Popis: |
Two design-basis accidents for the AP-600 reactor are formulated and evaluate~ in which significant bypass of the principal pH control system occurs. Some iodine released from the reactor primary system is retained in the Incontainment Refaeling Water Storage Tank (IRWST) water, never entering the containment where trisodium phosphate produces a high pH. Some of this iodine is volatilized and is transported into the reactor containment airspace. in the worst case, a small fraction is released to the environment at design-basis leak rate, yielding a total cumulative iodine release at 30 days of 0.0352 mol (0.023% of core iodine inventory) due to the iodine volatilization bypassing the pH control system. No fission product removal in the containment atmosphere (i.e., natural deposition sprays) is considered. |