First time in the TORUS..share your experience (keep it clean ;)

[Xenon_Free]

Mike, your last post was in violation of rule #7, "In truth he was lazy" and you proceeded to use his name.  His inability to get the job done may have just been due to poor work direction from you... it's at least as likely as someone just being "lazy".

XF

[Fermi2]

I never give poor work direction. I never used the guys name. The name I used was the big guy who had been to that same exact spot. If I did post the guys real name my guess is virtually every Fermi person on this board would post, Yep he's lazy.

Mike

[Xenon_Free]

Never used his name - really?  Here is a quote from the post:

"I'm not certain if you remember Don P.?"

I'll bet Don P. and all his coworkers know who that is.  I stand by my statement that your post was in violation of rule #7.

XF

[rlbinc]

Torus dregs can be some hot stuff. Consider a plant with some fuel defects and the Iodine and radionasties that go with it.
Pop an SRV, steam flow transports the radionasties into the Torus along with a load of tailpipe rust, necessitating cleaning.
Noble Gases stay in the airspace and decay into particulates. Nice rounded shape allows for settling, suction strainers allow a place for chunks to call home. Drain that donut for cleaning, the shielding goes down the drain, and voila - nastified Torus.

If it is or ever has been connected to an RCS - it can be nasty.

Play nice, chirrun.

[Fermi2]

And Don P was mentioned in a good light Nice try He also happens to be a good friend. Please reread the post.

Mike

[Fermi2]

Torus dregs can be some hot stuff. Consider a plant with some fuel defects and the Iodine and radionasties that go with it.
Pop an SRV, steam flow transports the radionasties into the Torus along with a load of tailpipe rust, necessitating cleaning.
Noble Gases stay in the airspace and decay into particulates. Nice rounded shape allows for settling, suction strainers allow a place for chunks to call home. Drain that donut for cleaning, the shielding goes down the drain, and voila - nastified Torus.

If it is or ever has been connected to an RCS - it can be nasty.

Play nice, chirrun.

Also, one start up of Torus Cooling after you've been on Shutdown Cooling for 70 days really helps transport those particles to the Torus!

[wlrun3@aol.com]

   ..."Noble Gases stay in the airspace and decay into particulates."...

   ...rlbinc...in your experience, what were those noble gases and their particlulate daughters...

   ...thankyou for your very helpful previous replies in past years...



 

[Fermi2]

I have yet to here of Noble Gas to Particulate being a major part of the source term for a Torus. If this were the case you'd see it along the steam lines too and so far as I know at least Fermi didn't have that problem. Now so far as the Torus one of the WORST systems in the plant takes suction from and at times discharges to the Torus. That being RHR. When we warmed up the RHR Piping at Fermi we lined it up to the reactor then dumped reactor water via the E1150F026 Valve which was orificed to 500 GPM. Between that and Torus Cooling after outages most of the dose had to come from there. Lifting SRVs probably spread it but the thing about an SRV, it was so far below Torus water level that the water in the Torus was a VERY effective Scrub, something like 99% effective, at least by the EOP Basis. It's why in BWR EOPs you vent via the Torus vice the Drywell.

Mike

[rlbinc]

Main Steam is full of Noble Gas.
Notably Krypton (mass around 88) and Xe (mass around 135).
Fundy review time. Both of those numbers are at the 'nips' of the Fission Yield Curve.
Your Off Gas System is designed to delay, via adsorption, these evil Noble Gases and reprobate kinfolk.
SRVs blow untreated Main Steam into T quenchers.
Some SRVs continue to leak a little - and for a long time - after a lift and reseat.
And those Noble Gases don't condense. They just hang out with the N2.
Given time, they decay. You'll find Sr instead of Kr and Cs instead of Xe. Both be particulate.
You Fermi-nites have popped your RPV Head during a refuel and lost your Reactor Building due to
these same types of nasties. (I know this because I read all your dirty little secrets in CAP)

BTW - your RHR flushes really suck if you get lots of RCS activity in your Torus after SDC. Nothing personal.
I'm just sayin'.

One of these days I'm going to be teaching again.

