Radiological Assessment of Steam Generator Removal and Replacement: Update and Revision

A previous analysis of the radiological impact of removing and replacing corroded steam generators has been updated based on experience gained during steam generator repairs at Surry Unit 2. Some estimates of occupational doses involved in the operation have been revised but are not significantly different from the earlier estimates. Estimates of occupational doses and radioactive effluents for new tasks have been added. Health physics concerns that arose at Surry included the number of persons involved in the operation, tne training of workers, the handling of quantitites.of low-level waste, and the application of the ALARA principle. A review of these problem areas may help in the planning of other similar operations. A variety of processes could be used to decontaminate steam generators. Research is needed to assess these techniques and their associated occupational doses and waste volumes. Contaminated steam generators can be stored or disposed of after removal without significant radiological problems. Onsite storage and intact shipment have the least impact. In-placing retubing, an alternative to steam generator removal, results in occupational doses and effluents similar to those from removal, but prior decontamination of the channel head is needed. The retubing option should be assessed further