Containment system and plant states

Question 1

State the function of the containment system

Answer 1

1. To prevent the release of fission products from the RC, and the submarines pressure hull
2. To protect the general public from effects of a reactor event

Question 2

What is included in the primary shielding?

Answer 2

1. Fuel plates
2. RPV
3. Primary pipework
4. Primary shield tank
5. Poly blocks

Question 3

What is included in the secondary shielding?

Answer 3

1. RC bulkheads
2. Tunnel and RSC deck
3. Hover tanks
4. Diesel oil fuel tank
5. Aft missile comp tank

Question 4

What is a hard system?

Answer 4

Systems that could withstand the maximum pressure of a reactor event without rupturing

Question 5

What is a soft system?

Answer 5

Soft systems cannot withstand the maximum pressure of a reactor event without rupturing

Question 6

List soft systems fitted with automatic valves

Answer 6

1. LP bilge system
2. Trim system
3. Ventilation system
4. SG reliefs
5. Chilled water system
6. SG water sampling
7. Atomphere analysing
8. Steam drains
9. APD
10. Tunnel pressure equalising (LPA)
11. MPA
12. Feed transfer system
13. Ballast system
14. AFT AFFF system

Question 7

Describe plant state A

Answer 7

1. Plant pressure greater than 35 bar 
or 
2. Plant temperature greater than 93 degrees celsius 
or
3. More than one CRDM is energised

Question 8

Describe plant state B

Answer 8

1. the reactor is shutdown
2. plant pressure is less than 35 bar
3. Plant temperature is less than 93 degrees celcius
4. Not more than one CRDM is energised

Question 9

Describe plant state C

Answer 9

1. The reactor is shutdown
2. Plant pressure less than 35 bar
3. Plant and pressuriser temp less than 93 degrees c
4. All CRDM’s de energised and fuses removed
5. Two means of decay heat removal
6. The decay heat rate is less than the heat removal capacity of the decay heat removal system
7. Plant pressure not being maintained by a steam bubble