Sinkhole develops under dam in US

The sinkhole was discovered on October 20 and was immediately plugged. However, some days later, it was discovered that seepage at the toe of the dam was ongoing.

To combat the issue, dam officials began lowering the levels of water to it's winter stage earlier than usual. Water levels at the dam are expected to be at winter levels by November 10.

Source

BOONE DAM STABILITY ISSUES… “TVA conducted a briefing for government officials… after discovery of a sink hole near the base… water and sediment [has been] found seeping from the river below the dam. TVA is continuously monitoring the dam… The dam is located upstream of all three TVA nuclear sites… The NRC Senior Resident Inspector was notified. The licensee is evaluating this event for potential impact on the design basis flooding level.”

a reply to: Daedal

I made a thread on this last night, but right as I was about to post it, my computer fritzed and lost it.

Here are some of the things I posted:

"On October 30, 2014, at 1100 EDT, TVA conducted a briefing for government officials and other stakeholders regarding the decision to accelerate the Boone Reservoir annual drawdown after discovery of a sink hole near the base of the embankment and a small amount of water and sediment found seeping from the river below the dam. TVA is continuously monitoring the dam and conducting an investigation to determine the source of the water seepage. 

"The dam is located upstream of all three TVA nuclear sites. There are currently no nuclear plant operability or safety issues, and TVA is assessing the impacts on the plant licensing bases. 

U.S. Nuclear Regulatory Commission
Operations Center
Event Reports For
10/30/2014 - 10/31/2014

KNOXVILLE, Tenn. — The Tennessee Valley Authority is accelerating the annual drawdown of Boone Reservoir near Johnson City, Tenn., after a sink hole was discovered near the base of the earthen embankment and a small amount of water and sediment was found seeping from the river bank below the dam.

TVA To Accelerate Boone Reservoir Drawdown for Inspection Work



FYI, sinkholes can grow to be huge and have a variety of thngs that can start them.

I will be watching this one.

Are there any fracking sites nearby? Fracturing layers of rock is only likely to crack water-resistant layers of rock and encourage water porous layers to dissolve. Then pumping water out of aquifers could also lead to layers of rock collapsing.

So who's idea was it to put three nuclear sites down stream from a giant dam?

Doesn't that seem rather stupid?

a reply to: VoidHawk

Someone who likes explosions. And Dominos.

Upstream of three nuclear sites, oh dear.

From what I've read in the past about sinkholes, they're usually only discovered once they've caved in and reveal what's been going on beneath the surface, unbeknownst to all.

I don't like the sound of a sinkhole underneath a dam that is upstream of three nuke sites. I wonder how big it is. Will the dam collapse when/if the sinkhole caves in?

Also of note, this is in the vicinity of a large earthquake a few years ago:

The Tennessee Valley Authority said today it is inspecting 15 of its dams and ash impoundments and all of its nuclear plants after an earthquake hit near Richmond, Va., on Tuesday.

TVA inspects dams, nuclear plants after earthquake

Think 'll message TA and see if he can dedicate a little attention to seismos in this area.

originally posted by: VoidHawk
So who's idea was it to put three nuclear sites down stream from a giant dam?

Doesn't that seem rather stupid?

The same dudes who build them on known and active fault lines. All brains and not a micro-gram of common sense between them.

How do these people get these jobs?

Just wanted to add that there are 7 nuclear plants downstream:

Sinkhole develops under dam in US — 7 nuclear reactors downstream — Water now seeping out — Gov’t notified of ‘stability issues’, plants begin evaluating potential flood impacts — Official: An ‘uncommon’ occurrence, we’re monitoring it continuously and working around clock — Structure same height as Niagra Falls

Energy News

Looking at where that earthquake is located, there is one large lake and two smaller ones. I hope they aren't connected underground:

goo.gl...

originally posted by: TNMockingbird
Just wanted to add that there are 7 nuclear plants downstream:

Sinkhole develops under dam in US — 7 nuclear reactors downstream — Water now seeping out — Gov’t notified of ‘stability issues’, plants begin evaluating potential flood impacts — Official: An ‘uncommon’ occurrence, we’re monitoring it continuously and working around clock — Structure same height as Niagra Falls

Energy News

It's 7 reactors at 3 plants.

3 reactors ar Browns Ferry, and 2 reactors each at Sequoya and Watts Bar as indicated in the following graphic:

A sinkhole discovered last week, and water and sediment seepage discovered this week, has prompted TVA to draw down Boone Lake to its winter pool quicker than normal.

The sinkhole located below the dam, and behind the administration building, has been filled in and repaired.

TVA to drop Boone Lake levels sooner than normal

I don't think you can just dump sand in it and call it good.



