Event Notification Report for October 17, 2011
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/16/2011 - 10/17/2011
EVENT NUMBERS
47348
Power Reactor
Event Number: 47348
Facility: WATTS BAR
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BILL SPRINKLE
HQ OPS Officer: STEVE SANDIN
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BILL SPRINKLE
HQ OPS Officer: STEVE SANDIN
Notification Date: 10/17/2011
Notification Time: 21:33 [ET]
Event Date: 10/17/2011
Event Time: 20:50 [EDT]
Last Update Date: 10/18/2011
Notification Time: 21:33 [ET]
Event Date: 10/17/2011
Event Time: 20:50 [EDT]
Last Update Date: 10/18/2011
Emergency Class: UNUSUAL EVENT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED 50.72(b)(2)(xi) - OFFSITE NOTIFICATION
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED 50.72(b)(2)(xi) - OFFSITE NOTIFICATION
Person (Organization):
MARK LESSER (R2DO)
FREDERICK BROWN (NRR)
BILL GOTT (IRD)
BRUCE BOGER (NRR)
VICTOR McCREE (R2RA)
MARK LESSER (R2DO)
FREDERICK BROWN (NRR)
BILL GOTT (IRD)
BRUCE BOGER (NRR)
VICTOR McCREE (R2RA)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
UNIT 1 DECLARED AN UNUSUAL EVENT BASED ON AMMONIA LEVELS EXCEEDING OSHA LIMITS
"Normal Operation of WBN [Watts Bar Nuclear] Unit 1 impeded in the Turbine Building, El. 685, West side of the Unit 1 Main condenser due to Toxic Gas (ammonia) concentrations of 75-79 ppm exceeding the OSHA Permissible Exposure Limit (PEL) of 50 ppm, and the ACGIH [American Conference of Governmental Industrial Hygienists] limit of 25 ppm. WBN Unit 1 returned to approximately 100% RTP on Monday, October 17, 2011, following a maintenance outage. Suspect excessive ammonia concentrations due to condenser vacuum pump continuous drains which may need throttling open to increase drain flow, following Unit startup. (Ammonia is used to treat feedwater for secondary chemistry control). There have been no injuries from this event. NRC Senior Resident [Inspector] has been notified. (Event Class 4.4.A, Toxic Gas, Unusual Event)."
The licensee informed both the State and local agencies. Notified FEMA (Blankenship) and DHS (Konopka).
* * * UPDATE FROM BILL SPRINKLE TO DONALD NORWOOD AT 0052 EDT ON 10/18/2011 * * *
At 0047 EDT on 10/18/2011, the licensee terminated the Notification of Unusual Event condition based on ammonia concentrations having been reduced to approximately 6 ppm. Normal personnel access to the affected area has been restored. Unit 1 remained at 100% power during this event with no changes or challenges to plant operations. During the event there were no additional EAL designators. During the event there were no significant changes in plant conditions. During the event there were no significant changes in plant radiological conditions. During the event there were no offsite protective recommendations made by the licensee.
The licensee notified the NRC Resident Inspector and State and local agencies.
Notified R2DO (Lesser), NRR EO (Brown), IRD (Morris), DHS (Gates), and FEMA (Blankenship).
* * * UPDATE AT 1354 EDT ON 10/18/11 FROM BILLY JOHNSON TO S. SANDIN * * *
"This information is being provided to the NRC for a 10CFR50.72(b)(2)(xi) notification.
"TVA is planning on making a news release to local media affiliates and posting the news release on TVA's website. This news release is in reference to the Notification of Unusual Event (NOUE) Watts Bar Nuclear Plant recently entered and exited for ammonia levels exceeding OSHA limits (reference EN 47348 and update).
"The licensee notified the NRC Senior Resident Inspector."
Notified R2DO (Lesser).
"Normal Operation of WBN [Watts Bar Nuclear] Unit 1 impeded in the Turbine Building, El. 685, West side of the Unit 1 Main condenser due to Toxic Gas (ammonia) concentrations of 75-79 ppm exceeding the OSHA Permissible Exposure Limit (PEL) of 50 ppm, and the ACGIH [American Conference of Governmental Industrial Hygienists] limit of 25 ppm. WBN Unit 1 returned to approximately 100% RTP on Monday, October 17, 2011, following a maintenance outage. Suspect excessive ammonia concentrations due to condenser vacuum pump continuous drains which may need throttling open to increase drain flow, following Unit startup. (Ammonia is used to treat feedwater for secondary chemistry control). There have been no injuries from this event. NRC Senior Resident [Inspector] has been notified. (Event Class 4.4.A, Toxic Gas, Unusual Event)."
The licensee informed both the State and local agencies. Notified FEMA (Blankenship) and DHS (Konopka).
* * * UPDATE FROM BILL SPRINKLE TO DONALD NORWOOD AT 0052 EDT ON 10/18/2011 * * *
At 0047 EDT on 10/18/2011, the licensee terminated the Notification of Unusual Event condition based on ammonia concentrations having been reduced to approximately 6 ppm. Normal personnel access to the affected area has been restored. Unit 1 remained at 100% power during this event with no changes or challenges to plant operations. During the event there were no additional EAL designators. During the event there were no significant changes in plant conditions. During the event there were no significant changes in plant radiological conditions. During the event there were no offsite protective recommendations made by the licensee.
The licensee notified the NRC Resident Inspector and State and local agencies.
Notified R2DO (Lesser), NRR EO (Brown), IRD (Morris), DHS (Gates), and FEMA (Blankenship).
* * * UPDATE AT 1354 EDT ON 10/18/11 FROM BILLY JOHNSON TO S. SANDIN * * *
"This information is being provided to the NRC for a 10CFR50.72(b)(2)(xi) notification.
"TVA is planning on making a news release to local media affiliates and posting the news release on TVA's website. This news release is in reference to the Notification of Unusual Event (NOUE) Watts Bar Nuclear Plant recently entered and exited for ammonia levels exceeding OSHA limits (reference EN 47348 and update).
"The licensee notified the NRC Senior Resident Inspector."
Notified R2DO (Lesser).