<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Laboratory for Dosimetric and Radon Instruments Calibration which is a part of Central Laboratory for Radiological Protection (CLRP) in Warsaw is equipped with <sup>241</sup>Am-Be neutron calibration source with activity of 185 GBq since 1999. The capsule was mounted in the OB26 type shielding container. The control room is separated from the above source by a concrete wall of 0.5 m in thickness. The calibration hall is adjacent to one side of the offi ce room. To comply with the requirements of the radiological protection system, the occupational exposure of persons that are working both in the offi ce and control room needs to be assessed. Two methods were involved for ambient dose equivalent rate determination. The active instrument measurements (AIMs) performed with the Berthold LB6411 neutron probe and the Monte Carlo simulation method (MCS) based on MCNP5 code. These estimations were completed for fi ve reference points. Additionally the γ radiation component was measured by RSS131 ionisation chamber. An increased value of the ambient dose equivalent rate from neutrons was observed in two reference positions. The fi rst observation was done in the control room while the second one in the offi ce room. Expected individual dose equivalents were evaluated based on the results of the AIM and on the expected working time in particular reference points. The annual individual dose equivalent associated with calibration activities using mentioned neutron source was estimated at maximum 0.8 mSv. </p></abstract>

Laboratory for Dosimetric and Radon Instruments Calibration which is a part of Central Laboratory for Radiological Protection (CLRP) in Warsaw is equipped with 241Am-Be neutron calibration source with activity of 185 GBq since 1999. The capsule was mounted in the OB26 type shielding container. The control room is separated from the above source by a concrete wall of 0.5 m in thickness. The calibration hall is adjacent to one side of the offi ce room. To comply with the requirements of the radiological protection system, the occupational exposure of persons that are working both in the offi ce and control room needs to be assessed. Two methods were involved for ambient dose equivalent rate determination. The active instrument measurements (AIMs) performed with the Berthold LB6411 neutron probe and the Monte Carlo simulation method (MCS) based on MCNP5 code. These estimations were completed for fi ve reference points. Additionally the γ radiation component was measured by RSS131 ionisation chamber. An increased value of the ambient dose equivalent rate from neutrons was observed in two reference positions. The fi rst observation was done in the control room while the second one in the offi ce room. Expected individual dose equivalents were evaluated based on the results of the AIM and on the expected working time in particular reference points. The annual individual dose equivalent associated with calibration activities using mentioned neutron source was estimated at maximum 0.8 mSv.

Occupational exposure to Am-Be neutron calibration source mounted in OB26 shielding container

Central Laboratory for Radiological Protection, 7 Konwaliowa Str., 03-194 Warsaw, Poland, Tel.: +48 22 811 0011, Fax: +48 22 811 0016

Institute of Plasma Physics and Laser Microfusion, EURATOM Association, 23 Hery Str., 01-497 Warsaw, Poland

Nukleonika

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Laboratory for Dosimetric and Radon Instruments Calibration which is a part of Central Laboratory for Radiological Protection (CLRP) in Warsaw is equipped with...

Occupational exposure to Am-Be neutron calibration source mounted in OB26 shielding container

Published Online: Sep 12, 2014

Page range: 97 - 103

Received: Feb 11, 2014

Accepted: Jul 21, 2014

DOI: https://doi.org/10.2478/nuka-2014-0016

Keywords
occupational exposure, active instruments measurements, neutron source calibration

© by Kamil Szewczak

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Occupational exposure to Am-Be neutron calibration source mounted in OB26 shielding container

Published Online: Sep 12, 2014

Page range: 97 - 103

Received: Feb 11, 2014

Accepted: Jul 21, 2014

DOI: https://doi.org/10.2478/nuka-2014-0016

Keywordsoccupational exposure, active instruments measurements, neutron source calibration

© by Kamil Szewczak

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
occupational exposure, active instruments measurements, neutron source calibration