ML18037A087

Responds to Notice of Violations Noted in Insp Repts 50-237/92-28 & 50-249/92-28.Corective Actions:Identified Ground Has Cleared W/O Any Action by Station Personnel & Operations Personnel Were Counseled on Procedure Adherence

ML18037A087
Person / Time
Site:	Dresden
Issue date:	02/19/1993
From:	Farrar D COMMONWEALTH EDISON CO.
To:	NRC
Shared Package
ML18037A086	List: ML18037A087
References
NUDOCS 9303240061
Download: ML18037A087 (14)

Text

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Commonwealth Edison 1400 Opus Place Downers Grove, Illinois 60515 February 19, 1993 V.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention; Document Control Desk

Reference:

Dresden Nuclear Power Station Units 2 and 3

Response

to Notice of Violation Inspection Report 50-237/92028; 50-249/92028 NRC Docket Numbers 50-237 and 50-249 T.O. Martin letter to L.O. Delseorge, dated January 20, 1993, transmitting inspection Report 50-237/92028; 50-249/92028 Enclosed is Commonwealth Edison Company's (CECo) response to the Notice of Violation {NOV)which was transmitted with the referenced letter. The NOV cited two Severity Level IVviolations requiring a written response.

The response to these violations is provided in the attachment, lf your staff has any questions or comments concerning this letter, please refer them to Denise Saccomando, Compliance Engineer at {708) 663-7285.

Sincerely, c3.W

~

D. Farrar Nuclear Regulatory Services Manager Attachment cc:

A. B. Davis, Regional Administrator - Region III J.

Stand, Project Manager - NRR M. N. Leach, Senior Resident Inspector - Dresden 930324006i 9303i8 PDR ADQCK 05000237 8

PDR ZNLD/2112/13 F<B S g 199~

ArrACHMENT RESPONSE TO NOTlCE OF VIOLATlON NRC INSPECTlON REPORT 50-237/92028, 50-249/92028

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'I 249%2I!2JULll 10 CFR 50, Appendix B, Criterion V, requires that activities affecting quality shall be prescribed by document instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.

k Procedure DOP 6900-07, Revision 9, "125Vdc Ground Detections", required that the procedure be immediately performed at DC system grounds above 60Vdc, and a B1 Work Request be submitted once the ground was located.

Furthermore, the procedure required, at grounds above 115Vdc, initiation of a 14

'ay time clock (administrative Limiting Condition for Operation {LCO))to locate and remove the ground and preparation of a Justification for Continued Operation (JCO) if the ground could not be located or isolated within 14 days.

Procedure DAP 07-05, Revision 9, "Operating Logs and Records", Paragraph B.5, required that when a LCO entry occurs, the event must be logged in the LCO Log.

Contrary to the above:

1.

On Seotember 26, 1992, when a 125Vdc system ground was present in Unit 3, the Licensee failed to initiate actions to locate and remove the ground.

In addition, the Licensee failed to initiate an administrative LCO and document the event in the LCO Log.

2.

On November 3, 1992, when 125Vdc grounds were present in both Units 2 and 3, an administrative LCO was initiated and logged in the LCO Log for Unit 3 only. The Licensee could not provide evidence that actions were taken to identify and remove the grounds in either unit.

3.

On November 12, 1992, when a 125Vdc ground was present in Unit 3, the licensee failed to initiate actions to locate and remove the ground.

ZNLD/2112/14

ATIACHMENT RESPONSE TO NOTICE OF VIOLATION NRC INSPECTION REPORT 50-237/92028, 50-249/92028 NF T E VIO3A~QH; Dresden Station concurs with item 1 of the violation as written. Dresden Station procedures provide clear guidance on required actions upon identification of dc grounds.

It is clear that personnel failed to meet management's expectations.

Investigation of the events indicated that personnel failed to follow established station procedures.

With the issuance of the violation Dresden Station initiated an investigation which revealed that station did take appropriate actions on November 3 and November 12th In regard to the November 3, 1992, ground involving Unit 3 (example 2), action was taken to identify and remove the ground. The Unit 3 Log entry states that a ground check was performed at 1857 tlours for a -155V ground on the 125Ydc system.

The ground was identified on bus 3A-2 circuit number 16 and Work Request D-13836 was written for investigation and repair of the circuit. Electrical Maintenance identified and replaced a broken terminal block. Further testing revealed that the auxiliary transformer 31 fire protection circuit was grounded.

Work Request 15077 was written to implement repairs.

In regard to the November 3, 1992, ground involving Unit 2 (example 2), action was taken to identify and remove the ground.

Work Request D-13806 was written for investigation of the ground; however, the ground cleared before Electrical Maintenance personnel could begin work, The Unit 2 ground was not documented in the LCO Log since it never reached the required 115 volts, as specified in DOP 6900-06, 125Vdc Ground Detection".

ln regard to the November 12, 1992, ground involvinq Unit 3 (example 3), action was taken to locate and remove the ground. The Unit Operator logged the -115Y ground, the ground checking, and the LCO in the Unit Log Book. The ground was located on bus 3A-2. No work request was written since Work Requests D-13836 and D-15077 were already open to investigate the ground on bus 3A-2. On November 16, 1992, Work Request D-14129 was written to document a -90V ground on the Unit 3 125Vdc system.

Electrical Maintenance personnel investiaated and resolved the ground under work requests D-13836 and D-1 5077. The ground was monitored until January 2, 1993, and never returned.

D For examole 1, the identified ground has cleared without any action by station personnel.

Operations personnel involved in the September 26, 1992, event were counseled by Operations's senior management with regards to the importance of procedure adherence.

