[ RadSafe ] Neutron detectors

Sat Mar 23 17:15:17 CDT 2013

The FarWest Technology's REM500 and the Thermo RadEye GN meter are available for neutron detection.

The shipping container that AmBe neutron source I use came with provides the necessary shielding for storage, as well as a lockable tab. There is a shield that is placed in front of it made out of layers of Plexiglas, aluminum and some rubbery material (I don't know what it is), that removes any need for neutron dosimetry unless I am calibrating the REM500.

Lawrence E. Smith
Senior Radiation Protection Technician
Vermont Yankee

   1. Neutron Source Safety (DOBBS, LYNN)
   2. Re: Neutron Source Safety (JPreisig at aol.com)
   3. Re: Neutron Source Safety (Thomas Johnston)
   4. Re: Neutron Source Safety (DOBBS, LYNN)

----------------------------------------------------------------------

Message: 1
Date: Fri, 22 Mar 2013 17:18:31 +0000
From: "DOBBS, LYNN" <DOBBSL at mailbox.sc.edu>
Subject: [ RadSafe ] Neutron Source Safety
To: "radsafe at health.phys.iit.edu" <radsafe at health.phys.iit.edu>
Message-ID:
	<8353A61C093E5042BB3AC6480A3A25D303B7F8DC at CAE145EMBP04.ds.sc.edu>
Content-Type: text/plain; charset="us-ascii"

A researcher at our University is currently wanting to purchase either a Cf-252 (27 uci/ 50 ngm) or an AmBe source (100 mCi) for a neutron flux of ~ 1E5.   I am in the process of developing safety procedures but honestly, I don't have a lot of expertise in neutrons.   My concerns are exposure (neutron and gamma dose), general radiation protection requirements, detection instrumentation, and the possibility of neutron activation.  Can anyone provide some SOPs they are currently using and a training course available for neutron source safety?
Thanks in advance,

Lynn B Dobbs
Radiation Safety Officer
University of South Carolina
Phone: 803-777-5268
Fax: 803-777-5275
DobbsL at mailbox.sc.edu<mailto:DobbsL at mailbox.sc.edu>

------------------------------

Message: 2
Date: Fri, 22 Mar 2013 13:46:40 -0400 (EDT)
From: JPreisig at aol.com
Subject: Re: [ RadSafe ] Neutron Source Safety
To: radsafe at health.phys.iit.edu
Message-ID: <6becf.30850419.3e7df300 at aol.com>
Content-Type: text/plain; charset="US-ASCII"

Dear Lynn B. Dobbs,

     The first thing you need to do is get a copy of  Cember's Health Physics book and read the relevant sections.  Also refer to the Radiation Health Handbook, the old  version, the Schlein version or whatever is relevant now.  See also Accelerator Health Physics by Patterson and Thomas, Kaplan's Nuclear Physics, Segre's Nuclear Physics book etc.  I  think
NCRP-51 will also help, and the updated version of NCRP-51.

     This isn't a big neutron source.  If you have  other neutron sources at the University, you may see they are kept in a bucket  of solid parafin, with a hole drilled down the middle.  You put the neutron  source in the hole in the middle and then there should be a parafin  (cylindrical) cap you put over the source in the hole.  You can then store  the neutron source with your other radiation sources, which are hopefully locked  away somewhere.  If you don't have one of these parafin buckets around,  someone in your 
machine shop should be able to make one fairly easily.   Don't know if they are 
available for sale somewhere.

     Neutron activation should not be a problem.   If you don't already 
have one, then the university needs to buy you some sort of  neutron detector, an Anderson-Braun detector (a Snoopy???), a remball or  whatever you can 
afford.  Ludlum makes some neutron detectors.   Google   neutron and detector  
on the internet.
The lab/persons using the neutron detector will need a neutron personnel dosimeter --- see Mirion's website, or Landauer or whoever.  The lab doing the neutron work might need a neutron detector also.
See Knoll's book on instrumentation to learn about detectors.  That  should pretty much cover it, pretty much.

     What are they doing with that neutron  source???

Joe Preisig

In a message dated 3/22/2013 1:22:15 P.M. Eastern Daylight Time, DOBBSL at mailbox.sc.edu writes:

A  researcher at our University is currently wanting to purchase either a
Cf-252  (27 uci/ 50 ngm) or an AmBe source (100 mCi) for a neutron flux of ~  
1E5.   I am in the process of developing safety procedures but  honestly, I 
don't have a lot of expertise in neutrons.   My concerns  are exposure 
(neutron and gamma dose), general radiation protection  requirements, detection instrumentation, and the possibility of neutron  activation.  Can anyone provide some SOPs they are currently using and a  training course available for neutron source safety?