Especially when you consider where this one is:

a reply to: jadedANDcynical

Mes Excuses!

I am sharing the internet and get excited when "times up"! I will be more careful from now on, Concerning for those of us downstream.

They say they have fixed it and that is promising however, with this being an uncommon occurrence, it may take more fixing so to speak...

local news

I really hope that they know what they are doing and can fix this properly the first time it sounds like it could have catastrophic consequences if they didn't fix it right!

So many sinkholes this year! They need too back off on fracking and mining our earth for awhile- ha wishfull thinking!

a reply to: TNMockingbird

Exactly what i was thinking!! Its not like they would have alot of expereince in fixing sinkholes under dams so its all just trial & error really i just hope that they managed to thoroughly investigate it and took the right course of action. Otherwise im sure we will be hearing about it!

originally posted by: VoidHawk
So who's idea was it to put three nuclear sites down stream from a giant dam?

Doesn't that seem rather stupid?

Hey, the government in South Africa put the largest ammunition depot (with 22 tactical nuclear weapons as well on site) in an area with 13 lightening strikes per square kilometer per month. Go figure eh? The people that make decisions in goobermints all over the world really are that negligent and/or nepotistic and/or corrupt and/or just good old fashioned stupid.

Cheers - Dave

I lived in that area years ago. The geology is made up of lots of sandstone and limestone. That's the perfect strata for sinkholes to form.

In this map you can see the basic geological makeup of all of the State of Tennessee.

There's also an intra-plate fault in that area. Go to page 157 in this pdf, for a map of the faults in the state.

Boone Dam is a concrete gravity-type dam 160 feet (49 m) high and 1,532 feet (467 m) long, and has a generating capacity of 81,000 kilowatts. While the main section of the dam is a concrete structure, the northern half of the dam consists of a 750-foot (230 m) earth-and-fill structure that seals off the floodplain adjacent to the main river channel

Wikipedia - Boone Dam.

So, part of the dam is also earth-and-fill rather than all concrete.

So, given what we know about sinkholes and earth-and-fill dams, we should increase our doom porn rating...


Dex

a reply to: DexterRiley

Dagnabit, I was actually juat sitting here thinking that it looked like a small culvert-casued sinkhoke or somesuch and then read your lovely post.

Has it been determined if the sinkhoke is near the earth and fill portion?

Bothersome enough that it's at the base of the thing to begin with...

I would think that once a sinkhole starts to create itself, then there is really no chance to plug it. To me this means that the underlying layers of rock are compromised, and unless there are some serious actions taken to not just plug the sinkhole but the surrounding rock and beyond will need to be reinforced. And I would think that also Any serious repairs would require the nuclear plants to be shut down, as the level of water would have to be lowered beyond the level of keeping the nuclear plants cool enough. This is a disaster waiting to happen.

a reply to: VoidHawk

It's perfectly logical to locate those three nuclear power sites downstream from a huge dam. Those sites need huge amounts of water for cooling and so it's more practical to locate them downstream where the pumping costs will be lower, than upstream. It's dollars. Got to keep costs down so the nuclear power plants don't become a bottomless money pit, sucking away more dollars for the electricity they produce than they can ever realistically earn.

Well okay, nuclear plants never really make a profit because their set-up costs and the billions more they have to spend even after shutting them down are so huge, but all the same, they need to try and look like they're keeping costs down.

I mean, there is absolutely nothing to be concerned about here! Everything is completely under control. As long as the water supply from the huge dam is stable there is no risk to the nuclear power stations at all. I mean, it's not like they're going to get suddenly inundated by a massive wall of water like happened with Fukushima. And Fuku's was a tsunami. This is just three nuclear power plants downstream from an enormous dam that can hold back more than 24,000,000,000 US gallons of water.*** So, they could only get flooded if something went seriously wrong with that huge dam, like it collapsed or sprung a major leak because its foundations were undermined by -- ummm -- by a sinkhole or something like that.

Oh, wait...

But hey, it's not like they'd just stand around and let a dam collapse! The main thing they're worried about is that those nuclear power stations get adequate water to meet their cooling requirements. And that's pretty well guaranteed. The only thing that might affect their essential supplies of cooling water would be if they had to drastically lower the water level in the dam.

Oh, wait...



*** According to the wiki article about Boone Dam HERE, its flood storage capacity is 93,534,000 m3, which is 24,709,068,524 US gal.

Oh GREAT news...

NRC Engineers Charge Gov’t Coverup — Reactor melt down an “absolute certainty” if dam fails — 100s of times more likely than tsunami that hit Fukushima[/ex]

enenews.com...