A Perfect Storm

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(HOST) Commentator Rebecca Coffey is a freelance writer with a special interest in mental health issues. And as a resident of Putney, she also takes an active interest in matters concerning Vermont Yankee. Most recently, she’s been paying close attention to the Dry Cask Storage Plan.   

(COFFEY) This summer, the Vermont Yankee nuclear power plant will begin storing high-level radioactive waste in 19-foot tall dry casks outdoors, on a concrete slab 254 feet away from the bank of the Connecticut River.

According to Dr. Leslie Kanat, a Geology Professor at Johnston State College, that’s a foot and a half beyond what he calls the "Probable Maximum Flood Level."

I suppose I ought to feel relieved – even if a foot and a half doesn’t sound like much.  Still, Holtec International, the company supplying the casks, reports that they stay operational even when submerged at 50 feet for 8 hours.

Holtec’s dry casks have vent holes at top and bottom.  Air enters at bottom, cools waste, and exits at top.  While Holtec’s tests have reassured me that river water would not be a problem for those vents, I’m not so sure about river mud.  

In 2002, Dr. Marvin Resnikoff, an international consultant on radioactive waste management, was asked by The CONNECTICUT Yankee Decommissioning Advisory Committee, how soon a cask would overheat if vents were blocked.  His answer:  Maybe a week.

There’s a nice margin of safety in that hypothetical week.  But the consequences of that margin being wrong could be unbelievably awful.  Because Dr. Resnikoff also reminded the committee that EACH of Connecticut Yankee’s casks contains a Cesium and Strontium inventory equal to 10 Hiroshima bombs.

Entergy has never suggested that mud could reach the vents of the dry casks at Vermont Yankee.  But according to Ray Shadis, technical director for the anti-nuclear watchdog group New England Coalition, it has acknowledged that river water could soak the ground surrounding the slab that holds the casks.  Shadis has an idea how that could be a problem.

If you shake even relatively dry soil hard, its strength and stiffness are reduced.  That’s called "liquefaction." It’s responsible for much of the damage during earthquakes.  If you actually add liquid to the mix, you create something like quicksand.  What if the Connecticut River Valley suffered a double whammy of flood plus even a minor earthquake?  Could the leading edge of the slab shift — or tip?

Vermont has been rattled 15 times since 1900.  And most scientists agree that we are entering an unstable time weather-wise, with melting ice caps, rising waters, and the possibility of more frequent flooding.

Entergy calls its dry cask storage plan temporary, but there’s wide acknowledgement that no permanent solution will be available any time soon. Given that, I can’t help but question the wisdom of creating another 20 years of radioactive waste – only to store it at river’s edge.

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