ML20153G491

Informs That Rev 1 to Event Rept ER-98-21 Contained Incorrect Date Re Completion of Corrective Action.Rev 2 to Subject Rept,Encl

ML20153G491
Person / Time
Site:	Paducah Gaseous Diffusion Plant
Issue date:	09/25/1998
From:	Pulley H UNITED STATES ENRICHMENT CORP. (USEC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GDP-98-1069, NUDOCS 9809300089
Download: ML20153G491 (7)

Text

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4 USEC

. A caob.: so.rsy comp.or September 25,1998 GDP 98-1069 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Paducah Gaseous Diffusion Plant (PGDP)

Docket No. 70-7001 Event Report ER-98-21, Rev. 2 A review of NRC Event Report ER-98-21, Rev.1 (NRC No. 34498) issued to the Commission on September 18, 1998, revealed an incorrect date which we want to bring to your attention. In Completed Corrective Actions, Enclosure 1, action number 2 contains the date July 7,1998, as the date the action was completed. This date is incorrect and has been corrected in the attached revised event report to read:

"On July 8,1998, caution tags were attached to electrical power strip receptacles in Building C-310 prohibiting use of the receptacles without permission of the Operations First-Line Manager (FLM)."

Any questions regarding this matter should be directed to Larry Jackson at (502) 441-6796.

Sincerely,

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Howard Pulley General Manager Paducah Gaseous Diffusion Plant j C,'. n -; p

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Enclosures:

As Stated cc: NRC Region III Office Q,

NRC Resident inspector - PGDP 9809300089 980925 PDR ADOCK 07007001' C

PDR[f I!O. Box 1410, Paducah, KY 42001 Telephone 502-441-5803 Fax 502-441-5801 herp://www.usec.com OfTices in Livermore, CA Paducah, KY Portsmouth OH Washington, DC

Docket No. 70-7001 GDP 98-1069 Page1of5 EVENT REPORT 1

ER-98-21, Rev. 2 DESCRIPTION OF EVENT On July 8,1998, at approximately 0958 hrs., the Normetex ptunp process gas leak detector (PGLD) power supply was interrupted when the circuit breaker supplying 110-volt power to the system tripped in Building C-310. An alarm was received in the area control room (ACR). The Plant Shift Superintendent (PSS) declared the Normetex PGLD system inoperable. Operations personnel initiated immediate steps according to procedure and at approximately 1008 hrs. a smoke watch was l

established in accordance with Limiting Conditions For Operation (LCO) 2.3.4.3.A-1.

At approximately 1010 hrs., the circuit breaker was reset, power restored, and the PSS declared the system operable at approximately 1033 hrs. On July 9,1998, at 0128 hrs., the Nuclear Regulatory Commission Headquarters (NRC-HQ) operations office was notified of this event in accordance with 10CFR76.120(c)(2).

At the time of the event, an instrument and calibration (I&C) technician plugged a Fourier Transform Infrared (FTIR) buggy into an instrument power receptacle located on the rear of cell cubicle 8.

Normally, FTIR buggies are plugged into electrical receptacles located on the columns to the rear of the cell; however, the employee noticed that there was standing water on the floor in the vicinity of column 8. Because of the presence of water on the floor, the employee believed that it would be unsafe to connect the buggy to column 8 and chose to plug into the instrument power electrical receptacle on the rear of the cell. When the buggy was plugged into the receptacle, the employee heard an alarm. After cleaning up the water, the employee disconnected the FTIR from the cell cubicle receptacle; reconnected using the receptacle located in the column; and proceeded to assist Operations personnel in determining the cause for the alarm. While investigating the cause for the alarm, it was discovered that two power indicating lights were not illuminated on the PGLD system panel. They noticed that an electrical breaker had been caution tagged indicating that operation of the breaker could afTect power to the PGLD system. It was difficult to determine the position of the breaker because of the caution tag. However, the breaker appeared to be approximately 1/8-inch oft the normal position. The caution tag was moved and the breaker immediately moved to the tripped position confirming that a trip had occurred.

The Normetex PGLD electrical circuit is shared by instrument electrical power receptacles located in cell cubicles 7,8,9, and 10. FTIR buggies were connected to instrument power receptacles at cells 8 and 10. This is in addition to other electrical loads, such as photohelics, on the system which overloaded the circuit and caused the circuit breaker to trip. When the alarm came in, all FTIR buggies, with the exception of the buggy located at cell 7, were disconnected and reconnected to an alternate power supply. After re-establishing power to cell 7, the FTIR buggy was reconnected to an alternate power supply located behind cell cubicle 5.

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Docket No. 70-7001 GDP 98-1069 Page 2 of 5 Beginning in 1995, there have been Significant Condition Adverse to Quality (SCAQ) investigations initiated as a result ofcircuit breaker trips caused by plugging equipment into power receptacles that also supply power to safety systems. Among the safety systems affected were PGLDs, criticality accident alarm systems (CAAS), and freezer / sublimer (F/S) control power.

