Advanced I&C

On-line Monitoring and Calibration Techniques in Nuclear Power Plants

Prepared by:H.M. Hashemian, President

Analysis and Measurement Services CorporationAMS Technology Center

9119 Cross Park DriveKnoxville, Tennessee 37923

USA

Presented at:International Conference on

Opportunities and Challenges for Water Cooled Reactors in 21st Century

Vienna International CentreInternational Atomic Energy Agency

Vienna, Austria

27-30 October 2009

Do Not Forget Sensors and Cables

2H.M. Hashemian

Process

Temperature Sensor

PressureTransmitter

Cables

Cables

Penetration

I&C Cabinets(Analog or Digital)

Control Room Area(Mild Environment)

Containment(Harsh Environment)

~150 meters

Proper Installation is Critical to Temperature Sensor Performance

3H.M. Hashemian

0

4

8

12

Res

pons

e Tim

e (s

ec)

Thermocouple Tag Number

DWM139B-01A

0

1

0 10 20 30 40 50 60

Time (Sec)

Step

Res

pons

e

Fast - GoodSlow - Bad

RTD

Thermocouple

Nuclear Power Plant Pressure Transmitter Failure Mode Detected by Pure Luck

4H.M. Hashemian

80

90

100

110

120

9:30 AM 10:00 AM 10:30 AM 11:00 AM 11:30 AM 12:00 PM 12:30 PM

RC

S Fl

ow (%

)

Time

JPF025B-04

FT-445

FT-444

Sensing Lines are Critical to the Performance of Pressure Transmitters

5H.M. Hashemian

Process Pipe or Vessel

Condensate Pot

Vent

ThermalInsulation

Rootvalve

Shield Wall

Penetration

Accessible Isolation Valve

Transmitter

PrimaryContainment

Wall

Restriction Device

Check Valve

~ 50 meters

Cable Diagnostics

1 2 3 4

RTD

-0.5

0

0.5

-200 0 200 400 600 800 1000

1,22,3

3,4

Distance (Feet)

6H.M. Hashemian

Signal Problems are Not Always in Cables

Current MeterN

eutr

ons

Current Voltage Source

+

NeutronDetector

7H.M. Hashemian

-

I – V Test

10H.M. Hashemian

MaintenanceClasses

Predictive Maintenance

Methods that use Data from Test

Sensors

Predictive Maintenance

Methods that use Data from Existing Process Sensors

Predictive Maintenance

Methods Based on Active Measurement

Signals

Detection of Fouling of

Venturi Flow Elements

Detection of Sensing Line

Blockages

Instrument Calibration Verification

Loose Parts Monitoring

Leakage Monitoring

Vibration Measurement

Sensor Installation Verification

Sensor Response Time

Testing

Cable Condition Monitoring

Conventional and Advanced Predictive Maintenance Technologies

Plant Implementation of On-Line Calibration Monitoring

H.M. Hashemian 9

PlantComputer

Data

Status of Plant Instrumentation

Plant Startup and Shutdown Data

10H.M. Hashemian

0

10

20

30

40

50

60

70

80

90

0 500 1000 1500 2000 2500

Pres

sure

Time (Minutes)

Startup Data KDL204A-01

0

10

20

30

40

50

60

70

80

90

0 300 600 900

Pres

sure

Time (Minutes)

Shutdown Data KDL204A-02

On-Line Calibration Monitoring Results Covering the Full Operating Range of a Transmitter

11H.M. Hashemian

-1.0

-0.5

0.0

0.5

1.0

7.5 20 30 40 50 60 70Operating Point (%)

+ (ALLOWABLE CALIBRATION LIMIT)

- (ALLOWABLE CALIBRATION LIMIT)

CRS038B-01D

evia

tion

(%)

Conclusions and Recommendations

• Do not forget the sensors, process-to-sensors interfaces, cables, connectors, and penetration

• The validity, accuracy, and fidelity of process signals depends on proper installation of sensors and flawless cables and connectors

• On-line monitoring techniques and in-situ test methods are now mature enough for ready use in nuclear power plants

• Regulators have approved the OLM concept to verify the calibration of nuclear plant pressure, level, and flow transmitters

• U.S. plants are applying for generic NRC licensing to implement OLM for online calibration monitoring of pressure, level, and for transmitters

• Research is needed to establish the uncertainty of modeling techniques for on-line calibration monitoring applications

H.M. Hashemian 12

Thank You

13H.M. Hashemian