Study on Radioactivity Associated with Common Salt Production Process of Two Salt Works in Tuticorin District, Tamil Nadu, India

Abstract

This study estimated the gross a, gross b, ⁴⁰K, ²⁰⁸Tl, ²²⁸Ac and ²¹⁴Bi activities in the sea and subsoil brines of two salt works at Vepalodai and Sahupuram in Tuticorin District, Tamil Nadu, India. It was observed that the sea brine of at Vepalodai, the gross a activity in the brine varied from 0.0009 to 0.0033 Bq L^-1 and the gross b activity varied from 0.0194 to 4.0405 Bq L^-1. At the subsoil brine of Sahupuram, the corresponding values varied from below detection limit (BDL) to 0.0032 and 0.0114 to 3.0352 Bq L^-1. ⁴⁰K activity was found to increase, source to bittern, viz., 4.006 to 221.006, at Veplodai and 3.247 to 204.462 Bq L^-1 at Sahupuram. The activity of the sea brine was higher than that of the sub-soil brine. The gross a and b activities were increasing at subsequent stages of production due to the concentration of brine. The sediments collected at different stages showed gross a activity varying from 42.0 to 362.0 Bq kg^-1, gross b activity varying from 1998 to 2498 Bq kg^-1. ²⁰⁸Tl, ²²⁸Ac activities varied from 111.2 to151.2 Bq kg^-1 and 40.1 to 73.4 Bq kg^-1. The corresponding values for Sahupuram salt works were 10.2 to 98.7, 1298 to 1548, 137.4 to 175.8 and 33.8 to 55.3 Bq kg^-1 for gross a, gross b, ²⁰⁸Tl, ²²⁸Ac, respectively. The analysis of the common salt from Vepalodai showed 14.4,107, 12.42, 13.10 and 3.8 Bq kg^-1 of gross a, gross b, ²⁰⁸Tl, ²²⁸Ac and ²¹⁴Bi, respectively and that from sub soil brine of Sahupuram showed 8.7, 24.6, 7.4, 9.46 and 3.4 Bq kg^-1. This study shows that the radioactivity in common salt is within the limit.