Office for Nuclear Regulation
An agency of HSE

LC20:  Modification to design of plant under construction

Site Inspection Planning

T/INS/020 - Issue 2

Issue date:
17-07-2009
Review date:
17-07-2012
Open Government Status:
Fully open
Approved By:
R C Gray

1  Purpose and scope

1.1  The purpose of this guidance is to facilitate a consistent approach to LC 20 compliance inspection and to provide assistance to inspectors while carrying out their duties in this area.  The guidance should not be regarded as mandatory.  Although every attempt has been made to deal with all the key features that are likely to arise in inspecting for compliance with this licence condition, additional aspects may need to be examined to ensure a comprehensive and complete inspection.

1.2  The guidance does not indicate when or to what extent these compliance inspections should be made as these matters are covered in individual inspectors’ inspection programmes.

1.3  The guidance provided is split into four main elements:

  1. Purpose of the Licence Condition
  2. Guidance on arrangements for LC 20.
  3. Guidance on inspection of arrangements.
  4. Guidance on inspection of implementation of arrangements.

2  Licence condition

Licence condition 20: modification to design of plant under construction

20(1)  The licensee shall ensure that no modification to the design which may affect safety is made to any plant during the period of construction except in accordance with adequate arrangements made and implemented by the licensee for that purpose.

20(2)  The licensee shall submit to the Executive for approval such part or parts of the aforesaid arrangements as the Executive may specify.

20(3)  The licensee shall ensure that once approved no alteration or amendment is made to the approved arrangements unless the Executive has approved such alteration or amendment.

20(4)  The aforesaid arrangements shall provide for the classification of modifications according to their safety significance.  The arrangements shall where appropriate divide modifications into stages.  Where the Executive so specifies the licensee shall not commence nor thereafter proceed from one stage to the next of the modification without the consent of the Executive.  The arrangements shall include a requirement for the provision of adequate documentation to justify the safety of the proposed modification and shall where appropriate provide the submission of this documentation to the Executive.

3  Purpose of Licence Condition 20.

3.1  This Licence Condition is part of the group of conditions (LCs 19 -22 & 35) designed to provide a system of rigorous and appropriate regulatory control of changes to plant or processes on the licensed site.  These changes may be brought about by construction, modification or commissioning of new plant, commissioning, modification or experiment on existing plant including any change of process, and decommissioning.  The purpose of this Condition is to control the modification to design of plant under construction.  The term modification is defined in Licence Condition 1(1).  Custom and practice limits the application of this particular Condition to modifications to new plant and is intended to ensure proper consideration of the safety implications before the modifications are implemented.

3.2  The actual process of construction and installation shall be progressed under arrangements made under Licence Condition 19.

3.3  Changes to an existing facility or process shall be progressed under arrangements made under LC 22.

3.4  Specific requirements for decommissioning including strategies and programmes shall be progressed under arrangements made under LC 35.

4  Guidance on arrangements for LC 20.

4.1  In addition to the general requirements for all Licence Conditions the licensee’s arrangements shall satisfy the specific Licence Condition requirements which are:

  1. A clear requirement that the arrangements control modification to the design of plant under construction. 20 (1)
  2. The requirement to submit for approval to the Executive (ONR) those parts of the arrangements the Executive may specify. 20 (2)
  3. The requirement that once approved by the Executive arrangements can’t be altered without the approval of the Executive.  20 (3).
  4. A system of classification of modifications according to their safety significance which takes due account of the modification being inadequately conceived or executed. 20 (4)
  5. The requirement to allow where appropriate the modification to be divided into stages. 20 (4)
  6. The requirement that where the Executive specifies a hold point the licensee shall not commence nor proceed from one stage to the next without the consent of the Executive. 20 (4).
  7. The requirement for the provision of adequate safety documentation to justify the safety of the construction or installation and where appropriate provide for the submission of this documentation to the Executive thereby providing regulatory control by requiring hold points in the implementation process.  20 (4).

5  Guidance on inspection of arrangements for LC 20

5.1  The following list includes elements of good practice which have been compiled from information currently available.  This list is neither exclusive or exhaustive and will be subject to review and revision in the light of operational experience.  Good practice elements may exceed the minimum compliance requirements.

5.2  If licensees have generic model(s) for arrangements then it is for the site to justify any deviation from the model(s).  Site staff should be able to demonstrate how their arrangements meet the regulatory requirements.  [Note: not all licensees use generic models].

5.3  Arrangements shall address the licence condition requirements.

5.4  Arrangements should include a system for classification by safety significance of modifications to design based on hazard which takes due recognition of the works being inadequately conceived or executed and should include a review process for each classification commensurate with safety significance i.e.robust review/assessment for the most significant safety classification and referral to the relevant safety committee or Nuclear Safety Committee as appropriate.  Arrangements should be specific about assuming the worst that can happen, i.e. inadequately conceived or executed, without reference to risk.  The use of a risk based classification system frequently results in lower categories being applied; however, the risk assumption used offers the potential for inadequate conception.  Good practice classification systems have categories linked to potential doses to members of the public and workers on the site.  In addition where there is the potential for significant off site doses (e.g. doses in excess of 5mSv for members of the public) or where dose limits for workers on the site could be exceeded such proposals should be referred to NII as well as clearing the licensee’s own due process

5.5  The classification system for safety significance should be consistent with that used for LC19, 21, 22 and 35.

5.6  Arrangements should allow ONR to agree or acknowledge and opt in or out of regulatory hold points as appropriate (flexibility for NII permissioning activities).

