RTOS in Nuclear reactors

Nuclear ReactorPrinciple: Nuclear energy is converted into electricity. 235U and 239Pu are the most common nuclear

fuels. Controlled Nuclear fission reactions is the main

principle in nuclear reactors. Nuclear fission of heavy metals is exothermic.

U235 + n → fission + 2 or 3 n + 200 MeV Chain reaction occurs when a neutron collides with

these fuel elements. Heat produced from nuclear fission of radioactive

atoms used to produce steam. Steam rotates turbines and generates electricity.

Nuclear Fission reaction

Controlled Chain Reaction

Uncontrolled Nuclear Fission

Nuclear Reactor

Construction

Types of Nuclear reactor

Reac

tor

Based on Component of

plant

Research reactor

Power reactor

Based on Fuel

Uranium Fuel

Light water

Plutonium fuel

Pressurized water

Boiling water

Control system

Temperature of the reactor must be monitored regularly.

If temperature is high, control rods (neutron absorbers) should be lowered further and coolant circulation must be increased.

If temperature is low, control rods must move up facilitating further fissions.

If leaks are detected or very high temperature, then emergency signal should be issued.

TasksDetect temperature Leak Detection

Control system

Console

Control rods Coolent flow regulation

Pump Control

AlarmLow priorityMedium priorityHigh priority

RTOS Kernel Objects Control system uses tasks, messages and

semaphores

Several tasks with priorities High priority-Emergency SCRAM signal Medium priority-Non critical leaks,

overcapacity periods Low priority-communicates with

operators

Messages- communication between tasks Semaphores

Controls the console that display messages to operator

Schematic of Nuclear reactor labelled with Tasks

Pseudo Codereactortemp(){int actualvalue; \\ value read inexternal setvalue; \\ value the reactor should be running atwhile(1) \\ loop forever{sendmsg(timer.1min); \\ delay by 1 minute between each measurementactualvalue=readtemp(); \\ read reactor’s temperature

Pseudo Code contd.if(actualvalue<setvalue) sendmsg(flowcontrol.close); \\ reactor cooling down,

\\restrict water flowelse if(actualvalue>setvalue) if(actualvalue>=dangervalue) sendmsg(scram.now); \\ reactor too hot, needs to be shut downelse sendmsg(flowcontrol.open); \\ reactor heating up, allow more water to flow}}

Pseudo Code contd.Binary_semaphore semconsole(); // define binary semaphore to control the console

void console(semconsole){

Acquire semconsole binary semaphore;

Display the message on consore for operator;

. . . . . . . . .

Release the semconsole binary semaphore;

}

References

1. "How Nuclear Reactors Work." - Nuclear Energy Institute. Web.

2. "Nuclear Radiation and Health Effects." Radiation. World Nuclear Association, 22 May 2015. Web.

3. Predko, Myke. "Real Time Operating Systems." Programming and Customizing the 8051. Tata Mcgraw Hill ed. Tata McGraw Hill Limited, 1999. 323-326. Print.

4. Himmelsbach, Vawn. "Nuclear Plant Powers up on Real-time OS." ITBusinessca. 4 Oct. 2006. Web.