In accordance with the classification system of sealed radionuclide sources in accordance with ISO 2919:1999, each type of produced sources is assigned a code based on the results of the tests, which contains:
- letter “C” or “E”
- five digits: class numbers for resistance to temperature, external pressure, impact, vibration, puncture, according to the order defined in the table below.
The class of a sealed source of a particular type is determined by testing of not less than 2 sealed sources (basу sample, simulators, dummy sources) for compliance with the norms of the influencing factors. A sealed source is considered to have passed the test if it remains sealed after each test. The tightness test is carried out in accordance with ISO 9978.
|1 *||2||3||4||5||6||X **|
|Temperature||—||-40 °С (20 min) +80 °С (1 h)||-40 °С (20 min) +180 °С (1 h)||-40 °С (20 min) +400 °С (1 h) and thermal shock to 20 °С||-40 °С (20 min) +600 °С (1 h) and thermal shock to 20 °С||-40 °С (20 min) +800 °С (1 h) and thermal shock to 20 °С||—|
|External pressure||—||25 kPa absolute to atmospheric||25 kPa absolute to 2 MPa absolute||25 kPa absolute to 7 MPa absolute||25 kPa absolute to 70 MPa absolute||25 kPa absolute to 170 MPa absolute||—|
|Impact||—||50 g from 1 m or ***||200 g from 1 m or ***||2 kg from 1 m or ***||5 kg from 1 m or ***||20 kg from 1 m ***||—|
|Vibration||—||3 cycles along 10 min from 25 to 500 Hz at 49 m/s2 (5gn) ****||3 cycles along 10 min from 25 to 50 Hz at 49 m/s2 (5gn) **** and from 50 to 90 Hz at 0.635 mm peak to peak and from 90 to 500 Hz at 98 m/s2 (10gn) ****||3 cycles along 30 min from 25 to 80 Hz at 1.5 mm peak to peak and from 80 to 2000 Hz at 196 m/s2 (20gn) ****||Not used||Not used||—|
|Puncture||—||1 g from 1 m or ***||10 g from 1 m or ***||50 g from 1 m or ***||300 g from 1 m or ***||1 kg from 1 m or ***||—|
|* No test
** Special test
*** Equivalent imparted energy
**** Maximum acceleration amplitude
In accordance with the tasks set, the consumer has the opportunity to choose the type of sources from the nomenclature that we proposed. The list of the most typical applications of sealed sources and the minimum classes required for them are given in the table below.
|Typical using area of a sealed source||Class|
|— sealed source||4||3||5||1||5|
|— source in block||4||3||3||1||3|
|— brachytherapy *||5||3||2||1||1|
|— surface applicators **||4||3||3||1||2|
|Devices with gamma sources (medium and high energy)|
|— unprotected source||4||3||3||3||3|
|— source in block||4||3||2||3||2|
|Devices with beta sources and low-energy gamma sources for X-ray fluorescence analysis **||3||3||2||2||2|
|Logging of oil wells||5||6||5||2||2|
|Ion generators ***|
|— static electricity neutralizers||2||2||2||2||2|
|— smoke detectors **||3||2||2||1||2|
|Control sources with activity > 1 MBq||2||2||2||1||2|
|— with dry storage of the source **||4||3||3||2||3|
|— with wet storage of the source ***||5||3||4||2||4|
|* Sources of this type can be subjected to considerable deformation during operation. Manufacturers and users can provide special tests for them
** Excluding gas-filled sources.
*** Source assembling and source in the block can be tested.