ML20012F021
| ML20012F021 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 03/29/1990 |
| From: | Creel G BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9004090316 | |
| Download: ML20012F021 (5) | |
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BALTIMORE I.
GAS AND h
ELECTRIC CHARLES CENTER P. O. BOX 1476
- BALTIMORE, MARYLAND 21203 Otomot C, CRtcL Vact PestsID4NT '
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March 29,1990
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U. S. Nuclear Regulatory Commission Washington, DC 20555 s-ATTENTION:
Document Control Desk m
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No' 11 Docket No. 50-317' Egolv to NRC Insnection Reoort No. 50-317/89-25
REFERENCES:
(a). Letter from J. C. Linville (NRC) to G.. C. Creel (BG&E), dated February 27, 1990. Inspection Report No. 50-317/89-25 Gentlemen:
Enclosed is our response to the Notice of Violation identified in Reference (a).
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Should you have any further questions regarding this matter, we will be pleased to l
discuss them with you.
Very truly yours, 1.'
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GCC/JV/db Attachment l-cc:
D. A. Brune, Esquire L
J. E.
Silberg, Esquire R. A. Capra, NRC
. D. G. Mcdonald, Jr., NRC W. T. Russell, NRC L. E. Nicholson, NRC i
T. Magette, DNR
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ENCLOSURE (1)
BALTIMOREGAS AND ELECTRICCOMPANY REPLY TO NOTICE OF YlOLATION NRC INSPECTION REPORT 50-317/89-25 STATEMENT OF YlOLATION Title 10, Code of Federal Regulations, Part 50, Appendix B, Criterion XVI, ' Corrective Action," requires, in part that measures shall be established to assure that conditions adverse to quality are promptly identified and corrected.
Contrary to the above requirements, the licensee failed to take action to resolve differences between root causes identified by the licensee and its contractor and to take appropriate corrective action related to the December 1986 plugging of an incorrect tube in Unit I steam generator number 12 detected April 23, 1988.
SUMMARY
This violation concerns corrective actions for an event in December, 1986 in which the wrong steam generator tube was plugged. This event was reported as Licensee Event
. Report (LER) 50-317/88-03.
The cause was personnel error by a
contractor.
Subsequent to the LER, the contractor disputed the facts reported in LER 88-03. A supervisor reviewed the contractor's contentions, but did not change the assessment of the facts or the root cause. However, this review was not documented. Additionally, the corrective action for the event was to discontinue use of the contractor but no formal methods of ensuring implementation or criteria for re-instatement were established, in reviewing this event subsequent to the notice of violation, the following facts were established:
1.
The root cause analysis associated with the LER was incomplete, and there was a misunderstanding of some of the facts by both Baltimore Gas and Electric Company
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(BG&E) and the contractor.
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2.
The root cause specified in the LER, personnel error by the contractor, was substantiated, but the details of the errors were revised.
3.
The dispute between BG&E and the contractor about whether the marked tube or an adjacent tube was plugged has now been resolved.
4.
The contractor has not been retained by BG&E for tube plugging since the event.
The contractor had demonstrated new equipment and processes for tube plugging to DG&E in order to be re-instated as an approved vendor, but the contractor's status was undocumented.
As a
result of the revised investigation, the contractor is being removed from the Approved Vendor's List (AVL) until documentation of adequate corrective measures is received.
5.
Corrective action taken subsequent to the LER and prior to the Nuclear Regulatory Commission's (NRC's) inspection was sufficient to correct the actual root cause and prevent recurrence.
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ENCLOSURE (1)
L HALTIMORE GAS AND ELECTRICCOMPANY L
REPLY TO NOTICE OF VIOLATION NRC INSPEC110N REPORT 50-317/89-25 i
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No improper steam generator repairs or conditions resulted from the errors in the root cause analysis or corrective action implementation of LER 88 03.
BACKGROUND During the Fall 1986 Refueling Outage, a contractor was employed to plug steam generator tubes in accordance with the contractor's procedures and Quality Assurance Program and using the contractor's Quality Control (QC) organization.
The contractor's procedure for plugging tubes required that tubes be located using either the position indication system on the contractor's Genesis robotic manipulator arm or by installing and using a template. The contractor chose to use the position indication system and a template was not installed.
Prior to the start of work, a list of the location numbers of the tubes to be plugged was given to the contractor.
Additionally, BG&E personnel marked the tubes designated to be plugged. The marks on the tubes to be plugged were made in accordance with BG&E's own procedure for plugging tubes and using a ZETEC SM-10 robotic manipulator arm. Marking tubes to be plugged and using these marks to locate tubes to 1
be plugged was not required or mentioned in the contractor's procedure. The marks were intended to allow the contractor to use a video camera to provide independent but informal verification that plugs were being installed in the correct location. The contractor's procedure did require QC verification of each step in the procedure, but provided no detail on how verification was to be performed.
The position indication system on ' the contractor's Genesis robotic manipulator failed during plugging operations. At the time, BG&E personnel were aware that the contractor was having problems with the system, but did not know that the system had failed. After this failure, the marks on the tubesheet were used as the sole mechanism for locating tubes to be plugged. This technique for locating tubes was not addressed in the contractor's procedure, and the procedure was not changed.
