PNO-III-15-010, Monticello Automatic Scram Due to Reactor Protection System Signal
| ML15331A344 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 11/27/2015 |
| From: | Kenneth Riemer NRC/RGN-III |
| To: | |
| Riemer K | |
| References | |
| PNO-III-15-010 | |
| Download: ML15331A344 (1) | |
PRELIMINARY NOTIFICATION - REGION III November 27, 2015 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-15-010 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 Monticello Nuclear Generating Plant Northern States Power Co.
Monticello, MN Docket: 50-263 License: DPR-22 Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable
SUBJECT:
MONTICELLO AUTOMATIC SCRAM DUE TO REACTOR PROTECTION SYSTEM SIGNAL DESCRIPTION:
On November 23, 2015, Monticello Nuclear Generating Plant was at full power when a lockout of the 11 recirculation pump occurred. The recirculation pump is used to circulate and control the flow of water through the reactor core. In addition to the lockout of the recirculation pump, the Reactor Protection System (RPS) sent a signal to isolate steam flow to the turbine and initiate an automatic reactor scram. All systems responded as designed. The causes of both the 11 recirculation pump lockout and the steam valve isolation signal are currently under investigation.
The NRC senior resident inspector was on site to observe the shutdown and portions of the licensees troubleshooting efforts.
This preliminary notification is issued for information only and no further action by the staff is anticipated.
Region III received initial notification of this occurrence via the Resident Inspector at 10:42 am (CST) on November 23, 2015. The information presented herein has been discussed with the licensee, and is current as of 11:35 a.m. (CST), on November 27, 2015.
ADAMS Accession Number ML15331A344 CONTACT:
Kenneth Riemer 630/829-9628 Kenneth.Riemer@nrc.gov
PRELIMINARY NOTIFICATION - REGION III November 27, 2015 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE - PNO-III-15-010 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 Monticello Nuclear Generating Plant Northern States Power Co.
Monticello, MN Docket: 50-263 License: DPR-22 Licensee Emergency Classification Notification of Unusual Event Alert Site Area Emergency General Emergency X Not Applicable
SUBJECT:
MONTICELLO AUTOMATIC SCRAM DUE TO REACTOR PROTECTION SYSTEM SIGNAL DESCRIPTION:
On November 23, 2015, Monticello Nuclear Generating Plant was at full power when a lockout of the 11 recirculation pump occurred. The recirculation pump is used to circulate and control the flow of water through the reactor core. In addition to the lockout of the recirculation pump, the Reactor Protection System (RPS) sent a signal to isolate steam flow to the turbine and initiate an automatic reactor scram. All systems responded as designed. The causes of both the 11 recirculation pump lockout and the steam valve isolation signal are currently under investigation.
The NRC senior resident inspector was on site to observe the shutdown and portions of the licensees troubleshooting efforts.
This preliminary notification is issued for information only and no further action by the staff is anticipated.
Region III received initial notification of this occurrence via the Resident Inspector at 10:42 am (CST) on November 23, 2015. The information presented herein has been discussed with the licensee, and is current as of 11:35 a.m. (CST), on November 27, 2015.
ADAMS Accession Number ML15331A344 CONTACT:
Kenneth Riemer 630/829-9628 Kenneth.Riemer@nrc.gov