PLANT LIFE EXTENSION NUCLEAR SAFETY IMPLICATIONS

I - INTEGRATED PLANT STATUS:

¨ PLiM processes and methodologies: an integrated program related to all aspects of plant degradation processes.

  • SSC nomination: the identification of those selected SSC whose ageing degradation it’s of great concern      (Buildings and Structures, Reactor and mechanical systems, Electrical and I&C systems).
  • Ageing degradation assessment: the process includes all methodologies used to assess the effects of ageing on     SSC, and to promote the adequate techniques for inspections and degradation mitigation:
    • SSC Condition Assessment (for important and less critical SSC)
    • SSC Life Assessment (for critical and limiting critical SSC)
    • SSC Systematic Assessment of Maintenance (FMEA and RCM methodologies)
  • Nuclear safety and plant performances integrated assessment: compliance with safety requirements and     licensing documentation.
  • Technological monitoring program: the program that treats all essential aspects adversely affecting safety or      reliability, other than those already assessed by the approved methodologies.
  • Standard criteria: nuclear safety, power production, environmental impact, costs and operating personnel safety.
  • Quality assurance improvement

   Plant SSC condition assessment after 30 years of operation: a preliminary activity of PLEX project containing the main aspects and plant SSC general conditions evaluation in order to identify the plant life extension project activities.

  • Actual plant condition.
  • PLEX project technical aspects overview and tasks schedules.
  • Existing environmental operating conditions.
  • Details on environment components affected by wastes and toxic and dangerous materials.
  • Time limited ageing analyses descriptions required for degradation evaluation:
    •   TLAA analyses (pressurizer, reactor inlet header, pressure tube and calandria vessel)
    •   Industrial experience
    •   Methods and models of probabilistic assessment (PSA, PRA)
    •   Nuclear specific civil-work experience
  • Plant condition assessment after 30 years of operation: Buildings and Structures, Reactor and Mechanical systems,  Electrical and I&C systems.

   Plant life extension project main activities:

  • maintenance activities during plant shut down state;
  • reactor fuel channel assemblies refurbishment;
  • nuclear steam plant systems refurbishment, including steam generators;
  • balance of plant systems refurbishment;
  • reactor core initial loading with fresh fuel;
  • reactor start-up and power production, including maintenance activities during extended   period.

    •    Plant SSC process and safety performances after 30 years of operation:

    • special safety systems performances;
    • plant protective and preventive process systems performances;
    • nuclear safety principles requirements completion;
    • essential nuclear safety functions completion

    II - ENVIRONMENTAL IMPACT ASSESSMENT: the process by which the direct, indirect, synergic, cumulative, main and secondary effects of a project on the environment and public health are identified, described and established, according to the in-force legislation.

      Environmental impact norms and regulations requirements:

    • environment protection activities control;
    • environmental impact assessment standard format and procedures;
    • environmental agreement and application approval procedures;
    • methodologies and guides for environmental impact assessment studies elaboration;
    • environmental impact assessment procedure for transfrontier conditions and public    hearing decision-making;
    • radiological safety basic norms;
    • computing and limiting norms for radioactive effluents released to environment.

      Environmental agreement stages:

    • application submittal and its initial evaluation;
    • project compliance with environmental impact assessment procedure;
    • environmental impact assessment study report elaboration;
    • environmental report analysis.

      Public acceptance:

    • public announcement and relevant documentation go public, if required;
    • informing public on the stages of environmental agreement and studies report;
    • local debates and hearings on project impact on environment;
    • administrative and organizational analyses on public acceptance;
    • public ennouncement of authority and project owner decision;
    • compliance evaluation on transfrontier environmental impact.

      Report format of environmental impact assessment study:

    • General;
    • Technological processes;
    • Wastes;
    • Potential impact on environment components and their mitigation;
    • Analysis and comparison of alternatives;
    • Environment monitoring programs;
    • Risk conditions;
    • Technical or practical difficulties during environmental impact assessment.

      Plant refurbishment activities impact on environment:

    • Land use;
    • Air quality;
    • Surface and underground water quality;
    • Aquatic biology;
    • Terrestrial biology;
    • Social-economical impact;
    • Radiological impact.

      Plant operation impact on environment:

    • One-way cooling systems effects on environment components;
    • Cooling tower effects on environment components;
    • Cooling reservoirs effects on environment components;
    • Electrical power transport lines effects on environment components;
    • Radiological impact of operation;
    • Social-economical impact;
    • Quality and employment of water table;
    • Postulated accident impact on environment.