NPCIL 18May2005 Recent Advances in Control and Instrumentation of Indian PHWRs'

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NPCIL 18-May-2005 Recent
Advances in Control and Instrumentation of
Indian PHWRs.

• Umesh Chandra
• Sr. Executive Director (RD,CI IT)
• Nuclear Power Corporation of India Limited
• TWG-NPPCI Meeting
• IEAE,Vienna
• May,2005

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NPCIL 18-May-2005

• The Present NPP Scenario in India
• 14 operating NPPs with a total capacity of 2720
  MWe
• 9 plants under construction with a total capacity
  of 4460 MWe.
• -These include 6 PHWRs, 2 PWRs (VVERs) and
  
• 1 PFBR.

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Nuclear Power Plants in Operation
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NPCIL 18-May-2005

• NPPs under Construction
• Units Location Type Capacity(MWe) Scheduled
• 
  Criticality
• TAPP-4 Tarapur PHWR 540 Oct. 05
• TAPP-3 Tarapur PHWR 540 July
  06
• KGS-3 Kaiga PHWR 220 Dec.06
• RAPP-5 Rawatbhata PHWR 220 May 07
• KGS-4 Kaiga PHWR 220 June 07
• RAPP-6 Rawatbhata PHWR 220 Nov.07
• KK-1 Kudankulam PWR (VVER) 1000 Sept.07
• KK-2 Kudankulam PWR (VVER) 1000 Sept.08
• FBR Kalpakkam FBR
  500 2010
• 
  Total 4460

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THREE STAGE NUCLEAR POWER PROGRAM

• Stage - II
• Fast Breeder Reactors
• 40 MWth FBTR - Operating since 1985
• Technology Objectives realised
• 500 MWe PFBR-
• Under Construction
• POWER POTENTIAL ? 350,000 MWe

• Stage - III
• Thorium Based Reactors
• 30 kWth KAMINI- Operating
• 300 MWe AHWR- Under development
• POWER POTENTIAL ? Very Large.
• Availability of ADS can enable early
  introduction of Thorium on a large scale

• Stage I PHWRs
• 12- Operating
• 6 - Under construction
• Several others planned
• Scaling to 700 MWe
• Gestation period being reduced
• POWER POTENTIAL ? 10,000 MWe
• LWRs
• 2 BWRs Operating
• 2 VVERs under
• construction

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NPCIL 18-May-2005

• Latest PHWR Plant at Tarapur
• TAPP-4 A 540 MWe PHWR has been made
  critical at
• Tarapur On 6th March, 2005
• Criticality was achieved in less than 5 years
  after first pour of concrete
• The plant will be synchronized to the grid
  shortly
• The plant is first of a kind, designed and built
  indigenously.

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NPCIL 18-May-2005

• 540 MWe PHWR Plants -TAPP34
• 392 Coolant Channels
• 37 Element Fuel bundles
• Calandria 8.5 Meters diameter and 6 meter long
• Two identical valveless PHT loops
• Pressuriser for normal PHT control
• ECCS High pressure water injection in all
  headers
• Two Independent Fast acting Shut down Systems
• Solid Shut-off Rods Liquid Poison Injection
• Regulation by Liquid Zone control System
• Computer based systems for reactor control,
  process
• control, monitoring and data acquisition

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NPCIL 18-May-2005

• New Control and Instrumentation for New
  Systems
• in 540 MWe PHWR over 220 MWe
• Liquid Zone Control System for reactor power
  regulation
• and controlling spatial xenon oscillations.
• In-core Flux Monitors (SPNDs) for control and
  protection of
• the Reactor.
• Use of Instrumented channel Monitoring System
• (ICMS) for bulk thermal power and combined
  zone
• power estimation.
• Introduction of Pressurizer in PHT Pressure
  Control.
• Shutdown system System2 Process Instrumentation

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NPCIL 18-May-2005

• Main Control Room of TAPP-34 (540 MWe PHWR)
• Unitized MCR
• Mosaic panels for miniaturization, flexibility
• and minimum construction time.
• Human engineering principles fully applied in
  design.
• Digital multi loop controllers and paperless
  recorders used and networked to central operator
  information system.

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NPCIL 18-May-2005

• Main Control Room Philosophy in TAPP-34
• The Main Control Room employs hybrid systems.
• System wise panels in the background and operator
  controls in front.
• Panels for different plant functions contain
  discrete control devices and displays.
• Comprehensive Plant Status in available on COIS
  screens on each panel.
• The operator consoles provide displays and
  operator interaction facilities for individual
  system.

