TOC removal from make-up water at Millstone Nuclear Generating Station

Through the use of mobile service companies, Northeast Utilities was able to evaluate various unit operations to determine the most effective method for improving make-up water chemistry. Because the tests were conducted on a full scale basis, the total impact on system chemistry was easily obtained. Since all systems were leased, no capital expenditures were required. Also, the leasing of fully piped, self-contained, quality control tested equipment allows start-ups to begin within hours of arrival on-site. For this particular water supply, the application of reverse osmosis technology appears to be optimum. To date, for Millstone Station, it is the only technology which has produced less than 50 ppb TOC make-up water quality. This has led to significant secondary system chemistry improvements. For other source water supplies, R.O. may not be the best or only approach. Indeed, there are many ion exchange and flash evaporator installations which are producing water of low TOC content. Having the marketplace option of leasing full scale equipment to evaluate if other processes can further improve water quality is an attractive alternative to small scale pilot studies