ML20212F879

Responds to NRC Re Violations Noted in Safety Insp Repts 50-295/86-23 & 50-304/86-22 on 860923-1014. Corrective Actions:Disciplinary Action Taken Against Individual Who Failed to Open Process Valve

ML20212F879
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	12/05/1986
From:	Farrar D COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
2474K, NUDOCS 8701120203
Download: ML20212F879 (5)

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m Commonwealth Edison

1. .C One First Nati aal Plaza. "N, Illinois Address Rc;dy to: Pod Offica Box 767 Chcago, li.inois 60690 - 0767 December 5, 1986 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Zion Nuclear Power Station Units 1 and 2 Response to I&E Inspection Report Nos.

50-295/86023 and 50-304/86022 NRC Docket Nos. 50-295 and 50-304

Reference:

November 4, 1986 letter from J. J. Harrison to Cordell Reed.

Dear Mr. Keppler:

This letter concerns the special safety inspection conducted by Z.

Falevits of your office on September 23 through October 14, 1986, of activi-ties at Zion Nuclecr power Station. The referenced letter indicated that certain of our activities appeared to be in violation of NRC requirements.

Commonwealth Edison Company's response to this violation is contained in the attachment to this letter. A two-day extension was obtained from B. L.

Burgess of your office by telecon on December 4, 1986.

If there are any questions concerning this matter, please contact this office.

Very truly yours, r

D. L. Farrar Director of Nuclear Licensing im Attachment ec: Region III Inspector - Zion J. A. Norris - NRR

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870112O203 861205 PDR O ADOCK 05000295 PDR 2474K DEC 8 1986

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ATTACHMENT ZION NUCLEAR POWER STATIOPJ RESPONSE TO NOTICE OF VIOLATION ITEM OF NONCOMPl.IANCE As a result of the inspection conducted on September 23 through October 14, 1986, and in accordance with " General Policy and Procedures for NRC Enforcement Actions," 10 CFR Part 2, Appendix C (1985), the following violations were identified:

Technical Specification 6.2.A states in part, " Detailed written procedures including applicable check off lists covering items listed below shall be prepared, approved, and adhered to:"

a. " Instrumentation operation which could have an effect on the safety of the facility."

b. " Surveillance . . . Tests and experiments" Specifically loop test Procedure 2S-MS-25 dated October 22, 1985 requires that impulse pressure to EHC transmitter be valved in at completion of transmitter replacement.

Contrary to the above properly detailed procedures for the following incidents were not in use:

(1) On September 20, 1986, following the replacement of turbine pressure transmitter 2PT-MS24, an EHC transient occurred and the reactor tripped. The event was due to a valving error whereby after replacing transmitter 2PT-MS24 the instrument mechanic acting on " Skill of craft" impulse opened the test connection valve rather then the isolation valve as required by system design. This resulted in 2PT MS24 being isolated from the system which resulted in the reactor tripping. In addition, test Procedure 2S-MS-25 was inadequate in that it did not provide the instrument mechanic with more specific detailed instructions or check off points for valving the transmitter back into the system.

(2) On September 22, 1986, an Operational Analysis Department (OAD) test engineer while investigating the degraded voltage problem, had opened a knife switch on 480v breakers 2474 circuitry.

! This prevented the auto closing of this breaker as requireu by design after bus 247 is tripped. This problem was subsequently identified by the operators performing an unrelated test.

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• CORRECTIVE ACTION TAKEN AND RESULTS ACHIEVED A. Technical Specification 6.2.1. states " Written procedures including applicable check off lists covering items listed below shall be prepared, implemented and maintained:". Items 6.2.1.E and 6.2.1.H state the following:

(E.) Instrumentation operation which could have an effect in the safety of the facility.

(H.) Test and experiments.

(1) The instrument referenced in item 1 of the violation is non-safety related and does not affect the safety of the facility. The MS24 1 transmitter is an input to the EHC system and is used in the " IMP IN" mode of operation of-the system.

The instrument mechanic replacing the 2PT-MS24 transmitter was given a procedure that gave him instructions on changing the transmitter and for performing a calibration of the transmitter.

There is only one process isolation valve for this type of transmitter. The mechanic had a specific sign off for " valve out the transmitter" and a specific sign off for " Valve in the transmitter". Both these sign offs were initialed in the procedure. The mechanic however, apparently did not open the process isolation valve, but instead opened the test tap isolation valve.

