SAFARI-1 Research Reactor Ageing Management Programme - EUROPEAN RESEARCH REACTOR CONFERENCE (RRFM) 2021 26-30 SPETEMBER 2021 Helsinki, Finaland

SAFARI-1 Research Reactor Ageing
Management Programme

EUROPEAN RESEARCH REACTOR CONFERENCE (RRFM) 2021
              26-30 SPETEMBER 2021
                 Helsinki, Finaland

Sammy Malaka (Necsa- SAFARI-1, South Africa)

Tuesday, September 28, 2021                        1

PRESENTATION OUTLINE

Introduction

SAFARI-1 Ageing Management Programme (AMP) Process

SAFARI-1 AMP Methodology and Assessment
Integrated Programmes in SAFARI-1 Ageing Management

Regulatory Requirements of Ageing Management

Successes and Challenges

Conclusion

                                                      2

Introduction
South African NUCLEAR FACILITIES & LOCATION

                                              3

SAFARI-1 Research Reactor

 20 MW pool-type research reactor
 Light water cooled and moderated
 Beryllium reflected
 Operational since 18 March 1965
 Impeccable safety and environmental record
 Recognised for high utilisation
    > 300 operational days per year
 Fully converted to LEU silicide fuel
 Utilisation:     Irradiations     for    isotope
    production,   neutron   activation    analysis,
    neutron beam-line research, silicon doping
 Successfully        implemented          Ageing
    Management Programme

                                                      4

AMP Introduction 1/2

■ The AMP is implemented through SAFARI-1 IMS which is subject to
   periodic review and Audit.

■ A series of workshop were held to perform ageing assessment and
   to formulate remedial actions to address ageing related issues.

■ The design basis of the facility contains no information to a pre-
   designated or intended design lifetime of the facility

■ The effect of neutron fluence on the fixed core structure based on
   current operation is predictable until a predetermined time based on
   actual experience and reported reference data of other facilities

                                                                       5

AMP Introduction 2/2

■ The operation threshold may vary depending on the
  remedial action addressing the soundness of the
  fixed core structures
■ For the purpose of the AMP 2020/1 and now 2029/30
  presents a convenient threshold extrapolated –
  separating the concept of current lifetime from that
  of lifetime extension
■ Thus the target lifetime extension of the current
  ageing management programme is 2030 and beyond
                                                      6

SAFARI-1 AMP PROCESS

■   Ageing Management Programme at SAFARI-1 is based on IAEA
    Guideline SSG-10 (October 2010), originally derived from
    DS-412 (Aug 08)
■   AMP objective extend life of SAFARI-1 to at least beyond 2030
■   SAFARI-1 Developed own AMP for application and implementation
    ►Ageing Management Philosophy / Strategy for the
     SAFARI-1 Research Reactor – 2009
    ►Ageing Management Plan for the SAFARI-1
     Research Reactor – 2010
    ►List of SAFARI-1 Ageing Management Projects –
     2011 updated annually

SSG-10: Ageing Management for Research Reactors

                              ■ Management systems for Ageing
                                 Management (AM)
                              ■ Concepts on Ageing and Safety
                              ■ Elements of AMP
                               Screening of SSCs
                               Identification and understanding
                                 of ageing degradations
                              ■ Management of Obsolescence
                              ■ RR Ageing Mechanism

Ageing Management Strategy
■ Purpose: establishing , integrating and implementing reactor
   AM
■ Scope: covers all aspects related to establishment,
   implementation and continuous improvement of AM
■ Objectives: to ensure continued adequacy of the safety level,
   reliable operation of the reactor and compliance with OLC /
   OTS
■ Assumptions & Constraints
    There is No SSC that cannot be replaced , repaired or improved to extend
     reactor life to 2030 and beyond
    Major Upgrades / Modification & Refurbishment of SSCs can only occur during
     shutdowns

■ Principles:
    Ageing Analysis, Reduction & Mitigation

Ageing Management Plan
■ The plan’s purpose is to outline the methodology for
   implementation of the AMP projects
■ The plan covers identified aspects of ageing of the SAFARI-
   1 Research Reactor taking into consideration but not
   limited to:-
    Service Conditions
    Anticipated Operational Occurrences
    Environmental Conditions
    Obsolescence

■ “Then” the projected end of life of the facility was assumed
   (at   the   present   rate   of   operation   was   provisionally
   approximated) to be around 2030.

AM Methodology & Assessment
■   Establish an Evaluation Team from all relevant disciplines (e.g. Reactor Safety,
    Engineering, Operations, Radiation Protection, Quality etc.) to assess ageing
    mechanism and formulated remedial actions.

