ML20198R511

Responds to NRC 860422 Ltr Re Violations Noted in Insp Repts 50-327/86-11 & 50-328/86-11.Corrective actions:MI-10.9 in Rev,Maint & Test Records Made Available for Review & SI-227.1 Revised to Include Clarification of Process

ML20198R511
Person / Time
Site:	Sequoyah
Issue date:	05/22/1986
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8606100097
Download: ML20198R511 (7)

Text

i TENNESSEE VALLEY AUTHORITY

, CHATTANOOGA. TENNESSEE 37401 j

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May 22, 1986 f

i U.S. Nuclear Regulatory Connaission Region II ATTN! Dr. J. Nelson Grace, Regional Administrator i

101 Marietta Street, NW, Suite 2900 i I

Atlanta, Georgia 30323 i

Dear Dr. Graces i

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SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - NRC-0IE REGION II INSPECTION REPORT l 50-327/86-11 AND 50-328/86 RESPONSE TO VIOLATION AND DEVIATION 1

Enclosed is our response to J. A. 01shinski's April 22, 1986 letter to S. A. White which transmitted IE Inspection Report Nos. 50-327/86-11 and j i

' 50-328/86-11 for our Sequoyah Nuclear Plant which cited TVA with one Severity Level IV Violation and one Deviation. Enclosure 1 is our response to the j

subject violation and enclosure 2 is our response to the subject deviation.  !

Conunitments are delineated in enclosure 3. We do not recognize any other j

actions described herein or the subject inspection report as conunitments.

1 If you have any questions, please set in touch with R. E. Alsup at FTS 858-2725.

To the best of my knowledge, I declare the statements contained herein are 4 complete and true.

Very tnsly yours, i

.1 TENNESSEE VAL Y AUTHORITY I

il R. L. Cridley, director Nuclear Safety and Licensing

Enclosure cc Mr. James Taylor Director (Enclosure)

Office of Inspection and Enforcement 1

U.S. Nuclear Regulatory Conunission j Washington, D.C. 20555 1

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\ l An Equal Opportumty Employer b'

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ENCLOSURE 1

RESPONSE TO VIOLATION i

NRC INSPECTION. REPORT No.50-327/86-11 AND 50-328/86-11 LETTER FRtM JOHN A. OLSHINSKI TO S. A. WHITE

' DATED APRIL 22, 1986 Violation 50-327/86-11-04 and 50-328/86-11-04 10 CFR 50, Appendix B, CriAerion V requires that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procadures, or drawings.

Contrary to the above,

a. ' On February 4 and 5, 1986, deficiencies were identified during performance of Electrical Maintenance Instruction MI-10.9 which demonstrated that the procedure was' inadequately prescribed and was not being properly implemented. These deficiencies included:

_ . 1. The procedure calls for five undervoltage (UV) trips prior to returning the reactor trip circuit breaker to service after maintenance, but Westinghouse recommends ten UV trips in NSD-TB-83-02, Revision 1, page 5.

. 2. The technical review of the procedure was inadequate due to such significant discrapancies as: poor quality drawings, which were difficult to read; typographical errors,which caused the technician to st0o work; the voltage specified to energize the undervoltage h' coil during maintenance was greater than the actual voltage inside 7 the ceactor trip breaker cabinet; the procedure calls for replacement of the und5rvoltage trip attachment (UVTA) after 1250 operations, but.provides no formal tracking of the trip attachments actuations and Step 6.3.11.3 requires that'the breaker trip force be recorded, but provides no place for recoe' ding the trip force.

3. The licensee did not have unique identification numbers for the reactor trip breakers prior to October 1985. Thus, the maintenance history on each breaker was not.coadily traceable.

b. On February 5 and 6, 1986, deficiencies were identified during perfocmance of Surveillance Instruction SI-227.1 which demonstrated that

' the procedure was inadequately prescribed and was not being properly implemented by instrument mechanics during post maintenance testing of

' reactor trip breakers. These deficiencies included:

1. The proeddare did not provide verification that appropriate initial condit13ns were established prior to performing the procedure.

Consequently, the test could not be successfully performed on February 5,1986.

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Step 9.0 of the procedure was vague in explaining use of activating test pushbuttons. As a result, the mechanic' involved initially was unable to properly initiate the test.

3.

Test personnel were not familiar with the procedure and methods used to identify components inside reactor trip breaker cabinets. This resulted in miswiring of test leads and misinterpretations of the procedure.

This is a Severity Level IV violation (Supplement I).

1. Admission or Denial of the Alleged Violation '

2 TVA admits the violation as stated.

2. Reason for the Violation On August 10, 1984, TVA revised its corporate program procedure for reactor trip breakers to reflect commitments made in our response to Generic Letter 83-28. This revision included the Westinghouse owner's Group Maintenance Program for DB-50 breakers and stated that the suggested 10 experience withUVno trips failures. shall be reduced to 5 based on past operating Further, it was concluded that 10 successful test trips would offer no more assuranca that the breaker will perform its intended function during operation than 5 successful test trips. Using this revised corporate procedure, the plant revised MI-10.9 accordingly; therefore, only five UV trips were required.

The illegible drawing in MI-10.9 identified by the inspector was a result of poor quality reproduction of the instruction from the master copy.

The typographical errors occurred as a result of an inadequate procedure the procedure reviewin by thethe field. responsible section before implementation of The reference voltage used at the UV trip attachment was equal to the solid state protection system (SSPS) power supply to the UV card.

