The Free Release Measurement Facility (FRMF) based on the 4 HPGe detectors and low-level background concrete shielding and installed in Madrid at Spanish designated metrology institute CIEMAT has been calibrated using Monte Carlo codes MCNP and PENELOPE, and the calibration  validated by measurement of reference materials and radionuclide sources standardized by European metrology institutes.

Real waste materials have been measured at FRMF and in CIEMAT’s and CMI’s laboratories:

• steel tubes, plates, wood, glass wool and cables from the Czech NPP in standard NUVIA IP1 containers of the volume of 0.4 m³ (Fig. 1).
• concrete, sand and soil from CIEMAT’s decommissioning site in CIEMAT Big-Bag geometry (Fig.2).

The mass activities measured at the facility and in laboratories have been determined and compared. Good agreement between has been achieved and maximum deviation between laboratory and on-site measurements did not exceed 10%.

The measurement results will be published in Applied Radiation and Isotopes journal.

Fig1

 

Fig 2