ULNRC-06162, Special Report 2014-05 Inoperability of Loose Parts Monitoring Instrument for Greater than 30 Day

Special Report 2014-05 Inoperability of Loose Parts Monitoring Instrument for Greater than 30 Day

ML14345B040
Person / Time
Site:	Callaway
Issue date:	12/11/2014
From:	Mclachlan M Ameren Missouri
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ULNRC-06162
Download: ML14345B040 (4)

Text

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'WAmeren Callaway Plant MISSOURI December 11, 2014 ULNRC-06162 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Ladies and Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

FACILITY OPERATING LICENSE NPF-30 SPECIAL REPORT 2014-05 INOPERABILITY OF LOOSE PARTS MONITORING INSTRUMENT FOR GREATER THAN 30 DAYS Enclosed is a special report addressing the inoperability of a loose parts monitoring instrument at Callaway Plant.

No new commitments are identified in this correspondence, and none of the material in this report is considered proprietary by Union Electric Company (Ameren Missouri).

If you have any questions or require additional information, please contact Mr. Thomas Elwood, Supervising Engineer, Regulatory Affairs and Licensing at 314-225-1905.

Mark McLachlan Senior Director, Engineering EMP Enclosure

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • PO Box 620 Fulton, MO 65251 AmerenMissouri.com STARS

• Alliance

ULNRC-06162 December 11, 2014 Page2 cc: Mr. Marc L. Dapas Regional Administrator U.S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Fred Lyon Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8B 1 Washington, DC 20555-2738

ULNRC-06162 December 11, 2014 Page 3 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 4150 International Plaza Suite 820 Fort Worth, TX 76109 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:

F. M. Diya D. W. Neterer L. H. Graessle T. E. Herrmann B.L.Cox S. A. Maglio T. B. Elwood Corporate Communications NSRB Secretary STARS Regulatory Affairs Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP)

Enclosure ULNRC-06162 Special Report 2014-05 Requirement Callaway Plant's Final Safety Analysis Report (FSAR) Section 16.3.3.5 contains requirements for reactor coolant system (RCS) loose-part detection instrumentation. The Limiting Condition for Operation (LCO) specified per FSAR 16.3.3.5 requires the loose-part detection system to be Operable in MODES 1 and 2. With a required channel inoperable for more than 30 days, Action A applies. It states, "With one or more Loose-Part Detection System channels inoperable for more than 30 days, prepare and submit a Special Report to the Commission within the next 10 days outlining the cause of the malfunction and the plans for restoring the channel(s) to OPERABLE status."

Cause of the Loose-Part Detection Instrument Inoperability Channel 7 of the Loose-Part Monitoring System (inlet to Steam Generator 'B') was declared inoperable and removed from service on 11/23/2014 due to random signal fluctuations. The channel noise is most likely due to a 60 Hertz signal being coupled onto the signal cable. This caused the system to become overloaded with data and rendered the system, specifically channel 7, unreliable.

Initial investigations have concluded that the channel degradation is likely associated with the accelerometer and hard-line cable which is located inside the bio-shield of the containment building.

The instrument will be returned to service in the next refueling outage.

The capability to detect loose metallic parts in the RCS will be retained with the remaining 11 operable channels. The redundant channel on Steam Generator 'B' (channel 8) is Operable. This will provide an alternate means for monitoring the RCS. This instrumentation ensures that sufficient capability is available to detect loose metallic parts in the RCS and avoid or mitigate damage to RCS components.

Plans for Restoring the Instrument to OPERABLE status Replacement of the accelerometer and/or hard-line cable, as well as post-maintenance testing, will be pursued during the next refueling outage (currently scheduled for March 20 16).

The potential for performing an online replacement was considered, but due to limited accessibility and high radiation dose rates required for this job, it was determined that replacement within a refueling outage is more appropriate.