 

[vagabond]

Main Steam is full of Noble Gas.
Notably Krypton (mass around 88) and Xe (mass around 135).
Fundy review time. Both of those numbers are at the 'nips' of the Fission Yield Curve.
Your Off Gas System is designed to delay, via adsorption, these evil Noble Gases and reprobate kinfolk.
SRVs blow untreated Main Steam into T quenchers.
Some SRVs continue to leak a little - and for a long time - after a lift and reseat.
And those Noble Gases don't condense. They just hang out with the N2.
Given time, they decay. You'll find Sr instead of Kr and Cs instead of Xe. Both be particulate.
You Fermi-nites have popped your RPV Head during a refuel and lost your Reactor Building due to
these same types of nasties. (I know this because i write your NRC exams and read all your dirty little secrets in CAP)

BTW - your RHR flushes really suck if you get lots of RCS activity in your Torus after SDC. Nothing personal.
I'm just sayin'.

One of these days I'm going to be teaching again.

 

I don't know anything, but wouldn't you also get Rb from Kr?  Isn't Xe-138 another Noble Gas of concern?

[rlbinc]

That must be the ticket. I know the Noble Gases are not stable.
That's why we normally delay their release by adsorption.

[Fermi2]

Uh of course you're gonna get lots of nasties if you flush a Recirc Loop straight into the torus.
I'm fully aware of what migrates down a steam line but it's NOt that huge in the Torus. Fermi lifted SRVs for a total of 45 seconds every 18 months, hardly enough to transport anything, especially from 6 % power.
The losing of the refueling floor was due to a procedural violation from what I heard.

[rlbinc]

Congratulations on your clean Torus. You won't find many.

[wlrun3@aol.com]

Main Steam is full of Noble Gas.
Notably Krypton (mass around 88) and Xe (mass around 135).
Fundy review time. Both of those numbers are at the 'nips' of the Fission Yield Curve.
Your Off Gas System is designed to delay, via adsorption, these evil Noble Gases and reprobate kinfolk.
SRVs blow untreated Main Steam into T quenchers.
Some SRVs continue to leak a little - and for a long time - after a lift and reseat.
And those Noble Gases don't condense. They just hang out with the N2.
Given time, they decay. You'll find Sr instead of Kr and Cs instead of Xe. Both be particulate.
You Fermi-nites have popped your RPV Head during a refuel and lost your Reactor Building due to
these same types of nasties. (I know this because I read all your dirty little secrets in CAP)

BTW - your RHR flushes really suck if you get lots of RCS activity in your Torus after SDC. Nothing personal.
I'm just sayin'.

One of these days I'm going to be teaching again.

 

   ...in the context of this thread, if it's any other element than krypton or xenon it's a particulate...am i right?...

   ...what is a "T quencher"?...

   ...recently noticed that there were 13 SRV's on the 4 main steam lines at the BWR model 5 LaSalle...

   ...do the number of SRV's differ with the 5 BWR models...

   ...if so, how many SRV's does each of the 5 models have...

[Xenon_Free]

Mike, I re-read your post (for the third time) and NOW I understand the story - I thought you were calling Don lazy and clearly you were not.  I stand corrected.

/Reaches for another piece of humble pie

[Fermi2]

Xenon, it's ok. I figured after your second post you must have misunderstood something so I referred you back to the post. Don P is one of my favorite nuke types ever and one of the last I'd ever say anything bad about.

rblinc, Fermi didn't have a clean Torus but no BWR has a dirty Torus simply due to SRVs it doesn't make sense as they rarely lift and when they do so it's under decay heat conditions . OR when Fission Product production is very low. Fermi didn't even have to place OffGas in service until 5% power so that should tell you how bad Noble Gasses were. Given we tested our SRVs around that power... Noble Gas has very little to do with it, when you test SRVs you do it with a clean core.

wlrun,

It depends on the BWR. Fermi had 15 SRVs and they didn't all open at the same time. each passed about 6.8% steam flow or so. Similarly sized BWRs might have less SRVs, it just depends on what style the utility elected to use. A T Quencher is at the end of the SRV Pipe. It's a horizontal pipe attached to the SRV Pipe (Thus looking like a T). There are a bunch of holes drilled into the pipe to distribute the discharge of the SRV Evenly. In this way you don't damage the Torus and you get more distributed heating of the suppression pool. IIRC the Tail Pipes at Fermi were at least 3.33 Feet below the lowest allowed TS Limit for Suppresion pool level (14 feet 4 Inches IIRC)

Mike