An Overview of the Reliability and the Fault Trends of the SRS

1
An Overview of the Reliability and the Fault
Trends of the SRS

• Cheryl Hodgkinson
• Daresbury Laboratory
• Synchrotron Radiation Department

2
Contents

• Introduction
• SRS Operational Statistics
• Analysis of the Operational Data
• Efficiency
• Fault Statistics
• Ageing and Obsolete Equipment
• Maintaining Reliability
• Capital Investment and Redundancy
• Risk Analysis
• Post Incident Investigation and Modifications
• Preventative Maintenance and Scheduling
• Conclusions and Acknowledgments

3
Introduction

• The Synchrotron Radiation Source
• 2GeV, 2nd Generation Light Source
• Constructed between 1975 and 1980
• Began scheduled user operations in 1981
• Some SRS systems, mainly injector components were
  salvaged from a previous accelerator
• Operational user facility for 26 years and
  scheduled for closure December 2008

4
SRS Reliability Data
5
SRS Fault Statistics
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Vacuum Incidents

• Usually an isolated single failure
• Difficult to predict and prevent
• failed RGA head
• Quadrupole absorber failed flowmeter
• Common Theme?
• SCW Absorber TVM 9
• Both very different failure mechanisms
• Both historical not needed in the current SRS
  configuration

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SRS Fault Statistics
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Ageing and Obsolete Equipment

• Early Equipment
• Built in-house
• Repairs in-situ (time)
• Can be repaired
• Later Equipment
• Plug-in
• Replaced with a spare
• Return to manufacturer for repair
• Support issues

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Ageing and Obsolete Equipment

• Concern regarding condition of in vacuum water
  circuits
• 17 year old absorber removed from storage ring
• Areas milled away to examine any wall thinning

RESULT No evidence of wall thinning or erosion
10
Ageing and Obsolete Equipment

• External water circuits
• Elbows
• Near feedthroughs
• Potential for vacuum incident during repair
• Potential to cause more serious failure

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Ageing Machine Its not just equipment!

• Its about people too!
• Loss of design and build knowledge, as staff
  retire
• Less documentation for older equipment, drawings,
  maintenance schedules, etc.
• Cant teach 20 years design, build and
  operational knowledge.
• Succession planning important
• You only know whats been missed when the fault
  occurs
• Lapses in maintenance schedules
• Longer fault rectification

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Capital Investment and Redundancy

• Capital investment
• Must be bid for against other priority items
• Only essential systems and components which would
  significantly improve efficiency
• Spares
• Hot
• Power Converters
• Storage Ring Klystron
• Vacuum vessels

Old RF PSU
New Commercial Unit
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Risk Analysis

• Benefit difficult to assess
• The biggest risk is the one you dont know about
• At top level
• Difficult to compare risk and focus resource
• How do you compare extremely reliable long lead
  time items against components that fail
  frequently, but are a fast repair?
• Does highlight major issues
• Linac Klystron

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Risk Analysis

• Most beneficial at individual technical group
  level
• Direct comparison can be made between equipment
  and fault hours contributed
• Led to successful modernisation in key areas
  based on safety and operational risk

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Post Incident Investigation

• Learning from incidents is important
• Committee is always formed to recover and also
  determine actions to prevent reoccurrence.
• Actions from recent faults
• Modification to TVM cooling pipes
• Revised interlock testing schedule
• Test rig to test thermionic valves on-site

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Preventative Maintenance and Scheduling
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Conclusions

• The SRS has provided reliable user operations for
  over 26 years
• Vacuum incidents are isolated incidents, which do
  not indicate any form of systematic failure which
  would limit the life of the SRS
• Only evidence of any systematic failure due to
  ageing is the failure of copper elbows on water
  circuits
• The high operating efficiency demanded by the
  light source community can be maintained on an
  ageing machine using a variety of techniques.

18
Acknowledgments

• The author would like to thank
• Previous SRS Operations Managers for compiling
  these statistics
• Current and past Operations Teams for providing
  the data
• Steve Griffiths of EEPS for providing his Groups
  Risk Analysis Data
• And Finally...........
• Daresbury Staff past and present for their
  contributions to SRS Operations