temperature control

1. By :
Chandra Mohan Sharma

2. Contents
 Company Profile
 Introduction
 Integrated Development Environment
(IDE)
 Real Time Operating System(RTOS)
 CPU Board (RT-20)
 RTD Input Module (RIM)
 Resistance Temperature Detector(RTD)
 Conclusion

3. Company Profile -NPCIL
 Nuclear Power Corporation of India Limited is a Public Sector Enterprise under
the administrative control of the Department of Atomic Energy (DAE),
Government of India, established in 1987.
 NPCIL is responsible for design, construction, commissioning and operation of
nuclear power reactors.
 NPCIL is presently operating 20 nuclear power reactors with an installed capacity
of 4780 MW.
 The Mission of the Company is ‘To develop nuclear power technology and to
produce nuclear power as a safe, environmentally benign and economically viable
source of electrical energy to meet the increasing electricity needs of the country'.
 The operating nuclear power units are:
 Tarapur Atomic Power Station Units-1,2,3&4.
 Madras Atomic Power Station Units-1&2.
 Rajasthan Atomic Power Station Units-1 to 6.
 Narora Atomic Power Station Units-1&2.
 Kakrapar Atomic Station Units-1&2.
 Kaiga Generating Station Units-1 to 4.

4. Introduction To CTMS
 CTMS :- Channel Temperature Monitoring System.
 CTMS as the name suggests, is a system to monitor the temperature of the
channels or hard-water pipes used in the reactor core which carry the heat
produced due to the fission reaction inside the core.
 These pipes carry the hot D2O to the steam generator. There are RTD’s at
the outlet of the each channel which detects the out temperature. This
system uses dual RTD’s so that the data from the field is continuously
available in case one RTD fails.
RTD
Fuel Channel
D2O Pipe Steam Generator
Fuel Channel
D2O Pipe
Fuel Channel
D2O Pipe
Fuel Channel
D2O Pipe
Fuel Channel

5.  Above given diagram is the block diagram of the Test Setup for the
Channel Temperature Monitoring System (CTMS).
 The data from the field is acquired by the RTD Input Module (RIM) board
and then it is sent to the RT20 board for processing and this board is
connected to a Cathode Ray Tube (CRT) Monitor which shows the result of
the processing done by RT20 board on the data acquired from the field.
 CRT is connected to the RT20 board on connector P4 by a serial
connection cable. RIM uses the I/O bus to transfer the data to the
processor for processing. The Input Output Interface Module (IOIM) and
Versa Euro Module (VME) are both types of interfacing modules that are
used to interface different boards to each other.

6. CTM Resource Requirements
The basic requirements for the design and development of CTM System are as
follows:
 Tornado Integrated Development Environment (IDE)
 Real Time Operating System (RTOS)
 Serial Connection Cables
 CPU Board (RT-20 Board)
 RTD Input Module Boards (RIM)
 ROM (Relay Output Module)
 IOIM (Input Output Interface Module)
 GBINC Board
 Resistance Temperature Detectors (RTDs)

7. Tornado IDE
 The Integrated Environment is used for software cross
development. It is an efficient way to develop real time and
embedded applications with minimal intrusion on the target system.
 Here we use “Tornado 2.2” which is an IDE developed by Wind
River Systems, Inc. and consists of VxWorks, a high performance
real time OS, application building tools (compilers and associated
programs), IDE i.e. C and C++ compilers and makefiles etc.
 Cross development environment ensures the smallest possible
differences between the target system during development and the
system after development.

8. Key features of the IDE are:
 An integrated source-code editor.
 A project management facility.
 Integrated C and C++ compilers and make.
 The browser, a collection of visualization aids to monitor the target
system.
 CrossWind, a graphically enhanced source-level debugger.
 WindSh, a C-language command shell that controls the target.
 An integrated version of the VxWorks target simulator, VxSim.
 An integrated version of the WindView software logic analyzer for
the target simulator.
 Customization options for many features, including integration of
alternate editors and configuration management (CM) tools, as well
as the entire Tornado GUI itself.

9. Building Projects in Tornado
There are two types of applications that can be created using tornado.
 Downloadable Application: A downloadable application consists of one
or more relocateable objects modules, which can be downloaded and
dynamically linked to VxWorks, and then started from the shell or
debugger.
 Bootable Application: It consists of an application linked to a VxWorks
image. It starts when target is booted.
To create a downloadable application, you must:
 Create a project for a downloadable application.
 Write your application, or use an existing one.
 Add the application files to the project.
 Build the project.
You can then download the object module(s) to the target system and run the
application.

10. A bootable application is completely initialized and functional after a target has
been booted, without requiring interaction with Tornado development tools.
A bootable application can be created as follows:
 Add the application project(s) to the VxWorks workspace (or vice versa).
 Edit the VxWorks initialization file usrAppInit.c, adding calls to the
application's initialization and startup routines.
 Use the project facility to help scale VxWorks.
 Build the bootable application.

