DOE programs in fire and materials

Diverse laboratory experiments and a review of the most recent dose rate data from operating plants have identified key factors responsible for the increase in shutdown radiation fields at a number of BWRs following implementation of HWC. This information suggests strategies to minimize radiation field increases under HWC and to avoid possible problems during chemical decontamination. The results from corrosion release and activity deposition laboratory experiments, performed under NWC, HWC, and cycling conditions, and the chemistry and structure of films that form under cycling conditions were compiled and reviewed. Operating plant experience under HWC, including the on-line gamma spectroscopy measurements performed at Hope Creek, was also studied. The radiation buildup measurements at Monticello, Brunswick-2, and Duane Arnold were also considered. The focus was to identify those areas that provided a general consensus about the factors responsible for activity buildup under HWC. Once this task was accomplished, the information was used to identity procedures that plant operators could utilize to mitigate undesirable effects.