Title: Online Calibration Monitoring of Process Instruments in NPPs Halden, 27 September, 2004
1On-line Calibration Monitoring of Process
Instruments in NPPsHalden, 27 September, 2004
Presented by Janos Eiler, Paks Nuclear Power
Plant Ltd.
2TWG - NPP CI Activities
3What is a TECDOC?
- Managing Modernization of Nuclear Power Plant
Instrumentation and Control Systems - Perception of needs for IC modernization
- Project preparation and feasibility study
- Modernization project implementation
- Questionnaire for IC modernization projects
4Overall Scheduleof Activities
- 2003 TWG NPPCI meeting suggested this new TECDOC
- The TWG believes on-line monitoring is one of the
most promising areas for IC development - (The current practice usually calls for
calibration verification of almost all
instruments every fuel cycle, regardless of their
calibration status)
5Overall Scheduleof Activities
- 2003 TWG NPPCI meeting suggested this new TECDOC
- 1st Consultants meeting, 15-18 March, 2004,
Vienna - 2nd Technical meeting, 27-29 September, 2004,
Halden - 3rd Consultants meeting, Spring 2005, (Vienna or
Soul?) - Expected publication Late 2005
6Objectives of Condition-Based Calibration (CBC)
- Develop new technologies for identifying drifting
instruments as a means of determining if and when
a transmitter or a loop must be calibrated - Implementing these technologies allows
calibration efforts to be focused on the
instruments that have drifted out of tolerance - Save calibration costs, reduce personnel
radiation exposure, and add to plant safety and
reliability
7Principle of Condition-Based Calibration
- Determine if calibration is needed.
- Track the output of instrument channels over the
fuel cycle - Identify drift, bias errors, noise and other
anomalies - Advantages
- it identifies calibration problems as they occur,
- accounts for installation and process condition
effects on calibration, and - includes most components of an instrument channel
in the calibration test as opposed to the
conventional procedures, which require some
components to be isolated and calibrated
individually - prevents unnecessary calibration of instruments
that have maintained their calibrations - Calibrate if needed.
8TECDOC coverage
- Instrument calibration reduction or increasing
the calibration intervals of process instruments
such as - pressure, level, and flow,
- temperature
- neutron flux transmitters
- and entire instrument channels
- Economic and safety benefits
- Regulatory approval process
- Quality Assurance (QA) requirements
- (This is the first of a series of TECDOCs)
9Related Documents
- NUREG/CR-6343, On-Line Testing of Calibration of
Process Instrumentation Channels in Nuclear Power
Plants, 1995 - EPRI TR-104965-R1 NRC SER, On-Line Monitoring of
Instrument Channel Performance, 2000 - American National Standard, ANSI/ISA-67.06.01-2002
, Performance Monitoring for Nuclear Safety
Related Instrument Channels in Nuclear Power
Plants. 2002
10Related TECDOCunder printing
- Plant Life Cycle and Aging Management Using
Improved IC Maintenance - Relationship between IC aging, life cycle
management and maintenance - Ageing and obsolesce process
- Cable ageing managements
- Role of IC in plant performance improvements
- Relation with IEC SC 45 A
- Publication in the middle of 2004
11Overview of traditional calibrations
- The nuclear power industry currently practices a
very conservative approach - Daily Channel Checks
- Surveillance Tests (sensor is not tested)
- Full-Channel Calibration
- Response Time Testing
12Application of the Channel Test Card
13Schematic of a Typical Redundant Instrument Set
Channel Test Card
Master Test Card
Resistance to Voltage Converter
Summing Amplifier
1
2
3
?T
Relay Test Card
Relay Test Card
Summing Amplifier
Lead Lag
Lead Lag
ISO
14Lessons learned from current calibrations
- Searches of the License Event Report (LER) and
Nuclear Plant Reliability Data System (NPRDS)
databases show that less than three percent of
pressure transmitters have drifted out of
tolerance. - This amounts to about 2.8 failures per plant per
fuel cycle from the NPRDS database and 0.66
failures per plant per fuel cycle from the LER
database assuming 100 reactors and two-year fuel
cycles. - This can provide substantial cost savings to
utilities including direct reductions in labor,
personnel radiation exposure, and material and
indirect savings from increased instrument
reliability and plant safety, simplified outage
planning and scheduling.
15Results of Search of LER
Number of LERs on Failures of Pressure
Transmitters during 1980-1992 (1886)
391 cases of calibration problems at over 100
nuclear power plants in 12 years.
