D00000112 - The Pebble Bed Modular Reactor Project In Reactor

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D00000112 - The Pebble Bed Modular Reactor Project In Reactor Powered By Docstoc
					   HTR 2006




   Reactor Pressure Modular
InThe Pebble Bed Vessel
Measurements for the PBMR DPP
      Reactor Project
              Presented by: G.I. Procter
                 Introduction
• Core Structures Instrumentation - The
  Measurements performed within the RPV

•   The need for Cores Structures Instrumentation
•   What is measured
•   How are Parameters Measured
•   Location zones for the measurements
•   New technologies
•   Challenges
•   Conclusion
    – Current status
    – Planned activities
Core Design
                                Core Design

Centre Reflector   Pebble Bed   Side Reflector    Core Barrel        RPV                      RCCS       Citadel

  Conduction
                    Radiation
                                 Conduction
                                                 Radiation
                   Conduction
                                                 Convection
                   Convection
                                                                                                         Conduction
                                                  Conduction                   Radiation

                                                             Radiation         Convection

                                                              Convection                    Convection


                                                                                               Radiation
                                                                  Conduction




                         Heat removal paths
                             Scope Of CSI
                                                                     Equipment room
        CITADEL                                                      Level + 24 M
                                   Pre amplifier Bay
                                       level 20M
 Detector
                                                                                    OCS
              Upper Citadel                                            CSI Rack
 Handling                                                                           Rack
Equipment        cavity
                                                SR      Amplifier
                                                CSI
                 Junction
                   Box             Reactor
                                    Citadel
                                  Penetration




                      In core
   Citadel Upper Cavity
                     SPND' s
                  Strain gauges
                     Thermo-
                     couples



                   Lower
                   Citadel
                   Cavity
                                                      CSI Racks on -15 m level

                Reactor PB




                                                               Strain        Thermo-
                                             SPND
                                                               gauge          couple
 Reactor                                    amplifiers
                                                              amplifiers      Input s
  Citadel
Penetration
                   CSI FUNCTIONS

• Primary function of CSI is for V&V
• In Core Source Range flux measurement for
  approach to criticality and initial start-up.
• In Core measurement of neutronic flux distribution
• In Core measurement of temperature distribution in
  graphite structures and core barrel
• Measurement of stresses in the Core Barrel (CB) and
  Core Barrel Support Structures (CBSS)
• Displacement measurement of CB top plate and Core
  Barrel Support Structures (CBSS)
                 What Is Measured
• All Measurements are done within the RPV.
   – Neutron Flux
      • 2 types of measurement
   – Temperatures
      • In Reflector zones
   – Stresses
      • Metalic Core Barrel
   – Displacement
      • Core Barrel Top Plate – CB Top Plate
      • Core Barrel Support Structure - CBSS
         How are Parameters Measured
• Temperatures
   – Thermocouples – signals processed directly in OCS
• Stress
   – Strain gauges

• Displacement
   – LVDT or other technologies

• Fluxes
   – SPND’s
   – Fission Chambers
              Neutron Flux Measurement
• For V&V Self Powered Neutron Detectors
  (SPND’s) are used.
   – Neutronic flux Level
      • Axial flux distribution
      • Azimuthal flux distribution
• For initial aproach to criticallity SR channels with
  fission chambers are used.
   – 5 Decades of range, from 0 power.
   – Neutronic Period – rate of change (Hyperbolic
     response curve)
   – Detectors not expected to survive full power operation
      – temperatures/pressure(9 MPa).
                Detector Location Zones

 .
Source Range
Detectors
                 3 Arranged symmetrically @
                 120º
                                                Central Reflector


SPND’s     3     3 Symmetrical Banks of 2 X 5   15 Inner SR
                 elevations @ 120º              15 Outer SR

Thermo     15    3 Symmetrical Banks of 5       Central Reflector
Couples
           15    3 Symmetrical Banks of 10      ISR
           15    3 Symmetrical Banks of 10      OSR
           39    3 Symmetrical Banks of 12      Bottom reflector
                 At 7 heights + other locations
                 on 0º azimuth
           30    3 Symmetrical Banks of 10      Top reflector
                Detector Location Zones 2
   . Couples
Thermo          92   3 Symetrical Banks of 21         Core Barrel
                     9 Symetrical Banks of 3 at 40º
                     azimuth separation.
                      2 on Centre point.
Strain Gauges   61   Distributed – Sides 33           Core Barrel
                                 - Top 18
                                 - CBSS 10

Displacement    8    4 Vertical + 4 Horizontal        CB top Plate
Sensors
                12   2 X 4 Vertical                   CBSS
                     4 Horizontal
                ANALYSIS PERFORMED
• Design analysis
   – Neutron Flux analysis
   – Gamma Flux analysis
   – Temperature distributions for all zones where the SSC of
     CSI will be located
   – Stress Analysis

• Measurement methods for displacement
  – Differential capacitance
  – LVDT
                      CHALLENGES
•Harsh Environmental Conditions For Sensors
   •High Temperatures for sensors and signal cables
   •High Neutron flux levels
   •High Gamma flux levels

•Different co-efficient of Thermal Expansion
   •Ceramics
   •Core Barrel
   •Reactor Pressure Vessel
   •Mineral Insulated Cables
   •Design Integration and Constructability.
                New Technology
• FIBRE OPTICS
   – Measurement of Temperature, Strain and pressure
      • Environmental limiting factors
          – Temperature
          – 1000º C Continuous operation
          – 2000º C Short duration
          – Pressure – tested to over 55 MPa
          – Neutron Fluence test > 2 X 1019
   – Radiation Measurement
      • Neutron Flux
      • Gamma Flux
      • Not tested at the required operating temperatures
• FFT based Acoustic Monitoring
   – Listen tube approach – permits application of an
     industrial unit with minor modifications.
                      Conclusions

• Current Status
  • Integration function being performed by PBMR

• Fibre Optic measurements
  • Technology not sufficiently matured at this stage. Only
    for supplementary measurements.

• Planned activities.
  – Define the properties of all Mineral Insulated cables
     • Sheath Material,
     • spacing between conductors
     • Insulation material
                     Conclusions

– Perform tests with MI cable installation procedures in co-
  operation with the graphite supplier.
– Interfaces resolutions to be completed during the
  remainder of 2006.
   • Core Structures Ceramics,
   • Core Barrel and
   • the Reactor Pressure Vessel.

– Perform constructability modeling - to aid in final
  construction sequence

– The CSI must be installed in the Core Barrel assembly by
  the 25 August 2009 – this is a fixed date, which must be
  met.
THANK YOU!
The Pebble Bed Modular
    Reactor Project
       Questions ?
              Measurement Ranges
• Reactor Period
  – - infinity to  -30 and < +3 to +infinity (s)


• FLUX Expressed as a % of full power
  – < 5 cps to  105 cps As a log signal for SR
  – 10-8 to 2 X 102 As a log signal for WR.
  – < 1% to 125% for PR

				
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posted:3/9/2011
language:English
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