Office for Nuclear Regulation
An agency of HSE

Operating experience feedback - screening, analysis, monitoring, review

BMM Annex 8

Issue No:
001
Approved by:
L Creswell

1  Purpose and scope

1.1  This procedure describes ONR’s processes for utilising operating experience feedback (OEF) from events reported by UK licensees and from overseas events to inform decisions on targeting interventions and a llocation of resources.  The scope of the procedure excludes OEF from ONR’s investigation of licensee events.

1.2  In addition, ONR’s OEF processes form the basis of the nuclear contribution to HSE’s Major Hazards Strategic Programme (MHSP) Public Service Agreement (PSA) Targets (or Departmental Strategic Objectives).  The nuclear PSA metric is defined in terms of “numbers of (UK licensee) events judged to have the potential to challenge a nuclear safety system”.

2  Policy

2.1  Under Nuclear Site Licence Condition 7 (Incidents on the Site), licensees are required to report events to ONR.  This reporting (hereafter referred to as licensee event reports) may be by telephone, fax, verbal report, e:mail or written report.     ONR will use licensee event reports as the source information for UK OEF and for the nuclear PSA metric.  

2.2  Criteria and guidelines given in this procedure should be used as a framework for determining which licensee events are nuclear safety significant for OEF and PSA purposes.  These criteria and guidelines aid consistency in, but cannot replace, professional judgement.

2.3  The source information for international OEF includes:

  1. International Nuclear Event Scale (INES).
  2. Incident Reporting System (IRS) – for reactor events.
  3. Fuel Incident Analysis and Notification System (FINAS)

Overseas events do not contribute to the nuclear PSA metric.

Responsibilities

3.1  Unit 4B  Regulatory Processing Unit has responsibility for:

  • Maintaining event logs
  • Facilitating the event screening process
  • Producing quarterly Operating Experience Feedback Reports for input to Regulatory Reviews
  • Producing Nuclear PSA Target Performance Reports (on behalf of Management Board)
  • Quality assurance checks on data.  

3.2  ONR Operational Unit Heads have responsibility for considering OEF Reports in Regulatory Reviews.

3.3  ONR Management Board has responsibility for conducting high level reviews of OEF Reports and of Nuclear PSA Target Performance Reports.

3.4  CoSAS Statistics Branch is responsible for carrying out independent quality assurance checks on the OEF screening, analysis and monitoring processes described in this procedure.

Procedure

4.1  Appendix 1 provides an overview of ONR’s processes for:

  1. Screening of licensee event reports for nuclear safety significance.  
  2. Analysis of nuclear safety significant licensee event reports. 
  3. Monitoring and review of licensee performance and basic causation for nuclear safety significant events for determining priorities and allocation of resources.

Screening for nuclear safety significance

UK licensee event reports

4.2  A ONR Screening Panel is responsible for making judgements on nuclear safety significance of events and hence their contribution to OEF and the nuclear PSA metric.  The Panel comprises a minimum of two nuclear inspectors whose knowledge and experience is adequate to address the range of events being considered.  Event information which is protectively marked is subject to review by nuclear inspectors authorised to handle such information.

4.3  The ONR Screening Panel screens licensee events for nuclear safety significance (and hence, contribution to the nuclear PSA metric) on a periodic basis.  The screening is conducted using the criteria and guidelines provided in Appendix 2.

4.4  The screening process involves:

  1. Independent screening of events by members of the ONR Screening Panel. 
    • A log of licensee event reports is provided to each Panel member in advance of a subsequent Screening Meeting.
    • Prior to the Screening Meeting, each Panel member:
      • Screens the events for nuclear safety significance.
      • Assigns “Cause” and “Consequence” Codes (in line with Appendix 2) to those events considered to be nuclear safety significant.
  2. A ONR Screening Panel meeting at which Panel members reach consensus on:
    • Events which are / are not nuclear safety significant
    • Assigned “Cause” and “Consequence” Codes for nuclear safety significant events.
    • Events on which the Panel needs further operational / technical information to make decisions on nuclear safety significance (“grey areas”).

    Typically, pre-meeting blinded judgements by the Screening Panel on which events are nuclear safety significant agree 70% of the time.  The level of pre-meeting agreement is monitored.

4.5  Panel Members consult operational or specialist nuclear inspectors in making “grey area” decisions on nuclear safety significance.

International events

4.6  The ONR Screening Panel considers overseas events for OEF purposes.

Analysis, monitoring and review of events

4.7  On a quarterly basis, ONR Division 4 Regulatory Processing Unit produces an Operational Experience Feedback (OEF) Report which analyses UK events data, provides a breakdown, by Division, of licensees’ performance and basic causation and tracks Directorate progress against the nuclear PSA target.    This OEF Report also encompasses lessons learned from overseas events.

4.8  The OEF Report is input to ONR’s system of “Regulatory Reviews” which operates progressively at all levels within ONR and makes decisions on regulatory priorities and targeting of resources.

