ML20078Q877
| ML20078Q877 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 12/14/1994 |
| From: | Graesser K COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9412230107 | |
| Download: ML20078Q877 (4) | |
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Commonwealth Edison 1
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Byron Nuclear Staten
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4450 North German Church Road
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Byron. IEnois 61010 December 14. 1994 U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention:
Document Control Desk
Subject:
Byron Nuclear Power Station Units 1 and 2 Response to Notice of Violation Inspection Report No. 50-454/94022: 50-455/94022 NRC Docket Numbers 50-454, 50-455
Reference:
Edward G. Greenman letter to Mr. Graesser dated November 14, 1994, transmitting NRC Inspection Report 50-454/94022: 50-455/94022 Enclosed is Commonwealth Edison Com]any's response to the Notice of Violation (NOV) which was transmitted wit1 the referenced letter and Inspection Report.
The NOV cited a Severity Level IV violation requiring a written response.
Comed's response is provided in the attachment.
If your staff has any questions or comments concerning this letter.
please refer them to Don Brindle. Regulatory Assurance Supervisor, at (815)234-5441 ext.2280.
Respectfully.
N K. L. Graesser Site Vice President Byron Nuclear Power Station Attachment (s) cc:
J. B. Martin. NRC Regional Administrator - RIII G. F. Dick. Byron Project Manager - NRR H. Peterson. Senior Resident Inspector. Byron L. F. Miller Jr., Reactor Projects Chief - RIII D. L. Farrar. Nuclear Regulatory Services Manager. Downers Grove 9412230107 941214 DR ADOCK 0500 4
F VIOLATION (454(455)/94022 02)
During an NRC inspection conducted from September 6. 1994 to October 20, 1994, a violation of NRC requirements was identified. In accordance with the
" General Statement of Policy and Procedure for NRC Enforcement Actions." 10 CFR Part 2. Appendix C (1994) the violation is listed below:
10 CFR Part 50. Appendix B (1994).Section V. states in part that activities affecting cuality shall be prescribed by documented instructions or procecures of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions or procedures, and include ap3ropriate acceptance criteria for determining that important activities lave been satisfactorily accomplished.
Byron Administrative Procedures. BAP 300-1
" Conduct of Operations." and BAP 330-1. " Station Equipment Out-of-Service Procedure." states in part that following maintenance or modification to a system / component, a verification of operable condition shall be made. Verification may be made by special testing, surveillance testing, or general inspection.
Contrary to the above, on October 13. 1994, the licensee did not verify that steam generator "C" was in an operable condition prior to refilling it. When the licensee placed the "C" steam generator into wet layup, approximately 3600 gallons of secondary side water drained onto the containment floor.
This is a Severity Level IV violation (Supplement 1).
REASON FOR THE VIOLATION While placing the "C" Steam Generator (SG) secondary side in Jartial wet layup, B & W Nuclear Technologies (BWNT) notified Operating t1at water was flowing from an unplugged tube on the cold leg side of the "C" SG.
BWNT stated that the hot leg side of tube 20-7 had been removed from the "C" SG.
however the cold leg side had not yet been plugged. Therefore, a flow path had been created from the secondary side to the primary side.
The tube pulling operation was being performed for the first time at Byron Station. As a result of the tube pulling operation both hot leg and cold leg plugs were required to be installed prior to filling the SG's.
In previous outages, the secondary side of the SG's could be filled without the plugging operation being completed.
In these 3revious outages, a flow path never existed nor would have existed from t1e secondary to primary side.
At 08:00 on 10/7/94. BWNT Site Manager notified Operations that the "C" SG secondary side closures were completed and hot leg alugs were welded in tubes 20-7 and 20-102 (the tubes removed from "C" SG).
iowever. BWNT Site Management did not verify with their OC that plugging for tubes 20-7 and 20-102 was completed on the cold leg side. At this point the "C" SG secondary side was considered to have been turned over to Operations. On 10/12/94 Operating started filling the "C" SG.
Since Operations had received notification from the BWNT Site Manager that the "C" SG secondary side closure was complete they did not contact SEC regarding the status of the SG's, the Operating staff lacked sufficient information available to correctly return the SGs to service.
This
information could have been obtained from several Station working groups that were involved in the tube pulling operation.