In February 1996, the Management Assessment & Analysis Team (MAAT) approved the corrective action plan for SCAQ PR-CO-95-1239. This SCAQ was generated as a result of a sample buggy plugged into a receptacle at a cell panel causing a breaker to trip, interrupting power to the PGLD system. The corrective action plan included modifications to pertinent procedures to avoid use of spare outlets in the cell panel for power to sample buggies in Buildings C-331, -333, -335, and -337; installation of plastic safety plugs to cover unused outlets and painting the safety plugs red; and attaching a "Do Not Use" label. On September 16,1996, a determination was made that SCAQ PR-CO-95-1239 "was inadequate and did not address the global issue ofinadvertent loss of power to safety equipment." Therefore, with the concurrence of MAAT, the six original corrective actions were canceled and replaced by six new corrective actions that included completion of an evaluation to determine if an Engineering Service Order (ESO) v<as needed to install additional 110-volt AC outlets. Engineering Evaluation, EV-C-813-96-06, concluded that the need for " additional outlets was not needed for power to the portable analytical buggies or for electrical tools in the vicinity of the cell panel." The evaluation recommended use of extension cords, properly sized to carry the load, connected to readily avai'able 120-volt outlets in the cascade buildings.

l SCAQ PR-CO-95-4883 was initiated as a result of the loss of all ground floor power in Building C-315, with the exception of the withdrawal room. This electrical outage occurred as a result of the operation of a stove in a break room overloading an electrical circuit. In April 1996, MAAT l

approved a currective action plan, which included a requirement to develop an ESO requesting an Engineering analysis on distribution panels in all other areas of the plant which supply electrical l

power to safety systems. Further, the ESO would evaluate the panel loading condition and include i

field walkdowns to verify the as-built status of drawings. This resulted in the initiation of ESO l

Z96620. In March 1997, MAAT approved cancellation of ESO Z96620, along with all corrective actions associated with this ESO. Justification for the cancellation was "the root cause for this SCAQ has been addressed and measures have been taken to prevent future problems." "All safety systems which have receptacles have been labeled and no safety system trips have occurred since these receptacles were labeled."

In June 1996, a problem report (PR-SU-96-3310) was generated as a result of an electrical circuit breaker trip in Building C-333. The trip was caused by connecting a test buggy to a receptacle at unit 5, cell 3 which overloaded an electrical circuit affecting the operability of PGLD heads. When j

the power cord was removed from the cell and the breaker reset, power was restored. The problem j

report indicated "there is no action plan available."

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Docket No. 70-7001 GDP 98-1069 Page 3 of 5 SCAQ PR-CO-96-2608 was initiated due to the loss of the main power supply to an F/S in Building C-337, because of a portable fan plugged into a power strip located in a cell cabinet. In July 1996, l

the MAAT approved a corrective action plan that included labeling F/S power strips and panels in l

Buildings C-331, -333, -335, and -337 to indicate that the power supply was for F/S instrumentation l

only.

l All requests to cancel SCAQs were made to the MAAT following approval by the functional manager as the issue owner.

During the period 1995-1996, corrective actions generated in response to SCAQs generally did not address generic safety system issues in buildings other than C-331, -333, -335, and -337. One l

exception was SCAQ PR-CO-95-4883, which was generated as a result of the power loss to all ground floor lighting in Building C-315, except the withdrawal room. This SCAQ's observation and l

analysis stated, " prior to September 4,1996," F/S receptacles, and " prior to August 1996," PGLD l

receptacles, were labeled to indicate "the receptacles were solely for the PGLD or F/S system." On l

November 20,1997, a corrective action in this SCAQ was closed out verifying the labeling of all l

F/S and PGLD receptacle / power strips in Buildings C-331,-333,-335,-337,-310, and -315. During l

1 this verification it was discovered that four labels were not attached to the receptacles, as required.

l The reason why the labels were not on the four receptacles is unknown. An additional action step l

required Maintenance procedure CP3-GP-GPl109," Configuration Control Program for Q, AQ, and l

AQ-NCS Structures, Systems, and Components," to be changed. On January 16,1998, included in the procedure change was an action step to ensure receptacles / power strips, field labeled as dedicated for PGLD or F/S, are not used for other electrical power supply purposes. A caution staterrent was added to the procedure which warned that use of electrical outlets labeled as dedicated for PGLD and F/S could cause a circuit overload and trip a breaker providing power to Qs AQ-NCS, or AQ-SSC systems. At the time of this event (July 8,1998), there was a caution tag attached to the tripped breaker that stated, "Do Not Use Without FLM Permission. May Affect PGLD Systems For Normetex Pumps." However, a caution tag was not attached to the power strip receptacle where the FTIR was plugged.

The corrective action process that existed prior to March 1997, was less rigorous than after March 1997. Plant procedure CP2-BM-C11031," Corrective Action Process At PGDP," with an effective date of March 23,1998, defines the management process for identifying off-normal conditions through the A ssessment and Tracking Report (ATR) reporting system. This procedure also defines l

the corrective action process including assigning, validating, implementing, verifying, and closing issues derived from the ATR system. Further, there has been increased emphasis in cross-l l

referencing issues and corrective actions. Compliance with this procedure will minimize the possibility ofineffective or incomplete corrective actions. The plant also implemented walkdown l

procedure CP2-PO-PO1031," Site Walkdowns/ Verifications," which is used to determine the scope I

of walkdowns and acceptance criteria for such evaluations as labeling outlets that may affect the l

PGLD.

