CY-98-121, Responds to NRC Request for Addl Info on Recent Operational Events at Plant.Corrective Actions That Have Been Taken, Discussed

Responds to NRC Request for Addl Info on Recent Operational Events at Plant.Corrective Actions That Have Been Taken, Discussed

ML20236S527
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	07/16/1998
From:	Mellor R CONNECTICUT YANKEE ATOMIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CY-98-121, NUDOCS 9807240407
Download: ML20236S527 (11)

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ONNECTICUT YAN K EE ATO MIC POWER COMPANY HADDAM NECK PLANT 362 INJUN Hollow ROAD e EAST HAMPToN, CT 06424-3099 July 16,1998 Docket No. 50-213 CY-98-121 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Haddam Neck Plant Results of Investigations on Recent Operational Events The purpose of this letter is to respond to an NRC request for additional information on recent operational events at the Haddam Neck Plant and w discuss the corrective actions that have been taken. This letter also presents the controls that are in place to ensure no similar events will occur during the upcoming reactor coolant system (RCS) chemical decontamination or other decommissioning activities. Also discussed is Connecticut Yankee Atomic Power Company's (CYAPCO) rationale as to why CYAPCO's management is confident that the Haddam Neck Plant is prepared to conduct the RCS chemical decontamination. This letter also provides an update on the status of the main stack radiation monitor.

Discussion Two recent operational events resulted in aggressive corrective actions being taken by CYAPCO. Neither event had nuclear safety, environmental safety or personnel health and safety consequences. However, CYAPCO is well aware that relatively minor events can be early warning signs of the potential for more significant events. As such, i these events were taken very seriously and aggressive actions have been taken.

"A" & "B" Waste Test Tanks Released Simultaneously - June 20.1998

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Background / Event i

On Saturday, June 20,1998, both the "A" and "B" waste test tanks (WTTs) were ready ]..~f h for discharge. Both contained water from plant systems which had been processed through lon exchangers to remove chemical and radioactive contamination. The WTTs were then isolated so that no additional water could enter the tanks and recirculated to a

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U. S. Nucirr Regul: tory Commission CY-98-121/Page 2 ensure pdequate mixing. Both tanks were then sampled for chemical and radioactive constituents pursuant to NPDES and NRC criteria. Internal discharge permits for both tanks were then prepared and, because the water in both tanks satisfied all requirements, the two WTTs were authorized for release.

While CYAPCO was in the process of discharging the "B" WTT, less than 800 gallons of water from the "A" WTT (already internally authorized for discharge) was also discharged. However, the "A" WTT was not intended by CYAPCO to be discharged at the same time as the "B" WTT. Investigations by CYAPCO personnel indicate that the discharge of the "A" WTT occurred because a valve associated with the "A" WTT was slightly open due to an inadvertent bumping of the valve by personnel working in proximity of the valve.

CYAPCO reviewed this event for deportability on Saturday and concluded that since we had planned to release the "A" WTT that this event did not meet the criteria for deportability.' Subsequent discussions on Monday, June 22,1998, concluded that CYAPCO did not plan on releasing the "A" WTT at the time it was released and that the amount of radioactive material released exceeded the threshold contained in the Haddam Neck Plant Ernergency Action Level Tables for an unplanned release.

Therefore CYAPCO concluded that this event was unplanned, and according to the Emergency Action Level Tables should have been reported on Saturday as an Unusual Event.

Corrective Action l CYAPCO chartered a Root Cause Team (RCT) to investigate the circumstances, root causes and recommended corrective actions. The root cause report has not been completed but the time line and causes have been identified and explained to management. The formal report is expected to be completed by July 27,1998 l

(CY-98-121-01). The RCT has preliminarily determined the cause of the discharge was L the accidental bumping open of a cross connecting valve and the cause of the misclassification of the event was caused by unclear and potentially conflicting guidance in the governing procedures and supporting documents. A contributing cause i

_ related to the classification is the lack of a questioning attitude displayed by the staff. A review of past records and questioning of operations personnel have not found any I similar instances of this type of valve mispositioning for liquid releases at the Haddam Neck Plant. The following actions have been taken:

1. Once discovered through an alarm and trip of the valve, the operators took action to investigate the situation and close the slightly opened valve.

2. The valve handle was removed and reinstalled 180 degrees from the original position, making it less susceptible to accidental bumping.  ;

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3. Rele.ases from the "A" and "B" WTT were suspended to allow installation of locking / restraints devices and to allow for additional training.

