What is NOUE?
NOTICE OF UNUSUAL EVENT is an event in progress or that has occurred which indicates a potential degradation of the level of safety of the plant. No release of radioactive material is expected unless further degradation of plant safety systems occurs.
Purpose of NOUE
The purpose of the NOUE classification level is to provide off-site notification and assure that the first step in any response later found to be necessary has been carried out, to bring the operating staff to a state of readiness, and to provide systematic handling of unusual events information in decision-making.
NOUEs are uncommon but do not represent a threat to the plant or public. Some examples1 of initiating actions for a NOUE ELC are:
- Abnormal coolant temperature and/or pressure or abnormal fuel
temperatures outside of technical specifications.
- Loss of an engineered safety feature or fire protection system function requiring shutdown by technical specification.
- Fire within the plant lasting more than 10 minutes after fire fighting efforts have begun.
- Other alarms or equipment malfunctions requiring plant shutdown.
- Security threat or attempted entry or attempted sabotage.
- Tornado crossing boundary site.
- Aircraft crash on-site or unusual aircraft activity over facility.
- Transportation of contaminated injured individual from site to off-site hospital.
- The above examples have been edited for a non-technical audience.
Nuclear Power Plant Actions at a NOUE:
- Promptly inform State and/or local off-site authorities of nature of unusual condition as soon as discovered.
- Augment on-shift resources as needed.
- Assess and respond to unusual condition.
- Escalate to a more severe class, if appropriate. OR
- Close out with verbal summary to off-site authorities; followed by written summary within 24 hours.
Broad View of State and/or Local Off-Site Authority Actions at a NOUE:
- Provide fire or security assistance if requested.
- Consider modified increased readiness measures for the State
Emergency Operations Center (SEOC).
- Escalate to a more severe class. OR
- Continue to monitor until verbal close out notification by Power Plant.
Detailed View of State Actions at a NOUE:
- The Nebraska State Patrol (NSP) Communications Center in Lincoln and the Nebraska Emergency Management Agency (NEMA) will be concurrently notified by the Nuclear Power Plant affected. (After normal working hours, the NSP Communications Center will notify the NEMA Duty Officer.)
- The NEMA Operations Officer will in turn will notify the Nebraska Health and Human Services Regulation and Licensure (HHS R&L) Point of Contact and the Governor's Authorized Representative (GAR).
- The HHS R&L Point of Contact telephones the affected Nuclear Power Plant and obtains the most current information.
- The HHS R&L Point of Contact then telephones the GAR with an assessment of the plant's condition.
- Based on the most current information, the GAR considers modified increased readiness measures for the SEOC, i.e.:
- Maintain the status quo.
- Activation of the SEOC (by the NEMA Duty Officer after hours) to continue monitoring.
- Activation of the SEOC and recall additional personnel to man it after hours only.
- Activation of the SEOC and escalate to a more severe class