IAEA Technical Working Group on Nuclear Power Plants Control and Instrumentation

1
IAEA Technical Working Group on Nuclear Power
PlantsControl and Instrumentation

• Vienna, AUSTRIA
• 23 to 25 May 2005
• Mario Oscar Sabransky
• IC and Electrical Maintenance Atucha 1 NPP
• Nucleoeléctrica Argentina Sociedad Anónima

2
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• INTRODUCTION
• 1974 Atucha 1 NPP (CNA1) began commercial
  operation.
• 1984 Embalse NPP (CNE) began commercial
  operation.
• 1980 Atucha 2 NPP (CNA2) started construction.
• 1994 NA-SA become operator of the in service
  NPPs and responsible for the management of human
  resources, equipments and installations of the
  temporarily stopped CNA2.

3
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants
TECHNICAL OVERVIEW
Since July of 2001 CNA1 reactor uses slightly
enriched Uranium (0,85 in weight)
4
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• Atucha 1 NPP milestones
• In 1989 a damage in a reactor cooling channel
  determined a long reactor internal updating
  process wich ends in the recent 2005 Scheduled
  Outage.
• Replacement of the 252 reactor cooling channels.
• Replacement of the 29 reactor control rods guides
  tubes.
• Refurbishing of the 29 reactor control rods
  lineal motors cabling.
• Replacement of all the reactor In Core
  instrumentation.
• Replacement of all the reactor Ex Core neutron
  flux detectors cabling.
• Installation of new level meters inside the
  reactor vessel.
• Installation of vibration instrumentation on the
  reactor vessel.

5
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• Atucha 1 NPP additional milestones
• 1996 Replacement of the electric generator
  stator and the complete associated
  instrumentation.
• 1999 - Replacement of the complete electric fast
  transfer device for new ABB digital technology.
• 2001 Reconvertion of the NPP due to the use of
  slightly enriched Uranium (0,85 in weight).
• 2003 Erection commissioning of a new reactor
  emergency cooling system (Second Heat Sink) with
  complete digital Teleperm XS instrumentation.
• 2003 - Replacement of the 400 MVA main block
  transformer. (Manufactured by a national
  company).

6
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• REACTOR PROTECTION SYSTEM (RPS)
• CNA1 Simatic DM (23 Dynamic logic) Teleperm B
  (A).
• Some added reactor trip criterions were
  installed with Simatic EDM (23 Dynamic logic)
  analogic signal processing Teleperm C Iskamatic
  A.
• A new emergency reactor cooling system was
  installed in complete digital technology Teleperm
  XS. Additional improvements and modifications to
  the whole RPS were carried on.
• CNE Relay 23 Static logic (SL) Fischer
  Porter (A)
• (A) analogic technology.
• (D) digital technology.
• (SL) Discrete static logic.

7
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• REACTOR CONTROL LIMITATIONS
• CNA1 Teleperm B (A) Simatic N (SL).
• Additional digital instrumentation were
  added allowing to obtain information in real time
  about the control rods behavior in case of a
  reactor trip.
• Improvements in the electric connection and
  cabling of the control rods were performed.
• CNE Control Computer VARIAN (D)
• AUXILIARY SYSTEMS CONTROL
• CNA1 Teleperm B (A).
• CNE Fischer Porter (A), ELSAG (A), Taylor.
• A new digital controller is in a
  qualification stage.

8
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• NEUTRON FLUX MEASUREMENT
• CNA1 Simatic (A) Teleperm B (A).
• Replacement of amplifiers using F3 (Fit,
  form Function) methodology with analogic
  modules built in the National Atomic Energy
  Commission (CNEA) laboratories.
• Installation of digital data acquisition
  system and special software in order to generates
  information about the neutronic noise from the
  in core netron flux detectors and from the vessel
  accelerometers instrumentation in order to detect
  abnormal phenomena (Early alert system) (Alerta
  Temprana).
• The whole in core ex core detectors and
  cabling inside the reactor room were replaced.
  Some detectors were provided by a national
  manufacturer associated with the CNEA.
• CNE Keithley (A), Sintrex (A).
• Some detectors and cabling inside the
  reactor room were replaced.

