Feedback of experience

Historical records of MS I should be periodically reviewed and analysed in order to identify any adverse trends in the performance of equipment or persistent problems, to assess impacts on system reliability and to determine root causes. The information thus obtained should be used to improve MS I programmes and should be taken into account in the ageing management programme. 

Arrangements for the feedback of MS I experience should include, but are not limited to, the following  

Collecting, evaluating, classifying and recording details of abnormal events or findings, in order to detect precursors, common mode failure mechanisms and deficiencies of equipment or personnel  

Providing experience gained from actual activities to the design groups, in order to enable them in the future to improve plant features which have a bearing on MS I, such as ease of access, ease of disassembly and reassembly, and implementation of the ALARA principle  

Validating collected reliability data to be used for probabilistic evaluations and for the technical specification of new components  

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The SPINLINE3 software components intended to run within safety processing units or networks have all been developed and qualified according to 1EC60880. They are fully documented and reviewable [5] by licensing bodies, under contractual agreement with confidentiality clauses. The re-usability of the Operational System Software component makes possible additional arguments based on feedback of experience. 

It has been recognized that the methods and tools used for the software development and V V, the respect of the requirements of lEC 60880, the experience of the software teams were suitable to produce software as error free as possible . This has been proven by the feedback of experience gained on similar projects that we have developed during the last 20 years. We have nevertheless been required to perform an additional analysis on the IE software, using an FMEA technique, in order to identify those parts of the... 

When performing an FMEA on mechanical, fluid or electrical system, failure modes of components such as pipes or resistors are generally understood, likely to happen and their consequences may be studied. A component is supposed to fail, due to some reason as wearing, aging or unanticipated stress. The analysis may not always be easy, but at least, the safety engineer can rely on data provided by the component manufacturer, results of tests and feedback of experience when available. 

In this paper, we have presented this software FMEA experienee including adaptation of the principles of FMEA to analyze a software program choice of a block of instmction (BI) approach to identify the components to analyze definition of the software failure modes associated with the Bis examples of the analyses performed on the SPINLINE3 Operational System Software feedback of experience... 

In addition to the internal feedback of experience, lessons learned from other power plants should be considered important contributions to the further improvement of MS I programmes. Such information is particularly important for countries with few operating units and in relation to types of reactor that are in use in several countries. The links between national and international systems for the feedback of experience in operational safety broaden the base of information on approaches to... 

The additional investment cost to reach this level of automation is minor in comparison to gains identified comparing the feedback of experience on German plant and French ones, the French ones being less automated than the German ones. 

It has been required to take into account the feedback of experience related to the mechanical problem of isolated safety injection lines when small leaks through the isolation valves may occur ( Farley-Tihange problem responsible for several small breaks on the safety injection piping). Implementation of on-line temperature and pressure measurements will allow to identify any small leak through the isolation valve to the primary circuit and the dedicated corrective actions can be taken to evacuate the leak to the Chemical and Volume Control System. ... 

A large field for cost savings is also concerned by the design of the nuclear auxiliary systems and not only the safety systems. The solutions used in France and Germany are quite different. The designers knew only their own design and were not able to harmonize themselves. This harmonization process was then made on the Utilities side mainly in comparing each feedback of experience. 

Provisions in the layout should be made early in the process of plant design as a valuable way of reducing P2. In this regard, feedback of experience from similar installations should be taken into account. Decisions on layout are of particular importance in relation to missiles and flooding hazards, and these considerations are addressed in the corresponding sections of this Safety Guide. 

The success of Superph,nix is now most important for the progress to commercial exploitation. The feedback of Superph,nix operating experience to the commercial designs of die future is formalised in the Knowledge Acquisition Programme (KAP). The interaction with the safety authorities is part of this feedback of experience, particularly for issues raised as a result of the unanticipated problems encountered with operation of such a prototype commercial sized plant. 

The feedback of experience from the operating plants is invaluable in providing assurance that commercial fast reactors can be successfully operated. This has been done and is always an important pan of an ongoing activity which has been agreed with EFRUG. 

The feedback of experience from plant operation demonstrates that the relative significance of the human factor with respect to plant safety has increased. Due to constantly enhanced technology, the human factor has moved up in the ranking of influencing factors. Measures to enhance the reliability of human action thus may contribute significantly to an increase in the safety of nuclear power stations. 

The design of nuclear power plant systems should be based on the feedback of experience gained in reducing radiation exposure at operating stations. 

But this incident also led the Safety Authorities to demand, at the end of October 1990, a general re-examination of the organization of plant operation and further safety studies, in particular of the sodium fire risk in the secondary galleries, and feedback of experience from the Phenix incident. 

Maturation of long intensive programmes of research into engineering of safety Feedback of experience in nuclear plant operating including the major lessons learned from the severe accidents to nuclear plants at Three Mile Island and Chernobyl ... 

INTERNATIONAL ATOMIC ENERGY AGENCY, A National System for Feedback of Experience from Events in Nuclear Power Plants, IAEA, Vienna (in... 

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