All,
I am trying to gather up some OPEX on what other facilities are using for rigging when lifting items into and out of spent fuel pools. Currently my facility uses chain rigging for lifting of large items into and out of the fuel bay. Unfortunately these chains are quite heavy and have caused some ergonomic concerns to be raised by the staff that use them. What I am looking for is a sling of some type that meets the following requirements:
1) must have a lift capacity rating of at least 20 metric tons
2) be of a material that is capable of being decontaminated, or at least provides for minimizing the amount of contmination that can become "fixed" to in the material weave etc.
3) be fairly easy to handle by two people
That about does it. The rigging will be used in a "3-leg" (primary D-ring with 3 "legs" of the sling material that attach to the lid) configuration to lower the lid for a dry fuel storage cask onto the cask while underwater only. Hope someone out there has some help.
Cheers,
Jim
You could go to wire rope slings, but they tend to be difficult to decontaminate since the contamination permeates into unreachable areas within the strands.
Synthetic slings are much lighter, but again it is a practical impossibility to decon them.
You could solve your weight problem by shortening the chains.
What is the diameter of the lid?
What is the diameter of the chain you are using?
How long are the chains?
What grade alloy are the chains?
I have many years of refueling experience but most of it as the refueling SRO. The only lifting devices that I have seen used underwater were either stainless steel wire rope slings or a lifting device engineered for the specific use that only had rigid metal supports with lifting lugs that did not get submerged. I hope this limited experience will be helpful.
We used kevlar to land the cask lids on an ISFSI project. They suck up the contamination, so you have to have clean enough water in your pool to keep them from becoming a dose issue. If you have that clean of water, you can control the loose contamination problem by keeping them stored under water in 55 gallon drums...then when you pull them out, they are wet enough that the contamination stays in place while you are moving to the pool, or whatever you are hooking up to. You need a deconner with a mop to clean up the drips, but we never had an issue with any real contamination spread.
Quote from: mutant on Feb 18, 2010, 10:08
How do the riggers perform the pre-use inspection of the slings? Have you contacted the manufacturer and asked what long term exposure to the SFP environment does to the integrity of the Kevlar?
The contamination was fixed enough that it was easy for the riggers to get up close & personal with the slings as they came out of the 55 gallon drum...as long as the slings were pulled at a slight angle by the crane, so the drips all fell on one side and the riggers stayed out from under the dripping portion.
The biggest problem was that we were at a PWR and the borated water pulled milky-looking residue out of the slings. I don't know if a pool with un-borated water would have this problem. I don't remember off the top of my head what they decided the chemical make-up of the residue was (talc?), but it didn't keep them from using the slings. I will try to track down some of the old group & see if anyone remembers how we decided there wasn't an issue with putting them in the pool like that.
I do remember that there were concerns about the life of the slings in borated water & someone (the manufacturer? our engineers?) blessed them off. I will try to get more details on that aspect, also.
Pretty much anything that goes in will stay contaminated. But contamination levels can be minimised so as not to prohibit reuse. Steal cable is what I have seen most and have used high pressure water to keep levels down,both as it came out of the water and after storage prior to use. Conditions in your pool will be the determining factor how much deconning is necessary. I have not seen the kevlar but it sounds good. Would be easier to keep clean. Good luck and if I come across anything I will post. MH
Quote from: Marssim on Feb 17, 2010, 01:46
check your PM's, I've done this before,...
(along with about 413 other interestingly motivated people in the lower 48, ;))
(http://www.nukeworker.com/pictures/albums/userpics/11535/normal_Shield_Lid_Install_3.jpg)
Was this at Yankee Rowe?
Quote from: UncaBuffalo on Feb 18, 2010, 06:06
The contamination was fixed enough that it was easy for the riggers to get up close & personal with the slings as they came out of the 55 gallon drum...as long as the slings were pulled at a slight angle by the crane, so the drips all fell on one side and the riggers stayed out from under the dripping portion.
The biggest problem was that we were at a PWR and the borated water pulled milky-looking residue out of the slings. I don't know if a pool with un-borated water would have this problem. I don't remember off the top of my head what they decided the chemical make-up of the residue was (talc?), but it didn't keep them from using the slings. I will try to track down some of the old group & see if anyone remembers how we decided there wasn't an issue with putting them in the pool like that.
