ISO 23467 specifies requirements for the ice plug technique with liquid nitrogen or dry ice as a refrigerant (cryogenic medium) on metal pipes of nuclear power plants. The freezing liquid can be a water or water mixture (e.g. boric acid mixture).
ISO 23467 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 tests is not in the scope of ISO 23467 and will be qualified separately.
ISO 23467 on piping in the nuclear power plants is useful to:
Isolation technology uses ice plugs to carry out repairs and maintenance on large diameter horizontal pipelines without shutting down the entire thermal-hydraulic installation.
ISO 23467 provides terms and definitions for basic concepts of nuclear energy, nuclear technologies, and radiological protection.
ISO 23467 is designed to provide a standardized procedure for online isolation through the freezing of the internal medium of the pipeline. This document includes methods for technologies to isolate equipment without isolation facilities by ice plug technology. Standardized ice plug isolation technology will facilitate the maintenance work.
ISO 23467