Personnel Error 587 (31)
Age-Related Problems 662 (36)
Other Causes 617 (33)
Calibration Drift 391 (59)
Flow Blockage 106 (16)
Fatigue / Vibration /Corrosion 165 (25)
16Implementation of CBC(not yet elaborated)
- Exactly how do we collect data, or what data do
we use for CBC in real plant applications? - Where (in what system) do we run CBC? What
additional (physical) installations are needed
for it? - What computer system does CBC need?
- Who is responsible for its operation and
maintenance? - Where (to whom) do we provide output from CBC? In
what form? - How and where are acceptance criteria applied?
17Related research
- EPRI
- UT
- ANL
- AMS
- HALDEN/IFE
- EDF
- AECL/OPG
18Standards and guidelines
- There are only a couple of formal documents on
their use - Instrumentation, Systems, and Automation (ISA)
Society - ISA Standard 67.06. Performance Monitoring for
Nuclear Safety-Related Instrument Channels in
Nuclear Power Plants., 2002 (Published by the
American National Standard Institute under
ANSI/ISA-67.06 01 2002 designation.) - International Electrotechnical Commission (IEC)
- IEC 61255. It is due for publication in 2006. The
standard is similar to ISA 67.06 mentioned above
and covers both the dynamic and static aspects of
instrument performance.
19Data acquisition foron-line monitoring
- Requirements for Data Acquisition
- Portable Data Acquisition Systems
- Synchronized sampling of portable data
acquisition systems - Resolutions, continuous recording, data storage
- Permanently Installed Data Acquisition Systems
- Isolation Requirements for On-line Data
Acquisition Systems - Analog Signal Conditioning
- Required Plant Conditions for Data Acquisition
- Integration of On-line Monitoring Systems with
Plant IC and Other Plant Computer Systems
20Data analysis foron-line monitoring
- Averaging Techniques and Consistency Checking
- Simple Average
- Weighted Average
- Band Average
- Parity Space
- Modeling Techniques
- Data-driven techniques and Neural Networks
- Fuzzy Logic
- First Principle Methods
- Estimation Methods
- Pattern Recognition
- Other Empirical Methods
- Statistical Methods
- Uncertainty Analysis
21Acceptance criteria foron-line monitoring
- Instrument Channel Uncertainties
- CSA Band and Drift Band
22Benefits andpitfalls of CBC
- Main advantages
- reduction of manpower requirements,
- reduction of radiation exposure to maintenance
personnel, and - reduction of risk associated with mis-calibration
of instruments and maintenance-induced reactor
trips. - checking instrument performance indicators
- Main challenges
- obtaining regulatory approval to implement
on-line monitoring, - uncertainties in data analysis methodologies, and
- cost of implementation
23Challenges in changing calibration strategies
- CBC is typically only performed at a single
operating point - difficult to establish acceptance criteria
- difficult to gain plant management acceptance
- regulatory issues
- personnel issues, jobs threatened by the
reduction in workload - reducing the opportunity of examining a sensors
installation material condition
24Regulatory aspects
- The approach varies depending on the generic
approach of the Regulator to the Licensee and
also the CBC strategy employed. - (USA) is a prescriptive regulator who expect
their expectations to be complied with - (UK) are non prescriptive and expect the utility
to provide an acceptable justification and
supporting evidence - (It is necessary to consider what impact CBC
might have on any assumptions made in the safety
analysis for the plant. In particular, the impact
(if any) on assumptions made about sensor drift
and reliability.)
25Key recommendations
- Will be elaborated when the TECDOC main body is
completed
26Examples ofBibliography items
- EPRI, Report 1003568 Collected Field Data on
Electronic Part Failures and Aging in Nuclear
Power Plant Instrumentation and Control (IC)
Systems, (September 2002). - HASHEMIAN, H.M., Verifying the Performance of
RTDs in Nuclear Power Plants, Temperature, Its
Measurements and Control in Science and Industry,
AIP Conference Proceedings, Volume 7, Part 2, pp.
1057-1062 (2002) - International Electrotechnical Commission, IEC
Standard, Nuclear Reactors Response Time in
Resistance Temperature Detectors (RTDs) In-Situ
Measurements, Rep. CEI/IEC-1224 (1993)
27Country reports
- Will be provided by the writing committee members
and other volunteers interested in the topic
28Contributors to drafting
- Chairman
- Hash Hashemian (USA, AMS)
- Members
- Mr. Dave Lillis (UK, Sizewell B NPP),
- Mr. Janos Eiler, (Hungary, Paks NPP)
- Mr. Hee Wan Ju (Rep. of Korea KHNP)
- Mr. Oivind Berg (Norway, IFE)
- Mr. Oszvald Glöckler (Canada, OPG)
- (Mr. Ki-Sig Kang, IAEA NPES)
29Thank you for your attention!