IOI-3 Plant Shutdown

Question 1

State the purpose of IOI-3, Plant shutdown

Answer 1

Safe shutdown from 12% power

Question 2

APRM scram and rod block setpoints with mode switch in STARTUP

Answer 2

rod block at >12%

Scram at >18% power

Question 3

APRM scram and rod block setpoints with the mode switch in RUN

Answer 3

rod block at <5%

no scram

Question 4

Admin cooldown rate for normal shutdown?

Answer 4

<90F

Question 5

Admin cooldown rate for soft shutdown?

Answer 5

<25F

Question 6

Minimum RPV temperature?

Answer 6

Vessel flange AND Head flange >70F

Question 7

Minimum reactor pressure to run two RWCU pumps in the post pump mode?

Answer 7

200#

Question 8

What is the reason for securing reactor depressurization while warming and placing shutdown cooling in service?

Answer 8

Prevent reactor pressure from decreasing below RHR pressure.

If reactor pressure decreases below RHR pressure, then steam voids can be created in the RHR piping resulting in WATER HAMMER when starting shutdown cooling.

Question 9

Reason for closely monitoring RPV level while placing shutdown cooling in service?

Answer 9

anomalies such as reference leg degassing

Question 10

What are the prerequisites of IOI-3?

Answer 10

12% power

turbine shutdown on turning gear

Recirc on LFMG with FCV @ max

RCIC lo press not bypassed

Question 11

Describe preferred pressure, temp, and reactor water level control in IOI-3 with:

MSIVs open?

Answer 11

Bypass valves, RWCU blowdown or FW on startup Lvl Control

Question 12

Describe preferred pressure, temp, and reactor water level control in IOI-3 with:

MSIVs closed?

Answer 12

SRVs, RCIC or CRD

Question 13

During a plant shutdown, when is the running RFPT secured?

Answer 13

500#

Question 14

During plant shutdown, what happens at:

500#?

Answer 14

The running RFPT is secured

Question 15

During plant shutdown, what happens at:

200#?

Answer 15

One RWCU pump is secured

Question 16

During plant shutdown, what happens at:

<135#

Answer 16

SDC is placed in service (as close to 40# as possible)

Question 17

During plant shutdown, what happens at:

120#

Answer 17

RWCU is placed into the pre-pump mode

All running condensate booster pumps are secured

Question 18

During plant shutdown, what happens at:

60#

Answer 18

RCIC automatically isolates

Question 19

During plant shutdown, what happens at:

<210F

Answer 19

Head vents are realigned to the Drywell Equipment Drain sump

Question 20

Do NOT run two RWCU pumps in post pump mode at <200# RPV pressure because why?

Answer 20

possible loss of NPSH can occur