Safety Standards related to Ageing and Long Term Operation

This section provides IAEA safety standards which are relevant to ageing and long term operation. In addition, the following new Safety Guide is under development and will be published in 2008, to provide key recommendations on ageing management:

For further information, please contact SKALTO.

Safety Fundamentals on the Safety of Nuclear Installations More

This document provides a fundamental rationale for ageing management. It shows basic objectives, concepts and principles of safety of Nuclear Installations including design (in Chapter 502 to 508 and Principles (10) to (15), operation and maintenance (in Chapter 510 to 513 and Principles (17) to (21)).

 

 

 

 

 

Requirements on Safety of Nuclear Power Plants: Design (NS-R-1) (Design Requirements) More

The Design Requirements prescribes in Chapter 5.47 (“AGEING”) that appropriate margins be provided in the design for all structures, systems and components important to safety so as to take into account relevant ageing and wear-out mechanisms and potential age related degradation, in order to ensure the capability of the structure, system or component to perform the necessary safety function throughout its design life, that ageing and wear-out effects in all normal operating conditions, testing, maintenance, maintenance outages, and plant states in a PIE and post-PIE also be taken into account, and that provision also be made for 22 monitoring, testing, sampling and inspection, to assess ageing mechanisms predicted at the design stage and to identify unanticipated behaviour or degradation that may occur in service.

It also requires in Chapter 5.45 (“EQUIPMENT QUALIFICATION”) that in the qualification programme, consideration be given to ageing effects caused by various environmental factors (such as vibration, irradiation and extreme temperature) over the expected lifetime of the equipment.

In Chapter 6.25 (“Design of the reactor coolant system”), it is required that the design shall reflect consideration of all conditions of the boundary material in operational states, including those for maintenance and testing , and under design basis accident conditions, with account taken of the expected end-of-life properties affected by erosion, creep, fatigue, the chemical environment, the radiation environment and ageing, and any uncertainties in determining the initial state of the components and the rate of possible deterioration.

Requirements on Safety of Nuclear Power Plants: Operation (NS-R-2) (Operation Requirements) More

The Operation Requirements prescribes in Chapter 6.1and 6.2 (Chapter 6 “MAINTENANCE, TESTING, SURVEILLANCE AND INSPECTION OF STRUCTURES, SYSTEMS AND COMPONENTS IMPORTANT TO SAFETY”) that the operating organization prepare and implement a programme of maintenance, testing, surveillance and inspection of those structures, systems and components which are important to safety to ensure that their levels of reliability and effectiveness remain in accordance with the assumptions and intent of the design throughout the service life of the plant. This programme shall take into account operational limits and conditions as well as any other applicable regulatory requirements and it shall be re-evaluated in the light of experience.

It also requires in Chapter 10.3 (Chapter 10 “PERIODIC SAFETY REVIEW”) that the PSR shall take into account the actual status of the plant, operating experience, predicted end-of-life state, current analytical methods, applicable safety standards and the state of knowledge.

Safety Guide on Periodic Safety Review of Nuclear Power Plants (NS-G-2.10) (PSR Safety Guide) More

This Safety Guide recommends in Chapter 4.18 (“EQUIPMENT QUALIFICATION”) that an equipment qualification procedure confirm that the equipment is capable of meeting, throughout its service life, the requirements for performing safety functions while subject to the environmental conditions (e.g. vibration, temperature, pressure, jet impingement, radiation, corrosive atmosphere, humidity) existing at the time of need, and taking into account ageing degradation of the equipment that occurs during service.

The PSR Safety Guide also provides in Chapter 4.22 to 4.24 (“AGEING”) the objective and recommendations on the review in the light of ageing.

Safety Guide on Maintenance, Surveillance and In-Service Inspection (NS-G-2.6) (MSI Safety Guide) More

This Safety Guide provides recommendations on methods, frequency and administrative measures for the in-service inspection programme for critical systems and components of the primary reactor coolant system aimed at detecting possible deterioration due to the influences of stress, temperature, radiation, etc. and at determining whether they are acceptable for continued safe operation of the plant or whether remedial measures are needed. Organizational and procedural aspects of establishing and implementing an NPP programme of preventive and remedial maintenance to achieve design performance throughout the operational life of the plant are covered in the MSI Safety Guide.

The MSI Safety Guide also provides guidance and recommendations on surveillance activities for SSC important to safety (i.e. monitoring plant parameters and systems status, checking and calibrating instrumentation, testing and inspecting SSC, and evaluating results of these activities). The aim of the surveillance activities is to verify that the plant is operated within the prescribed operational limits and conditions, to detect in time any deterioration of SSC as well as any adverse trend that could lead to an unsafe condition, and to supply data to be used for assessing the residual life of SSC.

Safety Guide on The Operating Organization for Nuclear Power Plants (NS-G-2.4) More

This Safety Guide provides recommendations on maintenance, in-service inspection and surveillance programmes. It also provides recommendations and necessary elements on management of ageing.

 

 

 

 

 

Modifications to Nuclear Power Plants (NS-G-2.3) More

This p rovides guidance and recommendations on controlling activities to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under control and that the modified configuration conforms to the approved basis for granting a nuclear power plant operating license. This guide deals with modifications to management systems as well as modifications relating to plant configuration. It does not have any specific parts relating to ageing but modification is one of the most important contributors to manage ageing. When a nuclear power plant has a plant to make some modifications on its SSCs or management systems, this safety guide could be a useful guideline.

 

Recruitment, Qualification and Training for Nuclear Power Plants (NS-G-2.8) More

This Safety Guide is to outline the various factors that should be considered in order to ensure that the operating organization has a sufficient number of qualified personnel for safe operation of a nuclear power plant. In particular, the objective of this publication is to provide general recommendations on the recruitment and selection of plant personnel and on the training and qualification practices that have been adopted in the nuclear industry since the preceding Safety Guide was published in 1991. Plant ageing includes not only equipment obsolescence but also ageing of human resources. This safety guide is an important guideline to cope with human resource ageing.


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