Operating rooms at John Cochran VA Medical Center reopened Thursday, more than a month after they were closed when employees noticed spots on surgical equipment. The VA also released plans for a $7 million expansion and equipment upgrade for the hospital's sterilization department. Investigators from Veterans Affairs and private companies spent the last month testing the hospital's sterilization process and determined the spots or corrosive pits on surgical trays were caused by "metallic etching from chemical reactions occurring at the atomic level," according to a statement released by the hospital. Sterilizing machines and equipment were replaced or fixed and any problems were resolved, according to hospital officials. The VA has not released the total cost of the shutdown and investigation. The director of the medical center earlier said the price had reached into the hundreds of thousands of dollars.