4. For any near term releases CYAPCO will either establish a boundary around the valve area to restrict work in the area or will have dedicated operations personnel stationed in the vicinity of the equipment to. assure the proper operation of the equipment (CY-98-121-02).

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5. All site personnel were advised at all hands meetings held on July 8,1998, that one of their responsibilities is to be aware of operating systems and to avoid bumping or inadvertently operating equipment. They were also instructed that if equipment is accidentally operated, they were to call the control room to notify operations and seek assistance.

6. The RCT has identified that the Shift Manager's initial deportability decision was not correct. CYAPCO has used this event as a learning mechanism and has shared the results of this event with the other Shift Managers. In addition, CYAPCO will be making the Director of Site Emergency Operations (DSEO) available to provide assistance to the Shift Managers in making classification and reporting decisions (CY-98-121-03). There is a resulting heightened awareness of the deportability requirements related to inadvertent releases of liquids.

7. The RCT determined that some responses to the event were inappropriate and some improvements were needed in procedures as well as human performance.

Related procedure (s) will be reviewed and revised as appropriate to ensure clear j guidance is provided. Training on classification and deportability will be enhanced. l These improvements will improve the responses of operators in these types of I evolutions in the future (CY-98-121-04). The improvements in the procedures and training are currently being developed.

i' Demineralized Water Leak - Juiv 7.1998 Backaround 1

On July 7,1998, plant personnel were installing valves in accordance with an approved l design modification on the dernineralized water system. This modification would allow the portion of the system in the spent fuel building to be isolated from the remainder of the plant. While the design modification was being installed, operators began an allowed evolution to add demineralized water to the volume control tank, believing that the work location in the spent fuel building was properly isolated. However, demineralized water was released from the line the individuals mre working on because a valve that was part of this tag out boundary was left out of position (i.e.,

open versus closed). Approximately 300 to 400 gallons of demineralized water sprayed from the pipes that were cut to facilitate the design modification, wetting some of the plant workers. Note, that none of the workers were contaminated or injured.

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U. S. Nucirr Regulatory Commission CY-98-121/Page 4 Corrective Action immediate action was taken to ensure the workers were not injured or contaminated and that no release to the environment had occurred. An Event Review Team (ERT) was chartered to investigate the circumstances, causes and recommended corrective actions from the event. The ERT has completed their investigation and has concluded that the root cause of this event is personnel error in that the valve was not placed in the closed position in accordance with the tag out. The primary cause is mispositioning of a valve by an operator. Fatigue, failure of an independent valve verification, and emergent work appear to be contributing causes. A "Do Not Operate" red tag was properly written and hung, but the valve was not placed in its proper closed position. It was also incorrectly independently verified to be placed in the closed position.

CYAPCO has not had a history of properly tagged valves being placed in the wrong position. The following actions have been taken:

1. A site wide work stand-down was declared on the evening of July 7,1998, and all work, except for work deemed by operations as necessary to support the safe operation of the plant, was stopped. The stand-down was in effect until Friday, July 10,1998, when specific work was allowed to restart under strict management ,

controls. l

2. A department manager meeting was held on the day of the event (July 7,1998) to  ;

solicit comments and determine corrective actions. As a result of this meeting,  ;

management initiated a corrective action plan that included the work stand-down, initiation of a generic valve training program, complete re-alignment and re-verification of the RCS boundary valve lineup and formation of an ERT.

3. During the stand-down, meetings were held with the entire site on July 8,1998. The  !

l meetings consisted of both a series of Senior Management meetings led by the Unit  ;

Director with site personnel and individual department meetings conducted by I

department managers. Contractors and CYAPCO employees were involved in these meetings. The demineralized water leak, the simultaneous release of the "A"

and "B" WTTs and two other recent events were explained to the staff. Feedback l from the staff was solicited and the staff responsibilities and management I l expectations were discussed. Attention to detail using the Stop, Think, Act and Review (STAR) process was emphasized. Also emphasized was the need for l workers, supervisors and managers to continually evaluate the amount of work being performed and to advise senior management if resource constraints exist.

