The Best Estimate Plus Uncertainty Challenge in the Current Licensing Process of Present Reactors

Table 2

Excerpt from the list of PIE for Atucha II Chapter 15 of FSAR.

No	Transient	Section FSAR	Adopted evaluation model	Class of accident
Increase in heat removal by the secondary system		15.1
2	FW system malfunctions that result in an increase in FW Flow (Stuck Open FW Control Valve)	15.1.2	CSA	AOO
Spectrum of steam system piping failures inside and outside of containment (MSLB)		15.1.5	—
5	Leak of MS line inside the containment	15.1.5.1	CSA/RCA/CBA	DBA
9	Inadvertent closing of the moderator cooler bypass CV	15.1.7	CSA	AOO
36	Uncontrolled CR withdrawal at the particular Power level that yields the most severe results	15.4.2	CSA	AOO
41	Spectrum of rod ejection accidents	15.4.7	CSA	DBA
Spectrum of SGTR		15.6.3	—
46	Single SG tube rupture (“Bordihn”: SG Tube Failure)	15.6.3.1	CSA	DBA
56	0.1A LOCA cold with sump swell operation	15.6.5.1.2.4	QA	DBA
Large break LOCA		15.6.5.1.3	—
57	2A LOCA cold (DEGB. Different Break Sizes and Positions are investigated)	15.6.5.1.3.1	CSA/RCA/CBA	SBDBA
72	Leakage on the refueling machine and auxiliary equipment	15.8.2	RCA	DBA
Anticipated transients without scram (ATWS)		15.9
74	Mechanical failure of the control rods in case of emergency power mode	15.9.1	CSA	SBDBA