I do remember that there were concerns about the life of the slings in borated water & someone (the manufacturer? our engineers?) blessed them off. I will try to get more details on that aspect, also.
Okay, I talked to the few ISFSI guys I still keep in touch with & they didn't remember much more than me...it's been 10 years... :(
Here's what I did get:
1. Rinse the slings each time before they go back in the pool...this will:
a. Minimize the milky residue.
b. Cause the slings to wick up as much clean water as possible, thus minimizing the amount of contamination they soak up.
2. We might have written off the chemical concern based on it being a D&D job. If you are still operating & have to consider primary water chemistry, you might not be able to use kevlar...but no one remembered for sure what the residue was...although talc was mentioned.
3. Everyone drew a blank on how we decided there wasn't a kevlar/boron life-of-sling issue.
I'll chase a couple more leads, but...sorry...
As a OSHA qualified rigger you never put slings in the water.. you use wire ropes or chains duh, you can put slings in the water, at that point they become a one time use
Quote from: Jr8black3 on Feb 21, 2010, 07:57
As a OSHA qualified rigger you never put slings in the water.. you use wire ropes or chains duh, you can put slings in the water, at that point they become a one time use
Not being a rigger myself, I can only assume that they 'engineered' their way around that prohibition.
Of course, we are also talking about an engineering staff that got their ISFSI shut down for two years when they used carbon steel casks in borated water...which turns out to be a good way to generate a lot of rust & hydrogen very quickly... :(
Quote from: Jr8black3 on Feb 21, 2010, 07:57
As a OSHA qualified rigger you never put slings in the water.. you use wire ropes or chains duh, you can put slings in the water, at that point they become a one time use
How does one become a "OSHA qualified rigger"? I've been rigging for 30+ years and never heard that term.Just wondering.
Thanks for the replies! I am working pretty closely with our Fuel Handling Ops folks to see what will work for them as well. My recommendation to them is probably going to be that the current practice is still the best for us, but that we should investigate going to a lower rated chain, our current rigging is rated for 54 Tons and we only are lifting 13 Tons. On the bright side I did convince them that the kevlar slings were probably not the best idea :)
Quote from: mutant on Feb 22, 2010, 08:05
From 1926.753(c)(2):
A qualified rigger (a rigger who is also a qualified person) shall inspect the rigging prior to each shift in accordance with § 1926.251.
From 1926.751:
Qualified person (also defined in § 1926.32) means one who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work, or the project.
That statement says "qualified rigger" where does it mention OSHA?
Quote from: Marssim on Feb 22, 2010, 05:30
In lieu of a time out flag might I suggest youze guys just take a breather from this one as this young referee urges you to;
(http://costumes.lovetoknow.com/images/Costumes/thumb/b/ba/Sexy_referee_costume.jpg/260px-Sexy_referee_costume.jpg)Sweet! You got it!
Quote from: stormgoalie on Feb 22, 2010, 07:47
On the bright side I did convince them that the kevlar slings were probably not the best idea :)
I finally found someone who remembers...the kevlar only got used until they chased us off for unrelated engineering problems...when we came back two years later, we threw away the kevlar & went with metal braided slings. Sorry for bringing up non-useful ideas! :/
http://www.nukeworker.com/forum/index.php/topic,23182.new.html#new
Quote from: UncaBuffalo on Feb 22, 2010, 06:33
I finally found someone who remembers...the kevlar only got used until they chased us off for unrelated engineering problems...when we came back two years later, we threw away the kevlar & went with metal braided slings. Sorry for bringing up non-useful ideas! :/
http://www.nukeworker.com/forum/index.php/topic,23182.new.html#new
No such thing as a "non-useful" idea! We actually talked out using kevlar and figuring out the best way to sleeve them possibly. Given the conditions in our spent fuel bay(s) we decided that the risk of a breach of the sleeve was too great and that any type of weaved kevlar sling was inappropriate. Thanks for your help!!!
Quote from: Jr8black3 on Feb 21, 2010, 07:57
As a OSHA qualified rigger you never put slings in the water.. you use wire ropes or chains duh, you can put slings in the water, at that point they become a one time use
WPPSS still uses Kevlar slings for most of their lifts (moisture seperator, cattle chute, etc.) in the pools on the refuel floor.
...and our tame engineer said that being able to use the Kevlar slings in water is one of their big advertising points...so you don't have to worry about rust, etc...
:)
YES! VINDICATION!!!