PNO-III-14-002, A: Update, Palisades Control Rod Drive Mechanism Housing Flaws: Difference between revisions
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{{#Wiki_filter:PRELIMINARY NOTIFICATION - REGION III March 14, 2014 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE | {{#Wiki_filter:PRELIMINARY NOTIFICATION - REGION III March 14, 2014 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-14-002A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. Some of the information may not yet be fully verified or evaluated by the Region III staff. | ||
Facility Licensee Emergency Classification Palisades Nuclear Plant Notification of Unusual Event Entergy Nuclear Operations, Inc. Alert Covert, Michigan Site Area Emergency Docket: 05000255 General Emergency License: DPR-20 X Not Applicable | |||
Facility Licensee Emergency Classification Palisades Nuclear Plant Entergy Nuclear Operations, Inc. | |||
Covert, Michigan Docket: | |||
==SUBJECT:== | ==SUBJECT:== | ||
UPDATE - PALISADES CONTROL ROD DRIVE MECHANISM HOUSING FLAWS | UPDATE - PALISADES CONTROL ROD DRIVE MECHANISM HOUSING FLAWS This Preliminary Notification updates information provided in PNO-III-14-002, associated with the licensees examination of the Control Rod Drive Mechanism (CRDM) housings, consistent with commitments made by the licensee to the Nuclear Regulatory Commission (NRC) following its previous outage. The CRDM housings are part of the reactor coolant system pressure boundary and are designed to prevent reactor coolant from leaking into the containment. The CRDMs are the mechanisms that withdraw and insert the control rods into the reactor and extend from the reactor head to about 14 feet upward. | ||
As a result of these examinations, the licensee identified flaws in 17 of the 45 CRDM housings and replaced all of the CRDM housings with new housings of a different design that is more resistant to developing this type of flaw. One of the 45 CRDM housings was replaced during the previous outage and the remaining 44 housings were replaced during the current refueling outage. | |||
This Preliminary Notification updates information provided in PNO-III-14-002, associated with the | Two NRC resident inspectors, assigned full time on-site to inspect and assess licensee activities, and an NRC regional inspector and subject matter expert, who was pre-staged on-site at the start of the refueling outage, observed the licensees examination of the CRDM housings and continue to evaluate the licensees corrective actions for the identified flaws. Additionally, NRC headquarters and regional experts conducted an independent and detailed review of the licensees technical evaluations and destructive testing of four of the housings with identified flaws. Based upon its independent review and assessment, the NRC concluded that the CRDM housings structural integrity was not compromised while the plant was operating. | ||
The NRC will document its conclusions in a publicly available inspection report. | |||
As a result of these examinations, the licensee identified flaws in 17 of the 45 CRDM housings and replaced all of the CRDM housings with new housings of a different design that is more resistant to developing this type of flaw. One of the 45 CRDM housings was replaced during the previous outage and the remaining 44 housings were replaced during the current refueling outage. | The State of Michigan has been notified. | ||
Two NRC resident inspectors, assigned full time on-site to inspect and assess licensee activities, and an NRC regional inspector and subject matter expert, who was pre-staged on-site at the start of the refueling outage, observed the | |||
flaws. Based upon its independent review and assessment, the NRC concluded that the CRDM housings | |||
The NRC will document its conclusions in a publicly available inspection report. | |||
The State of Michigan has been notified. | |||
The information in this preliminary notification is current as of 11:00 a.m. (EDT) on March 14, 2014. | The information in this preliminary notification is current as of 11:00 a.m. (EDT) on March 14, 2014. | ||
Eric.Duncan@nrc.gov | PNO-III-14-002A This information has been reviewed with plant management. | ||
This preliminary notification is issued for information only and no further action by the staff is anticipated. | |||
ADAMS Accession Number: ML14073A612 Contacts: Eric R. Duncan Alex Garmoe 630-829-9620 269-764-8971 Eric.Duncan@nrc.gov Alex.Garmoe@nrc.gov}} | |||
{{PNO-Nav|region=III}} | {{PNO-Nav|region=III}} | ||
Latest revision as of 07:52, 4 November 2019
| ML14073A612 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/14/2014 |
| From: | Eric Duncan, Alex Garmoe NRC/RGN-III/DRP/B2 |
| To: | |
| References | |
| PNO-III-14-002A | |
| Download: ML14073A612 (2) | |
PRELIMINARY NOTIFICATION - REGION III March 14, 2014 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-14-002A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. Some of the information may not yet be fully verified or evaluated by the Region III staff.
Facility Licensee Emergency Classification Palisades Nuclear Plant Notification of Unusual Event Entergy Nuclear Operations, Inc. Alert Covert, Michigan Site Area Emergency Docket: 05000255 General Emergency License: DPR-20 X Not Applicable
SUBJECT:
UPDATE - PALISADES CONTROL ROD DRIVE MECHANISM HOUSING FLAWS This Preliminary Notification updates information provided in PNO-III-14-002, associated with the licensees examination of the Control Rod Drive Mechanism (CRDM) housings, consistent with commitments made by the licensee to the Nuclear Regulatory Commission (NRC) following its previous outage. The CRDM housings are part of the reactor coolant system pressure boundary and are designed to prevent reactor coolant from leaking into the containment. The CRDMs are the mechanisms that withdraw and insert the control rods into the reactor and extend from the reactor head to about 14 feet upward.
As a result of these examinations, the licensee identified flaws in 17 of the 45 CRDM housings and replaced all of the CRDM housings with new housings of a different design that is more resistant to developing this type of flaw. One of the 45 CRDM housings was replaced during the previous outage and the remaining 44 housings were replaced during the current refueling outage.
Two NRC resident inspectors, assigned full time on-site to inspect and assess licensee activities, and an NRC regional inspector and subject matter expert, who was pre-staged on-site at the start of the refueling outage, observed the licensees examination of the CRDM housings and continue to evaluate the licensees corrective actions for the identified flaws. Additionally, NRC headquarters and regional experts conducted an independent and detailed review of the licensees technical evaluations and destructive testing of four of the housings with identified flaws. Based upon its independent review and assessment, the NRC concluded that the CRDM housings structural integrity was not compromised while the plant was operating.
The NRC will document its conclusions in a publicly available inspection report.
The State of Michigan has been notified.
The information in this preliminary notification is current as of 11:00 a.m. (EDT) on March 14, 2014.
PNO-III-14-002A This information has been reviewed with plant management.
This preliminary notification is issued for information only and no further action by the staff is anticipated.
ADAMS Accession Number: ML14073A612 Contacts: Eric R. Duncan Alex Garmoe 630-829-9620 269-764-8971 Eric.Duncan@nrc.gov Alex.Garmoe@nrc.gov