A collaboration between CANBERRA and EDF, owner of 58 Operating Reactor units in France.

To open this Application Note, click here

Background on the InSpector 1000 Digital Hand-Held Multichannel Analyzer CANBERRA’s InSpector 1000 Digital Hand-Held Multichannel Analyzer was introduced in 2003. It is a portable spectrometer that is capable of measuring dose-rate with an internal GM detector as well as making dose-rate, nuclide identification and activity measurements with an external gamma scintillation detector probe. An optional, external neutron probe is also available that can be used in parallel with the gamma probe.

The InSpector 1000 is available with a large variety of detachable and interchangeable external probes of various sizes and resolution:

• IPRON-1: 1” x 1” NaI(Tl) for difficult accessible areas
• IPROS-2: 2” x 2” NaI(Tl) – Temperature Stabilized for most applications when isotope mix is rather simple
• IPROS-3: 3” x 3” NaI(Tl) – Temperature Stabilized for very low background environmental measurements
• IPROL-1: 1.5” x 1.5” LaBr – Temperature Stabilized for more complex spectral analysis, thanks to its improved resolution (twice better than NaI(Tl))
• IPRON-N – Optional neutron probe for security applications

The existing gamma probes are able to generate spectra with optimum quality up to a dose-rate between 25 and 70 µSv/h (2.5 to 7 mrem/h), depending on the size of the probe. This dose-rate limit is considered low for a nuclear power plant when the measurement is near reactor coolant piping. High dose-rates in this area require heavy collimation of the probe which is not always easy to deploy.

Also, many utilities perform ISOCS™ measurements with germanium-based detectors and even heavier shielding and collimation – all transported on a cart. These systems provide extremely precise and absolute measurements when characterizing many critical areas in the plant. However, their use requires additional time for deployment, and some areas are very difficult to access with a cart-based system such that the measurements are not always practical or even possible to perform.

Introduction of the InSpector 1000/CZT Package

These two critical requirements, minimal time for deployment with a small, compact spectrometer and ability to perform nuclide identification measurements in a high dose-rate area, drove CANBERRA to develop a Cadmium Zinc Telluride (Cd-Zn-Te or CZT) package to go with the existing InSpector 1000. While still having good resolution compared to a scintillation detector, CZT detectors are much smaller and less sensitive than scintillation or HPGe detectors and can be operated at room temperature. These features make them perfect for taking gamma spectroscopy measurements in cramped, high dose-rate areas.

The new InSpector 1000/CZT Package includes:

• InSpector 1000
• CZT interface that clips onto the side of the InSpector 1000
• Series (based on expected dose-rate) of color-coded CZT probes that connect to the CZT interface:
• 5 mm³ for Dose-rate from 50 mSv/h to 200 mSv/h (5 rem/h to 20 rem/h). This probe is optional.
• 20 mm³ for Dose-rate from 10 mSv/h to 50 mSv/h (1 rem/h to 5 rem/h).
• 60 mm³ for Dose-rate from 0.1mSv/h to 10 mSv/h (10 mrem/h to 1 rem/h).
• 500 mm³ for Dose-rates < 3 mSv/h (300 mrem/h). This probe is optional.