PIPER-ONE Research: the experiment PO-SD-8 related to the evaluation of the Isolation Condenser performance. Post-test analysis carried out by RELAP5/MOD3-/7j Code

PIPER-ONE was a Boiling Water Reactor (BWR) simulator installed at the Scalbatraio Laboratory managed by Dipartimento di Costruzioni Meccaniche e Nucleari (DCMN, now DICI) of University of Pisa. PIPER-ONE was designed and constructed after the Three Mile Accident in 1979 to better understand Small Break Loss of Coolant Accident (SBLOCA) scenarios in Boiling Water Reactors (BWR). A dozen experiments were performed, including the experiment at the basis of the International Standard Problem (ISP) 21 in relation to which some information is given below. PO-SD-8 is a Natural Circulation experiment scenario expected to occur in Simplified Boiling Water Reactors (SBWR) where the use of the Isolation Condenser (IC) is foreseen by design in case of accident. The present experiment aims at identifying the capabilities of PIPER-ONE in performing this type of test and at proving the quality of the design of the installed IC