ML20196J015

Responds to NRC Re Violations Noted in Insp Rept 50-271/97-04 on 970420-0531.Corrective Actions:Operators Placed Plant in Stable State Using Appropriate Plant Operating Procedures & Post Trip Review Conducted

ML20196J015
Person / Time
Site:	Vermont Yankee
Issue date:	07/29/1997
From:	Reid D VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-271-97-04, 50-271-97-4, BVY-97-96, NUDOCS 9708010254
Download: ML20196J015 (4)

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, VERMONT YANKEE

- NUCLEAR POWER CORPORATION

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.- Ferry Road Brattleboro, VT 05301-7002 ENGINE R N OFFICE I

580 MAIN STREET BOLTON, MA 01740  ;

(508) 779-6711 July 29,1997 BW 97-96  ;

j United States Nuclear Regulatory Commission ,

ATTN: Document Control Desk Washington, D.C. 20555 l

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References:

(a) License No. DPR-28 (Docket No. 50-271)

(b) Letter, USNRC to WNPC, NRC Inspection No. 50-271/97-04, NW 97-101, dated 07/03/97 (c) LER 97-008, Rev. O " Plant Scram Due to Procedural Non-Complianco and Failure to Perform Self-Verification During Nuclear instrumentation Calibration",

BW 97-70, dated 05/23/97 l

Subject:

Reply to a Notice of Violation - Inspection Report No. 50-271/97-04 l This letter is written in response to Reference (b), which documents that certain of our activities were

- not conducted in full compliance with NRC requirements. This violation, classified as Severity Level IV, was identified during an NRC inspection conducted from April 20 to May 31,1997. Our response to the Violation is provided t-Lw:

i VIOLATION:

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l Technical Specification 6.5, " Plant Operating Procedures," states that detailed written l procedures, involving nuclear safety operations, surveillance, and testing requirements, shall  ;

! be prepared, approved, and adhered to. l Vermont Yankee Operating Procedure (OP)-4406, "LPRM Calibration and Functional Check,"

Revision 13, dated October 18,' 1996, requires in part, a proper sequence of actions in order to l

restore the APRMs to a normal mode of operation from the bypass mode used for this periodic calibration.

Contrary to the above, at 9:10 AM on April 24,1997, the Verntont Yankee personnel failed to adhere to written procedures when conducting OP-4406, in that they improperly left the " A" and "D" APRM mode switches in the "ZERO" position and failed to make necessary adjustments to the APRMs prior to their being removed from bypass, resulting in a reactor scram event. \

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RESPONSE

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Reason For The Violation \

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Vermont Yankee does not contest this violation. The event was caused by personnel error during 1 performance of Local Power Range Monitoring (LPRM) System calibration, in that a failure to complete

a procedural step resulted in the Average Power Range Monitoring (APRM) System Mode Switches for

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U.S. Nuclear Rigulatory Commission VERMONT YANKEE NUCLEAR POWER CORPORATION July 29,1997 )

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"A" and "D" channels being left in the "ZERO" position instead of the " OPERATE" position. '

Following the calibration of the LPRM detectors, the procedure d!rected that the affected APRM output i be adjusted to indicate core thermal power. Since the restcration of the APRM Mode Switches was )

omitted, the APRM output was unable to be adjusted. Without resolving this unexpected response, l the involved personnel proceeded with the activity. When requested, the licensed operator removed the APRM channels "A" and "D" from the bypass condit:on , without using proper self-checking ]

practices. When both APRM's were removed from bypass, each provided a half scram input to their '

respective Reactor Protection System (RPS) trip channels and a reactor scram occurred. An independent formal root cause was subsequently performed and documented in Vermont Y@ee Event ,

Report 97-0413. Since multiple barriers failed in order for the event to occur, a barrier assessment was -j performed during the formal root cause evaluation. The multiple barriers that failed included pre-job 1 l briefing, procedure quality, procedure development and review process, communications, work practices, knowledge and skill, and alarm response.

Root causes of this event were personnel errors in work practices and verbal communications.

1. Work Practices

a. Failure to follow procedure:

1) The Reactor Engineer (RE) failed to direct the instrument and Control (l&C)

Technician to perform the fourth action contained in a step.

2) The RE when unable to perform the verification / adjustment to the APRM l channels, moved on to the next step. This was contrary to a statement in the I step itself, VY procedural use and adherence requirements and management expectations for use of self-checking techniques.

b. Inadequate application of STAR (Stop, Think, Act, Review) techniques: The operator did not verify the correct system response between each APRM bypass switch manipulation. 1

2. Verbal Communications The RE failed to stop the calibration and communicate the questions /uricertaintles he l encountered when unable to verify the APRM response. I The contributing cauces of this event were inadequate procedure and cognitive human error .esulting from lack of skill / knowledge.

1. Inadequate Procedure l One step was written in a manner such that all actions were not clearly visible and easily performed. A missed action was imbedded in a multiple action step.

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2. Skill / Knowledge i

i A lack of knowledge on system /swhch functions was evident by the RE decision to restore the APRM channels to service in order to get a power meter reading.

