Safety substantiation – LTPR


The client was required, as part of the Magnox Swarf Storage Silo (MSSS) Long Term Periodic Review (LTPR) task, to undertake assessments of the current safety requirements of the plant in order to substantiate that the Safety Systems and Components (SSC) will deliver their required Safety Functions.

The shortage of sufficient SQEP resources within the client organisation led to this contract being initially awarded to a Multi Discipline Design House (MDDH) and subsequently handed over to a Task Design House (TDH). Neither of these framework contract holders completed the task as required by the client and hence Tenet was selected to complete this task in time for submission to the Office of Nuclear Regulation (ONR).

Services Provided

Phase 1: Tenet was contracted directly by the client to produce an initial phase assessment of the Structure, System Components (SSCs) against the Periodic Safety Review (PSR) Engineering Schedule and to produce a report outlining all the shortfalls including a review of the existing Design Justification Reports (DJR)

Phase 2: Tenet was contracted through Cavendish Nuclear Ltd under the Design Services Alliance (DSA) to review the current SSC assessments in the Control, Electrical & Instrumentation (CE&I) Design Assessment Report (DAR) in line with the Engineering Schedule in use at the time.  The SSCs were grouped under topic areas which corresponded to operational functions of the plant.

The total contract value was approximately £500k.

The following deliverables formed part of the package:

  • Configuration diagrams;
  • Production and Level 3 check of DARs for Part 2 Topics (13 reports in total);
  • Level 3 checking of Part 1 DAR;
  • Project plans, progress meetings and reporting

The majority of the work was performed by a small team of Functional Safety Engineers. However, the drawings and some of the information gathering was done by designers and a technical author was employed to ensure the Topic documents followed a consistent format.

Intergrated project solution

Effective collaboration was essential between all parties involved to ensure a consistent quality of output for the DARs.

In addition, following the failure to deliver by a MDDH and a TDH, it was essential for Tenet to ensure that its team of Functional Safety Engineers was briefed on a weekly basis of any changes which could affect document content.  Tenet worked very closely with the client project and planning engineers with weekly meetings so that they could effectively monitor and report that the project would be delivered to cost, to plan and of the quality expected by client standards and procedures.

Initially the Engineering Schedule was still subject to change. However, experience has shown that it is essential for all parties to agree what is expected of a project and to work to a clear scope.  Provision of a frozen version of the Engineering Schedule enabled any corrections and changes to be properly managed.

Key Tenet personnel with SC clearance were given the necessary training to become monitored workers to enable access to the building to allow them to perform plant walk-downs to assess the current condition of the site Plant.

Cost savings

Tenet’s approach was to initially demonstrate to the client Intelligent Customer that a solution of basing the team entirely within 401 Faraday St. as opposed to the client offices would be the recommended solution; this allowed the most efficient use of available resources.  The main liaison to Tenet was provided with a hot desk in order to attend on a regular basis for any queries generated during the project and the package was managed effectively to ensure that this did not affect the quality or programme.

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The collaborative and open approach enabled Tenet to deliver a high quality suite of drawings and documents and costs were controlled by the ability to utilise the most appropriate resources available in the Tenet office. The project was delivered quickly and to a high standard, with Tenet gaining many plaudits both informally and through our customer feedback process.

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