05000461/LER-2021-002-02, Core Alterations with Source Range Monitor Inoperable Results in Condition Prohibited by Technical Specifications
| ML22308A068 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/01/2022 |
| From: | Chalmers T Constellation Energy Generation |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| U-604729 LER 2021-002-02 | |
| Download: ML22308A068 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4612021002R02 - NRC Website | |
text
Clinton Power Station 8401 Power Road Clinton IL 61727 U-604729 November 1, 2022 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 2021-002-02 Constellation 10 CFR 50.73 Enclosed is Licensee Event Report (LER} 2021-002-02: 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 10 CFR 50.73.
There are no regulatory commitments contained in this report.
Should you have any questions concerning this report, please contact Mr. David Livingston, Regulatory Assurance Manager, at (217) 937-2204.
Respectfully, ~r Thomas D. Chalmers Site Vice President Clinton Power Station
Attachment:
Licensee Event Report 2021-002-02 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 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 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 for this condition. The root cause of this event was the Refuel Senior Reactor Operator (SRO) did not recognize SRM A was inoperable because the shift turnover and relief procedure did not include a step to verify SRM status. Corrective actions include a procedure change to verify SRM status prior to commencing fuel movement for the shift. 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 TS.
PLANT AND SYSTEM IDENTIFICATION
General Electric - Boiling Water R~actor, 3473 Megawatts Thermal Rated Core Power Energy Industry ld_entification System (EIIS) codes are identified in text as [XX].
EVENT IDENTIFICATION 002 02 Core Alterations With Source Range Monitor Inoperable Results in Condition Prohibited by Technical Specifications A.
Plant Qperating Conditions Before the Event Unit: 1 Mode: 5
_ -Event Date: October. 3, 2021 Mode Name: Refueling B.
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) fnstrumentation, 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 Octobe-r 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 - lmmediately*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 or the Event. -
The root cause of this event was the Refuel Senior Reactor Operator (SRO) did not recognize the
- plant condition change of SRM A being inoperable because the shift turnover and reiief procedure did not include a step for the oncoming Refuel SRO to contact the control room for SRM status prior to commencing fuel movement for the shift. Contributing and organizational causes il)clude: (1) fuel move sheets not having specific guidance in the notes for the fuel moves, and (2) procedurally-driven work practices and a la.ck of recent events related to performing core alterations with *an inoperable SRM h~ve resulted in the site-becoming out of step with industry best practices.
NRG FORM 3615A {0B-,2020),
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NRC FORM 386A (08-2020)
U.S. NUCLEAR REGULATORY COMMISSION
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- 3. LER NUMBER YEAR Clinton Power Station, Unit 1 _
06000461 BEQU.ENTIAL NUMBER REV NO 2021 002
- NARRATIVE D.
Safety Conseque~ces The condition.described in this LER is reportable under *1 O 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 refuel shuffle within the North-We15t 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 Functi~nal Failure.
E.
Corrective Actions
As rioted 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.
Corrective Actions completed and planned include:
02 Revision of the shift turnover and relief procedure to add a step fur the oncqming Refuel SRO to contact the MCR for SRM status prior to commencing fuel movement for the shift.
Pre!;ientation of a Ca_se Study on outage decision making as pre-outage training to selected outage personnel and Reactor Engir.ieers.
Training for Reactor Engineers on development of Fuel move sheets, including examples from this event.
,J Reyiew of best methods to align with.fleet and industry standards for Core Alterations.
- F.
Previous Similar Occurrences A review of previous LE Rs did 110( identify any events that were similar to* the condition described in this LER.
G.
Component Failure Data
Not applicable to tflis event.
- NRG FORM 366A (08-2020)
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