LC22 - Modification or experiment on existing plant

Site Inspection Planning

T/INS/022 - Issue 1

Issue Date:

24/12/02

Review Date:

24/12/05

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 22 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:

2. Licence Condition

Licence Condition 22: Modification or experiment on existing plant

22(1). The licensee shall make and implement adequate arrangements to control any modifications or experiment carried out on any part of the existing plant or process which may affect safety.

22(2). The licensee shall submit to the Executive for approval such part or parts of the aforesaid arrangements as the Executive may specify.

22(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.

22(4). The aforesaid arrangements shall provide for the classification of modifications or experiments according to their safety significance. The arrangements shall where appropriate divide the modification or experiment into stages. Where the Executive so specifies the licensee shall not commence nor thereafter proceed from one stage to the next of the modification or experiment 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 or experiment and shall where appropriate provide for the submission of the documentation to the Executive.

22(5). The licensee shall if so directed by the Executive, halt the modification or experiment and the licensee shall not recommence such modification or experiment without the consent of the Executive.

3. Purpose of Licence Condition 22

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 ensure that adequate arrangements exist to control all modifications and experiments on existing plant or processes.

3.2 The term "modification" is defined in Condition 1(1) and covers any alteration to buildings, plants, operations, processes or safety cases and includes any replacement, refurbishment or repairs to existing buildings, plants or processes.

3.3 Construction and installation of new plant shall be progressed under arrangements made under LC19.

3.4 Modification to the design of new plant under construction shall be progressed under arrangements made under LC20.

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

4. Guidance on arrangements for LC 22

4.1 In addition to the general requirements for licence conditions the licensee's arrangements shall satisfy the specific licence condition requirements which are:

4.2 The arrangements should cover the update of all relevant documents including plant drawings and safety documentation (Conditions 14 and 15), operating rules (Condition 23), the maintenance schedule (Condition 28) and operating instructions (Condition 24) for all stages of the modification or experiment, from its initial proposal through to and following commissioning. The modification or experiment may require personnel to undergo elements of additional training (Condition 10) before the commencement of operations, and to demonstrate that staff satisfy the requirement to be SQEP and/or DAP where this is appropriate (Conditions 12 & 26).

5. Guidance on inspection of arrangements for LC 22

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 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 Arrangements should ensure where a modification is preceded by a paper justifying changes to the safety case only, which may not require NII agreement, that sufficient reference is made in the original paper to subsequent planned engineering changes to the plant, which may be justified by lower category submissions, to allow the NII assessment to include a complete appreciation of all of the consequences of the safety case change.

5.6 A series of minor modifications could have a significant, cumulative effect on safety and inspectors should ensure that this is taken into account in the arrangements which accordingly should interface with the requirements for the licensee to have a safety case under LC 14, 23, 21(8) and for the periodic and systematic review and reassessment of safety cases under LC15.

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

5.8 The classification system for safety significance should be consistent with that used for LC19, 20, 21 and 35.

5.9 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.

5.10 Arrangements should identify the requirements for the licensee's construction/installation programme(s) to include adequate time for assessment of safety submissions by NSD 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.

5.11 A procedure should be in place for tracking ALL modifications and linkages between them (supported by register(s) as appropriate).

5.12 Arrangements should be in place for recording, tracking and progressing technical queries, concessions and omissions on all modifications.

5.13 Arrangements should require an implementation Quality Plan or similar scheme for each modification which addresses:

5.14 Arrangements should require that the case for each modification considers its impact on the live safety case.

5.15 Arrangements should require that there is a clear linkage to other supporting arrangements LC 12 SQEPs, LC 14 Safety Documentation, LC 20 Modifications to Design of Plant Under Construction, LC 24 Operating Instructions and LC 28 Examination, Inspection, Maintenance and Testing.

5.16 The arrangements should anticipate the possible need to make modifications which are urgent or temporary and present measures to include and adequately control them, including addressing their potential to affect safe operations on the site. In addition urgent modifications safety case submissions shall be supported by appropriate engineering/process detail to enable regulators to assess their adequacy.

6. Guidance on inspection of implementation of arrangements for LC 22

6.1 It is for Inspectors 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 reallocate progress of specific regulatory matters on a topic within his unit or division.

6.2 The following list of areas for inspection of implementation of arrangements for compliance with LC 22 has been compiled. This list is neither exclusive nor exhaustive and will be subject to review and revision in light of operational experience.

6.3 Sample, check the licensee's safety classification system for modifications, challenge as necessary.

6.4 Sample check the licensee's control of implementation of modifications, including:

6.5 Sample, check the application of the licensee's safe system of work process for control of construction/installation hazards (conventional, nuclear, environmental).

6.6 Sample, check application of licensee's arrangements for progressing and recording issues arising from modification(s) including the management of technical queries, concessions and omissions.

6.7 Sample, check that there are appropriate links to the safety case requirements for every stage of development of design, construction and installation of the modification and that those responsible for undertaking and implementing these activities are aware of/have access to the safety case requirements.

6.8 Sample, check time limits for completion of modifications and that there are no undue delays. (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 close-out modification sample(s) to ascertain whether all items/areas associated with the modification have been completed or adequate progress made to enable the facility or process to move to the next stage or be fully implemented. Areas to consider here include:

6.10 A modification package may include construction, installation and commissioning activities and therefore there should be clear linkage with supporting LC arrangements e.g LC 21.

6.11 Where NSD 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 6.9 above.