■   Develop an Ageing Matrix
    ► Identify Ageing Mechanisms (as listed in SSG-10)
    ► Evaluate applicability and effect of all Ageing Mechanisms to all SSC relevant to
      safety (Safety Critical) and operational sustainability
■   Identify projects to remedy /mitigate the effect of Ageing Mechanisms

■   Prioritise projects for implementation
    ► Performed by Evaluation Team
    ► Based on Impact Factors and Urgency Factors
         ● Impact Factors (I) : Reportable Nuclear Event, Radiological Exposure, Injury, Environmental Impact,
           License Compliance, Lifetime Limitations, Public Non-Acceptance, etc.
         ● Urgency Factors (U) : Time when project outcome is needed less time of project completion
    ► Priority = I X U and the scale ranges from 0 to 100%

■   Implement Projects by Priority

■   Re-evaluate effectiveness of Implementation periodically

Assessment of Ageing Effects

■   The ageing assessment of the             SSC Groupings
    SAFARI-1 facility was facilitated by a   1.   Reactor block, fuel and internals

    generic spreadsheet based matrix         2.   Cooling systems
                                             3.   Confinement and containment
■   The matrix gives a set of SSCs in the    4.   Instrumentation and controls
    vertical axis and ageing                 5.   Power supply
    mechanisms in the horizontal axis        6.   Auxiliaries (e.g. fire protection,
                                                  crane, hot cells and radiological
                                                  waste handling etc.)
                                             7.   Experimental facilities
                                             8.   Structures
                                             9.   Non SSC:
                                                  ►   Documentation (e.g. SAR, OTS /
                                                      OLCs, design control and
                                                      management systems) and Staff
                                                      training etc.

                                                                                       12

Ageing Mechanisms
A.   Radiation – change of properties
B.   Temperature – change of properties
C.   Creep due to stress/pressure
D.   Mechanical displacement/fatigue/wear from vibration and
     cyclic loads
E.   Material deposition (e.g. crud)
F.   Flow induced erosion
G.   Corrosion
H.   Damage due to power excursions and operational events
I.   Flooding – deposition and chemical contamination
J.   Fire – effects of heat, smoke and reactive gases
K.   Obsolescence and technology change
L.   Change in requirements or acceptable standards
M.   Other (time dependent phenomena)                      13

Ageing Evaluation Matrix

 14

Remedial Actions Prioritisation of
Projects

  ■ Importance Factor:

  ■ Urgency Factor:

  ■ Priority (P) = Importance Factor (I) x Urgency Factor (U)
  ■ P = I X U ranges from 0 to 100%

Prevention and Mitigation of Ageing effects

  ■ The prevention and mitigation of ageing effects may be
      accomplished by:
   Appropriate provision made during the design of the
      reactor;
   Surveillance and testing activities to assess; degradation
      of components and systems;
     A preventative maintenance programme;
     Periodic evaluation of operating experience;
     Optimization of operating conditions and
     Repairing, replacing or refurbishing of SSCs
                                                             16

Prevention and Mitigation of Ageing effects

 ■   Besides technical aspects some other important factors should be taken
     into consideration:-
  Safety: What are the safety implication of continuing operation of the
     degraded system or even taking it out of service?
  Environmental and regulatory compliance: Is it possible to continue
     operation of the reactor without impairing / damaging / prejudicing
     environmental and regulatory requirements?
  Strategic need: What is the working programme of the reactor and what are
     the real organisational or national needs?
  Costs: What are the costs involved ? Are the changes within reach!
     Affordability, Economics of Scale, ROI, Benefits vs Cost Analysis etc.

 All these factors need to be considered in a systematic way in the Prevention
 and Mitigation of Ageing Effects.                                            17

Periodic Evaluation of AMP
■ In AM Strategy: A periodic evaluation of the SAFARI-1
   reactor will be done every 5 years to determine the steps
   required to keep the reactor operational

■ What we have not done/ what we need to do in future:
 Evaluation of implemented projects to assess whether
   identified ageing issues have been adequately addressed

 Periodic Safety reviews that demonstrates ageing status??
 Independent assessment of the AMP (Internal Audit
   are done)
                                                               18

AMP Implementation at SAFARI-1

 1
     • Conduct AMP Workshops

 2
     • Determine Ageing Mechanisms

 3
     • Develop Assessment Matrix

 4
     • Provide Remedial Actions (RA)

 5
     • Classification of RA

 6
     • Prioritisation of RA

 7
     • AMP Projects listing

 8
     • Update / Track Status
                                       19

Maintain a List of Ageing Management
Projects
  • Maintain a list of Ageing
    Management Projects
  • List is updated annually for
    projects progress and status
  • Maintain the Project
    Classification

