ISO INTERNATIONAL STANDARD 18195 First edition 2019-02 Method for the justification of fire partitioning in water cooled nuclear power plants (NPP) Méthode de justification de I'efficacité de la sectorisation incendie des centrales nucléaires utilisant I'eau comme fluide caloporteur Reference number IS0 18195:2019(E) so @ IS0 2019 IS0 18195:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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 CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 0111 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 18195:2019(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. ..1 2 Normativereferences ..1 3 Terms, definitions, symbols and abbreviated terms. ..1 3.1 Terms and definitions .2 3.2 Symbols... ..4 3.3 Abbreviated terms. .5 4 Method for justification of nuclear safety fire partitioning: global approach ..5 4.1 Objectiveofthemethod ..5 4.1.1 The basis of design: standard fire resistance tests. .5 4.1.2 Aim, limitations, and precautions .6 4.1.3 Minimum requirements concerning the qualification of the method practitioners ..8 4.2 General principle of the method .8 4.3 Design of the partitioning: justification of the adequate performance of fire barriers.. ..10 4.4 Fire barriers and structural elements.. 10 4.5 Overall flowchart (flowchart 1) .11 5 Determination of the design basis fire temperature curve (room fire curve) .12 5.1 General considerations in room fire scenarios. ..12 5.1.1Typical development stages of a compartment fire ..12 5.2 Defining the design basis fire temperature curve for a room ..13 5.3 Requirements concerning calculation tools .14 5.4 Assumptions and input data for numerical calculations .15 5.4.1 Fixed automatic fire fighting system (credited or not) ..15 5.4.2 Modeling assumptions .16 5.4.3 Characteristics of a room .16 5.4.4 Nature of fuels. .17 5.4.5 Firescenarios 18 5.4.6 Recommended value for pyrolysis rates .23 5.5 Design basis fire temperature curve calculation process 23 5.5.1 Data input 23 5.5.2 Modelling of the fire volume and scenarios 23 5.5.3 Modelling options. .23 5.6 Determination of the fire temperature curve. .24 6 Determination of the performance of fire barriers (performance curve diagram) .27 6.1 Principles. .27 6.2 Characterization of the performance diagram: global methodology.. .27 6.3 Phase 1: analysis of the standard test. 28 6.4 Phase 2 branch A: determination by calculation 29 6.4.1 Study approach. 29 6.4.2 Selection of representative experimental curves 30 6.4.3 Calculation tools and choice of the modelling 30 6.4.4 Thermal properties of materials. 31 6.4.5 Plotting performance curves from the reference curves 33 6.4.6 Plotting"steady state" curves. .35 6.4.7 Plotting the performance diagram .35 6.5 Phase 2 BRANCH B: working out a new family system .35 6.5.1 Study approach for branch B .35 6.5.2 Experimental check (step 5B). 36 6.6 Phase 2 branch C: specific characterization tests. .37 6.7 Alternative performance curves .38 @ IS0 2019 - All rights reserved iii