4. The procedures for tagging and tagging verification were reviewed and modified to I clarify the roles of the initial tagger, the verifier and the job supervisor. The tagger is to physically touch the valve and verify it is in the proper position. The independent verifiei m not work together with the initial tagger. The independent verifier must also php ally touch the valve to verify its position. The job supervisor must also

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' CY-98-121/Page 5 l , perform an additional visual verification of the tags and confirm the valves are in the proper position for the work task, if only single isolation is provided. The procedures have been modified to accomplish these actions and are currently in use. " Toolbox" training sessions on the changes to the procedures were held on July 15,1998, with all plant departments.

l S. Work is being restricted to only those activities necessary for the RCS decontamination and other work which will not impact or distract from the RCS _

decontamination. The work is being controlled by a newly established Work Control Review Team (WCRT) composed of the Department Heads from the major departments (Operations, Maintenance, Decommissioning and Health Physics) involved in the RCS decontamination. The specific responsibility of the WCRT is to assure that no work is undertaken which detracts focus from the decontamination.

All emergent work, which is defined as any work not in the schedule two weeks in advance, must be reviewed and approved by the WCRT.

6. - A basic valve manipulation and position training program was instituted for all personnel on site who may manipulate or verify valve positions. All personnel ,

qualified to do tagging or to request tagging were required to attend.

7. After the all hands and department meetings, another management meeting was held on July 8,1998, to review feedback and determine what additional corrective l actions should be taken. The result included the development of additional actions designed to check trouble reports on equipment and to perform an extent of condition on valve tagging.

8. Any trouble reports associated with the RCS decontamination equipment were re-reviewed for potential implications for the decontamination. No implications to the RCS decontamination were found during the review.

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l 9. An extent of condition review of valve and other tagging is being undertaken to L assure that there are no other situations similar to this event. This review has been l biased toward ball valves, valves in primary systems, and valves tagged on night ,

! shifts. One hundred valves have been checked, and this has resulted in the I discovery of two other valves that were not in the proper position. CYAPCO has identified that the individual responsible for positioning and tagging these mispositioned valves was the same individual responsible for positioning and tagging the demineralized water valve that resulted in the July 7,1998, event. The independent verifier for these two valves was a different individual. A review was '

performed on the other components positioned and tagged by the initial manipulator, and no further errors were identified. CYAPCO also plans to visually check all currently tagged components that were verified by the individual who failed

- to properly position the three valves and by both of the people who failed to properly verify the position of these valves.(CY-98-121-05)

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10.The entire RCS decontamination boundary valve positioning and tagging will be re-done and then independently verified once all the decontamination procedure prerequisites have been satisfied.(CY-98-121-06) l

11. Appropriate disciplinary action has been taken based on the facts gathered to date.

i Other actione will be taken, as appropriate, based on any emerging information.

12.The ERT determined that operator fatigue was a contributing factor because the mispositioning and verification occurred late on a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> night shift by individuals i returning to work after at least one day off. Site supervisors who may supervise individuals who work on the night shift will be advised to be alert for potential night shift fatigue especially when workers return from days off or vacations.

j (CY-98-121-07) Workers will be reminded of their responsibility to get adequate  !

[ sleep prior to night shifts and notify their supervisors of any adverse l conditions.(CY-98-121-08) 13.Other jobs restarted after the stand-down were required to have their tags verified in accordance with the revised procedures. No anomalies were identified.

RCS Decontamination l The corrective actions from the events discussed previously provide additional assurance the RCS decontamination will be successfully accomplished. .The RCS decontamination itself has had over one year of detailed preparation and planning.

Specific controls, training and reviews have been planned and implemented to assure i the RCS decontamination is performed safely. They include:

1. The RCS decontamination is being treated as an Infrequently Performed Test or Evolution (IPTE). As an IPTE, dedicated management leads are assigned on a l full time basis throughout the decontamination. An IPTE requires a detailed pre-l Job brief for all individuals involved in the RCS decontamination. The brief -

involves the organization, responsibilities, preparation, overall controls, process descriptions, management expectations, and communications for RCS decontamination.

2. A dedicated staff has been assigned to the RCS decontamination. The staff consists of Siemens (the RCS decontamination vendor), operations, engineering, l mechanical, electrical, health physics, and chemistry personnel. This staff has worked to establish the system configurations and boundary for the RCS decontamination and is familiar with the equipment and procedures. There will be managers assigned from Siemens, an operations Shift Manager, and a CYAPCO RCS Decontamination Manager / assistants on shift to manage this activity.

