Gamma Camera

[RT@OPG]

Does anyone have any experience to share about using gamma cameras in a nuclear plant?  What type do you have or have you used and what did you use it for?  Did it do the job for you that you thought it would do?  Any thoughts on the subject would be appreciated.

[Roll Tide]

Are you referring to a radiography source?

[Pochron]

 Roll-Tide
Demonstration at Pt. Beach circa 1998. Point and shoot, large heavy camera. Identifies radiation intensive areas by color.
Contact Innovative Industrial Solutions,
Stan Robinson.
E-mail: srobinson@i-i-s.net
Ph#: 479-968-4266 X 11

[Roll Tide]

Thanks Pochron, I had heard a sliver of info on the camera you describe a few years ago. I just couldn't see going through a major search if the question was really about radiography (I have yet to heard a radiographer refer to his depleted Uranium shielded Co-60 as anything but a "camera".)

[PWHoppe]

We had a demonstration of soemething like this at Dc Cook several years back, not sure if it's the same one. It seemed to work ok, we did looky loo's in the Rx cavity and it did ID hot spots. It also found area's of high contamination. We also used it some in the aux building to look at some lines to see if we could find the hot areas without actually doing a dose intensive survey. The rooms in question were a "rats nest" of lines where it was very hard to differentiate one source from another. Again it seemed to work fairly well. I wish I could remember more specifics but I'm old and my memory isn't what it used to be...

[jjordan]

We had Stan Robison come to Brunswick 3 or 4 years ago. The camera worked very good, was very usefull to find hot spots. There were different colors for the different intensities of radiation. I'll see if I can find some of the pictures!
JJ

[RT@OPG]

Thanks for the help so far - I did mean the camera for finding hot spots not the radiography camera.  If it works I was wondering why we don't have one cause it sounds like it would save a lot of dose and work.

[jjordan]

It's all about the money! They are probably quite costly, and it's cheaper to lease on for a few weeks and do what you need, and not have all of your money tied up just sitting around in a closet somewhere!
JJ

[RAD-GHOST]

I have worked with the camera's on several projects and they have their Pro's & Con's.  It seems like a great tool in the D&D Industry, for identifying source locations, like they say, "A picture is worth a thousand words"! 

On one commercial project, a transfer canal repair, it brought a ton of confussion!  Management decided to use the camera to assess the area prior to performing any actual work.  Even though a survey had been conducted, the old fashion way, ( probe on a rope ), the pictures were cutting edge technology and management ran with them as direction!  The actual survey numbers somehow became lost in translation and the focus became one source, one number,( 8000 Rem ), and one nicely colored picture!  After all, there was our transfer canal, with a beautiful rainbow of colors, each identifying a range of intensity and the source location, at least that's what they thought.  It seems that geometry plays a factor when using the camera.  Snap a picture from 200 feet away and the accuracy of the details decreases proportionally. 

Management, in the infamous wisdom, designed the shielding plan, solely on the bases of the pictures, one of those engineering thingy's!  In goes the shielding crew, directed to the source identified in the pictures.  After the lead was in place and a few dose rates taken, out they came.  How did the shielding effect the general area dose rates?  Very little to NONE!  The primary source, estimated at about 8,000 Rem, was thought to be the principal producer of the entire picture color band, when in fact it was produced by a collection of other high intensity sources, ( 200 to 800 Rem ), in the area.

On the side of the camera, it did in fact identify the situation, but since nobody was really familiar with the data, or how to interpret the pictures, the facts were lost.  The original picture depicted an elongated, tear drop shaped color ban from the highest source, which also happened to encompass the location of several other contributing sources.  Originally the color band was deemed to be shine from one sole source.  The elongated dimentions were explained by component shielding on one side and open air on the other.  The powers to be, thought the general area dose rates, ( 3000+ mRem/Hr ), would be resolved with a few lead blankets.  Once the initial shielded was in place, the other sources showed their actual contribution the areas dose rates.  The camera received poor reviews and was credited with about 600 mRem of extra exposure. 

Better the camera, then the Ego's!

In summation, they make a great tool when used in conjunction with other assets!

Hope this helps, RG 

[Atomic Frog]

 I found this on the web
     
http://www.ail.com/NuclearDetectionImages.htm

O's GammaCam™ represents a completely new dimension in assessing nuclear radiation fields by producing accurate two-dimensional images of gamma ray emitting objects. The portable system provides real-time pseudo-color gamma ray imagery superimposed on a conventional black and white video picture. Remote operation of the sensor head allows safe acquisition of gamma ray images in high radiation environments while minimizing worker exposure.

