Richland-area nuclear plant’s earthquake risk minimized, study claims

RICHLAND – Earthquake risks at the nuclear power plant near Richland were underestimated when the facility was built and plant officials have downplayed the possible threats, a new study says.

The study, commissioned by activist group Physicians for Social Responsibility, reviewed seismic research and investigations conducted in the 30 years since Energy Northwest’s Columbia Generating Station was built.

Faults near the plant stretch longer and deeper than originally thought, additional faults have been found and new signs of relatively recent seismic activity discovered, the study says.

Energy Northwest hasn’t acted on the new information, the group says, even after federal regulators asked the plant’s operators to evaluate it in 2010 for additional earthquake risk.

“They need to study and upgrade the plant. If it can’t be upgraded, it should be shut down,” said Steve Gilbert, Washington state chapter president for Physicians for Social Responsibility.

Plant officials said they are aware of the study and take earthquake risks seriously, having partnered with the Pacific Northwest National Laboratory in Richland on a large-scale seismic study.

They said an initial reading of the Physicians for Social Responsibility’s report indicates it is largely theoretical.

“They’re taking public documents and seem to be arranging them to tell a unique story that isn’t necessarily in context,” Energy Northwest spokesman Mike Paoli said.

Fukushima piqued interest

Construction of the vitrification plant to glassify nuclear water at the Hanford Nuclear Reservation was halted by the U.S. Department of Energy in early 2006 when seismic data indicated it wasn’t designed to adequately handle a severe earthquake.

The vitrification plant issues got Physicians for Social Responsibility’s attention and provided the impetus for the study, Gilbert said. The March 2011 meltdowns at three Japanese power plants, caused by a coolant failure brought about by a tsunami, gave further reason to investigate. The Fukushima and Richland plants are of a similar design.

Terry Tolan, a Kennewick-based consulting geologist, wrote the Physicians for Social Responsibility report. He used his past research in the Columbia Basin and that of other researchers and sources such as the U.S. Geological Survey to back his findings. He could not be reached by the Tri-City Herald on Friday.

The power plant was built to seismic standards determined by several factors, such as the location and nature of nearby geological features, including the Rattlesnake Hills and Saddle Mountains, the study said. Historical incidents, including a 6.5- to 7.4-magnitude earthquake that struck the Pacific Northwest in December 1872 and another that hit near Milton-Freewater in 1936, also were considered.

But research cited in Tolan’s report said some faults have been found to be longer and deeper, creating the possibility of more-dangerous earthquakes. The one responsible for the Yakima Ridge is now known to extend east into the Hanford site.

The epicenter of the 1872 quake, originally estimated to have been at least 180 miles from the power plant, is now thought to have been within 100 miles of the plant, increasing the potential risk of similar incidents in the future, the report said.

“No seismic structural upgrades have been made at the Columbia Generating Station despite all of the geologic evidence that has been assembled over the past 30 years which has dramatically increased the seismic risk at the site,” the summary of the study said.

The power plant, federally relicensed last year to operate through 2043, is equipped to withstand earthquakes, including seismic bracing to hold components firmly in place, Paoli said.

There haven’t been any physical modifications made to the plant to further help stabilize it in case of an earthquake, but Energy Northwest’s assistant vice president for engineering, Dave Swank, told the Herald it wasn’t built to minimal standards.

“There’s a lot of margin built in,” he said.

Seismic study underway

The nuclear energy industry took a collective step back to consider the implications of a severe earthquake after Fukushima, Paoli said. It was what motivated Energy Northwest to partner with PNNL on a broad seismic study of the region. About 15 to 20 independent seismologists and other experts are expected to turn in their findings to federal nuclear regulators in March 2015. Their initial results haven’t indicated a heightened risk to the facility, plant officials said.

The U.S. Nuclear Regulatory Commission asked Energy Northwest in a 2010 letter to reassess seismic risks partially because of the concerns raised at the Hanford vitrification plant construction site 10 miles away.

The plant’s operators responded that the power plant and the vitrification facility are far enough apart and on different enough terrain that their risks are different.