Modernization of I

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Modernization of IC systems at theNPP Krko
Darko Pavlin, Sinia Cimea and Matja
Podjavorek Slovenian Nuclear Safety
Administration
1st Joint EPRI IAEA Workshop on Modernization
of Instrumentation and Control (IC) Systems in
NPPs 3-6 October 2006, Vienna
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Introduction

• NPP Krko
• Major NPP Krko (IC) systems modifications
  implemented since 1983
• Process Information System (PIS)
• Annunciator System Replacement
• Slovenian (IC) legislation
• Conclusion

NPP Krko
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NPP Krko

• Westinghouse
• 2 loop PWR
• capacity 700 MWe
• investment of republic Slovenia and Croatia
• architect engineering - Gilbert
• decision for construction - 1970
• beginning of operation - September, 1981
• synchronisation to electric network - October,
  1981
• commercial operation - January, 1983

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Major NPP Krko IC systems modifications
implemented since 1983

• ATWS Mitigation Safeguard Actuation Circuitry
  (AMSAC)
• Inadequate Core Cooling Monitoring System (ICCMS)
• Process Information System (PIS)
• Annunciator System
• Off-line data acquisition of chemical analysis
  data (prim sec. sampling) - Chemnet
• RCP and TU Vibration monitoring
• Core Monitoring and Operations Support System,
  BEACON-TSM System
• Meteorological Monitoring System
• Seismic Instrumentation

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Major NPP Krko IC systems modifications
implemented since 1983, cont.

• SG Blowdown Control (digital discrete controllers
  and digital indicators)
• Heater Drain Control, PLC
• Condensate Polishing, PLC
• Water Treatment, PLC
• Switchyard Control Monitoring (ABB Micro SCADA
  - although it has remote control capabilities in
  the MCR it is used for switchyard monitoring
  only)
• Emergency Response Data System (ERDS)
• FP- Fire protection (Detection) system

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Process Information System (PIS)

• The Process Information System (PIS) was
  installed in NEK in 1992 as part of the post TMI
  requirements
• The main purpose of the PIS was to monitor
  critical functions (Critical Function Monitoring
  System - CFMS)
• CFMS was designed to meet SPDS (Safety Parameter
  Display System) requirements of NUREG-0696
  (Functional Criteria For Emergency Response
  Facilities), NUREG-0737 (Clarification of TMI
  Action Plan Requirements) Item I.D.2, and
  NUREG-0737 Supplement 1
• Major features of the CFMS include
• A Critical Safety Function Monitor which defines
  conditions to assess the status of six critical
  safety functions (criticality, core cooling, heat
  sink, RCS integrity, containment and RCS
  inventory),
• Engineering Safety Features equipment monitoring
• Plant process and area radiation monitoring, and
• Meteorological conditions monitoring

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Process Information System (PIS)

• Other functions of the PIS are
• Insufficient Core Cooling Monitoring System
  (ICCMS)
• Post-trip review data acquisition
• Nuclear process calculations
• Primary to secondary leakage calculations
• Calorimetric calculations
• QPTR evaluations
• PIS is a non-safety related system used to
  provide supplementary information to the operator
  and to inform him of off-normal conditions
• Data is collected by the redundant data
  acquisition equipment and transmitted to a fully
  redundant distributed computer system
• PIS data is also obtained from other process
  computers through separate serial or fast
  Ethernet communication links

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Process Information System (PIS)

• Last upgrade of PIS system (May 2006) included
• Wax replaced with Alpha technology
• The newest ABB PMS platform
• New data connections (MicroScada, Beacon, VibMon,
  CK-CPS)
• Upgraded application software inclusion of ARP
  procedures
• GPS time synchronization
• The effects of the upgrade were
• Improvement of overall PIS performance and
  availability during transients
• Expanding the PIS capability to receive and send
  process parameters to different process computers
• Easier and less expensive maintenance
• PIS can now also be used for issuing commands to
  other non-safety digital control systems
• Issues during licensing
• Effects on safety systems (control room
  ventilation)
• Expansion of PIS functions to control other
  systems

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Annunciator System Replacement

• former Annunciator System (Betalarm1000)
• gathered a switching contact and controlled the
  operation of a lampbox to turn on and off a
  dedicated lamp window
• was installed 25 years ago and it was becoming
  increasingly more difficult to provide technical
  support and replacement parts
• new Annunciator System (SER4100 BL1500)
• use of flagship sequential event recorder to
  record switching contact which are time stamped
  and processed to a number of outputs
  (annunciators, visual display units, printers and
  computer for data archiving and post analysis)
• the BL1500 has been designed to have the
  identical form factors as the lampboxes supplied
  25 years ago with the BL1000.
• therefore the operators were presented with an
  identical control room as before the installation

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Annunciator System Replacement

• Advantages of the new system
• Event recording
• Post event analysis
• Redundancy
• Expandability
• Re-configuration flexibility
• Advanced Alarm Filtering capabilities
• Availability of spares

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Annunciator System Replacement

• Open issue during licensing
• approval of software
• SNSA has taken into consideration
• system standards list
• NPP reference list
• Post-performance problem
• inoperability of power supplier
• new configuration without power supply redundancy

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Slovenian (IC) legislation

• ZVISJV Act on protection against ionizing
  radiation and nuclear safety (Official Gazette of
  the Republic of Slovenia no. 67/2002, 24/2003,
  46/2004)
• Reg. E1 Regulation on the conditions for
  siting, construction, commissioning, commencement
  of operation and operation of nuclear facilities
  (Official Gazette of the SFRJ no. 52/88)
• Reg. E2 Regulation on the compilation and
  contents of the safety report and other
  documentation necessary for the assessment of the
  safety of nuclear facilities (Official Gazette of
  the SFRJ no. 68/88)
• Some WENRA requirements on IC systems are
  already included in current Slovenian nuclear
  legislation, and also new regulation (consistent
  with WENRA) is being prepared
• Most of the WENRA requirements are already
  implemented in the Krko NPP

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Conclusion

• During the 20 years of commercial operation more
  than 400 modifications (and a lot of this
  modifications are related with IC system) have
  been implemented in the NPP Krko
• The next important modifications will be the DEH
  (Digital Electro Hydraulic) system for the
  control and supervision of the TG
  (Turbine-Generator) set (scheduled for outage
  2007)
• All of these modifications are performed on the
  non-safety related IC system
• New regulations will be in compliance with the
  WENRA requirements

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Thank you for your attention!
Triglav with 2864m the highest mountain in
Slovenia