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CY-98-121/Page 7 3,. Training specific to the RCS decontamination was provided to personnel involved to ensure a broad understanding of the RCS decontamination process.

Specific training for personnel performing operations activities during the RCS decontamination was also given. Introductory RCS decontamination training sessions and table top discussions were held with each shift to provide an overview of the RCS decontamination. Detailed training for the operators on shift has been psovided to assure knowledge of the evolutions to be performed during the RCS decontamination.

4. Two recent similar RCS decontamination were performed in the industry at Big Rock Point and Maine Yankee. CYAPCO has met with people from these utilities and incorporated lessons learned to ensure that CYAPCO has made good use of recent industry experience.

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5. -The valve lineup for the RCS decontamination is based upon a thoroughly evaluated and Plant Operations and Review Committee (PORC) approved procedure. The lineup will be performed once the prerequisites are complete.

The RCS decontamination valve lineups and verifications will be independently performed with the individuals physically separated by either time or distance when performing the lineup and verification. The valves will be physically (i.e.,

hands-on) verified in their proper position in accordance with the revised procedures on tagging.

6. Evolutions of the RCS deconta'mination will be performed using detailed procedures specifically written for the RCS decontamination. The procedures were developed by the RCS decontamination project team which includes personnel from Siemens, operations, engineering, mechanical, electrical, health physics, and chemistry, and have had substantial review by operations and by dedicated personnel from other departments. The procedures and the related safety evaluations received extensive interdisciplinary review and were approved by the PORC. Contingency plans have been developed to handle a variety of problems that are unlikely to occur but are possible. These potential problems include flow anomalies, resin loading, leaks, permanganic acid reactions, medical emergencies and carbon dioxide leaks.

7. Prior to placing chemicals in the systems, the system will be run in its RCS l

. decontamination mode with cold water to assure proper flows and no leakage.

This testing allows the operators to become familiar with the actual operating conditions before any heat is applied to the system or any chemicals are added i to remove contamination.

8. A readiness review team has been employed to review the planning, readiness and performance of the RCS decontamination. This consists of three experienced industry personnel who will assure that the preparation and performance of the RCS decontamination meets or exceeds industry standards.

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, The team will present its recommendations to the Vice President - Operations and Decommissioning who in tum will make the decision on whether it is prudent to commence with the RCS decontamination.

9. Other independent reviews of the RCS decontamination have been conducted by the Independent Management Assessment Committee which reports to the CYAPCO Board of Directors, the Nuclear Safety Assessment Board, and the CY Oversight department. The feedback from these resources to senior management has been positive.

10. Senior site management oversight of the RCS decontamination will be available seven days per week. The Vice President, Unit Director and Engineering Director are very familiar with the technical and management aspects of the RCS decontamination.

11. The WCRT has been established to assure a site wide focus on the RCS decontamination. The WCRT is composed of the department managers most l involved in the RCS decontamination and their responsibility is to limit work performed during the RCS decontamination to only work which does not detract from the RCS decontamination.

12. CYAPCO has instituted a dedicated Radiation Protection organization tr .upport the RCS decontamination. This group will be led by a Health Physics

' Management lead. Reporting to this individual will be lead individuals who will be responsible for activities related to radioactive waste management support, Chemistry lab support, and Health Physics operational support. These lead individuals will have people reporting to them to support each phase of the job.

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13. Three control areas have been established where Health Physics personnel will be monitoring and controlling health physics activities associated with the RCS decontamination. Control wiii be maintained by, among other things, teledosimetry (remote monitoring devices), dedicated health physics personnel to perform the RCS decontamination, strict access control for RCS decontamination related areas, the use of over twenty cameras to monitor activities and the use of extensive air sampling and monitoring at appropriate locations.

14. Health Physics has developed detailed estimates on the amount of activity that is expected to be removed (400 to 500 curies) by the RCS decontamination with the major contributor being Cobalt-60. The effects of an inadvertent spill of the decontamination fluid on personnel has been reviewed and found not to adversely impact worker health and safety. CYAPCO has estimated the RCS decontamination project to result in 39 REM exposure for personnel.

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l 1,5. QYAPCO might perform discharges from other sources during the RCS decontamination period. Regardless of the source, these discharges will be in accordance with our technical specifications and NPDES permit.

.16; The RCS decontamination has been designed to be conducted without a.

significant quantity of water being removed from the system. Any water removed from the decontaminated system will be stored onsite prior to processing through installed plant systems. It is not anticipated that this waste will be processed l during the RCS decontamination.

