Seismic Monitioring

Question 1

The safe shutdown earthquake (SSE) and the operating basis earthquake (OBE) magnitude readings are

Answer 1

0.20g and 0.10g, respectively

Question 2

The seismic monitoring system is located…

Answer 2

…only in Unit 1.

Question 3

The purpose of the seismic monitoring system is…

Answer 3

… to detect and record seismic activity and determine its magnitude.

Question 4

If any accelerometer exceeds its setpoint…

Answer 4

… it will cause all recorders to start.

Question 5

The Seismic Monitoring Panel receives power from…

Answer 5

distribution panel NNN-D11.

Question 6

When seismic motion is reported or the SEISMIC OCCURRENCE alarm is annunciated in the control room, the STA is required to perform…

Answer 6

… a Level 1 evaluation within 1 hour.

Question 7

E-plan classifications must be made…

Answer 7

… within 15 minutes of when indications are available which show that an EAL has been met or exceeded.

Question 8

Summarize actions to take if the ground motion is greater that OBE.

Answer 8

Primary action is to notify each Unit of need to shutdown to mode 3 for any Unit that is in mode 1 or 2, and ensure that alarm response procedures are carried out for system isolation and inspection.

• Perform emergency plan classification
• If an OBE has been exceeded, all three units must be shutdown to mode 3.
• Suspend fuel handling operations.
• Various plant inspections and walkdowns.

Question 9

When ground motion is between ____ and OBE then…

Answer 9

For cases where an event has exceeded 0.01g but not the OBE, the Analysis of Seismic Event procedure requires communication to the Unit 1, 2 ,3 SM, component/system inspections, verification that AFN-P01 and associated