LVC-390

The Series 390 calorimeter is a high-sensitivity differential measuring instrument designed for the characterisation of nuclear materials and more particularly for the analysis of radioactive waste and the quantification of radioactive elements (e.g. curium, plutonium, tritium) contained in metal containers.

 

Highlights

Differential calorimetry technique:

  • NDA method (non-destructive assay).
  • cylindrical sample volume 60 litres maximum.
  • predictive software: determines equilibrium and measurement end point, therefore reducing measurement time.
  • movable or fixed: calorimeter is fixed or mounted on a trolley, separate electronics rack.
  • enhanced safety: possibility of installation in a glove box or hot cell.
  • ease of calibration: Joule effect calibration (removable or built-in).
  • large measurement window: power measurement range from 10 mW to 13 W.
  • ultra sensitive: measuring accuracy < 1%, precision < 0.5%.
  • ease of use: use of the state-of-the-art thermal analysis software interface CALISTO.
  • ease of sample access: the sample and reference chambers are accessible from the top of the calorimeter, opened by an automated system with an actuator.

 

 

Specifications

Calorimeter type Isothermal heat Flow Differential
Number of cells 2
Volume of measurement cell (litres) 60
Measuring range (mW) 10 – 13000
Approximate measuring range (gT) (1gT ~ 325 mW) 30 – 40 000 mgT
Approximate measuring range (gPu) (1gPu ~ 3 mW) 3 – 4300 gPu
Temperature range (°C) 25 – 40
Accuracy (%) 1
Precision (%) 0.5
Measurement time (h) 5-6 (predictive calculation)
Cooling system Water
Calibration system Standard electrical heaters
External dimensions Width / depth / height (mm) 1500 x 1000 x 960
Weight (kg) 1000

 

Principle

The LVC-390 is based on the Calvet calorimetry principle: the sensors surround the sample and the reference, collecting all the heat emitted by the sample.
The Peltier sensors generate a voltage difference proportional to the difference in heat flow between the reference cell and the measurement cell, both regulated at a fixed temperature.

 

Applications

The waste from the dismantling of buildings at nuclear sites or from storage casks containing residues of radioactive materials is subject to rigorous accounting.
Conventional methods of measuring radiation (gamma ray spectrometry, neutron counting) are frequently sensitive to problems of attenuation caused by the matrix of the package, where the radioactive material is disseminated among assorted objects (glass, plastic, metal, etc).
Calorimetry is the ideal measurement method. The coupling of gamma ray spectrometry and calorimetry can be used to determine the isotopic composition and the quantity of radioactive species respectively.

 

Software

The calorimeter uses SETARAM Calisto LVC software running on PC. Calisto LVC software enables users to prepare experimental conditions, start the experiment and process the results.
Calisto also provides a wide range of tools to help users customise their experiments:

  • Definition of standardised procedures in order to record the signal from the calorimeter, the calorimeter temperature and the Joule effect power.
  • Calibration of the calorimeter by means of the Joule effect.
  • Processing of experimental data and stored procedures (sorting, filtering as a function of the instrument and the user, etc).

Option: “prediction of signal at equilibrium” package. This is a computerised numerical extrapolation system that predicts the value of the signal at equilibrium and detects the end of measurement.