2CAN042402, Special Report of Non-functional Main Steam Line Radiation Monitor

Special Report of Non-functional Main Steam Line Radiation Monitor

ML24102A282
Person / Time
Site:	Arkansas Nuclear
Issue date:	04/11/2024
From:	Keele R Entergy Operations
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
2CAN042402
Download: ML24102A282 (1)

Text

Riley D. Keele, Jr.

entergy Manager, Regulatory Assurance Arkansas Nuclear One 4 79-858-7826

2CAN042402

April 11, 2024

ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Special Report of Non-functional Main Steam Line Radiation Monitor

Arkansas Nuclear One, Unit 2 NRC Docket No. 50-368 Renewed Facility Operating License No. NPF-6

Arkansas Nuclear One - Unit 2 (ANO-2) Technical Requirements Manual (TRM) 3.3.2, Radiation Monitoring Instrumentation, requires one Main Steam line radiation monitor shall be functional on each Main Steam line in Modes 1, 2, 3 and 4. The required action section of 3.3.2 stipulates, "With less than one Main Steam line radiation monitor functional on each Main Steam line, initiate the preplanned alternate method of monitoring the associated parameter within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 1) either restore the non-functional channel to functional status within 7 days of the initial loss, or 2) prepare and submit a Special Report to the NRC within 14 days following the event outlining the action taken, the cause of the inoperability and the plans and schedule for restoring the system to functional status."

On March 29, 2024, with ANO-2 in Mode 1, the "B" Main Steam Line Radiation Monitor (2Rl-1057) was declared non-functional as a result of erratic high readings. TRM 3.3.2. was entered at 2140 on March 29, 2024. Troubleshooting and repair efforts were initiated, and the preplanned alternate monitoring methods for primary to secondary leakage were initiated.

Troubleshooting efforts determined the failure was the result of a faulty detector. Repair efforts included replacement of the detector and the detector power cable. Post maintenance testing and the monthly Radiation Monitor Surveillance have been completed with satisfactory results. 2Rl-1057 is now functional and has been returned to service. TRM 3.3.2 was exited at 1135 on April 11, 2024.

This letter contains no new regulatory commitments.

If there are any questions or if additional information is needed, please contact Riley Keele, Manager, Regulatory Assurance, Arkansas Nuclear One, at 479-858-7826.

Entergy Operations, Inc. 1448 SR 333, Russellville, AR 72802 2CAN042402 Page 2 of 2

Sincerely,

RDK/bka

cc: NRC Region IV Regional Administrator NRC Senior Resident Inspector - Arkansas Nuclear One NRC Project Manager - Arkansas Nuclear One