Abstract
The aim of nuclear power plant ageing management is to
maintain an adequate safety level throughout the lifetime
of the plant. In ageing studies, the reliability of
components, systems and structures is evaluated taking
into account the possible time-dependent degradation. The
phases of ageing analyses are generally the
identification of critical components, identification and
evaluation of ageing effects, and development of
mitigation methods.
This thesis focuses on the use of reliability methods and
analyses of plant- specific operating experience in
nuclear power plant ageing studies. The presented
applications and method development have been related to
nuclear power plants, but many of the approaches can also
be applied outside the nuclear industry. The thesis
consists of a summary and seven publications. The summary
provides an overview of ageing management and discusses
the role of reliability methods in ageing analyses. In
the publications, practical applications and method
development are described in more detail.
The application areas at component and system level are
motor-operated valves and protection automation systems,
for which experience-based ageing analyses have been
demonstrated. Furthermore, Bayesian ageing models for
repairable components have been developed, and the
management of ageing by improving maintenance practices
is discussed. Recommendations for improvement of plant
information management in order to facilitate ageing
analyses are also given. The evaluation and mitigation of
ageing effects on structural components is addressed by
promoting the use of probabilistic modelling of crack
growth, and developing models for evaluation of the
reliability of inspection results.
Original language | English |
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Qualification | Doctor Degree |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 28 May 1999 |
Place of Publication | Espoo |
Publisher | |
Print ISBNs | 951-38-5375-6 |
Electronic ISBNs | 951-38-5376-4 |
Publication status | Published - 1999 |
MoE publication type | G5 Doctoral dissertation (article) |
Keywords
- nuclear power plants
- ageing management
- reliability methods
- systems analysis