ML23065A193

Interim 10CFR21 Notification for Schneider Electric P/N: ASP840-000 Modicon Primary/Secondary Power Supply Failures

ML23065A193
Person / Time
Site:	Surry
Issue date:	03/03/2023
From:	Paidy D United Controls International
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML23065A193 (1)

Text

10CFR21 INTERIM NOTIFICATION LETTER

March 3, 2023

U.S. Nuclear Regulatory Commission Document Control Desk Washington D.C. 20555-0001

Subject:

Interim 10CFR21 Notification for Schneider Electric P/N: ASP840-000 Modicon Primary/Secondary Power Supply Failures

This is to notify the US Nuclear Regulatory Commission that, in accordance with the provisions of 10CFR Part 21, UCI has identified a potential issue and are submitting this interim report of the event.

==

Description:==

On September 7, 2022, Dominions Surry Power Station notified UCI that Qty. 3 Schneider Electric P/N: ASP840-000 Modicon Primary/Secondary Power Supply units that were supplied by UCI in 2014 had failed after installation. Hard failures that shutdown the associated PLC were observed. The first unit was installed since June 6, 2017 and then failed in August of 2022. The second and third units failed approximately 3 days after installation. All units appeared to function properly at initial installation.

Evaluation:

The subject items were returned to UCI on October 19, 2022 for evaluation. Items were received at UCI with substantial shipping damage noted. One item was received with a loose transformer inside the unit. All items were received with bent or cracked cases. These issues are attributed to poor shipping practices as items were not supplied in such conditions and these issues would have been noted at receipt by the utility. Due to the complexity of the items and unavailability of design documentation, further evaluation of item failures requires manufacturer (Schneider Electric) evaluation. UCI is returning the items to the manufacturer for evaluation of failed components. Once the manufacturer evaluation has been completed, UCI may investigate further as to the possible causes of these failures.

UCI will not be able to complete this investigation within the 60-day regulatory timeline due to the need for outside manufacturer evaluation. This interim report is being submitted per the requirements of 10 CFR 21 to notify the NRC of this possible deviation and to document UCIs continuing evaluation to determine if this failure represents a substantial safety hazard. UCI requested two evaluation extensions of 60 days on November 4, 2022 and January 3, 2023. UCI was to provide further evaluation by March 4, 2023. As of March 3, 2023 the item manufacturer has not yet completed their evaluation of the cause of item failure and cannot provided an expected completion date; thus, UCI requests an additional evaluation extension of 120 days.

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UCI continues to follow up with the manufacturer on the status of the item evaluations and plans

to provide further evaluation by July 2, 2023.

Extent of Condition:

Will be determined once root cause(s) of the power supply failures are known.

Corrective Actions:

Will be determined once root cause(s) of the power supply failures are known.

Summation:

In summary, Qty. 3 Schneider Electric P/N: ASP840-000 Modicon Primary/Secondary Power Supply units failed to operate several days after installation at Dominions Surry Power Station with hard failures that shutdown the associated PLC. The units were returned to UCI and initial observations indicated heavy shipping damage that was not present when initially supplied.

Further evaluation of the damaged components requires manufacturer evaluation due to item complexity and proprietary design documentation. Investigation into the root cause(s) of the failures is ongoing. Evaluation of whether these failures represent deviations or failures to comply that would be associated with substantial safety hazards will be complete by July 2, 2023.

Respectfully Submitted,

Divya Paidy Director of Operations United Controls International

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