This was considered an acceptable practice since the coil is rated for 48V DC and the low voltage dropout point is actually measured. An engineering evaluation by an Electrical Maintenance engineer determined that counting the UVTA actuations was unnecessary. This '

was based on estimating the number of automatic trips every reactor year plus maintenance / response time actuations every year and

multiplying that number times the 40-year life of the plant. The 1 estimated to replacenumber was below the 1250 operations as a recommended value the attachment.

Failure to the compiling record datathe breaker trip force was an oversight when sheet.

However, the data sheet does require a double signoff that the trip force was less than a specified value.

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Before Generic Letter 83-28, the reactor trip breakers at Sequoyah Nuclear Plant (SQN) were non-critical systems structures and components (CSSC), and records were not3 required to be maintained. Identification for maintenance or any testing was by breaker cabinet, unit, and train.

Subsequent to the generic letter, the breakers were upgraded in Quality Assurance (QA) level and added to the CSSC list. Since that time, maintenance history is available.

A review of maintenance history records of performance of SI-227.1, Revision 2, has shown that this postmaintenance test was successfully completed three times before the February 5 and 6,1986 performance without error or difficulty by the Instrument Maintenance Group.

Since the February 5 and 6,1986 performance, the test has been sucessfully completed, and again no problems were noted. This performance record clearly indicates that the procedure was adequate to perform the test.

The difficulties encountered on the February 5 and 6, 1986 performance is contributed to improper scheduling by Instrument Maintenance management.

The SI was not scheduled to be performed at the time the inspectors were at SQN, and the request by the inspectors to see a performance of the SI was done at a time near shif t turnover such that the test was performed by a backshift crew when it is normally done using a day shift crew.

3. Corrective Action Taken and Results Achieved At the time the inspection team was at SQN, a revision to MI-10.9 was in the Word Processing Unit (V"U). Subsequent to the comments by the team, a major rewrite of the inst 2 iction has been done and is presently in the WPU. The reactor trip breakers have been separated from MI-10.9 into c separate instruction, MI-10.9.1. Initially, MI-10.9 included other breaker testing. Efforts are being made to eliminate any typographical errors and to improve the overall quality of the instruction.

Maintenance history of the reactor trip breakers is presently being maintained as QA records. As stated earlier, before issuance of Generic Letter 83-28, the trip breakers were non-CSSC, and no records were maintained. However, since that time, maintenance and test records are available for review, and since October 1985, unique identifiers added to the breakers will further enhance the traceability of maintenance history.

SI-227.1 is being revised to include enhancements to simplify and clarify the step-by-step process to complete the testing. Management for the Instrument Maintenance Group has discussed the need for more careful scheduling and assignment of work activities to ensure that personnel performing maintenance activities are familiar with procedures before work begins. ,

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4. Corrective Steps Ta' ken to Avoid Further Violations The procedural changes being made to MI-10.9 and SI-227.1 trill er. hance the maintenance and testing activities on reactor trip breakers.

These revisions will be completed and implemented by June 30, 1986.

5. Date When Full Compliance Will Be Achieved Full compliance will be achieved on June 30, 1986, when the instruction changes are completed.

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e ENCLOSURE 2 RESPONSE TO DEVIATION NRC INSPECTION REPORT No.50-327/86-11 AND 50-328/86-11 LETTER FROM JOHN A. OLSHINSKI TO S. A. WHITE DATED APRIL 22, 1986 Deviation 50-327/86-11-05 and 50-328/86-11-05 In a letter to NRC dated November 7, 1983, TVA committed to develop a program for trending of reactor trip breaker parameters to assess any possibility of performance degradation of the reactor trip breakers. The licensee indicated that the trending program recommended by the technical standard consisted of the following:

o The compilation of all maintenance activity records into a history file.

o The use of the Nuclear Plcpt Rel);bility Data System for breaker failure data.

o A Maintenance Request System.

The licensee concluded by stating that "the above suggestions would be used a

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at Sequoyah to develop a program for tren'ing d of parameters to assess any

, possibility of performance degradation."

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/' contrary to the above, as of February 7, 1986, the licensee has failed to develop a program for trending of reactor trip breaker parameters to assess any possibility of performance degradation.

SON Response A formal trending program on reactor trip breakers was not implemented at SQN due to a failure to identify and track this commitment until its completion.

TVA has implemented a corporate commitment tracking system managed by the Office of Nuclear Power, Division of Licensing and Safety. This staff, in conjuction with site personnel, reviews documents submitted to NRC for

commitments and ensures that they are identified and tracked. This same computerized-tracking system is used by each plant section as a tool to plan and schedule work to ensure that NRC commitments are completed in a timely

! manner. Procedures are in place to implement the corporate tracking system.

l This process and the management attention allocated to ensure its effectiveness should preclude recurrence of a similar event.

The commitment made in our November 7, 1983 letter to NRC will be completed by June 30, 1986, as part of our revision to MI-10.9 for reactor trip breaker maintenance. This revision will include trending such parameters as dropout voltage of the UVTA, breaker insulation resistance, coil and insulation j resistance of the UVTA, and trip-bar force. It is expected that any possibility of performance degradation of the reactor trip breaker will be noted from assessing these and other parameters.

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O-ENCLOSURE 3 COMMITMENTS

1. By June 30, 1986 we will revise SI-227,1 to enhance the maintenance and testing activities on reactor trip breakers.

2. By June 30, 1986 we will revise MI-10.9 to enhance the maintenance and testing activities and ensure adequate trending of reactor trip breakers.

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