Risk-Based Allowed Outage Time and Surveillance Test Interval Extensions for Angra 1

Table 5

Modification of pump probabilities to simulate staggered testing strategy.

System	Modification of common-cause failure to start probability to reflect staggered testing
SIS—Pumps A and B	𝑄^′CCFS=1/2⋅𝑄CCFS
SWS—Pumps A and B, or B and C, or A and C	𝑄^′CCFS=1/2⋅𝑄CCFS
SWS—Pumps A and B and C	𝑄^′CCFS=1/3⋅𝑄CCFS
AFWS—A and B motor-operated pumps	𝑄^′CCFS=1/2⋅𝑄CCFS