At 1258
CDT on August 10, 2020, Duane Arnold Energy Center declared an Unusual Event due to a loss of offsite power due to
high winds. The event at the single unit plant resulted in an
automatic scram from 82 percent power (Mode-1) to zero percent power (Mode-3). They are headed to Mode-4. There is damage on site, but the Reactor Building is intact. All rods inserted and cooling is being addressed via
Reactor Core Isolation Cooling (
RCIC) for level control and Safety Relief Valves are removing decay heat to the torus. Both Standby Diesel Generator are running.
The licensee notified the NRC Resident Inspector, the Iowa Department of Emergency Management, and the Linn County and Benton County Emergency Management agencies.
Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
- * * UPDATE ON 08/10/2020 AT 1554 EDT FROM CURTIS HANSEN TO OSSY FONT * * *
This report is being made under CFR 50.72 (b)(2)(iv)(B) for an automatic reactor scram due to loss of offsite power due to high winds.
In addition, this report is being made under CFR 50.72 (b)(3)(iv)(A) and (B) due to PCIS [(Primary Containment Isolation System)] Groups 1, 2, 3, 4 and 5 [activating] due to loss of offsite power. All isolations went to completion. RCIC injecting for level control.
All rods fully inserted during the scram. The plant electrical line up is both SBDGs (Standby Diesel Generators) are running.
Decay heat is being removed via SRVs (Safety Relief Valves) to the torus.
Progress towards shutdown cooling.
NRC Senior Resident [Inspector] notified at 1448.
Notified R3DO (Pelke).
