A van carrying radioactive materials used for medical diagnostic purposes overturned on the University Avenue on-ramp to the westbound Interstate 10 Freeway in Redlands, splitting open a case. No radiation was released in the area, authorities said. Ellen Donlin, driver of the van owned by Syncor International Corp. of Sylmar, was not injured in the accident, a company spokesman said. When the van spun off the road, a case of lead bottles containing low-level radioactive materials was cracked. California Highway Patrol officials who monitored the area said the lead bottles did not appear to be damaged and they found no radiation leakage.