Sales and leases to both the Department of Energy (DoE) and commercial nuclear facilities demonstrate that the GammaCam™ is a useful tool in identifying gamma radiation sources and reducing exposure to personnel. The recorded gamma ray images can be used in multiple applications including survey management, job planning, inspection, and shielding evaluation. In addition to being a valuable ALARA tool, GammaCam™ improves the initial site characterization of Decontamination and Decommissioning job sites and characterization of unknown sources. By identifying the highest gamma radiation sources, the GammaCam™ provides valuable dose reduction information. Before and after images captured by the GammaCam™ are a useful tool in validating gamma radiation source elimination.

GammaCam™ Applications

Commercial Nuclear Power Plants

Streamline Critical Path Survey Management
Safe, Remote Surveys of Large Areas
Evaluation of Shielding Requirements and Implementation
Monitoring of Dynamic Radiological Conditions
Cost Effective Sorting of Radioactive Waste
Homeland Security - Nuclear Material Control

Homeland Security
- Counter Terrorism
- Treaty Verification
- Security/Inspection Camera
Emergency Responders
Port of Call/Border Protection
Characterize Suspect Vehicles, Containers
Decontamination and Decommissioning (Site Cleanup) - Environmental Restoration Applications

Expedite Site Characterization Using Remote Surveys
High Radiation Environments
Source Term Determination in Curies
Survey Hard to Access Areas
Evaluate Effectiveness of Decontamination Activity
Nuclear Navy

Safe Evaluation of Radiological Areas
ALARA Tool to Reduce Personnel Exposure
Clarify Complex Radiological Conditions
Public Health

Fugitive Sources Located
Validates DOT Guidelines
Characterize "Mystery" Sources
Medical safeguards
Medical imagery
Nuclear Medicine Control
GammaCam™ Model M31 Sensor Module Specifications

Spectral Range
< 50 keV to > 1.3 MeV

Detector
High density terbium-activated scintillating glass

Sensitivity
1 µR integrated dose for Cs-137 point source and 7:1 SNR (6 µR/hr above background at sensor head)

Exposure Time
User selectable, 10 milliseconds - 10 minutes, Software Summing for >10 minutes

Field of View (FOV)
25 degrees Narrow FOV Mode, 50 degrees Wide FOV Mode

Spatial Resolution
1.3 degrees Narrow FOV Mode, 2.6 degrees Wide FOV Mode

Dynamic Range
Instrument: >10E7,
Single Image: >10:1

Color or B&W Video FOV
73 degrees Horizontal, 55 degrees Vertical

Temperature
Operation: 5 degrees C - 40 degrees C,
Storage: -20 degrees C- 50 degrees C

Humidity
0 - 99% noncondensing

Detection Head
Weight: 60 Pounds,
Size: 19 in. Length,
10 in. Width,
15 in. Height,
Tripod Mountable

Processor
Rugged Portable Computer (IBM PC Compatible), Intel Pentium CPU, 32 Megabytes RAM (min), Active Matrix LCD Color Display, Internal Hard Drive, PC Card Slot (Type II/TypeIII)

Standard Software
GammaSoft™

System Power
215 Watts, 110 - 240 VAC 50/60 Hz



Hope that helps

        FROG   

[rmigliac]

The GammaCam is now made by ITT Corporation who have introduced two new models, the LT27 and the LT31.  There is a website dedicated to the system, www.GammaCamNow.com, where you can download various whitepapers and reports describing the systems use and benefits in actual nuclear power plant maintenance and Decontamination and Decommissioning applications.

[whytne1]

Does Anyone have any OE on The RadCam made by RMD?

[IPREGEN]

I worked with the AIL crew when the camera was in development and test. It used a tungsten slotted mask that they would rotate part way through the shot to only allow radiation to be seen that was in front of the camera (no side or angled dose). This was overlayed on an image with the intensity looking like a weather radar. The highest doe would be red with lower going to yellow and so on. It did not give dose rates at that time so a hot spot was relative to the surrounding area dose. Good techs with good meters could provide more useful information. There just wouldn't be the colorful photos.

[rmigliac]

I worked with the AIL crew when the camera was in development and test. It used a tungsten slotted mask that they would rotate part way through the shot to only allow radiation to be seen that was in front of the camera (no side or angled dose). This was overlayed on an image with the intensity looking like a weather radar. The highest doe would be red with lower going to yellow and so on. It did not give dose rates at that time so a hot spot was relative to the surrounding area dose. Good techs with good meters could provide more useful information. There just wouldn't be the colorful photos.

The AIL system was the first generation GammaCam.  The current 3rd gen systems now provide dose estimates as if the tech held a probe at 30 cm from the source.  A key feature is that the tech can take the scan away from areas with elevated dose rates and identify the hot spots remotely.