SAFARI-1 AMP PRIORITY PROJECTS

   Nuclear Safety Channels ----            Silicon Roller Service Station –
    Completed                                 in progress ??
   Area Monitoring System Upgrade---       Charcoal Ventilation Filter
    Completed                                Efficiency Measurement Capability-
   Gamma Safety Channels Upgrade ----        -- Completed
    Installation in progress                Fresh Fuel Vault Upgrade ---- in
   Neutron Control Channel ----              progress
    installation in progress                Primary Heat Exchanger
   Automatic Flux Controller ---            replacement --- in progress
    Completed                               Reactor Vessel Assessment –
   Rod Drop Monitor Upgrade --–              Completed
    Completed
                                            Biological Shield Assessment –
   Ventilation System refurbishment –        Completed
    Completed
                                            Plant Health Safety Assessment
   Stack Monitoring System upgrade ----      – in progress
    Completed
                                            Portable External Plug-in Power
   R1 and R2 Liquid effluent Tanks          Supply ------ On hold
    upgrade ---- in progress
                                            Emergency Water Return------ in
   Beam lines upgrades ---- in progress      progress                         21

INTEGRATED PROGRAMMES / MANAGEMENT SYSTEMS IN SAFARI-1
AGEING MANAGEMENT PROCESS

   MAINTENACE PROGRAMME                     MAINTENACE PROGRAMME
                                              Preventative Maintenance
   ISI PROGRAMME                                 Routine maintenance
                                                  Periodic inspections
   MANAGEMENT OF CRITICAL SPARES                 Functional inspections
                                              Corrective Maintenance
   SAFETY CLASSIFICATION OF SSC’S PROCESS
                                                  Ad-hoc - “Request for
                                                  Maintenance” data base
                                             CRITICAL SPARES
   SAFAETY REASSESSMENTS F-D
                                              SSC considered critical spare if the
                                                cannot be obtained within 4 days
   REACTOR SAFETY COMMITTEE
                                                of the specific failure and no
                                                redundancy exists during
   INSARR (2013) RECOMMENDATIONS               operation
                                             SAFETY CLASSIFICATION OF SSC’S
   PLANT HEALTH STATUS REVIEW                Rate SSC according to their
                                                importance to safety
                                              Aligned with IAEA doc : SSG-30

REGULATORY REVIEW / REQUIREMENTS FOR
 AGEING MANAGEMENT PROJECTS     (1/2)

■   Technical discussions with Regulator on ageing management projects

■   Agree in principle of regulatory review / requirements approach

■   Ageing Management Projects categorisation
     Project Category (PC) 3, 2, 1
     Quality Class (QC) 1, 2, 3
     Safety Class (SC) 1, 2, 3

■   Design Baseline / Licensing Design Pack

■   SC/QC 1 & 2 submitted for approval / acceptance

■   SC-3 submitted for information

REGULATORY REVIEW / REQUIREMENTS FOR
AGEING MANAGEMENT PROJECTS (2/2)

 AM Projects / Modification / Upgrade developed :-
 Regulatory review/ Licensing and project file

       Licensing Strategy
       System Design Description
       PMP
       Quality Assurance Plans
       Technical Comparison of new and existing systems
       Supplier Qualification Audit plan (SC-1/2)
       Installation and Commissioning plan
       Safety Assessment Reports / Radiological Dose Assessment
       Commissioning Report
       FAT Reports (if applicable)
       Design Review / verification (if Applicable)
       URS / Specification documents

Successes and Challenges
   Instrumentation and Maintenance projects
   Successfully implemented instrumentation projects as part of the AMP
   Improved plant instrumentation instruments reliability and performance
   Reactor Vessel Assessment
   Provided a justification to the Nuclear Regulator for revised accumulated power limit (Assessing
    Neutron irradiation effects) Done!
   However, a re-assessment need to be done prior to 2030 to justify fluence limit safety for
    continuous operation beyond 2030
   Update SAR (Safety Analysis Report) to motivate continuous operation up to 2030 and beyond.
   Biological Shield Assessment
   Results from the assessment show that the biological shield is fit for continuous operation up to
    2030 and beyond.
   Plant SSC Health Safety Assessment - 80 % complete
   It is a challenge to confirm health status of selected critical SSCs
   The health assessment initiative is bearing results and still under internal review

Conclusion

■   In Integrating ageing management and maintenance requirements with other programmes – careful
    management is required to avoid duplication of effort and wastage of scarce resources

■   Ageing management of inaccessible equipment is vital since replacement and repair is not usually an
    economically feasible option

■   Sharing of operational experiences by tracking generic failures and monitoring effectiveness of
    ageing management activities is vital of ageing management programme success

■   In SAFARI-1 Proposed modifications to SSCs as well as modifications to the operation, maintenance
    and/or utilisation of the reactor, where such modifications have significant impact on the safety of the
    reactor and its facilities are presented for review to the RSC – Reactor Safety Committee – This have
    assisted considerably in facility safety assurance and adherence!

■   The regulator / reactor operator technical discussion on regulatory review process of AM projects
    facilitated projects delivery timelines
■   AMP provide a clear implementation process to comply with regulatory requirements

Questions?
             27