4.9  Also, on a quarterly basis, ONR Division 4 Regulatory Processing Unit produces a nuclear PSA Target Performance Report for the MHSP on behalf of ONR’s Management Board.

4.10  ONR’s Management Board undertakes a high level review of the OEF Report and of the PSA Target Performance Report to ensure adequate consideration of issues with potential to impact on nuclear safety and achievement of PSA targets.

5  Quality assurance

5.1  Adequate records will be maintained to demonstrate compliance with all aspects of this procedure.  These records include:

  • Separate logs for events assigned as nuclear safety significant and those assigned as non-nuclear safety significant.
  • Independent Screening Evaluation Sheets
  • ONR Screening Panel Meeting Evaluation / Action Log Sheets

5.2  ONR Division 4 Regulatory Processing Unit undertakes a quarterly quality check to review whether any events considered non-nuclear safety significant by the Screening Panel have been assigned an INES 1 or above rating by the licensee.   Such events are referred back to the Screening Panel. 

[Note: (3)The INES system exists solely to assist with the timely understanding of the significance of radiological events through the rapid promulgation of reports with a simple scale rating for use by the nuclear community, the media and the public.  Given this function, the INES system is not considered to be appropriate for deciding on nuclear safety significance of events for ONR regulatory purposes.  However, it is highly unlikely that application of the criteria and guidelines (Appendix 2) for making judgements on nuclear safety significance would result in exclusion of events rated at INES level 1 or above.]

5.3  ONR Division 4 Regulatory Processing Unit monitors on a quarterly basis the proportion of events that are nuclear safety significant to identify any marked changes.   Significant changes over time will be referred to the Screening Panel to assess the consistency of the nuclear safety significance judgement process.  

5.4  CoSAS Statistics Branch provides an independent check of ONR’s OEF processes in terms of event screening, analysis and monitoring.

References

  1. ONR’s Fast Stream Reporting Process, INS/011, Issue 1, 27/3/00
  2. Guidance: ONR’s Fast Stream Reporting Process, G/INS/003, Issue 002, 10/11/05.
  3. ONR BMM Annex 5B, UK INES Reporting – Agreed Interface Arrangements, Issue 002, 11/10/02.

Appendix 1
Operating experience feedback process
UK licensee events screening, analysis, monitoring and review

1. Licensee Event Reports received by Operational Divisions (as events occur)

2. Licensee Event Reports received by ONR Regulatory Processing Unit via Operational Division Administrative Staff (as events occur) or directly from licensees
(Note: Protectively marked event reports are retained by appropriate Operational Division)

3. Licensee Event Reports put onto ONR Regulatory Processing Unit Event Log database (as events occur) by Administrative Staff (See Note in (2) above covering protectively marked event reports)

4. Periodic screening of Licensee Event Reports by ONR Screening Panel for determining which events are nuclear safety significant (and contribute to nuclear PSA metric) and assigning “Cause” and “Consequence” codes:

  1. Independent screening (prior to Screening Meeting)  of Licensee Event Reports by ONR Screening Panel members
  2. ONR Screening Panel Meeting to
    • validate members’ independent screening results,
    • reach consensus on events which are nuclear safety significant     
    • action further interactions with operational /specialist inspectors where consensus cannot be reached

5. ONR Regulatory Processing Unit Administrative Staff record screening results. (See Note in (2) above covering protectively marked event reports)

6. ONR Regulatory Processing Unit produces Analysis (Operational Experience Feedback Report) on Quarterly basis of Licensee Event Reports – Divisional performance, basic causation and trends - for input to ONR “Regulatory Reviews” for determining priorities and targeting of resource 

7. ONR Regulatory Processing Unit produces Nuclear PSA Target Performance Report on quarterly basis for HSE Major Hazards Strategic Programme

8. ONR Regulatory Processing Unit Operating Experience Feedback Report reviewed at Regulatory Review meetings to determine priorities and targeting of resource   

9. ONR Management Board provides high level review on Quarterly basis of Nuclear PSA Target Performance Report and of Regulatory Processing Unit OEF Report

10. ONR Regulatory Processing Unit quality assurance checks

11. HSE CoSAS Statistics Branch provides independent quality checks on ONR process

Appendix 2
Criteria and guidelines for making judgements on nuclear safety significance of events

The Consequence and Cause codes given below form the basis for determining which licensee events are nuclear safety significant and therefore contribute to the PSA metric.  Interpretation of these codes and the licensee events to which they relate requires professional judgement.  However, general guidelines on interpretation are provided below.    

