And all the buildings at the plant were supposed to be "watertight", according to the NRC.
From AP (6/27/2011):
Floodwater seeps into Nebraska nuke plant building
OMAHA (AP) -- Missouri River floodwater seeped into the turbine building at a nuclear power plant near Omaha on Monday, but plant officials said the seepage was expected and posed no safety risk because the building contains no nuclear material.
An 8-foot-tall, water-filled temporary berm protecting the plant collapsed early Sunday. Vendor workers were at the plant Monday to determine whether the 2,000 foot berm can be repaired.
Omaha Public Power District spokesman Jeff Hanson said pumps were handling the problem at the Fort Calhoun Nuclear Station and that "everything is secure and safe." The plant, about 20 miles north of Omaha, has been closed for refueling since April. Hanson said the berm's collapse didn't affect the shutdown or the spent fuel pool cooling.
Nuclear Regulatory Commission spokesman Victor Dricks described the situation as stable. NRC Chairman Gregory Jaczko plans to inspect the Fort Calhoun plant on Monday as part of a pre-arranged visit to Nebraska.
(The article continues.)
Doesn't it all sound familiar for people who have been following Fukushima?
Hypothetical progression of the minor "incident" at Fort Calhoun, after the established Fukushima model:
"Everything under control, buildings are watertight."
"Well, there was some "seepage" in the turbine building, but everything is secure and safe. It's all part of the plan."
"Well, the turbine building is actually flooded, but the reactor building is secure."
"Well, there's some water puddles in the reactor building, but the Containment Vessel is secure."
"Well, ....."
In this picture of the plant (H/T Dominique), I see sandbags against some openings. Is this what they meant by "watertight"? (More photos at this link.)