Thanks in  advance,

Lynn B Dobbs
Radiation Safety Officer
University of  South Carolina
Phone: 803-777-5268
Fax:  803-777-5275
DobbsL at mailbox.sc.edu<mailto:DobbsL at mailbox.sc.edu>

_______________________________________________
You  are currently subscribed to the RadSafe mailing list

Before posting a  message to RadSafe be sure to have read and understood the RadSafe rules.  These can be found at: 
http://health.phys.iit.edu/radsaferules.html

For  information on how to subscribe or unsubscribe and other settings
visit:  http://health.phys.iit.edu

------------------------------

Message: 3
Date: Fri, 22 Mar 2013 13:54:12 -0400
From: Thomas Johnston <tjohnstn at gmail.com>
Subject: Re: [ RadSafe ] Neutron Source Safety
To: "The International Radiation Protection (Health Physics) Mailing
	List"	<radsafe at health.phys.iit.edu>
Message-ID:
	<CAEApWp2QafDUUQkPY-_y3QUFWdB2KEBAmjGSSW+PPvT3cjBjOA at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Hello,
May I extend an unofficial invitation to visit our facility.  This is what
we do.  Please submit a proposal and if accepted and approved you will
receive this training that you are looking to obtain, for free.

Please visit our site here at NIST and learn about the varoius programs and
opportunities available.

NIST Center for Neutron Research
http://www.ncnr.nist.gov/   On the left side of the page look for the 'User
Information' section. This should prove useful if you plan to visit.

Neutron Source Strength Calibrations
http://www.nist.gov/pml/div682/grp03/neutron-source-calibrations.cfm

Our facility offers a free Summer school and other programs for student at
all levels, high school and above, and even teacher courses for Middle
School and above.

Best regards and I am glad you asked,

Thomas

Thomas Johnston

Health Physicist

NIST Center for Neutron Research

National Institute of Standards and Technology

100 Bureau Drive, Stop 1733

Gaithersburg, MD 20899

301-975-5815

Radiation Safety: http://safety.nist.gov/radiation_safety/

*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
**This message has not been reviewed or endorsed by my employer.*

On Fri, Mar 22, 2013 at 1:18 PM, DOBBS, LYNN <DOBBSL at mailbox.sc.edu> wrote:

> A researcher at our University is currently wanting to purchase either a
> Cf-252 (27 uci/ 50 ngm) or an AmBe source (100 mCi) for a neutron flux of ~
> 1E5.   I am in the process of developing safety procedures but honestly, I
> don't have a lot of expertise in neutrons.   My concerns are exposure
> (neutron and gamma dose), general radiation protection requirements,
> detection instrumentation, and the possibility of neutron activation.  Can
> anyone provide some SOPs they are currently using and a training course
> available for neutron source safety?
> Thanks in advance,
>
> Lynn B Dobbs
> Radiation Safety Officer
> University of South Carolina
> Phone: 803-777-5268
> Fax: 803-777-5275
> DobbsL at mailbox.sc.edu<mailto:DobbsL at mailbox.sc.edu>
>
> _______________________________________________
> You are currently subscribed to the RadSafe mailing list
>
> Before posting a message to RadSafe be sure to have read and understood
> the RadSafe rules. These can be found at:
> http://health.phys.iit.edu/radsaferules.html
>
> For information on how to subscribe or unsubscribe and other settings
> visit: http://health.phys.iit.edu
>

------------------------------

Message: 4
Date: Fri, 22 Mar 2013 19:00:54 +0000
From: "DOBBS, LYNN" <DOBBSL at mailbox.sc.edu>
Subject: Re: [ RadSafe ] Neutron Source Safety
To: "radsafe at health.phys.iit.edu" <radsafe at health.phys.iit.edu>
Message-ID:
	<8353A61C093E5042BB3AC6480A3A25D303B7F9DA at CAE145EMBP04.ds.sc.edu>
Content-Type: text/plain; charset="us-ascii"

Joe:
Thank you so much for the information on the neutron sources.   I was hoping these sources would be "small" enough not to warrant too much regulatory headache since we will add it to our license.

The researcher is developing neutron detectors so he will need these sources when the unit is ready to be tested.  His set-up included an aluminum box around the source and detector so that was my concern for neutron activation of the aluminum.  We will have the source in a secure locked cabinet when not in use, and I am waiting to see what type container it will be shipped in- they may provide the necessary shielding when it is stored.  The only other source we had was a Cf-252 from many years ago and it was shielded with a huge paraffin container.  I think we could get a shield made easily if needed.
We do have an old "rem ball" that we will attempt to get calibrated.  If not, we will look to purchase one.

Again- Thank you for your response.
Have a great weekend.

Lynn B Dobbs
Radiation Safety Officer
University of South Carolina
306 Benson School
Columbia  SC   29208
Phone: 803-777-5268
Fax: 803-777-5275
DobbsL at mailbox.sc.edu<mailto:DobbsL at mailbox.sc.edu>

------------------------------

_______________________________________________
RadSafe mailing list
RadSafe at health.phys.iit.edu
http://health.phys.iit.edu/cgi-bin/mailman/listinfo/radsafe

End of RadSafe Digest, Vol 1245, Issue 1
****************************************