TVA, Kingston Plant Root Cause Analysis

[Guest]

Interesting reading ...

http://www.tva.gov/kingston/rca/index.htm

JR

 

[Fluvial]

Creepy.

 

[wilheldp_PE]

Can you sum it up in 13 words or less?

 

[Fluvial]

TVA's containment levee did the Electric Slide.

Or,

A slippery footing can bust yo ash.

 

[Guest]

Block failure exacerbated by translational base failure.



JR

 

[Fluvial]

No kudos for my joke?

 

[wilheldp_PE]

Was your joke the formatting in the form of a Rocky & Bullwinkle episode? If so, kudos.

Your summaries aren't helping. Which is what I suspected...so I didn't bother to read even one section of the original report.

 

[Guest]

No kudos for my joke?

Total kudos for the creep reference!!

Your summaries aren't helping. Which is what I suspected...so I didn't bother to read even one section of the original report.

You said 13 words or less ...

However, if you want a GOOD digestion of the material, check out the ppt prepared by AECOM for the press release/presentation. That gives you the nuts and bolts of the analysis without getting lost in the jungle of the report.

JR

 

[Fluvial]

Total kudos for the creep reference!!

I thought you'd like that one.

Your summaries aren't helping.

What I gathered from it was this (JR please correct me if I'm wrong):

In the 1950's, a containment dike was built for storing the wet ash. This dike was founded on alluvial soil.

In the 70's, it was decided to increase the containment walls vertically so that more ash could be stored. The new containment dike system was built inside the original dike. This new system was founded on previously deposited ash.

Dikes were built on top of dikes, kind of a wedding-cake effect.

Underneath a portion of the new dikes was a layer of 'slimes'. This is very very fine ash particles which are wet. These slimes can creep over time.

The beginning of the failure was when a portion of the new dikes slid (because of the creeping slimes). The sliding dikes piled up against the original dike, which gave way, allowing ash to spill out into the Watts Bar reservoir, as well as damaging some structures.

That about right?

 

[wilheldp_PE]

What I gathered from it was this (JR please correct me if I'm wrong):
In the 1950's, a containment dike was built for storing the wet ash. This dike was founded on alluvial soil.

In the 70's, it was decided to increase the containment walls vertically so that more ash could be stored. The new containment dike system was built inside the original dike. This new system was founded on previously deposited ash.

Dikes were built on top of dikes, kind of a wedding-cake effect.

Underneath a portion of the new dikes was a layer of 'slimes'. This is very very fine ash particles which are wet. These slimes can creep over time.

The beginning of the failure was when a portion of the new dikes slid (because of the creeping slimes). The sliding dikes piled up against the original dike, which gave way, allowing ash to spill out into the Watts Bar reservoir, as well as damaging some structures.

That about right?

I guess I should have expanded it to 100 words or less...but I honestly didn't think the extra words would help. With the exception of "alluvial soils", I pretty much understand this now.

 

[Guest]

That about right?

That's correct. I would place emphasis on the 'slime' formation at the foundation-level because it cause the failure to happen sooner rather than later. However, from an operational perspective, the slopes would eventual hit a critical failure point since the F.S. was creeping (pun intended) towards < 1.0 (e.g. unstable, failure imminent).

I guess I should have expanded it to 100 words or less...but I honestly didn't think the extra words would help. With the exception of "alluvial soils", I pretty much understand this now.

If you follow the press statement; they indicate:

• Unusually weak silt/ash slime foundation
• Hydraulically placed loose wet ash
• increased loads due to higher fill
• fill geometry & setbacks

Does that tell you much?

With respect to the alluvial soil, alluvium is just the method by which the sand/silt/clay are deposited; in this case by riverine/shoreline mechanisms. It is pertinent to note because alluvium typically consists of 'weak' silts - it is not a preferred material upon which to found structures like an earthen embankment.

JR

 

[Fluvial]

Interesting news article - others are contesting AECOM's findings:

http://www.knoxnews.com/news/2009/jul/12/d...pill-continues/

 

[chaosiscash]

^^ I'm not saying Thacker is wrong, after all, his solution is a lot simpler. But it seems around here that the guy is playing up the "Them LA boys don't know nothing about East Tennessee" angle pretty heavy, and might just be trying to drum up some more business for his local company. Like I said, I'm not saying the guy is wrong, but there may be more to it than him just being a "concerned citizen".

 

[Guest]

Interesting news article - others are contesting AECOM's findings:
http://www.knoxnews.com/news/2009/jul/12/d...pill-continues/

I was just handed this very article today.

^^ I'm not saying Thacker is wrong, after all, his solution is a lot simpler.

The problem with Thacker is that he is deriding the slime layer theory and overstating AECOM's presentation of the layer.

I have read the entire AECOM analysis and reviewed the information. It is pretty solid IMHO.

I will read through Thacker's work before commenting on it; I only have the summary pieces thus far.

But it seems around here that the guy is playing up the "Them LA boys don't know nothing about East Tennessee" angle pretty heavy, and might just be trying to drum up some more business for his local company. Like I said, I'm not saying the guy is wrong, but there may be more to it than him just being a "concerned citizen".

I see where it has taken some down-home spun rhetoric. I will reserve comment until I have had a chance to read over Thacker's rebuttal.

JR

 

[Fluvial]

Has Thacker been privy to all the information that AECOM reviewed? Seems unlikely to me.

 

[Guest]

Taken from Thacker's White Paper, page 4

Presented in the following section are the results, which are admittedly based on a limited amount ofdata. In particular, I have little information as to how the Kingston facility was built and

monitored during construction. Also, I have incomplete data on the sequence of the

failure(s) to assess if the results of my modeling match actual events.

Engineering properties used in the analysis for the sluiced ash, compacted ash

outslopes, and compacted earthen fill dikes are based on information provided on TVA’s

web site and my experience at other facilities. Due to my limited information, I did not

include the foundation soil in the modeling.

I think that speaks volumes ... when you are openly dismissive and pejorative towards a noted expert.

JR

 

[Fluvial]

Agreed. Arriving at a conclusion despite no data is speculative at best. I would never put my name on something like that.

 

[Capt Worley PE]

Me neither. I would think it would diminsh his rep in professional circles.

However, if he wants to be a professional witness, I think it sends a clear message to attourneys that he's willing to dismiss things and not delve to deep to acheive what ever 'professional jusgement' they desire.

 

[chaosiscash]

However, if he wants to be a professional witness, I think it sends a clear message to attourneys that he's willing to dismiss things and not delve to deep to acheive what ever 'professional jusgement' they desire.

Good point. And there are an awful lot of lawsuits out there from people whose land was crapped up.