9
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• TURBINE CONTROL
• CNA1 Transidyn B (A) Simatic N (SL)
• CNE Elettrónica San Giorgio ELSAG (A)
• IN SERVICE REFUELING MACHINE CONTROL
• CNA1 Teleperm B (A) Simatic N (SL)
• A digital data acquisition system was added
  in order to detect in real time interaction
  between the cooling channel and the refueling
  machine.
• The surveillance of the coolant channels
  behavior in real time is also obtained.
• CNE Control Computer VARIAN (D)

10
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• ALARM SIGNAL PROCESSING
• CNA1 Simatic MS1 S200 (ASL).
• New alarms and a HMI from digital Teleperm
  XS were added.
• Replacement of the paper recorders by
  paperless recorders were started.
• A digital help for the operation
  (VisualData) real time system were added in a LAN
  over the Main Control Room and the whole plant
  through appropriate firewall.
• CNE Fischer Porter (ASL).
• Replacement of most of the paper recorders
  by paperless recorders were implemented.
• A gateway that will allow to visualize the
  plant parameters in real time over the LAN is in
  implementation.

11
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• RADIATION CONTAMINATION
• CNA1 CNE Mainly analog (A) technology in the
  plant systems and environment.
• New digital systems were added.
• New digital personnel monitors (portals)
  and handy meters were added.
• Some digital personnel monitors are from a
  national manufacturer INVAP.
• FIELD PROCESS TRANSMITTERS
• CNA1analog 0/20 mA four wires. (Siemens,
  Hartmann Braum)
• Some devices are being replaced for new
  technology when necessary.
• Electronic (A) thermostats were replaced
  for new (D) technology.
• CNE analog 4/20 mA two wires. (Foxboro,
  Rosemount, Taylor)
• Some devices are being replaced for new
  technology when necessary.

12
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• Atucha 2 NPP
• The CNA2 NPP is not still in operation.
• Erection was temporarily suspended due to
  budgetary reasons.
• Since the plant is restarting the erection
  process, the actual status of the IC is shown in
  the next slide.

13
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• Atucha 2 NPP Instrumentation
• RPS Simatic EDM (23 Dynamic logic) Teleperm
  C800/Iskamatic A (A).
• Reactor Control Limitations Teleperm ME (D)
  Iskamatic A (A).
• Neutron Flux Measurement Sinuperm C (A).
• Turbine Control Iskamatic A (A).
• In Service Refueling Machine Control Simatic S5
  (D) Iskamatic B (A).
• Alarm Signal Processing Simatic MS3 (ASL).
• Digital signaling Siemens Computer.
• Auxiliary Systems Control Iskamatic B/C and
  Teleperm C (A).
• Radiation Contamination Measurement Sinuperm M
  (D).
• Field Process Transmitters Siemens 0/20 mA four
  wires (A).

14
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• TREATMENT OF OBSOLESCENCE
• The Argentine NPPs have not carry out until this
  moment a systematic substitution of the IC
  component by digital technology.
• The new improvements are developed using modern
  digital technology, most of the times acquiring
  data from the original analogic instrumentation.
• The replacement of obsolete sensitive modules are
  performed by F3 methodology through qualified
  laboratories.(CNEA / COG).
• A systematic approach to the digital substitution
  will be essential in the next future according
  with the results of the life extension studies

15
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• CHALLENGES FOR THE TRANSITION TO DIGITAL
• (From the point of view of Human resources)
• Analog technologies are not well handled by new
  young human resourses, while new digital
  technology is sometimes difficult to handle for
  old staff.
• Therefore few people is capable to handle both
  technologies of the plant during the transition.
• The maintenance of new knowledge must be kept
  during the transition.
• On the other hand, and taking into account
  the low failure rate of the new equipment, the
  workers could be deviated to others fields losing
  certain degree of knowledge and skills.
• Therefore the IC team resources must be
  increased during the first stage while dealing
  with both technologies, keeping a sustainable
  learning process.

16
Status of the Instrumentation Control in the
Argentine Nuclear Power Plants

• RECOMMENDATIONS FOR THE IAEA NPP IC PROGRAMMES
• Promote the sharing of information and experience
  in the field of IC digital upgrading of the
  worldwide activities.
• Financial support programmes helping delegates to
  participate in courses and workshops about real
  and sucessfull experiences.
• Developement of practical methodologies, tools
  and guides in order to support the process for a
  systematic approach to digital replacement of the
  obsolete IC in de NPPs, focused also in the
  correct determination of priorities.