11. VxWorks (RTOS)
 Modern real-time systems are based on the complementary concepts of
multitasking and intertask communications. A multitasking environment
allows a real-time application to be constructed as a set of independent
tasks, each with its own thread of execution and set of system resources.
The intertask communication facilities allow these tasks to synchronize and
communicate in order to coordinate their activity.
 Another key facility in real-time systems is hardware interrupt handling,
because interrupts are the usual mechanism to inform a system of external
events. To get the fastest possible response to interrupts, interrupt service
routines (ISRs) in VxWorks run in a special context of their own, outside any
task's context.
 Multitasking provides the fundamental mechanism for an application to
control and react to multiple, discrete real-world events. The VxWorks real-
time kernel, wind, provides the basic multitasking environment. Multitasking
creates the appearance of many threads of execution running concurrently
when, in fact, the kernel interleaves their execution on the basis of a
scheduling algorithm . VxWorks uses Round Robin Scheduling Algorithm.
On a context switch, a task's context is saved in the task control block (TCB).

12. Task State Transitions:
Task Scheduler Control Routines
CALL DESCRIPTION
kernelTimeSlice() Controls round-robin scheduling.
taskPrioritySet( ) Changes the priority of a task.
taskLock( ) Disables task rescheduling.
taskUnlock( ) Enables task rescheduling.

13. CPU Board (RT-20)
 This is the main module where microprocessor resides and it is identified
as RT-20. It is a VME Bus based CPU Board and uses Motorola
MC68020, a 32-bit microprocessor at 16 MHz Clock speed. The Board
has provision for 512 KB of EPROM (256 KB used only) and dual ported
high speed 512 KB of battery backed SRAM.
 The board has provision for MC68882 Floating Point Numeric
Coprocessor. It has Dual Asynchronous Receiver Transmitter
(DUART).
 VME Bus interface is provided using VIC068A.

14. Decode & Control Local Memory EPROM On Board IO SIO PIO
Logic SRAM
RTC DISP DPSRAM
MC68020 Floating Point
Processor
LOCAL BUS
Micro-Controller
MC68881
VME ADD DATA & FRONT PANEL Front Panel Switches and P3, P4
Control INDICATORS Connectors
VIC068A
VME BUS
Block Diagram of RT-20 Board

15. RTD Input Module (RIM)
 RIM stands for RTD Input Module. This is a standard Euro size module with
two 64 pin Euro connectors naming P1 and P2. The inputs from field RTDs
come to the module on P1 and P2 is placed on I/O motherboard.
 INPUT SECTION: It accepts 32 RTD inputs on P1. The inputs from field
RTDs come to the module on P1. The RTD inputs from field come to TB
(Terminal Box) and then these are transmitted to RIM through Flat Ribbon
Cable (FRC).
 The resistive input is converted to voltage input by passing 1 mA constant
current through RTDs and voltage across the RTDs is fed to the MUX.
 The inputs are multiplexed using 8-channel multiplexer and output is fed to
an instrumentation amplifier. The inputs are band limited, so that the noise
should be filtered out.

16.  ADC: The output of this amplifier is connected to the Buffer input of an
Analog to digital converter (ADC). The ADC used, is a 12-Bit Successive
approximation type, with the maximum conversion time of 10 µS.
 The End of Conversion is sensed by the status pin of the ADC which can
be accessed by the D0 bit on the output data bus on P2 connector.
 OUTPUT SECTION: The 12-bit output of ADC then goes to buffers (U11,
U12 & U15). This data is now ready to access by RT-20 through IOIM for
further manipulation or decision making.
 The module interfaces with the I/O Bus on P2 connector.

17. There are 32 channels depicted by c1 to c32. Also all channels are connected to their
respective RTD’s depicted by RTD1 to RTD32

18. Resistance Temperature Detector(RTD)
 RTD (Resistance Temperature Detector) is basically a temperature
sensitive resistor.
 It is a positive temperature coefficient device, which means that the
resistance increases with increase in temperature.
 The resistive property of the metal is called its resistivity. The resistive
property defines length and cross sectional area required to fabricate an
RTD of a given value.
 The resistance is proportional to length and inversely proportional to the
cross sectional area:
R= r X L / A
Where R = Resistance (ohms)
r = Resistivity (ohms)
L = Length
A = Cross sectional area

19. Conclusion
 The Temperature monitoring system is one of the primary
necessities in a nuclear power plant as the temperature in the
reactor must be controlled so that a related hazard could be
prevented.
 This will help safeguard many lives, amenities and equipments.
This is why the motto of NPCIL is “Safety First and Production
Next”.
 So for this sole purpose there are Channel Temperature
Monitoring Systems fitted in every nuclear power plant which
monitors the temperature of the reactor core and if the temperature
rises or falls above or below the respective predefined threshold
value, the system generates an alarm and some predefined action
related to that alarm is performed.

21. QUERIES??????