5.7  Arrangements should include a requirement for modification proposals to be systematically compiled, reviewed, assessed, revised, extended, validated, verified, approved or cancelled by staff who are SQEP/DAP.  This should include as a minimum multiple agreement, separate assessment and independent authorisations prior to implementation.  Where appropriate independent company safety departments and expert staff should also confirm satisfaction with the proposal.

5.8  Arrangements should identify the requirements for the licensee’s construction/installation programme(s) to include adequate time for assessment of safety submissions by ONR and or other regulators.  This time should be independent of that required for their own internal peer review processes, which should be complete before submission to the regulators.

5.9  Arrangements should require an implementation Quality Plan or similar scheme for modifications to plant under construction which addresses:

  1. all hazards during design, construction and installation (nuclear, conventional, environmental)
  2. procedures - what needs to be done -  how it is done -  how it is closed out
  3. issues tracking and close-out
  4. responsibilities and how the licensee controls the work of contractors
  5. the requirement for contractors to comply with licensees arrangements and system of work.

5.10  Arrangements should require that there is clear linkage to a live safety case to show safety case development in line with the modification activity.

5.11  Safety case submissions should be supported by appropriate engineering/process detail to enable regulators to assess their adequacy.

5.12  Arrangements should require that there is a clear linkage to other supporting arrangements e.g. LC 14 Safety Documentation, LC 20 Modifications to Design of Plant Under Construction, LC24 Operating Instructions and LC28 Examination, Inspection Maintenance and Testing.

5.13  Arrangements should allow for the Executive to achieve regulation of projects using the secondary powers provided under the licensee’s arrangements, i.e. the agreements to modifications should be via licence instruments.

6  Guidance on inspection of implementation of arrangements for LC 20

6.1  Inspectors are required to apply their experience and discretion to determine the extent and depth of a particular inspection taking due account of a number of factors such as safety significance, complexity, importance and technical specialism of the area.  In some cases it may be possible for the inspector to re-allocate progress of specific regulatory matters on a topic within his unit or division.

6.2  The following list of areas for inspection of arrangements for compliance with LC 20 has been compiled from best information available.  This list is neither exclusive or exhaustive and will be subject to review and revision in light of operational experience.

6.3  Sample, check licensee’s safety classification system for modification to design of plant under construction and challenge as necessary.

6.4  Sample, check the licensee’s control of implementation of the modification to design of plant under construction including,

  1. whether work has been approved before commencement
  2. whether appropriate liaison has taken place to meet other regulatory requirements.  (ONR may not be the lead regulator in all areas i.e. planning approval, CDM regulations, fire certificate, environmental aspects.)
  3. whether responsibilities are clearly defined and recognised, including interfaces between licensees and contractors.
  4. whether instructions have been written for significant on-site activities
  5. whether control and supervision of staff and contractors is adequate.
  6. whether adequate segregation is in place to limit interaction with other operational plant.

6.5  Sample, check the application of the licensee’s system in place for progressing issues arising from modification of design of plant under construction including the management of technical queries, concessions, omissions.

6.6  Sample, check that there are appropriate links to the safety case requirements for any modification to design of plant under construction and that those responsible for undertaking and implementing these activities are aware of/have access to the safety case requirements.

6.7  Sample check that the licensee has adequate arrangements for identifying the current status and progress of modifications throughout construction and that these are fully completed. i.e. that relevant drawings, operating and maintenance instructions are produced to ensure that prior to entering normal operations the status of all plant and modifications is adequately reflected in the safety case.

6.8  Sample, check time limits for completion of modification of design of plant under construction and that there are no undue delays. Although delays may largely be a commercial matter for the licensee, clearly there is a need for the inspector to ensure that this does not impact upon NII’s ability to assess any safety documentation in support of the release of any holdpoint.  Additionally, undue delays should not adversely affect the ability of the licensee to deliver project milestones that may have been declared elsewhere, i.e. decommissioning programmes.  Progress on some activities may be critical to the success of others, the knock-on effects of delays should be recognised by the licensee.

6.9  Sample, check that activities associated with the modification of design of plant under construction have been completed or adequately progressed to enable, the facility or process to progress from one stage to the next.  Areas to consider here include:

  1. training (SQEPs).
  2. completion of documentation including, drawings, instructions and procedures
  3. maintenance schedule updated and implemented to reflect new status
  4. operating rules and or instructions updated and implemented to reflect new status as appropriate
  5. adequate controls are being exercised over temporary plant/construction aids e.g. hard wire links for C&I, defeat of interlocks, spades in process lines
  6. as built is as designed and specified
  7. all regulatory and other hold point points have been honoured and have received appropriate authorisation.

6.10  Where ONR consent is required to proceed beyond a hold point sample check that licensees due process has been completed in addition to the elements listed is 6.8 above

 

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Updated 21.09.10