17. The RCS decontamination will be started in three phases. The first phase will run the system is a clean cold condition to assure configuration, flows and leak tightness. The next phase will be a general heat up to chemical decontamination l

temperatures, and again we will check for leaks. The final phase will be the actual injection of chemicals. The chemicals will only be injected after CYAPCO l assures itself that the system is ready. This approach will help to ensure that

- there are no leaks of radioactive material from this process to the environment.

I Main Stack Radiation Monitor RMS 14B l

CYAPCO was also requested to provide the status on the work involving the main stack )

radiation monitor, RMS 14B. Listed below, please find a summary of events along with a discussion of the corrective action.

j. Background l Several issues have recently been identified concerning the ability of RMS 14B to monitor effluent particulate and gaseous releases. The issues included isokinetic flow, sample line deposition, total stack flow, and containment purge flow. A commitment t was made to complete corrective actions on these issues prior to the RCS Decontamination.

L Corrective Action / Status i

All testing and hardware corrective actions have been completed. Some procedure .

revisions as a result of the testing and hardware changes have yet to be completed. I The corrective actions and status are as follows: ,

1. The total stack flow was verified by a special test which determined the velocity profile in the ventilation duct leading to the stack with one and two PAB ventilation fans as well as the fuel building ventilation fan running. The flow was determined to be above the flow indicated on the flow monitor. The total stack flow monitor was

, replaced with a' new temporary monitor and calibrated. .

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U. S. Nuclear Regulatory Commission CY-98-121/Page 10 2,. Engineering evaluations were completed using the revised stack flows to determine the appropriate isokinetic flow to RMS 14B and the appropriate isokinetic ratio for one and two fan operation. The RMS 14B surveillance procedure was revised to reflect the appropriate isokinetic flow, stack flow rates and isokinetic control ratio to assure isokinetic sampling.

' 3. As part of the dioctyl phthalate (DOP) testing, it was determined that there were l loose connections in the tubing from the stack to the Primary Auxiliary Building

! which reduced the efficiency of the sampling. The tubing was replaced and the heat trace and insulation were reinstalled.

l 4. The RMS 14B surveillance was re-performed with the revised parameters and l performed satisfactorily. A DOP test of the entire system was performed and RMS 14B had an efficiency of 95% which was acceptable (i.e., only five percent sampling line losses).

l l 5. The containment purge ventilation flow was verified by a special test which l determined the velocity profile in the duct. The ventilation flow indicator was l determined to be reading low. The containment purge flow monitor was replaced j L with a new temporary monitor and calibrated.

6. Changes to chemistry procedures associated with the sample line deposition correction factors and procedures associated with the containment purge flow have been identified and will be revised prior to the injection of chemicals for the decontamination.(CY-98-121-09) l

7. CYAPCO has performed surveillance on the HEPA filters and has ensured that they are capable of performing their intended function.

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8. CYAPCO will also assure both PAB flow and containment flow will be processed through HEPA filters prior to release, so that no un-filtered air is released to the environment. (CY-98-121-10) i-L Commitments l CYAPCO has made commitments within this letter and has uniquely identified each commitment with its own unique commitment identifier (i.e., CY-98-121-XX). All other statements contained within this letter are provided for information only.

L Conclusion f

The specific issues associated with the above cited events have been investigated and general as well as specific corrective actions have been developed. CYAPCO realizes that it is necessary to take these events seriously and has taken prompt and aggressive action. These actions, in addition to the already extensive actions in preparation for the l

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CY-98-121/Page 11 RCS decontamination, provide CYAPCO management the confidence that the RCS '

decontamination will be safely performed.

Throughout this entire evolution, CYAPCO will continue to keep the NRC and Connecticut Department of Environmental Protection informed of the status of this

. project. If the NRC or Connecticut Department of Environmental Protection should have any questions on the above, please contact Mr. G. P van Noordennen at (860) 267-3938.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY

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V R. A. Mellor \

Vice President - Operations and Decommissioning cc: H. J. Miller, Region 1 Administrator T. L. Fredrichs, Project Manager, Haddam Neck Plant W. J. Raymond, Senior Resident inspector, Haddam Neck Plant D. Galloway, CT DEP Monitoring and Radiation Division

! D. Gardner, CT DEP Monitoring and Radiation Division l

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