On 10/12/94 at 21:19, Operations reported that SG "C" was filled. Then, on 10/13/94 at 00:15, a BWNT representative notified Operating that water was flowing from an unplugged cold leg tubesheet penetration and was flowing out of the primary manway onto the floor. On 10/13/94 at 00:30, the BWNT Site manager was notified that water was flowing from the "C" SG manway opening on the cold leg side.
CORRECTIVE STEPS TAKEN AND RESULTS ACHIEVED The immediate actions that were taken following this event are summarized below:
- 1. The outage expeditor was contacted about the leak from the "C" SG.
- 2. The channel head emergency suction pumps were used to move water into the containment sump.
- 3. A combination of Comed and BWNT laborers were used to remove the water spilled on the floor.
The BWNT Site Manager and BWNT OC reviewed Enclosure 1 of the applicable BWNT plugging procedure and they concluded that tube 20-7 was not plugged on the cold leg side.
Once access to Containment was granted, immediate actions were taken on tube 20-7 (cold leg) to install a mechanically rolled plug. Tube 20-7 was subsequently plugged and the newly installed plug was independently verified by both BWNT OC and an SEC Programs Engineer. A second Station independent verification was performed by another SEC Programs Engineer on tube 20-7 to verify the plug was installed in the correct tube location.
The Station verification process is a two step process.
First, two Station personnel independently verify that the plug has been inserted in the correct location, then after the plug has been mechanically rolled into the tubesheet, one person verifies that the plug has been installed correctly.
On 10/13/94, a letter was written by the Technical Lead Health Physicist to the Technical Superintendent summarizing the effect of the release path.
The radiological impacts of the events surrounding the filling of the Unit 1 "C" SG were reviewed.
A potential release path to the environment existed while the PORV was open and one SG tube was not plugged.
However, there was no motive force to cause a release.
Once the tube filled with water, the release path was eliminated.
In addition, the Unit 1 "C" main steamline area radiation monitor trends were reviewed during the period the PORV was open and no elevated readings were noted.
After this event Comed and BWNT created a SG Secondary Side Close-Out Check List that was used for close out of the remaining SG's. The purpose of this check list was to provide a listing of applicable activities required to return the secondary side of the SG's to the Operating department for normal system fill and/or testing following BWNT maintenance. The process improvement resulting from these forms was to establish better control of contractor activities at the station and to ensure adequate review of the equipment prior to releasing to the Operating department. A similar checklist was also created for steam generator primary side activities. Included as part of these checklists are various activities that must be addressed by all working groups involved prior to returning the primary or secondary side of the SG's to the l
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Operating department.. In completing these forms it gives Operations the added assurance that all activities necessary to return the SG's to them has been completed.
Each of these activities will be verified as com)lete by the signature of the'following aersonnel responsible for overseeing t1ese l
activities: the BWNT Site ianager. BWNT 0A/0C. The responsible Comed representative will review applicable work packages for completeness and sign indicating concurrence. After the appropriate working groups have signed the form, the Work Control Superintendent must sign and date to concur that it is acceptable to remove the Out Of Service (00S) on the listed SG secondary side.
This: form or a revision of it will be used in the future for turning over the SGs to Operations.
CORRECTIVE STEPS THAT WILL BE TAKEN TO AVOID FURTHER. VIOLATION l
The SG Secondary Side Close-Out Check List. or a similar form will be incorporated in the Byron Station procedures. The Byron Station Maintenance Procedures (BMP's) will specifically address the problem of controlling steam generator activities and they will require the Work Package are)arer to include the checklists with the applicable Work Request for )otl secondary side and primary side activities.
By incorporating these checklists in appropriate Comed procedures. Comed personnel will maintain control over all i
steam generator working groups.
Byron NTS Item #454-200-94-03200-01 will track completion of this activity.
Byron Station will also perform an overall review of contractor control and offsite Comed organizations coordination processes.
These reviews will include the current level of control and coordination, and the establishment of clear expectations on work practices and standards at Byron Station.
l Appropriate procedures and process controls will be established to assure expectations are met.
This review will be complete by 6/95 and implemented by 9/95.
Byron NTS Item #454-100 94 02202-01 will track completion of.this activity.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED Byron Station achieved full compliance on 10/13/94 when the SG Secondary Side Close-Out List was approved for use for BIR06 and all future SG inspection / repair close-out activities. The procedure revisions for the SG close-out checklist will be incorporated for use in the next scheduled Byron SG inspection period, scheduled for February 9. 1994 (B2R05).
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