Reactor Scram Flashcards
How are crew made aware of a reactor scran by MRS ?
Sound the general alarm
Make full main broadcast:
-“reactor scram 3x, reduce electrical loads throughout the sub”
A Reactor scram is a full or partial shutdown of the reactor as a result of ?
An automatic scram caused by the reactor protection system ( full or partial )
A Full or partial scram manually initiated by the operators
A failure of the rod control system
What’s a full scram ?
What’s a partial scram ?
A full scram is when all 4 rod groups drop into the core fully to shutdown the reactor.
A partial scram is when 1 of the 4 groups drops into the core usually group 3 to shutdown down the reactor.
What is the main aim of the ships company and the reactor operators once the reactor has scrammed and is safe
reduce the steam demand on the system to conserve temp and facilitate the fastest possible recovery.
One of the key load reductions which occurs as part of the EOP action is the shutdown of one of the two TGs this results in ?
Short term loss of a non essential bus bar
The TG is shutdown
The requirement to carefully manage and where possible reduce the electrical load on the battery whilst reactor is shutdown.
The requirement to carefully manage and where possible reduce the electrical load on the battery whilst reactor is shutdown is managed by what ?
Check list 57
When an EOP occurs the ME dept increases its manning to ?
One full 6 man team on watch.
A second full watch (the team who would be next watch) closes up AFT of 74 bulkhead to provide a standby pool of manpower.
When the reactor scrams you have to reduce steam load so you shut down the two main engines as they use the most steam so how is propulsion supplied ?
Emergency Propulsion System
The EPM is supported by the battery only during the scram and the MR team will brief command on the time the battery can sustain the DC load to allow a decision to be made about running the diesels if required.
Where is the transfer from double main engine drive to EPS drive done from ?
Remotely carried out from the manoeuvring room
What is done to identify the reason for the reactor scram ?
Operators will carry out EOP actions and whilst keeping the plant and sub safe experts will investigate and diagnose the cause.
Once the cause has been identified a recovery plan will be produced and preps to restart the reactor will commence.
The MR team conduct a thorough assessment of all info associated with the scram and take the necessary actions to fix the problem these can include?
Checking that the plant related issue has not caused any damage and it’s safe to restart the reactor.
Repairing a defect.
Utilising an alternative form of control to enable the reactor to be restarted.
Ensuring the plant is in the condition which allows reactor restart to occur.
The MR team will begin to restart the reactor when ?
The scram EOP has been completed.
The issue causing the scram has been cleared.
The pre-requisites for scram fast recovery are met.
To restart the reactor the MR team will do what ?
Withdraw the rods to restart the reactor.
Restore steam propulsion.
Restore all systems and return the electrical system to the normal line up.
Once the MR team have conducted the scram fast recovery and the reactor is producing usable heat the plant will be returned to the normal line up by ?
Restoring all electrical supplies.
Transfer from EPS drive back to main engine drive.
Restart the second TG and restore the electrical distribution system to normal line up
Carry out a charge on the battery to restore capacity
Who carries out most of the required actions in a reactor scram and does it require the sub to go to emergency stations ?
Most of the required actions are performed by MEs and it doesn’t require the sub to be at emergency stations.
