List 2

Question 1

Define plant state B

Answer 1

PSB is the normal shutdown state but with reduced temperature. This minimises energy release if an accident occurs.

Question 2

What is the function of the separator?

Answer 2

To remove trapped water from steam, this is achieved by centrifugal force.

Question 3

What is the function of the dump steam valve?

Answer 3

To control the discharge steam to the main condensers during the following operations:

a. Power range testing
b. Reactor cooldown
c. Emergency (upstream steam leak)

Question 4

Where does the valve spindle leakoff collect from?

Answer 4

1. Generator turbine control valve spindles inner pockets.
2. TGCSEV spindle inner pocket
3. MT ahead and astern throttle valve spindles inner pockets
4. Cruise valve spindle inner pocket

Question 5

What is the function of the steam drains system (SD)?

Answer 5

To remove condensate from the steam systems and associated equipment and to enable the systems to be completely drained of water during shutdown periods.

Question 6

Where is the astern section of the main turbine?

Answer 6

The astern section is at the FWD end of the rotor and consists of a curtis wheel.

Question 7

Name 4 items on the shaft line diagram.

Answer 7

Propulsor
Main turbines
Thrust block
Raft

Question 8

What is the system code for the main feed system?

Answer 8

FW

Question 9

Briefly describe the main circulating water pump

Answer 9

The pp consists of a 5 blade impeller mounted directly onto the rotor of a canned 2 speed AC motor.

Question 10

What is the function of the clean sea water system?

Answer 10

To supply pressurised and filtered sea water to the following:

a. Main shaft FWD and after seals
b. Main shaft emergency seal and FWD stern tube bearing
c. MCWP motor cooling circuit

Question 11

List 4 items cooled by the aft ship’s fresh water cooling system

Answer 11

a. CW plants
b. LO coolers
c. TG air coolers
d. Evaporators

Question 12

What happens if a power transient occurs?

Answer 12

The spray valve opens and sprays cold water onto the steam bubble. This collapses the bubble and reduces pressure back to the normal operating band.

Question 13

In what order do the primary relief valves open?

Answer 13

Steam, low then high.

Question 14

What is W501 and what does it do?

Answer 14

It is an electrically controlled solenoid vv which is activated in the event of a leak.

Question 15

What tanks does the coolant discharge system drain into?

Answer 15

Active and non-active

Question 16

Which valves do the VOG’s operate?

Answer 16

1. Main isolating valves (MIV)
2. Surge line isolating valves (SLIV)
3. High pressure decay heat removal isolation valves (HPDHR)
4. Primary relief valve isolating valves (RVIV)

Question 17

What are the functions of the reactor fresh water cooling system? What does it cool?

Answer 17

Functions to provide a continuous flow of cool water to the following:

a. MCP cooling jackets
b. Control rod drive
c. Mechanism cooling jackets
d. Coolant treatment system non regen cooler
e. Primary shield tank cooling coils
f. MG sets

Question 18

What is the function of the HPDHR system?

Answer 18

1. Remove decay heat from the reactor core following loss of normal heat sink
2. Remove decay heat from the core during normal shutdown

Question 19

System code for the primary shield system?

Answer 19

H