Date: Thu, 24 Oct 2002 16:39:08 -0500
From: Terry Tope <tope@fnal.gov>
Subject: E907 & Freon 13B1
To: Martha Heflin <martha@fnal.gov>, dykhuis@fnal.gov,
Rajendran Raja <raja@fnal.gov>, David_Northacker <dnorth@fnal.gov>,
Winslow Baker <winbaker@fnal.gov>,
"Peter D. Barnes" <pdbarnes@llnl.gov>, pkesich@fnal.gov
X-Priority: 3
Hi everyone. I propose we meet at 1:30 PM on Monday the 28th in the
WH11 SW conference room to discuss the Lab's policy on the usage of
Freon 13B1.
There are really two issues:
(1) Can we use the exemption banning Freon use based upon either " a
procedure" or "a test standard"?
(2) If we can use the exemption, we will have to choose between
recycling and incineration. Recycling appears to be the policy
preferred option. However, most users would be recycling pure freon,
not a mixture of 4 gases which complicates recycling. This
incineration of the mixture may be the way to use Freon. Venting does
not appear to be an option, even in small amounts.
If this time does not work for everyone, let me know what will.
Thanks,
Terry Tope
Fermi National Accelerator Laboratory
630.840.2666
Date: Tue, 29 Oct 2002 16:05:26 -0600
From: Terry Tope <tope@fnal.gov>
Subject: Freon use for E907
To: Leon Beverly <beverly@fnal.gov>, David_Northacker <dnorth@fnal.gov>,
Rajendran Raja <raja@fnal.gov>, "Peter D. Barnes" <pdbarnes@llnl.gov>
X-Priority: 3
This email summarizes the meeting that took place today concerning the
usage of Freon 13B1. Teri Dykhuis is the Fermilab ES&H employee who
is the lab's expert on EPA regulations and has 15 years of experience
dealing with the EPA. After reviewing the EPA regulations concerning
Freon 13B1 she does not see any legal way to knowingly vent Freon
13B1. The Freon 13B1 would have to be recovered if used. After
recovery it would have to be recycled or properly destroyed.
It appears that E781 vented Freon 13B1 to the atmosphere. However,
the law banning venting did not go into effect until 1998, so this
experiment predated the ban. The production ban also went into effect
in 1998.
Freon 13B1 is also known as Halon 1301 and is used in fire suppression
systems. There are numerous rules and regulations now covering these
systems to prevent inadvertent releases of the gas. However, if a
fire does occur these fire suppression systems will vent significant
amounts of the gas into the environment. Thus the argument reasonably
arises that E907 should be allowed to vent the very small amount of
Freon 13B1 required as its insignificant. However, Teri points out
that her experience with the EPA has shown that the EPA will not agree
to this obvious reasoning. It comes down to the fact that the
regulations do not allow intentional venting.
The question arose can the EPA be petitioned for a special exemption?
Teri said that would be a last resort. Most likely they will
interpret the rules just as she has and deny the request. Secondly,
asking the EPA if Freon can purposely vented might draw attention to
the lab and even create an audit.
Raja and Northacker will talk with Ken Nelson and other chamber
experts to see if a Freon substitute can be found. Due to the lower
rate of E907 it may even be possible that the quenching
characteristics of the Freon will not be needed.
Probably the simplest way to avoid venting Freon would be to compress
the entire used gas mixture into some sort of vessel and then ship it
to somewhere to be destroyed. I will enquire about the practicality
of this.
The most complicated way to recover Freon would be a distillation
system where the Freon is separated out from the Isobutane and Argon
with liquefication. This is likely far beyond the budget of the
experiment.
Sorry to bring bad news.
Terry Tope
Fermi National Accelerator Laboratory
630.840.2666
From: "Ken Nelson" <kennelso@uvahea.phys.Virginia.EDU>
To: "Rajendran Raja" <raja@fnal.gov>
Sent: Tuesday, October 29, 2002 5:36 PM
Subject: Re: Fw: Freon use for E907
Raja,
Please pass this message onto Dave et al,,
I do not have any experience with an electronegative "quencher" other
than Freon13-B1. I recall there was an R&D effort in Japan to
identify other freons to serve this purpose in the context of
Resistive Plate Chambers (RPC's). This work was done ~ 5yrs ago.
Is it defintely known that the Iowa chambers will not work with
Ar-Ethane 50/50 ? Certainly the operating voltage would be lower than
with magic gas. One problem with argon ethane is that charge from the
entire track length will be collected on the wire (with freon 13-B1
one tunes the mixture to collect the ionization from only a couple of
mm). Using Ar-ethane then would lead to more late pulses and charge
load, which might give problems at high rates.
Ken
Date: Tue, 29 Oct 2002 17:48:02 -0600
From: Rajendran Raja <raja@fnal.gov>
Subject: Fw: Fw: Freon use for E907
To: Terry Tope <tope@fnal.gov>, Dave Northacker <dnorth@fnal.gov>,
Peter Barnes <pdbarnes@llnl.gov>, Leon Beverly <beverly@fnal.gov>,
Rajendran Raja <raja@fnal.gov>,
Ken Nelson <kennelso@uvahea.phys.Virginia.EDU>
X-Priority: 3
Here are comments from Ken Nelson [previous message]. I note that we have a low rate
experiment. Also, would Magic Gas (with Methylal" a al E690 chambers
work ?
Raja
Date: Wed, 30 Oct 2002 09:02:44 -0600
From: Terry Tope <tope@fnal.gov>
Subject: Re: Fw: Freon use for E907
To: Rajendran Raja <raja@fnal.gov>, Dave Northacker <dnorth@fnal.gov>,
Peter Barnes <pdbarnes@llnl.gov>, Leon Beverly <beverly@fnal.gov>,
Ken Nelson <kennelso@uvahea.phys.Virginia.EDU>
X-Priority: 3
I did a quick web search out of curiosity....
I think this is what Ken Nelson is talking about...Japanese efforts to
replace 13B1
http://www.awa.tohoku.ac.jp/belle/ieee96.ps.gz
These two links talk about using R134a in RPC chambers
http://zebu.uoregon.edu/~uochep/talks/talks02/strom.pdf
http://www.hep.princeton.edu/~marlow/talks/rice/rice.pdf
while this link talks about using R134a tetrafluoroethane (C2H2F4)
http://atlas.web.cern.ch/Atlas/GROUPS/MUON/TDR/pdf_final/RPC.pdf
and this link talks about MINOS replacing R13B1 with SF6 and R134a in a
Argon/Isobutane mixture
http://www-numi.fnal.gov/numinotes/public/ps/numi0240/numi0240.ps.gz
PDB, 11/5/02