Bad Decisions 1

[JedClampett]

This one caught my eye because not only is it a structural issue, but my old employer is involved. I can picture heads rolling right now, if they haven't already.

 

[csd72]

Wow, a fairly small job with huge consequences. Always the type of job that you want to avoid as a consultant.

 

[Xera]

I worked for a guy with the same thought process. "If they can do it, we can do it cheaper." "I have seen it done before."

 

[bridgebuster]

"A man has got to know his limitations." - Harry Callahan

 

[JedClampett]

csd72, not to quibble, but replacing a steam generator at a nuclear power plant is a huge job, running into the hundreds of millions of dollars. And this doesn't even count the replacement power cost. I don't think the article ever mentions this. But the amount of savings in the self management of the project ($15,000,000) was relatively small.
I worked in the nuclear industry for about 15 years, and for the life of me, I can't figure out why they didn't make the hatches in the containments big enough to get the steam generator (a piece of equipment prone to wear and tear) out. I guess they thought they would last the lifetime of the plant.

 

[SteelPE]

I guess this is a great example of why people shouldn't practice outside of their knowledge/discipline.

What could possibly go wrong!

 

[racookpe1978]

Of the several steam generator replacement jobs I've been part of the planning process, each had enough room for the SG to be removed and re-inserted.

But that would be for the original sized SG - A larger steam generator - even if only by only a few inches to the tip of a nozzle or the diameter of the PV - would make the new one too large to fit through the removal path.

 

[RFreund]

I'm surprised that it was Sargent Lundy. They are a fairly well known name in the Nuclear industry and I know more than a few smart people I graduated with that work there now... I should ask them about it.

JedClamptt not sure what location your were at but any chance you know a Prof. John O'Leary?

EIT

 

[JedClampett]

Doesn't sound familiar. Did he work at S & L?

 

[JStephen]

I dunno, in articles like this, it's hard to sort out BS from verity.

It's not at all clear to me that doing things the "right" way would have prevented the problem. That seems to be the assumption, but since the problem basically hadn't happened before, I would think the cause is a good bit more indefinite than supposed.

Had they hired Bechtel or others in the first place, regardless of the outcome, somebody could be writing an equally scathing article about them blowing millions of bucks when they had people on their own staff who had done this etc etc. Hindsight is wonderful.

 

[RFreund]

Jed-

Yes, It would have been some time ago and most likely the Chicago office, he now is a professor at IIT or has been for a while I should say.

JStephen-

Very true.

EIT

 

[Elite7]

Since there are other very senior nuclear engineers who have already commented, I'm a bit hesitant about adding my own 2 cents, but for the benefit of non-nuclear readers, I'd like to point out that a PCCV (prestressed concrete containment vessel) is provided with a significant amount of residual prestress (over 1 MPa) so as to remain uncracked in LOCA (loss of coolant accident) or MSLB (main steam line break). Since the steam generator replacement is carried out during shutdown, neither of these accidents is possible. As such, it makes sense to relieve the prestress sufficiently before cutting into the PCCV.

Radial shear and inter-laminar tension are also "gotchas". They're very easy to overlook, but are significant in any thin curved shell.