! Corrective Steps That Have Been Taken And The Results Achieved b  :

l:, immediatelinterlm: The following actions have been completed.

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U.S. Nuclear Rrgulatory Commission VERMONT YANKEE NUCLEAR POWER CORPORATION July 29,1997 Page 3

1. After the scram, operators placed the plant in a stable state using the appropriate plant operating procedures.

2. A post trip review was conducted by Operations Department.

3. A review and revision of the LPRM Calibration and Functional Check procedure was conducted prior to subsequent use. Two LPRM calibrations have been performed without incident since the scram.

4. Lessons learned were presented to all Licensed Operators, Reactor Engineers and Instrument and Control Technicians prior to plant restart.

5. An independent Root Cause investigation was conducted.

6. The need for procedural compliance was reinforced to Reactor Engineering Personnel.

7. A plan' staff meeting for all departments was held to discuss human performance aspects of this went. Management's expectations for procedural adherence and prompt communication of problems when they arise was reinforced.

8. Operations standard for self-verification (STAR Stop, Think, Act and Review) was subsequently developed and issued June 29,1997.

Additionally, station management has increased oversight of reactivity management activities to ensure management expectations are clearly understood and reinforced. Reactor Engineering self-assessment activities have increased in the area of reactivity management. Particular emphasis is being placed on self-checking, pre-evolution briefings, communications and procedure adherence. The need to anticipate and verify expected system and plant response, and develop contingency actions for potential unexpected responses is also emphasized. Prior to the last LPRM calibration which was performed on June 26,1997, a partial revision to the procedure was performed to further improve quality since the barrier assessment performed in the root cause analysis ident:fied tha vulnerability to a full scram by testing two channels at the same time. Specifically, the procedure was revised to perform steps for one APRM channel at a time and separate Individual cctions within one step into separate steps. In addition, as part of the long term corrective actions noted below, the LPRM calibration procedure will undergo a complete review, anct be revised as necessary, along with other Reactor Engineering procedures.

Corrective Actions That Will Be Taken To Avoid Further Violations Long Term:

1. Vermont Yankee will review all RE procedures that, if performed incorrectly, c7uld cause a half or full scram. Vermont Yankee will designate such procedures " Continuous Ibe" procedures.

Vermont Yankee will verify that such procedures conform to the requiremenu of procedure AP 0037, Appendix B, Vermont Yankee Procedure Writer's Guide. The anticipated completion is October 31,1997. I

2. The LPRM Calibration and Functional Check and other similar RE procedures are being evaluated for possible assignment to the E&C Department. Reactor Engineering would then provide assistance to E&C, as needed. The anticipated completion is October 31,1997.

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• U.S. Nuclear Rigulatory Commission VERMONT YANKEE NUCLEAR POWER CORPORATION j July 29,1997 l Page 4 I

3. Training will be provided to Reactor Engineering personnelin the aress of Neutron Monitoring and Reactor Protection Systems. The anticipated completion is Septeniber 30,1997.

4. The Operations Standard for Reactivity Management will be revised to document existing management expectations for retuming bypassed instrumentation to service. The anticipated completion date is September 1,1997.

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5. A new training module for Licensed Operator Requalification and Auxiliary Operator Requalification will be developed and presented reinforcing self-verification (STAR) techniques.

The anticipated completion is December 31,1997.

In the course of reviewing events per the ER process, human performance, procedure quality, communications, and work practices have been recentlyidentified and acknowledged as areas needing increased management overs!ght and involvement. Although the scram occurred due to human performance error, Vermont Yankee does not believe the recent performance issues identified are indicative of an overall adverse performance trend where human performance errors have resulted in significant plant challenges or transients. Station management has fostered a low threshold for initiating Event Reports (ERs). Consequently, the quantity of ERs has increased significantly and has resulted in identifying an adverse precursor performance trend similar to those identified in Reference b). Senior station management has and continues to provide strong day-to-day involvement in the corrective action process resulting in early identification of adverse performance trends and development of commensurate corrective actions.

, Serdor plant management is currently developing an action plan for improving human performance at l Vermont Yankee. Input into the action plan was discussed with all VY managers in a workshop on July l 23-24, 1997. Anticipated programmatic changes include improved pre-evolution briefings and post-evolution critiques. The Vermont Yankee Observation Program is also being modified to emphasize .

l human performance during field observations. We have also recently developed and implemented a l Stop, Think, Act and Review (STAR) laboratory. This training has been provided to limited plant staff. l We anticipate wider use of this important training in the future. We are confident these continued performance improvement initiatives will result in improved human performance. We will continue to identify trends and implement corrective actions focused on improving human performance using the Event Report process.

I Date When Full Compliance Achieved Vermont Yankee achieved full compilance when the LPRM Calibration was performed correctly in accordance with the procedure on May 19,1997.

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We trust that the enclosed information is responsive to your concerns; however, should you have any questions or require additional pertinent information, please do not hesitate to contact us.

Sincerely, Vermont Yankee Nuclear Power Corporation 69 4 Donald A. R Senior Vice President, Operations cc: USNRC Region I Administrator USNRC Resident inspector - VYNPS USNRC Project Manager - VYNPS

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