Our department is accredited and licensed for the individual monitoring of the personnel occupationally exposed to ionizing radiation. Personal dosimetry is performed by Passive Dosimetry Laboratory. The Passive Dosimetry Laboratory has been accredited by the Accreditation Body of Serbia according to SRPS ISO/IEC 17025:2017, for measurements using the whole body, eye lens and extremity dosemeters in photon fields.
For supervision and monitoring purposes, the occupationally exposed workers are classified as follows:
- Category A: those exposed workers who are liable to receive an effective dose greater than 6 mSv per year or an equivalent dose greater than 3/10 of dose limits per year for the lens of the eye, for the skin, or extremities;
- Category B: those exposed workers who are not classified as category A workers.
This classification is according to “Rulebook on Limits of Exposure to Ionizing Radiation and Measurements for Assessment of the Exposure Levels (Official Gazette RS 86/11 and Official Gazette RS 50/18 )”
The whole body radiation dose from external radiation is recorded using passive, thermoluminescent dosemeters (TLD), in terms of operational dosimetry quantity Hp(10). Based on guidance given to workers, the dosemeter is worn at the chest level, outside the protective apron, if used. There are cases where two dosemeters may be used, inside and outside protective apron. In these cases, the dosemeter outside the apron is placed close to the protective thyroid collar. . In the case of Category A workers, the dosemeters are changed monthly. Category B workers can wear one dosemeter for more than a month, but less than 3 months. The majority of our Category B workers change their dosemeters quarterly.
In addition to whole body dosimetry, we provide individual monitoring for the dose to the extremities or the skin, and the lens of the eye, using dedicated TLD calibrated in terms of operational quantities Hp(0.07) and Hp(3), respectively.
We are also accredited to environmental monitoring in terms of H*(10) using passive dosimetry systems.
Measurement system
Our Laboratory is using Thermo Scientific™ Harshaw™ and RadPro thermoluminescent dosemeters (LiF:Mg,Ti and LiF:Mg,Cu,P), with two fully automated Harshaw TLD readers, model 6600 Plus. The calibration factors for both readers are determined in S-Cs field for Hp(10) and Hp(0.07), and in N-60 for Hp(3).
For the process of dose archiving and reporting, we are using custom made program “TL dozimetrija”.
Whole body dosemeter
Whole body dosemeter consists of an asymmetrical holder and an aluminum card with two Teflon encapsulated chips of near tissue-equivalent thermoluminescent material (LiF:Mg,Ti). Each card is uniquely barcoded.
Ring dosemeter
Ring dosemeter is a reusable TLD worn on a finger, used for extremity dose assessment. Our Laboratory is using Thermo Scientific™ DXT-RAD™ Extremity Dosimeter. This is a disk detector (LiF:Mg,Ti and LiF:Mg,Cu,P) with an integrated circular barcode placed into an adjustable, plastic ring, and sealed with plastic cup. The results of ring dosemeters are given in terms of personal dose equivalent at depth 0.07 mm (Hp(0.07)).
Eye dosemeter
Eye lens dosemeters are used for evaluating the personal dose equivalent at depth 3 mm (Hp(3)). When assessing the eye lens dose, Thermo Scientific™ DXT-RAD™ Extremity Dosimeter is affixed to the head at the height of the eyes. This is a disk detector (LiF:Mg,Cu,P) with an integrated circular barcode placed into an adjustable, plastic ring and sealed with a plastic cup.
Not all occupationally exposed workers should have their eye lens dose monitored. Some examples where monitoring should be considered are: (1) medical workers involved in cyclotron operation, CT-guided interventional procedures, manual brachytherapy, some nuclear medicine procedures, fluoroscopy-guided interventional procedures, (2) some workers in nuclear facilities and (3) industrial radiographers.
Environmental dosemeter
In addition to personal monitoring, this Laboratory is accredited for environmental monitoring in terms of H*(10) using passive dosimetry systems.
The environmental dose measurements are also done by two Harshaw 6600 Plus readers that are calibrated in S-Cs field according to ISO 4037-3.
An environmental dosemeter consists of a symmetrical holder and an aluminum card with two Teflon encapsulated chips of thermoluminescent material (7LiF:Mg,Cu,P). Each card is uniquely barcoded.
Intercomparisons
The Laboratory is participating in the EURADOS and IAEA intercomparisons whenever they are available for the quantities that are measured. This is a requirement of our Quality Management System and of the protocol that we fallow (Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation (RP160), EC, 2009).
Request for individual and environmental monitoring
Monitoring is provided upon request; the procedure includes the following steps:
- Communication (via phone, e-mail or fax) with the Laboratory in order to make a written agreement for the requested work;
- If an agreement is made, the Laboratory sends TL dosemeters to user company via national Postal service (Post of Serbia) if other is not arranged;
- The users are wearing dosemeters for the proscribed period. After the period ends and the user receives new dosemeters for next period, user company sends back worn dosemeters;
- When dosemeters arrive at the Laboratory they are prepared for reading;
- As soon as the readout has been completed, the report is made and sent to the user with dosemeters for the next period;
- Invoices can be sent separately or with dosemeters and the payment of a debit amount is done to the Vinca Institute bank account.
Contact
T: +381 11 3408 892, 3408 586, 3408 485, 3408 576, 6308 433 F: +381 11 6308 433