This document specifies requirements for the ice plug technique with liquid nitrogen or dry ice as 
refrigerant (cryogenic medium) on metal pipes of nuclear power plants. The freezing liquid can be 
water or water mixture (e.g. boric acid mixture).
This document specifies technical requirements of ice plug generation, formation judgment and 
removal, measures before, during and after ice plugging and requirements for personnel and non-
destructive testing.
The application of the ice plug isolation technique is principally not allowed on cladded pipes or pipes 
with internal coatings. The application for pressure test is not in the scope of this document and will be 
qualified separately.st edition 2020-11 Ice plug isolation of piping in nuclear power plant Mise en ？uvre de la technique d’obturation cryogénique sur les tuyauteries de centrales nucléaires Reference number ISO 23467:2020(E) ？ ISO 2020 ISO 23467:2020(E) COPYRIGHT PROTECTED DOCUMENT ？ ISO 2020 All rights reserved. Unless otherwise specified, or required in the context of