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Response to "Yellowstone Supervolcano - When should we start to worry?"

Re: Yellowstone Supervolcano - When should we start to worry?

Dear Ian:

It's not that there's been ~ 300 quakes since Saturday or even that they're all within a mile or two of each other, the worrisome part is that they are all within a few hundred yards of each other vertically, extending from the surface down to 7.2 km potentially defining a single "chimney" under high pressure causing hydraulic fracturing along its entire length, (http://www.seis.utah.edu/req2webdir/recenteqs/Maps/Yellowstone_full.html ). The National Park Service reports the magma chamber is as shallow as 8 km and if the major chamber is that close to the chimney reaching to 7.2 km, we may be in for an eruption.

We need more info on this location and the USGS should be tasked to deploy the best active seismic and Magnetotelluric, (to discern whether the chimney contains water or magma), mapping equipment at the Lake ASAP to accurately define the chimney and magma chamber. While an explosive eruption of the entire caldera may not necessarily ensue penetration of the chimney into the chamber, response to such an event would be daunting, to say the least.

In particular, I direct your attention to the problem the resultant ash clouds will pose to safe operation of nuclear plants. Despite the numerous catastrophic issues associated with the eruption, I raise this issue due to the potential for greatly extending the damage over vast areas from a few decades to hundreds of years needed for released fission fragments to decay to acceptable levels.

The safety of containment of radioactive materials is threatened because nuclear power plants will not have sufficient clean water reserves to maintain extended cooling of reactor cores and spent fuel pools after ash deposition contaminates all surface waters. All downwind plants will have to immediately suspend operation of their secondary cooling loops to prevent disabling erosion of all moving parts and piping by the ash in their normal water supply.

The remaining ~7% of reactor thermal output retained in the latent heat of radioactive decay in fuel rods will require use of reserve water supplies for emergency core blow downs that were never intended to supply enough water for the extended periods of time that ash could fall and otherwise contaminate surface cooling water from rain runoff.

Moreover, these reserve water pools are already providing cooling for spent fuel rods which could also melt if their water is consumed for blow down steam replacement. The use of ash-contaminated water for primary loop cooling poses the same problems of pump and pipe erosion and accumulation of sediments in the core would cause water circulation problems that could lead to fuel assembly overheating. The air filtration systems in containment buildings were also not designed to stop release of nuclides under near continuous and extended blow down circumstances.

It is imperative that the NRC immediately coordinate with DHS/USCG for emergency acquisition of all available water tankage to store uncontaminated water, or settle and filter contaminated water, for extended use by nuclear facilities. DHS should also consider seizure of all drilling equipment, (operation of any engine in ambient ash will be limited), to supply ground-filtered water to power plants and the public, (ash is so fine that filtration of any type will be very limited, particularly where air and water filter replacement will be limited).

This will also necessitate insuring that all required tank trucks, transport trucks, barge tugs and tank vessels have sufficient spare air filters, water pumps and pump impellers. While prior lack of planning may be excused due to the improbability of such an event, the ongoing events at Yellowstone Lake demand immediate attention to this potential catastrophe beyond anything experienced in recorded history, which could be devastatingly compounded by our failure to stockpile sufficient clean cooling water for reactors.

Tom Lakosh