PWR primary shutdown and startup chemistry guidelines

Under EPRI sponsorship, an industry committee, similar in form and operation to other guidelines committees, was created to develop PWR shutdown and startup chemistry recommendations. The committee reviewed the available data and determined that there was justification for a chemistry guideline in this area, since a coordinated shutdown program could help avoid some of the problems that had been reported. Though reduced radiation fields might be a long-term benefit of continued application of shutdown and startup chemistry, the committee determined that data were not available to propose that as a goal. These guidelines present a series of principles to optimize a shutdown and startup strategy for both refueling and mid-cycle shutdowns. The principles reflect general guidance to ensure cooldown under reducing conditions, avoid increasing pH, maximize cleanup and, finally, establish an oxidizing environment. Consistent with other guidelines documents, these guidelines also present technical bases, analytical methods and data evaluation techniques. Current plans are to combine these recommendations with the PWR Primary Water Chemistry Guidelines during the Revision 3 process, scheduled for 1995.