A series of in-reactor tests including constant elongation rate test (CERT) experiments, electrochemical potential (ECP, also called corrosion potential) and chemistry measurements have been run in the Swedish Ringhals 1 boiling water reactor (BWR). The tests included start-up conditions, and steady state power operation conditions with presently current water chemistry (200-400 ppb O2, PWC) or alternate water chemistry (5 ppb O2, AWC). AWC normally is not capable of producing intergranular stress corrosion cracking (IGSCC) in sensitized austenitic stainless steel.

During one AWC test the reactor water was contaminated by degradation of ion exchange resin intruded into the reactor water. Appreciable IGSCC occurred in a variety of sensitized austenitic stainless steels. It is shown that nitrate and sulfate originating from radiolysis of the resin are candidates as cause for the observed IGSCC occurrence. During another test under reactor start-up conditions chemistry transients from resin intrusions apparently enhanced transgranular stress corrosion cracking of low alloy steels, and also may have initiated IGSCC in Inconel Alloy 600.

It is pointed out that a variety of radiolysis products from impurities must be considered for possible enhancement of SCC in structural alloys in BWR environments.

Subject
Water, Materials, Intergranular stress corrosion cracking, Boiling water reactors, Reactors, Nickel based alloys, Water chemistry, Impurities, Oxygen, Stainless steel, Conductivity, Resins, Hydrogen
© 1984 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
1984
Association for Materials Protection and Performance (AMPP)
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