required by Technical Specification SR 3.8.1.14, the inboard HPCS generator bearing failed due to a lack of sufficient lubrication.
Afler the bearing failed, an interdepartmental team was formed to determine the cause of the bearing failure. The team concluded that a low initial oil level of the bearing reservoir was the direct cause of the failure. The reason for the low initial level was a l
misinterpretation of the meaning of the markings on the bearing reservoir sightglass. The operators inappropriately interpreted that the two marks on the sightglass, used to determine proper oil level, were minimum and maximum levels. However, the upper mark i
Attachment A l
to U-602468 Page 2 of 6 actually represented the minimum standby level (engine not operating) and the lower mark represented the minimum operating level (engine operating). This, coupled with the chronic oil leak, allowed the oil level at the beginning of the operability test to be less than required to ensure proper lubrication.
The reason for the violation is a failure to recognize the consequences of a minor oil leak on the operation of plant equipment.
Corrective Steps Taken and Results Achieved The HPCS diesel generator shafl and bearing were repaired by MWR D50137. This work i
was completed on April 15,1995. Also, the inboard and outboard HPCS generator sightglasses were clearly marked to show a normal standby oil level band and a minimum acceptable operating level. This was accomplished by MWR D50439. The operating procedure, CPS No. 3506.01, " Diesel Generator Support Systems," and surveillance procedures CPS No. 9080.02,9080.14, and 9080.23 which also operate the diesel generator were revised to defme the meaning of the new sightglass markings and the action required when the oil level reaches the low level marks.
The Division I and 11 generators were reviewed for this problem but the bearings contained in these generators are greased and not oil lubricated so no sightglasses are present.
Corrective Steps to Avoid Further Violations Management has a heightened awareness of the impact of even a minor oil leak and of the proper marking of oil sightglasses. This is evidenced by the establishment of Plant Manager Standing Order PMSO-78, " Plant Component Oil Consumption" which requires the logging of all oil that is added to permanent plant equipment between scheduled maintenance intervals. This information is forwarded to engineering and is reviewed and trended to help identify any chronic leaks or excessive consumption.
Also, all plant rotating equipment requiring the addition of oil was reviewed and equipment considered critical was identified. This list contains both safety and non-safety related equipment. This review classified 198 pieces of equipment as being critical.
Engineering is reviewing this equipment to determine the proper oil level required for any critical equipment with sightglasses. At the completion of this review, a maintenance standard will be issued. This maintenance standard will provide detail on the proper oil level for each piece of critical equipment that uses a sightglass for oillevelindication.
This maintenance standard will be issued by July 31,1995.
Attachment A to U-602468 Page 3 of 6 Date When Full Comoliance Will lie Achieved Illinois Power is currently in full compliance with 10 CFR Part 50, Appendix B, Criterion XVI regarding this issue.
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Attachment A to U-602468 Page 4 of 6 Response to Notice of Violation 50-461/95003-01b(DRS)
The Notice of Violation states in part:
"10 CFR Pan 50, Appendix B, Criterion XVI, " Corrective Action," states, in part,
" Measures shall be established to assure that conditions adverse to quality such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected."
Contrary to the above, as of the start of this inspection on March 27,1995, the licensee had failed to ensure that a condition adverse to quality, hardening ofgrease in ABB K-line breakers, was promptly identified and corrected."
hq_kground and Reason for Violation In March 1989, Illinois Power Company received a 10 CFR Part 21 notification from Asea Brown Boveri (ABB) concerning contaminated lubricant in two HK circuit breakers at D. C. Cook Nuclear Plant. This contamination caused the grease to become hardened and the breakers to fail to close on command. Clinton Power Station does not have any ABB IIK circuit breakers installed in the plant. Contrary to section 3.1.2 ofNRC Inspection Report No. 50-461/95003(DRS), this notification did not document any failures of the 480 volt K-Line circuit breakers. It did identify that there was the potential for a similar type of failure on the 480 volt K-Line circuit breakers. CPS has thirty-three 480 volt K-Line circuit breakers in safety-related applications. Review of the 10 CFR Part 21 Notification showed that the primary concern was to ensure proper lubrication of the breakers when parts were replaced and " dependent upon the cleanliness of the environment, periodic checks for contamination should be performed." The statement "The circuit breaker requires no lubrication during its normal service life," is also contained in the 10 CFR Part 21 Notification. This notification did not contain any required time period to check for contaminated grease. Attached to the notification was a copy of the vendor manual that was current when the notice was received. This manual did not have a requirement to periodically check the breaker for contaminated grease. The requirements to ensure proper lubrication of replacement parts stated in the 10 CFR Pan 21 Notification are repeated in CPS No. 8410.02, "480 Volt Power Circuit Breaker, Generic Procedure For" which is the preventive maintenance procedure for ABB 480 volt K-Line breakers. Illinois Power believes that these actions were adequate in response to l
the 10 CFR Part 21 Notification.
i In June 1991, ABB issued an update to the vendor manual which recommended that all j
ABB 480 volt K-Line circuit breakers undergo a refurbishment every 10 years.
