05000461/LER-2021-002, Core Alteration with Source Range Monitor Inoperable Results in Condition Prohibited by Technical Specifications
| ML22010A207 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 12/01/2021 |
| From: | Chalmers T Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| U-604661 LER 2021-002-00 | |
| Download: ML22010A207 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4612021002R00 - NRC Website | |
text
Clinton Power Station 8401 Power Road Clinton, IL 61727 U-604661 December 1, 2021 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461 Subject: Licensee Event Report 2021-002-00 Exelon Generation,)
10 CFR 50.73 Enclosed is Licensee Event Report (LER) 2021-002-00: Core Alterations With Source Range Monitor Inoperable Results in Condition Prohibited by Technical Specifications. This report is being submitted in accordance with the requirements of 1 O CFR 50. 73.
There are no regulatory commitments contained in this report.
Should you have any questions concerning this report, please contact Mr. Dale Shelton, Regulatory Assurance Manager, at (217) 937-2800.
Respectfully, cTh~:~rs Site Vice President Clinton Power Station
Attachment:
Licensee Event Report 2021-002-00 cc:
Regional Administrator - Region Ill NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety-Illinois Emergency Management Agency
Abstract
On 10/3/21, with Clinton Power Station (CPS) in Mode 5 (refueling) with core alterations in progress, it was determined CPS had operated in a condition prohibited by Technical Specifications (TS). At 0950 CDT it was identified that a fuel bundle had been placed in the North-West quadrant of the core while Source Range Monitor (SRM) 'A' was inoperable, contrary to TS 3.3.1,2, Instrumentation - SRM Instrumentation. Additionally, at time of discovery, a second fuel bundle move within the quadrant was in progress with the fuel bundle seated, but not released from the fuel handling machine grapple. Operators verified the following actions were met: TS 3.3.1.2 Action E.1 - Immediately Suspend Core Alterations except control rod insertion and TS 3.3.1.2 Action E.2 - Immediately initiate Action to fully insert all insertable control rods in cells containing one or more fuel assemblies. The fuel bundle moves were determined to be part of the planned and analyzed sequence for the refuel shuffle, Therefore, there was no impact to the health and safety of the public or plant personnel from this condition. The cause of this event is under investigation. The causal factors that resulted in this condition and the associated corrective actions will be provided in a revision to this LER. The condition described in this LER is reportable under 10 CFR 50, 73(a)(2)(i)(B), any operation or condition which was prohibited by the plant's TS.
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PLANT AND SYSTEM IDENTIFICATION
General Electric -- Boiling Water Reactor, 3473 Megawatts Thermal Rated Core Power Energy Industry Identification System (EIIS) codes are identified in text as [XX].
EVENT IDENTIFICATION 002 00 Core Alterations With Source Range Monitor Inoperable Results in Condition Prohibited by Technical Specifications A.
Plant Operating Conditions Before the Event
Unit: 1 Mode: 5 Event Date: October 3, 2021 Mode Name: Refueling
- 8.
Description of Event
Event Time: 0950 CDT Reactor Power: 000 Clinton Power Station (CPS) Technical Specification (TS) 3.3.1.2, Instrumentation - Source Range Monitor (SRM) Instrumentation, requires an SRM [RIT] in the reactor core quadrant and an adjacent quadrant be operable during core alterations within the quadrant. The North-West core quadrant is monitored by SRM 'A.'
On October 3, 2021, CPS was in Mode 5 with core alterations in progress. At approximately 0950 CDT it was identified that a fuel bundle had been placed at position 07-44 in the North-West quadrant of the core while SRM 'A' was inoperable, contrary to TS 3.3.1.2. Additionally, at time of discovery, a second fuel bundle move within the quadrant was in progress with the fuel bundle seated, but not released from the fuel handling machine [CF/FHM] grapple at position 21-36.
TS 3.3.1.2 Action E.1 - Immediately Suspend Core Alterations except control rod [JD] insertion was verified to be met. TS 3.3.1.2 Action E.2 - Immediately initiate Action to fully insert all insertable control rods in cells containing one or more fuel assemblies was also verified to be met.
C.
Cause of the Event
The cause of this event is under investigation. The causal factors that resulted in this condition and the associated corrective actions will be provided in a revision to this Licensee Event Report (LER).
D.
Safety Consequences
The condition described in this LER is reportable under 10 CFR 50.73(a)(2)(i)(B), any operation or condition which was prohibited by the plant's TS. The core alterations were evaluated for Shutdown Margin in accordance with CPS Procedure 9811.01, Shutdown Margin Determination.
The fuel bundle moves were determined to be part of the planned and analyzed sequence for the
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refuel shuffle within the North-West core quadrant. As a result, there was no impact to the health and safety of the public or plant personnel from this condition. In addition, this event does not meet the criteria for a Safety System Functional Failure.
E.
Corrective Actions
As noted above, the core alterations were evaluated for Shutdown Margin in accordance with CPS Procedure 9811.01, Shutdown Margin Determination and were determined to be part of the planned and analyzed sequence for the refuel shuffle within the North-West core quadrant. Additional corrective actions will be provided in a supplemental LER, as appropriate.
F.
Previous Similar Occurrences A review of previous LERs did not identify any events that were similar to the condition described in this LER.
G.
Component Failure Data
Not applicable to this event.
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