ENS 54034
ENS Event | |
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11:33 Apr 28, 2019 | |
Title | Control Blade Inoperable |
Event Description | On April 28, 2019, at 0633 CDT, with the University of Missouri-Columbia Research Reactor (MURR) operating at 10 MW in the automatic control mode, the Lead Senior Reactor Operator (LSRO) was conducting surveillance Technical Specification (TS) 4.2.a, which states, 'All control blades, including the regulating blade, shall be verified operable within a shift.' During this verification of control blade operability, shim control blades 'A,' 'B,' 'C,' and the regulating blade were verified operable. However, shim control blade 'D' would not move in the inward direction. The LSRO then immediately shut down the reactor by initiating a manual scram by placing Master Control Switch 1S1 to the 'TEST' position. The LSRO completed all immediate and applicable subsequent actions of reactor emergency procedure REP-8, 'Control Rod Drive Mechanism Failure or Stuck Rod,' and verified all shim control blades were fully inserted.
This email is a required notification per TS 6.6.c(1) to report to the NRC Operations Center that an Abnormal Occurrence, as defined by TS 1.1.b, has occurred. MURR was not in compliance with all of the Limiting Conditions for Operations (LCOs) as established in TS Section 3.0. The failure of the control rod drive mechanism to insert shim control blade 'D' is a deviation from TS 3.2.a, which states, 'All control blades, including the regulating blade, shall be operable during reactor operation.' In addition, shim control blade 'D' would not have inserted during the activation of any rod run-in function listed in TS 3.2.f - shim control blades 'A,' 'B,' and 'C' would have inserted. All reactor safety system scram functions were unaffected and remained operable during this event. Troubleshooting revealed a broken wire to the inward motor winding of shim blade 'D' control rod drive mechanism. The wire was repaired, and the shim control blade 'D's operability was tested satisfactorily. Permission from the Reactor Facility Director was obtained prior to reactor startup per TS 6.6.c(4), and the reactor returned to 10 MW operation at 1319 CDT on April 28. A detailed event report will follow within 14 days as required by TS 6.6.c(3). |
Where | |
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Univ Of Missouri-Columbia Columbia, Missouri (NRC Region 0) | |
License number: | R-103 |
Reporting | |
Non | |
Time - Person (Reporting Time:+24.77 h1.032 days <br />0.147 weeks <br />0.0339 months <br />) | |
Opened: | Bruce Meffert 12:19 Apr 29, 2019 |
NRC Officer: | Joanna Bridge |
Last Updated: | Apr 29, 2019 |
54034 - NRC Website | |
Univ Of Missouri-Columbia with Non | |
WEEKMONTHYEARENS 553802021-07-26T22:31:00026 July 2021 22:31:00
[Table view]Non Reactor Shutdown Due to Control Rod Drive Failure ENS 546602020-04-09T19:32:0009 April 2020 19:32:00 Non Abnormal Occurrence ENS 546532020-04-08T06:00:0008 April 2020 06:00:00 Non Research and Test Reactor Forced Shutdown Due to Failure of Regulating Blade Drive Mechanism ENS 544532019-12-20T03:21:00020 December 2019 03:21:00 Non Technical Specification Deviation ENS 544362019-12-10T06:12:00010 December 2019 06:12:00 Non Technical Specification Violation Requiring Shutdown ENS 541872019-07-30T00:03:00030 July 2019 00:03:00 Non Technical Specification Deviation ENS 540342019-04-28T11:33:00028 April 2019 11:33:00 Non Control Blade Inoperable ENS 538492019-01-28T01:13:00028 January 2019 01:13:00 Non Control Blade Inoperable ENS 538412019-01-21T18:35:00021 January 2019 18:35:00 Non Deviation of Ts 3.3.A(1) for Anti-Siphon Device Found Inoperable ENS 534332018-05-30T12:10:00030 May 2018 12:10:00 Non Technical Specification Deviation ENS 532442018-03-04T09:08:0004 March 2018 09:08:00 Non Technical Specification Deviation ENS 531422017-12-30T13:17:00030 December 2017 13:17:00 Non Technical Specification Required Report for an Abnormal Occurrence ENS 528412017-07-05T05:00:0005 July 2017 05:00:00 Non Abnormal Occurrence Due to Source Range Inoperability During Reactor Start-Up ENS 527022017-04-20T19:49:00020 April 2017 19:49:00 Non Technical Specification Required Report for an Abnormal Occurrence 2021-07-26T22:31:00 | |