*Consequence (actual / potential)

  1. Inadvertent criticality
  2. Radiation / contamination release
  3. Loss of containment
  4. Radiation exposure (internal / external)
  5. Loss of operational / process control
  6. Plant/ equipment failure
  7. Plant/ equipment damage / defect
  8. Challenge to safety case
  9. Reduced safety margins / safety barriers
  10. Breach of operating limits and conditions, licence conditions and other relevant regulations
  11. Enforced plant shutdown – automatic / manual
  12. None
  13. Other (Specify)

*Cause(s) – causal factors

  1. Plant / equipment defect / degradation
  2. Maintenance failure
  3. Design deficiency
  4. Modification deficiency
  5. Operational process deviation / defect
  6. Loss of services
  7. External event  - natural / man-made
  8. Human performance
    1. Training
    2. Procedural
    3. Intentional / misinformed / unintentional or lapse
    4. Management system

* If more than one code (Consequence or Cause) can apply to an event, the most relevant code should be adopted.  General Guidelines on Interpreting Licensee Events for Nuclear Safety Significance

  Event type / Comments

1

Events meeting Ministerial Reporting and HSE Publication Criteria (given below) to be considered as nuclear safety significant:

  1. Dangerous occurrences reportable under the Nuclear Installations (Dangerous Occurrences) Regulations 1965.              
  2. Confirmed exposure to radiation of individuals which exceed, or which are expected to exceed, the dose limits specified in Schedule 4 to the Ionising Radiations Regulations 1999.
  3. Examination, inspection, maintenance, test or operation of any part of the plant revealing that the safe operation or condition of the plant may be significantly affected.
  4. A confirmed breach of, or discharge expected to breach quantitative limits of a Certificate of Authorisation for the disposal of radioactive waste issued under the Radioactive Substances Act 1993.
  5. Abnormal occurrences leading to a confirmed release to atmosphere or spillage of a radioactive substance which exceeds or is expected to exceed, the limits set out in Column 4 of Schedule 8 of the Ionising Radiation Regulations, 1999, except where the release is in a manner specified in an Authorisation under Radioactive Substances Act 1993.
  6. abnormal occurrences leading to a release or suspected release or spread of radioactivity, on or off site, which requires special action or special investigation by the Operator.

Criteria for Defence sites also include events that might attract public or media interest. .

2

Events graded by the licensee under “Nuclear” or “Radiological” categories are candidate nuclear safety significant events.

3

Radiography Events reported under IRRs to HSE’s Radiation Specialists for both nuclear and non-nuclear sites.  Therefore, not considered nuclear safety significant due to “double counting” issues.

4

Conventional Health and Safety Events not considered nuclear safety significant if there are no implications for nuclear safety.    

5

Emergency Services attending nuclear licensed sites for non-nuclear emergencies  (“Blues and Twos” ) not considered nuclear safety significant

6

Legacy radioactive material identified as result of improved monitoring equipment – nuclear safety significant if event meets Ministerial Reporting and HSE Publication criteria.

7

Environmental Events (e.g. release of non-radioactive chemicals / oil or breach of Environment Agencies’ Authorisation Limits) not nuclear safety significant unless event causing release etc has nuclear safety implications.

8

Where several facilities / sites are shutdown for the same reason with several Event Reports raised:

  1. If shutdown is precautionary, include associated Event Reports as a single nuclear safety significant event and single contribution to PSA metric.
  2. If actual problems identified on each facility / site, include each Event Report as nuclear safety
    significant and multiple contribution to PSA metric.

9

Transport Events

  1. Excepted material is out with Nuclear Site Licence requirements so not nuclear safety significant and excluded from PSA metric
  2. For nuclear material,
    1. if Event originated on the nuclear site, include as nuclear safety significant and in PSA metric.
    2. if Event occurred off the nuclear site, not nuclear safety significant and excluded from PSA metric because it is covered within remit of Department for Transport.

10

Security Events not nuclear safety significant, excluded from PSA metric – covered by Security Section

11

Aircraft Over Flying Events not considered nuclear safety significant and excluded from PSA metric – outside ONR and licensee control - covered by Civil Aviation Authority

12

Events reported by Ministry of Defence related Nuclear Site Licensees considered for nuclear safety significance in line with “Cause” and “Consequence” criteria (Appendix 1)

13

Events covering non-nuclear site licensee Ministry of Defence related Authorisees – not within ONR regulatory vires.  Therefore, not considered for nuclear safety significance or for PSA metric.

14

Contamination Events considered nuclear safety significant and included in PSA metric for:

  1. Confirmed intake of radioactivity.
  2. Contamination found outside a controlled area requiring restrictive measures, e.g. access restrictions, to be imposed.
  3. Contamination found on skin or personal clothing outside a controlled area.
  4. Widespread contamination of an accessible area (primarily in Designated Areas defined in Ionising radiation Regulations 1999 – Controlled / Supervised Areas)
  5. Failure of Personal Protective Equipment in use

[Note – These criteria are closely linked with Ministerial Reporting Criteria 1 given above.]

15

Events involving Naturally Occurring Radioactive Materials (NORM) not considered nuclear safety significant – these materials do not arise from nuclear processes

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Updated 04.06.10