Resolution of Generic Safety Issues: Item A-6: MARK I Short-Term Program (Rev. 2) ( NUREG-0933, Main Report with Supplements 1–34 )
During the conduct of a large scale testing program for an advanced design BWR pressure suppression containment system (MARK III), new suppression pool hydrodynamic loads associated with a postulated LOCA were identified which had not been explicitly included in the original design of the MARK I containment systems. These additional loads result from the dynamic effects of drywell air and steam being rapidly forced into the suppression pool (Torus) during a postulated LOCA event. Consequently, it was determined that a reassessment of the MARK I containment system design would be required. This item was originally identified in NUREG 03712 and was later declared a USI in NUREG-0510.186
This USI was RESOLVED with the publication of NUREG-0408.701 All plant-unique analyses and required equipment modifications were reviewed and accepted by the staff and appropriate TS changes were made by the affected licensees.