Refurbishment activities include cleaning and relubrication of circuit breaker parts. Illinois l
Power's review of the updated manual did not identify that there was a new l
recommendation to refurbish ABB 480 volt K-Line circuit breakers every 10 years.
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Attachment A to U-602468 Page 5 of 6 In September 1994, condition report 1-94-09-061 was initiated to document that the review of the ABB vendor manual update received in 1991 failed to identify the change in vendor maintenance recommendations. The change in the vendor manual was then forwarded to the maintenance department by procurement engineering for review against current maintenance practices. Maintenance then reviewed the update and determined that Plant Engineering needed to review the manual because of the significant change to current work practices that was being recommended by the vendor. The completion of the condition report was extended from March 1,1995 to October 31,1995 to allow this review. No evaluation of the potentialimpact to plant equipment was performed prior to extending the due date of the condition report. However, during the NRC engineering and technical support inspection an inspector questioned the status of the vendor manual review and implementation of the 10 year refurbishment recommendation for ABB 480 volt K-Line circuit breakers. Illinois Power showed the inspector that the inadequate review of the vendor manual update had been identified on a condition report, but an evaluation on the impact of not performing the recommended maintenance had not yet been performed. In response to the inspector's concerns the engineering stafrevaluated the potential for an ABB 480 volt K-Line circuit breaker to fail to operate because the recommended refurbishment had not been performed. The evaluation focused on the potential for hardened grease in the mechanical portion of the breaker to prevent the breaker from operating. This evaluation reviewed industry history as well as NRC Information Notice 95-22, "IIardened or Contaminated Lubricants Cause Metal-Clad Circuit Breaker Failures." NRC Information Notice 95-22 showed that hardened grease had not caused any failures of 480 volt ABB K-Line circuit breakers. The evaluation concluded that the ABB 480 volt K-Line circuit breakers at Clinton Power Station were operable and that there was no data to support that the circuit breakers will fail within the next five years.
Illinois Power believes that the reason for the violation is that an inadequate technical evaluation of the impact of not performing the recommended maintenance on ABB 480 volt circuit breakers was not performed prior to extending the completion date of the condition report. CPS No. 1016.01, " Condition Reports" does require that a justification for the extension to a corrective action due date evaluate the impact of the change, but clear guidance to evaluate the impact on plant equipment or procedures is not given. Any extensions to condition reports are approved by the Director of the department responsible for the condition report.
Corrnlive Sgps Taken and RAsults Achieved During the inspection a detailed evaluation of the operating experience of these breakers was performed. This review indicated that there was not an immediate concern with the 4S0 volt K-Line circuit breakers installed at Clinton Power Station.
Illinois Power does agree that the 480 volt K-Line ABB circuit breakers do require refurbishment at some interval. Illinois Power plans to have a detailed program to refurbish all 480 volt K-Line ABB safety-related breakers by August 16,1995. Illinois
1 Attachment A to U-602468 j
Page 6 of 6 Power will test and refurbish at least seven installed spare safety-related ABB 480 volt K-Line breakers by December 31,1995. Illinois Power believes that these spare breakers have a higher potential for failure since they are not regularly exercised. The testing will help establish the condition of the inservice breakers at Clinton Power Station. Unless breaker failures due to hardened grease are observed, all inservice safety-related ABB 480 volt K-Line circuit breakers will be refurbished prior to startup from the eighth refueling outage. If failures due to hardened grease are observed, Illinois Power will evaluate the test results and evaluate completing the refurbishment of all safety-related 480 volt K-Line circuit breakers sooner.
Carnsthe Steps to Avoid Further Violations The form used to justify the reason for extension of condition reports has been changed to prompt the originator to evaluate the impact of the extension on plant equipment and procedures. CPS No. 1016.01 will also be revised to more clearly describe what must be evaluated in order to justify extending the due date of a corrective action contained in a condition report. This revision will be approved by August 30,1995.
Attachment B j
to U-602468 j
Page1of3 t
L Response to Notice of Violation 50-461/95003-02(DRS)
The Notice of Violation states in part:
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10 CFR Part 50, Appendix B, Criterion XI, " Test Control," states, in part, "A test program shall be established to assure that all testing required to demonstrate that i
structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents." Criterion XI also states, in part, " Test results shall be documented and evaluated to assure that test requirements have been satisfied."