The root cause of this event was personnel error.

(2) Several corrective actions were initiated to help prevent future occurrence of this type event:

a. Disciplinary action was taken against the individual who failed to open the process isolation valve on 2PT-MS24 transmitter.

b. The Instrument Maintenance Supervisor discussed this event with 1

shop personnel. Past errors committed by the IM Department and

the need to eliminate this type of error were also discussed.

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c. The Assistant Superintendent of Maintenance discussed the error and its cost to the company in lost generating capacity, revenues, and decline in public confidence with the Instrument, Electrical, and the Mechanical Maintenance Departments. This event was also discussed with the Technical Staff Department.

His discussion emphasized the need for more attention to detail in performing tasks.

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d. The procedure used was evaluated and found to be adequate for its non-safety related purpose. However several improvements will be made to the procedure.

(1) The Unit 2 procedure has been rewritten to separate the MS24 Instrument loop into a independent procedure.

i (2) A second verification has been incorporated into the Unit l

2 MS24 instrument loop procedure. Unit 1 is presently in a refueling outage.

B. The second item addressed in the violation concerned an Operational Analysis Department (OAD) test engineer opening test switches without the proper procedures. The Operational Analysis Department (OAD) engineer was called to perform a relay calibration check on the second level undervoltage relay at the request of the Technical Staff Engineer performing the troubleshooting. Work requests were written for the OAD

Engineer to check the relay calibration of the second level undervoltage relays and for the Electrical maintenance department to check the control switch of the "0" diesel generator for possible faulty contacts. The f OAD Engineer arrived and was given approval to proceed with his relay calibration. To perform the calibration on the relay, it was required that test switches be open to isolate the relay from the system thus defeating it's protective function. The Technical Staff Engineer decided

that before the "0" diesel control switch was manipulated the "0" diesel should be given an auto-start signal. The operators were instructed to perform section 7 of a periodic test for safeguards actuation (PT-10).

This section was chosen because it gives an auto-start signal to "0" diesel generator. This would prove that the "0" diesel generator was operable during the secondary undervoltage event. However, Section 7 of the performance test not only started the diesel but it also performed a bus drop before the test section was concluded. The bus drop occurred

as expected but the 480V transformer feed breaker failed to auto close as expected. The test switches that the OAD test engineer opened blocked the undervoltage reset signal, this prevented the reset of the undervoltage condition, es'n though the bus was energized. Without the

undervoltage condition bei reset, the 480V transformer feed breaker could not close.

The root cause of the even' the Technical Staff Engineer not being aware of the test configurt n required to check the calibration of the second level undervoltage : v.

A The Technical Staff Engineer was coordinating the troubleshooting and failed to connect the fact that the two parallel activities, relay calibration and diesel start testing, would produce the unexpected results.

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The ORD representative assigned to the station and the Technical Staff Engineer involved in the event have reviewed the event and been reminded to adequately review the status of equipment and potential effects on the plant prior to initiating action.

OORRECTIVE ACTION TO BE TAKEN TO AVOID FURTHER VIOLATION A. To avoid future indirect reactor trips from non-safety related instruments due to personnel error:

(1) The Teltrument Maintenance Supervisor will review the non-safety related instrument calibration procedures to determine if there are other non-safety instruments that could cause an indirect reactor trip or cause a significant plant transient. The instruments that are identified will have a second verification, the applicable precautions, limitations, and clarification, if needed, added to their procedure.

(2) The Unit 1 MS-24 loop procedure will be altered as discussed above for Unit 2.

B. To avoid future coordination problems with OAD:

(1) The Technical Staff Electrical Group will provide training for their engineers on the Operational Analysis Department calibration

, methodology. This training will include the necessary steps required before an OAD test engineer can calibrate the various types of relays at the station.

(2) The OAD test engineer will'use the work request form to identify test switches which are to be open and closed during trouble

, investigation. These switches will be written into the work instruction section of the Work Request Form.

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(3) An administrative procedure change will be made to clarify the required setup and precautions needed for OAD to perform its work.

DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED L

The review of the Instrument Maintenance non-safety related procedure will be completed by June 30, 1987.

l The training for the Technical Staff Electrical group will be completed i i by February 15, 1987.

The administrative procedure changes and the necessary changes to the Unit 1 MS-24 loop procedure will be completed by April of 1987.

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