The objectives of this pilot project can be summarized as follows:

• Develop a general procedure to apply PLiM methodology, including guidelines for life assessment reports (LA’s), condition assessment reports (CA’s) and systematic assessment of maintenance reports (SAM’s).

• Test these procedures and get feedback from the field application in order to improve them.

• Convince all plant staff about the importance of the PLiM programme and the role they should play as active participants.

• Gain experience in the application of the methodology to start the next stage of the programme.

The first approach to a life assessment study was performed by CNE personnel for the steam generators during the last two years. This study, together with the knowledge acquired during training, has set the basis to develop the life assessment procedures and guidelines.

Besides steam generators, other four major components are being analyzed: Main feedwater pumps, moderator heat exchanger and pressure and inventory control system feed pumps. The selection of these components resulted from a screening stage in which safety and economical issues are considered, in order to determine the most important structures, systems & components (SSC’s) to be analyzed. During the screening it is also possible to determine for which components a LA analysis is needed, and for which a CA would be sufficient. It is worth noticing that a residual risk is associated with any screening process since there are components for which a lower depth or no analysis is indicated.

Life assessment: analysis is a deep study that is intended to gain as much knowledge as possible about the component. To achieve this, three main tools are used, documentation review, interviews and walk downs.

(a) Documentation review: the extent and usefulness of this review strongly depends upon the information management policy followed by the plant. If the information was properly managed, details from construction, major maintenance and design modifications, historical operation parameters, failures and inspection plans applied can be obtained.

At CNE, most of this information is correctly storaged and classified. However, it was sometimes needed to check few reports from early operation years with responsible personnel. In these cases, cooperation among different plant areas resulted essential.

Beside plant information, it is necessary to review international literature in order to get updated information about what is being done in similar plants around the world. As this regard, international organizations such as International Atomic Energy Agency (IAEA), Electric Power Research Institute (EPRI), World Association of Nuclear Operators (WANO), and CANDU Owner Group (COG) are important sources of information.

(b) Interviews: as it was previously stated, interviews were found to be a powerful tool for those cases where information was not either clear or available. However, even having enough information about the component, the operational experience from operation and maintenance staff is always valuable and should not be underestimated.

(c) Walk downs: walk downs should be aimed to detect anomalies that cannot be appreciated using the other tools described above. Inefficiency of supports and insulators are classical defects that can be detected during walk downs.

As well as it is done for interviews, walk downs are carefully prepared trying to do specific question in order to get specific answers.

Once the information is collected, reports are made consisting in an introduction to the component features, component historical behavior, review of the maintenance, inspection and monitoring practice used in plant, and finally the analysis of the Ageing Related Degradation Mechanisms (ARDMs). Conclusions from these reports will allow us to do recommendations in order to reach design life satisfactorily, and to consider the possibility of extending component life.

Condition assessment: analysis methodology is similar to that used for Life Assessments, but in a lower depth. CA’s are mostly performed for active components whose performance can be easily followed by operation parameters, or for those components that were found to be not so critical during screening stage.

Systematic assessment of maintenance: is a detailed analysis of the maintenance strategies that are being used for a system. As a result of the application of a SAM study, the following is expectable:

• Identify the optimum preventive maintenance programme

• Obtain the right balance between preventive and corrective maintenance

• Provide means to monitor maintenance efficiency and effectiveness

CONTRIBUTORS TO DRAFTING AND REVIEW

Barbulescu, P.	CNE — Prod, Romania
Bhardwaj, S. A.	NPCIL, India
Blahoianu, A.	CNSC, Canada
Cleveland, J.	International Atomic Energy Agency
Jeong, Ill Sock	KEPRI, Republic of Korea
Kang, Ki-Sig	International Atomic Energy Agency
Kyung, Soo Lee	KEPRI, Republic of Korea
Moses, C.	CNSC, Canada
Nickerson, J.	AECL, Canada
Nuzzo, F.	AECL, Canada
Versaci, R.	CNEA, Argentina

1st Consultants Meeting

Vienna, Austria: 10-13 January 2005

2nd Consultants Meeting

Mississauga, Canada: 23-25 November 2005

[1] Systematic ageing management process is the application of the Plan-Do-Check-Act cycle to operations, maintenance, and engineering actions aimed at achieving effective ageing management, which is based on the understanding of ageing.

[2] Definition of scope — Typically, the process starts with a complete listing of all the SSCs that constitute the “plant” (such as the subject index (SI) listing, typically consisting of over 1000 items). These are reviewed to eliminate SIs that are not relevant to safety or power production.

[3] Work breakdown — The SIs selected for review are grouped into common subject areas. These common subjects are then divided up into subcomponents corresponding to the disciplines involved and the responsible organizations.

[4] Inspection results are documented to allow assessment of degradation rate for each plausible degradation mechanism. Where inspection results are not available, they are scheduled and focussed to assess the degradation mechanism of concern.

• Once degradation rates are known, a life assessment for the equipment can be made. If the life assessment reveals a life that is less than the target life, programmes are required to address the gap.

[5] Components with * met the criteria for NPLA components but were covered by other programs.

[6] EPRI — Electrical Power Research Institute.

[7] NMAC — Nuclear Maintenance Application Center.

[8] EPRI Preventive Maintenance Basis Database Client/Server, Versions 6.0/1.0, Product # 1009584

[9] AECL- Atomic Energy of Canada Limited.