Improved plastic liner for Indian nuclear power reactor containment and irradiation test of coating

The plastic liner or the heavy duty paint coating system in a nuclear power reactor building of the Indian Pressurised Heavy Water type, forms part of the last one of the multiple radioactive barriers, namely the concrete containment envelope and therefore, deserves the attention of a class II safety system. The duties of this paint coating call for an elaborate testing and evaluation before the coating is approved for containment service. This paper deals with indigenous development of suitable paint coatings for such application and associated development of tests, quantification of test parameters, simulation of integrated aggressive environment (so as to be able to predict the change in properties at the end of service life), evaluation of a performance oriented specification with due weightage to the functional requirements and establishing acceptance criteria with product ranking system. While doing the development work a common irradiation test of candidate coating for this duty along with those devised and developed for high radiation areas like fuelling machine vault, has been conducted to observe the post-irradiation performance and radiation threshold of the same. The results of these have also been included in this paper. (author). 6 refs., 3 tables