Steam Generators

[Rennhack]

Lessons Learned: Steam Generators

The purpose of this forum is to document on-the-job work experiences. Submit your best solutions for various jobs and processes. This is not to be plant specific, rumor, slander or urban legend. Postings will be reviewed, verified, edited for content, and archived for future reference. Post a summary for review if you wish to post a thesis or position paper. We are getting fewer and fewer, but before the knowledge is lost forever and plant / sites reinvent the wheel; we need to document what we have learned.

[HAIRDUDE]

Okay Folks.
This ain't helpin' me out a bunch. Throw me a friggin bone here. I'm the ALARA Planner at P.I. and I am in the process of planning my end of our upcoming SGR. I need all the info ya' can scrape together. Where did you do one? What went well? What went wrong? What was the fix? It doesn't have to be a tech document. Just tell me stuff like: "They tried this and it really helped out a lot because..." or "They insisted on doing this and it ended up coming back to bite them in their collective a$$ in the long run..." This kind of info is what I need. I understand what Mike is doing here. This kind of information archive could be exactly what improves many of the work processes in the nuke business.

I like it Mike. Keep up the good work!

Floyd Flanigan

[Carolina Jethro]

Hey Floyd, I liked the way  your former employers used management types to do nozzle dams and diaphragms. The one thing that I can remember ( haven't done generators since we did them at Harris) is the need to have spares for tools and instruments close by in case of failures in High dose jobs. Good Luck with your outage!

[DecommMan]

I am interested in obtaining a historic listing of what plant steam generators have already been changed out and then where it has been announced that this will occur in the not to distant future.

[retired nuke]

Use skilled craft everywhere you can ! At PB2, MK used laborers to install the ID shielding support tripods. They tried hard, and we thought it went well. But at StLucie, we used BM to do it. They were given the tripods, and we explained what we were trying to accomplish with them, including the weight load of the shielding. They came back with special tooling made so that nobody had to even lean into the pipe to install the tripods.

Also, do not shortcut with the pipe end decon. It may seem like a waste of dose, because the remote narow groove welding is supposed to be perfect, but the first weld that doesn't pass QA will suck to grind out if the ID is still nasty.

Make your shielding package as precise as you can. Then go back and find more places to shield. You have so many damned man-hours in the loop area that even reducing a traffic area by a few mR/hr will help over the outage.

Setup webcams in Ctmt so that the JAFOs can sit in their offices and see the pretty generators move at a snails pace, instead of crowding the Ctmt to get a look-see.

Don't get all wound up on rad controls when they cut the generators out - there will only be a 1/4" gap - and nobody will be in the area during the lift. Just make sure RP is the first one in after the genny is removed - do your setup then.

Have fun, good luck, and watch out for the backcharges .....

[HAIRDUDE]

Thanx for the heads-up Carolina Jethro and any and all info present and future from any other posters. If all of the info on this kind'a work was shared all along, the process would be more finely tuned by now. Amazing how it ends up being a bunch of rad techs who take the initiative to improve the process. It almost sounds like we care..... Did I say that out loud?

Floyd

[RadJazz]

Dido on the comment to use experienced craft.  Invaluable to a SGR.  The camera use is also very ALARA.  Everybody who thinks he/she is anybody wants to take a peek without any regard to dose. Management needs a good understanding of this and reside to abiding by and to Rad Controls.
Be ready in your yard (O/S) for the mess.  everyone concentrates on the containment end and forgets what happens outside.  Have some experienced Rad Techs there as well.  Whatever can go wrong these Techs can anticipate it, deal with it, and save your butt. 

[starry1st]

Since containment is so busy and crowded during a SGR it's important to have people (usually laborers) watch the walkways during heavy lifts.  At Calvert Cliffs, they had a near miss from something heavy being dropped and people underneath.  Thankfully no one got hurt, but after that they instituted human barriers under the heavy lifts on each level. 

[Phurst]

but after that they instituted human barriers under the heavy lifts on each level. 

UNDER? Heavy lifts? Ouch. Hope they had AFLAC.

[UncaBuffalo]

Also, do not shortcut with the pipe end decon. It may seem like a waste of dose, because the remote narow groove welding is supposed to be perfect, but the first weld that doesn't pass QA will suck to grind out if the ID is still nasty.

IF everything goes right on pipe end decon, then it's PROBABLY a good ALARA tool (I've seen the numbers come out the other way, too...just depends on the bias of the ALARA person crunching the data.)  HOWEVER, it's NOT a fool-proof system.  They say the system shut-off is instantaneous when you lose vacuum, but we proved THAT incorrect at Harris.   First indications of a problem (for HP...obviously the guy running the thing knew he had a problem, but do you think he'd tell us?) were CAM alarms from the refuel floor...and the basement...and the AUX building....  Suffice it to say I would vote AGAINST pipe end decon if they asked me!