ISO INTERNATIONAL STANDARD 16645 First edition 2016-10-01 Radiological protection Medical electron accelerators Requirements and recommendations for shielding design and evaluation Radioprotection - Accelérateurs médicaux d'électrons - Exigences et recommandations pour la conception et I'évaluation du blindage Reference number ISO 16645:2016(E) ISO @ IS0 2016 Cop IS0 16645:2016(E) COPYRIGHT PROTECTED DOCUMENT @ IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +4122 749 09 47 [email protected] www.iso.org Copyright ihtermational Organization for Standardization @ IS0 2016 - All rights reserved IS0 16645:2016(E) Contents Page Foreword .. Introduction.. ..vi 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions 3.1 Quantities. 3.2 Definitions .4 4 Shielding design goals and other design criteria .6 4.1 Shielding design goals. ..6 4.2 Shielding design assumptions 7 5 Role of the manufacturers, of the radiation protection officer or qualified expert and interactions between stakeholders ..8 5.1 General. 5.2 Linear accelerator manufacturer ..8 5.3 Shielding material vendor. .9 5.4 Architectural firm/general contractor .10 5.5 Radiation protection officer or qualified expert ..10 5.6 The licensee. .11 6 Radiation fields around a linear electron accelerator .11 6.1 General .11 6.2 X-ray radiation.. ..11 6.2.1 Primary X-ray beam 6.2.2 Primary electron beam bremsstrahlung .12 6.2.3 Secondary X-ray radiation 12 6.2.4 Tertiary X-ray radiation. .13 6.3 Neutron radiation. .13 6.3.1 General. ..13 6.3.2 Direct neutron radiation .14 6.3.3 Scattered and thermal neutron radiation .14 6.3.4 Primary barrier neutron radiation .15 6.4 yradiation .15 6.4.1 General .15 6.4.2 Maze y radiation .15 6.4.3 Door radiation. 15 6.4.4 Primary barrier y radiation ..15 6.4.5 Air radiation. ..16 7 Shielding materials and transmission values ..16 8 General formalism for shielding calculation . ..18 9 Shielding calculation for conventional devices ..20 9.1 General 20 9.2 Primary barriers 20 9.2.1 Radiationcomponents 20 9.2.2 Barrier with a unique material. .21 9.2.3 Barrier with multiple layers. .21 9.3 Secondary barriers.. 22 9.3.1 Radiation components 22 9.3.2 Barrier with a unique material 23 9.3.3 Barriers with multiple layers. 24 10 Doors and mazes .24 10.1 General, .24 orzsaraAlh rights reserved iii Copyright International c IS0 16645:2016(E) 10.2 Radiation components 25 10.3 Standard maze 25 10.3.1 Maze X-ray scatter calculations. 25 10.3.2 X-ray direct Leakage. 30 10.3.3 Maze neutron and capture gamma calculations 31 10.4 Two legged maze. 33 10.5 No maze - Direct-shielded doors. 34 10.5.1 General. 34 10.5.2 Shielding at the far side of a direct-shielded door entrance 35 10.5.3 Shielding at the near side of a direct-shielded door entrance. 37 10.6 No door at maze entrance 39 10.7 Door Calculations. 40 10.7.1 General 40 10.7.2 Maze door calculations. 40 10.7.3 Direct Shielded Door Calculations 41 11 Shielding calculations for special devices 41 11.1 General 41 11.2 Robotic arm accelerator. 41 11.3 Helical intensity modulated radiotherapy 42 11.4 Dedicated device for intra operative radiotherapy with electrons 42 12 Ducts. 43 12.1 Duct impact on radiation protection. .43 12.2 Recommended location and geometry 43 12.3 Additional shielding 44 12.3.1General. 44 12.3.2 Neutron and capture gamma radiation passing through the interior of the shielded duct 44 12.3.3 X scattered radiation passing through the interior of the shielded duct .45 12.3.4 Scattered radiatio