During eddy-current testing of Unit I steam generator No.12 on April 23,1988, a plug was found in the outlet tube sheet in a tube adjacent to the tube which should have been plugged. The error was reported as Licensee Event Report 88-03.
As part of the investigation for LER 88-03, BG&E personnel reviewed a copy of the video tape showing the insertion of the mispositioned plug. The picture quality was poor and BG&E personnel concluded that the video showed the plug being inserted into the tube adjacent to the marked tube.
On June 13, 1988, shortly after LER 88-03 was issued, the contractor sent a letter to BG&E stating the video tape showed the plug had been installed in the tube marked by BG&E This contradicted a statement made in LER 88-03. This dispute is the basis of the violation, flowever, the letter also ecknowledged that plugging activities were being condue:ed with an inoperable position indication system as stated in the LER.
s ENCLOSURE f1)
BALTIMOREG AS AND ELECTRICCOMPANY l
REPLY 1D NOTICE OF YlOLATION NRC INSPECTION REPORT 50-317/89-25 i
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Upon receipt of the letter from the contractor, BG&E personnel again reviewed the copy of the video tape and concluded that the picture quality was too poor to make a positive determination whether the mark was located correctly. The poor picture quality supported BG&E's contention that tube plugging should have been terminated when the position indicator failed. This re-evaluation and its conclusion were not appropriately documented or communicated to the contractor.
Upon receipt of the Notice of Violation, BGAE obtained the original video tape from the contractor. The picture quality of the original tape was sufficient to determine conclusively that the plug was installed in the tube that was marked. This indicates that BG&E - had marked the incorrect tube and this was a contributing factor in plugging the wrong tube. This contributing factor is not addressed in LER 88-03.
The cause of the error in marking the tube could not be determined but is suspected to be personnel error since review of subsequent eddy current data supports the adequacy of ZETEC SM-10 equipment and calibration.
The corrective action for LER 88-03 consisted of not using this contractor until they responded and initiated corrective actions. Shortly after the LER was issued, the contractor demonstrated and discussed new processes and equipment to BG&E personnel. The status of the removal and re-instatement of the contractor was not documented on the Approved Vendor's List, and their status was unclear at the time of the NRC inspection.
A more thorough root cause analysis of plugging the wrong tube identified the following errors:
1.
Failure of the position indicator on the contractor's Genesis robotic manipulator arm. (This failure was known to the contractor's personnel prior to the start of plug installation on the tube that was incorrectly plugged.)
2.
Failure of the contractor to recognize that the failure of the position indicator required termination of plugging operations because procedure prerequisites were not satisfied with the position indicator inoperable.
Without the position indicator or a template, the contractor's procedure provided no method for locating the tubes to be plugged.
3.
Failure to document the loss of the position indicator either in the procedure or j
on a Field Action Request. This would have resulted in the identification of the failure to follow procedures while operations were still in progress or during the work package closcout.
4.
Marking the tubes to be plugged when it was not part of the procedure and then marking the wrong tube.
5.
Conducting plugging operations in violation of the procedure by using marks for position indication, a method not authorized by the procedure, instead of installing a template or repairing the manipulator's position indicator, i ;
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ENCLMURE m 3
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-1 BALTIMORE GAS AND ELECTRICCOMPANY REPLY TO NOTICE OF VIOLATION NRC INSPECTION REPORT 50-317/89-25 I
6.
Failure of the contractor's supervision and QC personnel to stop plugging activities or change the procedure when they became aware activities were not
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being conducted in accordance with the procedure.
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7.
L ack of detail in the procedure about the method used to locate a tube.
CORRECTIVE ACTIONS
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As stated in LER 88-03, the plugging error was identified and the correct tube was plugged in 1988. The improperly located plus remains installed. The plug and tube were evaluated and found acceptable.
A Non-Conformance Report (NCR) has been issued to document this event. This NCR stipulates that the contractor involved in this event be identified on the AVL as not authorized for plugging steam generator tubes until the contractor's program is evaluated and the specific concerns identified are corrected.
LER 88-03 is being revised to document the additional causes and contributing factors identified since the LER was issued. The LER will be reviewed by the Plant Operations and Safety Review Committee.
BG& E's procedure for plugging tubes, unlike the contractor's procedure, does require marking the tubesheet prior to plugging tubes. Subsequent to the event, changes to BGAE's procedure for plugging tubes added optional checks to verify correct marking of the tubes. An optional check has been used since the event occurred. The additional check used consists of passing a probe through the tube after both ends are marked to assure both ends of the same tube are marked. The optional checks will be made mandatory.
CORRECTIVE ACTIONS TAKEN *ID AVOID FURTIIER VIOLATIONS Insufficient depth of assessment and root cause analysis is an identified root cause category in the Calvert Cliffs Performance Improvement Plan (PIP). The associated action plan uses training and organizational changes to address weaknesses in achieving timely, effective corrective actions in response to identified weaknesses.
Corrective action procedures in use at Calvert Cliffs have been revised subsequent to the LER. These revisions involved formal tracking and documentation of corrective actions. Review and closcout by the Plant Operations Safety Review Committee and the l
Quality Control Unit would have been required for a similar event. Additional measures to requhe review and closcout of LER corrective actions by the Licensing Unit were I
initiated subsequent to discovery of this violation.
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DATE WilEN FULL COMPLIANCE WILL BE ACIIIEVED:
Full compliance has been achieved.
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