IEC 60988:2009

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Purpose and description of loose parts detection
  4.1 General
  4.2 System definition
  4.3 System outline
5 System requirements
  5.1 Basic structure and design criteria
  5.2 Signal acquisition
      5.2.1 Selection and installation of the sound sensors
      5.2.2 Preamplifiers
  5.3 Signal processing
      5.3.1 General
      5.3.2 Band-pass filters
      5.3.3 External output signal
      5.3.4 Amplifier
  5.4 Signal storage and signal display
      5.4.1 Background noise monitoring
      5.4.2 Digitisation and storage
      5.4.3 Audio unit
      5.4.4 Information display
  5.5 Signal monitoring
      5.5.1 General
      5.5.2 Alarm level monitor
      5.5.3 Logic element
  5.6 Calibration
      5.6.1 General
      5.6.2 Mechanical functional test unit
      5.6.3 Electrical calibration unit
6 Initial start-up and operation
  6.1 System testing before initial start-up of coolant
      circulating pump
  6.2 Preliminary surveillance without alarm levels
  6.3 Adapting the system to the plant requirements
7 Surveillance programme
  7.1 General
  7.2 Reference recordings
  7.3 Measurements during operation
      7.3.1 Preliminary surveillance
      7.3.2 Surveillance
  7.4 Actions following an alarm
  7.5 Periodic testing of the system
      7.5.1 General
      7.5.2 Functional tests
      7.5.3 Electrical system test
      7.5.4 Test impacts
8 Documentation
Annex A (informative) - Description of loose parts detection
                        with typical sound traces
Annex B (informative) - Description of detailed functions of
                        each block of the functional block
                        diagram
Annex C (informative) - Examples of digital loose parts
                        monitoring systems
Annex D (informative) - Comments on evaluation
Bibliography

IEC 60988:2009 is applicable to on-site systems used for continuous monitoring of structure-borne sound measured at the reactor coolant pressure boundary of light water reactors for the purpose of detecting loose parts. The main technical changes with regard to the previous edition are as follows:
- to bring the contents up to date with technology change in some areas and to reconsider and improve the recommendations;
- to include considerations and recommendations on digitalization for loose parts monitoring systems to cover requirements for such systems;
- to include improved and updated recommendations on storage, information display, alarm level monitor and logic elements;
- to give recommendations on functional and performance measures proven in use for operation of the monitoring system including updated details on the necessary actions after detection of a loose part;
- to improve the consistency and clarity and the layout of the contents and to correct any errors found in the previous version.