ALTERNATIVE RISK-BASED CRITERIA FOR TRANSPORTATION OF RADIOACTIVE MATERIALS ON THE UNITED STATES DEPARTMENT OF ENERGY HANFORD SITE

Radioactive materials transportation safety is of significant interest at the U.S. Department of Energy (DOE) Hanford Site. The Site covers about 1,450 km2 (560 mi~ of desert. Radioactive waste sources are often widely separated from the facilities that characterize, treat, and dispose of the waste. The site layout, therefore, requires that radioactive materials be transported on roadways and railways for significant distances in areas remote from controlled facilities. Onsite transportation within a DOE controlled site is generally safer than offsite transportation using public highways. Commercial transportation on public highways involves many unknowns, such as rapidly changing road conditions and weather, driver fatigue from long~istance operation, and highly variable traffic conditions. The effect of these variables is reflected in the significant differences in onsite and offsite traffic accident statistics and accident severity. The onsite transportation accidents at the Hanford Site have been demonstrated to be less severe than the offsite accidents, and the onsite accident rate is only a small fraction of that for public highways (Wang et al. 1991). The onsite controlled environment clearly provides an additional margin of transportation safety when compared to the public highways. It is, therefore, appropriate to rely on this additional margin of safety to justify the use of alternative packaging systems for selected onsite transportation operations.