ZNLD/2112/15

ATIACHMENT RESPONSE TO NOTICE OF VIOLATION NRG INSPECTION REPORT 50-237/92028, 50-249/92028 E TIVE E

K T

D E

VI The Operations Manager has discussed failure to followestablished procedures with the Shift Engineers.

Beginning on February 10, 1993, the Shift Engineers tailgated with their respective crews the importance of following procedures.

They were reminded that adherence to procedures is a basic expectation and is required to ensure safe, reliable operations.

DATE F

LL MP AN E Full compliance was achieved when the individual was counseled.

ZNLD/2112/16

ATlACHMENT RESPONSE TO NOTICE OF YIOLAllON NRC INSPECTION REPORT 50-237/92028, 50-249/92028 RE 10CFR50, Appendix B, Criterion XVI,requires that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment; and nonconformance are promptly identified and corrected.

Contrary to the above, in February and April 1992, the licensee identified oversized fuses in various safety related circuits including the Emergency Diesel Generator exciters and Low Pressure Coolant circuitry. As of December,

1992, this condition adverse to quality had not been corrected.

F RT EVI The fuse verification program identified fuses that were inadequately sized.

These discrepancies were noted on Technical Problem Reports (TPRs) and forwarded to Corporate Engineering for resolution.

The Engineering evaluation of the fuse in the Unit 2 Low Pressure Coolant injection (LPCI) circuitry states that, "the currently installed 20A fuse, Bussmann Type MIN, in Panel 902-32, provides adequate protection for the circuit," and that the "existing installed 20A fuse protects the circuit." The evaluation also indicated that the fuse may not coordinate with the upstream 30A circuit breaker.

No safety significance or operability concerns were attributed to this potential lack of fuse coordination.

Engineering did, however, recommend replacement of the fuse. When the evaluation arrived at Dresden, the fuse coordinator prioritized replacement of the LPCI fuse commensurate with its lack of safety significance and operability concerns.

No specific due date was assigned for the fuse replacement.

Engineering's operability assessment of the fuses in the Unit 2 diesel generator excitation cabinets recommended no compensatory actions to ensure operability (i.e. the system is operable with the currently installed fuses).

Two 30A fuses and one 40A fuse were installed in the Unit 2 excitation cabinet, instead of the 25A fuses presented in the system drawing. The evaluation again included a recommendation to replace the subject fuses.

It stated that during an abnormal fault condition, the fuses may not protect the primary windings of control transformers.

The recommendation was based on guidance from GE Bulletin GET-3039G, "How to Select an Apply Power Fuses, Types EJ-1 and EJ0-1." An Action Due Date forfuse replacement of February 28, 1993, was assigned by Engineering.

The reasoning behind the assigned due date was based upon the engineering judgment that any expected fault condition that a 26A fuse could protect against would also be protected by a 30A or 40A fuse.

ZNLD/2112/17

ATIACHMENT RESPONSE TO NOTICE OF VIOLATION NRC INSPECTION REPORT 50-237/92028, 50-249/92028 Since identification of the diesel fuse discrepancy in April, 1992, Dresden Station has taken numerous actions to address Engineering's fuse replacement recommendation.

Most significant of these actions was a more detailed engineering calculation that supported continued operation with the currently installed diesel generator fuses.

This calculation states that "GE 25A, 30A, and 40A fuses, Type EJ0-1, willclear the fault before any damage is done to the primary windings of the transformer or the circuit." This evaluation confirmed Engineering's previous operability assessment and the engineering judgment of the fuse coord nator.

Dresden Station believes that the LPCI fuses were not replaced prior to the inspection period because no safety or operability concern exists with the currently installed fuse.

For the diesel generator fuses, numerous actions were taken to replace and procure the fuses and fuse clips prior to the assigned Action Due Date of February 28, 1993.

Dresden does acknowledge, however, that Engineering's recommendations should have been dispositioned in a more timely manner.

Dresden identified the need for additional administrative controls for fuses identified for replacement under the fuse upgrade program.

Examination of the current Dresden Administrative Procedure (DAP) 11-27, "Control and Maintenance of Fuses and the Fuse List," indicated that it did not provide direction for dispositioning of TPRs issued prior to October, 1992.

RR TIVE P

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D E

V 0 The Unit 2 LPCl fuse was changed out on February 19, 1993. The Unit 3 LPCI system has also been inspecte8.

The Unit 3 LPGI fuse has the correct amperage, but is a MIN-type fuse rather than the recommended KTN-type fuse.

While no operability concerns have been raised, Dresden willstill replace the Unit 3 LPCI fuse the next time LPCI is out-of-service.

For good engineering practice, the one 40A diesel generator fuse on Unit 2 willbe replaced with a 30A fuse by April30, 1993. A Document Change Request was submitted on February 19, 1993 to update the amperage on all related drawings to 30 amps.

To augment administrative controls until DAP 11-27 is revised, the Modification Implementation Supervisor has issued a memorandum to the fuse coordinator incorporating direction for fuse replacements identified in Technical Problem Reports issued prior to October, 1992.

ZNLD/2112/1 8

ATTACHMENT RESPONSE TO NOTICE OF VIOLATION NRG INSPECTION REPORT 50-237/92028, 50-249/92028 RECTIYE TEP KE T

V ID ER DAP 11-27, will be revised by March 31, 1993, to incorporate the interim directions described in the above memorandum.

DTE F

LL PLIN E Full compliance was achieved with the issuance a memorandum to the fuse coordinator incorporating direction for fuse replacements identified in Technical Problem Reports issued prior to October, 1992.

ZNLD/2112/3 9