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NPCIL 18-May-2005

• Main Features of IC of 540 MWe PHWR
• Most of the control, monitoring and test and
  
• surveillance functions are computerized.
• Some protection functions use microprocessors
• The information from all the above systems as
• well as from stand alone controllers
  recorders
• are sent to a Central Operator Information
• System (COIS) through Gateways.
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NPCIL 18-May-2005

• Evolution of Digital Systems in Indian PHWRs
• Computerization of Control and Monitoring
  functions began from NAPS (1990) incorporating -
• - Reactor Regulating System
• - Control of on-power refueling machines
• - Control Room Computer System
• Protection function computerized in KAPS
  (1993-95)
• - Programmable Digital Comparator System
• - Channel Temperature monitoring system

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NPCIL 18-May-2005

• Main Control Systems in KGS-1,2 and RAPS-3,4
  plants (1999-2000) including Station PLC,
  DPHS-PCS and DPHS-RRS are computerized.
• In TAPP-34, all major Control, Monitoring, Test
  Surveillance and operator information systems
  are digitized.
• Protection functions are hardwired (except PDCS
  in
• SDS-1) with a provision to monitor important
  parameters through Test and Monitoring Systems.

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NPCIL 18-May-2005

• Technology Employed for Digital IC
• All digital systems employed for IC are custom
  built systems.
• The systems are designed and developed
  indigenously.
• Hardware manufacture, integration and
  installation is done by Electronics Corporation
  of India.
• Verification and validations carried out by an
  independent IV V Group.
• Full documentation with IV V reports are
  submitted for licensing by AERB.

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NPCIL 18-May-2005

• Independent Verification and Validation in
  NPCIL
• Design Basis Report (DBR), approved by AERB, is
  the baseline document.
• The reviews are carried out at the following
  stages of system development
• -  Requirements formulation
• - System Architecture design
•   -  Hardware/Software Specification
• -  Hardware/Software Implementation
• - System Integration

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NPCIL 18-May-2005

• For each system, a Task Force is responsible for
  the entire review process.
• The reviews for design documents are carried out
  as per checklists.
• The system is validated by IVV team
  developers.
• The depth of review for software code walkthrough
  varies with the safety class of the system.
• The system documents and their review reports and
  the report on validation of the system by IVVC
  Task Force are submitted to AERB for regulatory
  approvals.

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NPCIL 18-May-2005

• Proposal for TC meeting
• Dependability Issues in Software Maintenance
• Computer based IC systems are developed,
  documented and tested in accordance with rigorous
  procedures.
• In the maintenance phase, hardware changes in the
  system are generally well analyzed, tested and
  documented in a dependable way due to maturity in
  hardware engineering methodologies. However, due
  to the nature of work the additions/modifications
  in the software tend to be relatively less well
  analyzed, tested and documented, leading to side
  effects that may be discovered much later in
  systems operating life. Due to incompleteness in
  software details documentation, certain
  information about the system design may not be
  captured, leading to difficulties in later
  maintenance.

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NPCIL 18-May-2005

• The proposed TC meeting is aimed at bringing
  together the experts from IAEA member states for
  sharing their experiences in software maintenance
  and methods to ensure dependability of the
  software maintenance process. The proposed topics
  for discussion are
• Experiences in software maintenance these would
  cover the case histories for software errors
  introduced during maintenance and their root
  cause analysis
• Software change procedures impact analysis,
  change implementation and validation
• Software tools to support software maintenance

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NPCIL 18-May-2005

• Proposal for TC meeting
• Improving Nuclear Power Plant Performance
• The requirement of maximizing nuclear plant
  performance in terms of fuel utilization, plant
  power output and plant availability has to be
  balanced against the safety requirements. The
  limits on plant process parameters for safe
  operation are generally more conservative to
  provide for the inaccuracy in plant parameter
  measurements or uncertainties in system state
  estimation. These are, in turn, dependent on
  sensors, IC systems and safety analysis. Plant
  equipment health monitoring also plays an
  important role in optimizing maintenance and
  plant availability.

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NPCIL 18-May-2005

• The proposed TC meeting would focus on exchange
  of information on various factors involved in
  improving NPP performance,including
• -Sensor Technologies
• -Instrumentation and Control (IC) systems
• -Monitoring, test and maintenance management
• Systems
• - Human issues
• - Safety Analysis

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NPCIL 18-May-2005

• Thanks for your attention