Procedure CPS 2602.01, " Heat Exchanger Performance of Shutdown Service Water Coolers covered by NRC Generic Letter 89-13," Revision 8, a written test procedure required to demonstrate that structures, systems, and components would perform satisfactorily in service, specified that functional testing be performed for the diesel l
generator (DG) shutdown service water (SX) heat exchangers to demonstrate that the t
heat exchangers would perform satisfactorily in service by verifying their adequacy to
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transfer design basis heat loads to the ultimate heat sink.
I Contrary to the above, the licensee failed to evaluate the test results for DG SX heat exchanger functional tests performed on January 5,1994, April 28,1994, and May 3, j
1994, to assure test requirements were satisfied in that the test results did not meet the acceptance limits specified by procedure CPS 2602.01 and the evaluations of the test I
results did not demonstrate the adequacy of the heat exchangers to transfer design basis i
heat loads to the ultimate heat sink.
l I}ackground and Reason for Violation i
During a routine inspection of the engineering and technical support program (reference NRC inspection report 50-461/95003(DRS)) conducted from March 27 through May 19, 1995, an NRC inspector reviewed the results of heat exchanger performance tests required by NRC Generic Letter 89-13. The tests were conducted in accordance with CPS No.
2602.01, "IIeat Exchanger Performance of Shutdown Service Water Coolers Covered by NRC Generic Letter 89-13." The inspector identified that the results of heat exchanger performance testing conducted on four different emergency diesel generator heat exchangers in 1994 were not properly evaluated. The test results of the diesel generator heat exchangers showed that the performance of the heat exchangers was in the alarm range provided in the procedure. The test engineer did provide an evaluation of the test results in the test results review section of the procedure. However, the evaluation i
focused on why the test conditions caused the test results to show performance in the l
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Attachment B to U-602468 Page 2 of 3 alarm range, not on the ability of the heat exchanger to transfer design basis heat loads to the ultimate heat sink. The test engineer believed the test results did not accurately reflect the true heat transfer capability of the heat exchanger. This beliefwas based on previous engineering evaluations performed on these heat exchangers under similar conditions.
Illinois Power believes that the failure to adequately evaluate test results was due to the lack of procedural guidance on what constitutes an adequate evaluation of a heat exchangers performance test.
Corrective Steps Taken and Results Achieved In response to the inspector's concerns regarding the adequacy of the evaluation of the four diesel generator heat exchanger tests, engineering performed a computer analysis of the results of these tests. This analysis determined that the heat exchangers would have been able to adequately transfer design basis heat loads to the ultimate heat sink.
In response to this condition, Illinois Power conducted a review of all heat exchanger performance tests conducted using CPS No. 2602.01. This review identified that tests performed on the Division II and Division III switchgear heat removal system (VX) i chillers had results that showed the heat exchanger performance was in the alarm condition. These test results were approved as acceptable. An evaluation of the test results was performed at the time the test results were approved. However, this review was not adequate to justify that heat exchanger performance was not in an alarm condition. The results did indicate that the heat exchangers could transfer the design basis heat loads to the ultimate heat sink. The test evaluations performed on the results of the VX chiller tests did identify that the flow through the heat exchanger was too low to provide meaningful test results. The flow through the heat exchangers was less than 10%
of the design flow for the system. The low flow was created by the temperature regulating valve throttling flow during chiller operation. By design, the regulating valve is only 10%-20% open during normal chiller operation. To establish the required design flow to the chiller the temperature regulating valve must be full open. This action causes the chiller to be inoperable. Prior to January 1,1995, the VX heat exchanger test could only be performed with the regulating valve full open during an outage. This was because of a two hour Technical Specification requirement to restore the system to an operable status during plant operation. However, Amendment 95 to the CPS Technical Specifications, efTective January 1,1995, allows the system to be out of service for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This allows the proper test conditions for performance testing to be established during plant operation. The heat exchanger performance tests for the Division II and III VX heat exchangers will be performed with the regulating valve full open by September 30,1995.
,4 Attachment B to U-602468 Page 3 of 3 Corrective Stsps to Avoid Further Violations CPS No. 2602.01 will be revised to provide clear guidance on what must be considered when performing an evaluation of heat exchanger performance test results. This will be complete by September 15,1995. Also, all test engineers that conduct heat exchanger performance testing using CPS No. 2602.01 will be briefed on this violation and what constitutes an adequate evaluation of test results. This action will be completed by July 31,1995.
Date When Full Compliance Will Be Achieved Illinois Power is currently in full compliance with 10 CFR Pan 50, Appendix B, Criterion XI regarding this issue.
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