IEEE Std 603-1998 (Revision of IEEE Std 603-1991) IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations Sponsor Nuclear Power Engineering Committee of the IEEE Power Engineering Society Approved 1 July 1998 IEEE-SA Standards Board Abstract: Minimum functional and design criteria for the power, instrumentation, and control por- tions of nuclear power generating station safety systems are established. The criteria are to be ap- plied to those systems required to protect the public health and safety by functioning to mitigate the consequences of design basis events. The intent is to promote safe practices for design and eval- uation of safety system performance and reliability. Although the standard is limited to safety sys- tems, many of the principles may have applicability to equipment provided for safe shutdown, post- accident monitoring display instrumentation, preventative interlock features, or any other systems, structures, or equipment related to safety. Keywords: actuated equipment, associated circuits, Class 1E, design, failure maintenance by- pass, operating bypass, safety function, sense and command features, sensor The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright @ 1998 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 1998. Printed in the United States of America. ISBN 0-7381-0326-8 No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Ind Nreroductonornetworking permitedwithoutlicensefromH Not for Resale IEEE Standards documents are developed within the IEEE Societies and the Standards Coordinat- ing Committees of the IEEE Standards Association (IEEE-SA) Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an inter- est in participating in the development of the standard. Use of an IEEE Standard is wholly voluntary. The existence of an IEEE Standard does not imply that there are no other ways to produce, test, measure, purchase, market, or provide other goods and services related to the scope of the IEEE Standard. Furthermore, the viewpoint expressed at the time a standard is approved and issued is subject to change brought about through developments in the state of the art and comments received from users of the standard. Every IEEE Standard is sub- jected to review at least every five years for revision or reaffirmation. When a document is more than five years old and has not been reaffirmed, it is reasonable to conclude that its contents. although still of some value, do not wholly reflect the present state of the art. Users are cautioned to check to determine that they have the latest edition of any IEEE Standard. membership affiliation with IEEE. Suggestions for changes in documents should be in the form of a proposed change of text, together with appropriate supporting comments. Interpretations: Occasionally questions may arise regarding the meaning of portions of standards as they relate to specific applications. When the need for interpretations is brought to the attention of IEEE, the Institute will initiate action to prepare appropriate responses. Since IEEE Standards rep- resent a consensus of all concerned interests, it is important to ensure that any interpretation has also received the concurrence of a balance of interests. For this reason, IEEE and the members of its societies and Standards Coordinating Committees are not able to provide an instant response to interpretation requests except in those cases where the matter has previously received formal consideration. Comments on standards and