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Docket No. 70-7001 GDP 98-1069 Page 4 of 5 Power was lost to the PGLD for approximately 12 minutes which affected the ability of the PGLD l

to detect a UF release. However, the safety significance is considered low because, concurrent with l

6 the breaker trip, the alarm in the ACR actuated, as designed; Operations personnel initiated l

immediate steps according to the alarm response procedure; and within 10 minutes of the breaker l

trip a smoke watch was established in accordance with the LCO.

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CAUSE OF EVENT A. Direct Cause The direct cause for this event was the loss of power to the PGLD, as a result of an electrical l

circuit breaker trip. Plugging the FTIR buggy into the receptacle, which was not labeled, l

overloaded the electrical system.

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B. Root Cause The root cause for this event was corrective actions need improvement. Implementation of CP2-l BM-CIl031," Corrective Action Process at PGDP," will minimize the possibility ofineffective l

and/or lack of corrective actions. Current corrective action processes contain the necessary rigor l

to ensure that corrective actions are effectively implemented and timely, and closures are l

l verified. The completed corrective actions are compensatory attainments designed to enhance l

responsibility to ensure continued rigor when developing and reviewing corrective actions. The l

planned corrective actions are considered appropriate, considering the low safety significance l

of the event. The planned corrective actions cannot preclude the possibility of recurrence, but l

minimize the possibility of a similar event.

l CORRECTIVE ACTIONS A. Completed Corrective Actions

1. In June 1998, the General Manager approved and disseminated the "PGDP Management l

Assessment and Analysis Team Charter."

The charter identifies the MAAT's l

function / objective; membership and structure; and responsibilities.

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2. On July 8,1998, caution tags were attached to electrical power strip receptacles in Building l

C-310 prohibiting use of the receptacles without permission of the Operations First-Line Manager (FLM).

Docket No. 70-7001 GDP 98-1069 Page 5 of 5

3. On August 4,1998, the manager of Safety, Safeguards, and Quality addressed the MAAT relative to this event and the necessity to ensure that effective corrective actions are implemented.

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4. On August 11,1998, the manager of Commitment Management forwarded a copy of the l

interim event investigation report to the members of MAAT for purposes oflessons learned.

l Areas for particular emphasis were marked in the report.

l B. Planned Corrective Actions

1. By January 15,1999, Engineering will walkdown, identify, and document any additional l

electrical receptacles / power strips that are powered from circuits that also power PGLD and l

F/S systems not previously identified during the November 20,1997, verification (SCAQ l

PR-CO-95-4883).

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2. By February 18,1999, Operations will label the electrical receptacles / power strips identified l

in corrective action number 1, above. The label will indicate that the receptacle should not l

be used to supply power to auxiliary equipment.

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3. By July 30,1999, Operations will complete a walkdown using the walkdown procedure to l

define scope and acceptable criteria of all electrical receptacles / power strips labeled as l

dedicated for PGLD and F/S systems to ensure labels are in place and visible. Electrical l

receptacles / power strips without labels, if any, will be relabeled and an assessment and l

tracking report (ATR) initiated.

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4. By August 6,1999, Operations will develop and implement a plant-wide procedure l

providing direction relative to plugging auxiliary equipment into receptacles / power strips l

identified in corrective actions number 1 and number 2, above. Further, Operations will j

include guidance for the FLM to respond to requests to plug auxiliary equipment into l

receptacles / power strips that are not labeled.

I EXTENT EXPOSURE OF INDIVIDUALS TO RADIATION OR RADIOACTIVE MATERIALS None LESSONS LEARNED This event demonstrates the importance of assuring completion of effective corrective actions and verifications by issue owners during commitment closure.

Docket No. 70-7001 GDP 98-1069 Page1of1 Event Report ER-98-21, Rev. 2 List of Commitments

1. By January 15, 1999, Engineering will walkdown, identify, and document any additional l

electrical receptacles / power strips that are powered from circuits that also power PGLD and F/S l

systems not previously identified during the November 20,1997, verification (SCAQ PR-CO-l 95-4883).

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2. By February 18,1999, Operations will label the electrical receptacles / power strips identified in l

corrective action number 1, above. The label will indicate that the receptacle should not be used l

to supply power to auxiliary equipment.

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3. By July 30,1999, Operations will complete a walkdown using the walkdown procedure to define l

scope and acceptable criteria of all electrical receptacles / power strips labeled as dedicated for l

PGLD and F/S systems to ensure labels are in place and visible. Electrical receptacles / power l

strips without labels, if any, will be relabeled and an assessment and tracking report (ATR) l initiated.

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4. By August 6,1999, Operations will develop and implement a plant-wide procedure providing l

direction relative to plugging auxiliary equipment into receptacles / power strips identified in l

corrective actions number 1 and number 2, above. Further, Operations will include guidance for l

the FLM to respond to requests to plug auxiliary equipment into receptacles / power strips that l

are not labeled.

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