This is not a Yes or No question as some small risk is always present in any activity. However the degree of risk can be described and compared to other risks.

TSCA is a well-designed hazardous waste incinerator with both a primary and secondary combustion chamber in which all the gases are brought to the high temperature necessary to destroy about 99.99 percent or more of the organic toxins present. Any remaining ashes which are essentially free of organic compounds and contain heavy metals and traces of radioactive elements are packaged and are sent to an appropriate waste disposal site. The hot gases are quickly quenched with water, de-misted and passed through a cyclone separator to remove large particles. The gases then pass through a caustic scrubber to remove acidic compounds and finally through two electronic precipitators which eliminate fine particulates. The quenching water and scrubbing solutions are processed to meet the state standards before their release.

The off-gases are continuously monitored for oxygen, carbon dioxide and carbon monoxide to insure the combustion is complete. The stack gases are monitored for opacity (particulates) and radioactivity. For many of the remaining substances, good real time monitors are still in the testing or development stage. For this reason, the emission levels of these are calculated by analyzing the feed materials and computing the emission level from the destruction ratios which were determined during the EPA acceptance test burns taking great care to duplicate the operating conditions. As a check on the performance, the destruction of carbon tetrachloride, which is very hard to destroy is carefully measured. From these test burns the EPA and the State establish permitted release levels.

The results of these methods show that over the last six years TSCA has averaged 0.6 % of its permitted stack emission levels for metals and other elements, and 2.4 % of the permitted radiation level (0.06 % of the local background radiation). The EPA standards are generally conceded to be conservative. The opacity of TSCA off-gasses is typically zero. Two downwind radiation monitors showed no radiation above background and are now turned off except when the thermal relief valve (TRV) is opened during untoward events which occur about twice a year.

Thermal release events sound scary but they indeed are quite safe for two reasons. First, just prior to the opening of the TRV any liquid feed is stopped in time for most of it to be processed and not released. The solid feed is stopped and purged as fast as possible at a lower temperature to be reprocessed later. Secondly, the down time taken to review the cause of the event is long enough so that the material released by the event is less than would have been released at full operation.

There also have been concerns that the trucking associated with TSCA contributes to the radioactive wastes stored in Oak Ridge and presents significant risks to our highways. First, since the TSCA ashes containing most of the radioactivity are returned to the shipper there is almost zero net gain of waste from TSCA operations. Second, since the total amount of radioactive waste shipped out is about ten times the gross amount shipped in, Oak Ridge gains a great deal in the exchange of services for waste we don't want kept here.

As for the shipping itself, radioactive wastes are greatly misunderstood. For the most part, they rank at the bottom of the US DOT hazard rankings along with smoke detectors. The small amount that ranks higher does so because it is contaminated solvents, not because of its radioactivity. All of it ranks below gasoline or propane and many other truckloads on the roads. Curiously, the highest ranking material includes medical isotopes (and spent nuclear fuel rods). These shipments receive great planning and care to avoid problems. The trucks carrying explosives are an even higher hazard and are unranked to be treated on a case by case basis.

In conclusion, TSCA is well designed , well operated and, unless the EPA standards are in error by a factor of about 100 or more, TSCA is safe. Due to the low hazard and extra care, radioactive waste shipments may be among the safest on your highways.