Executive summary
Date(s) of inspection: August 2024
Aim of inspection
To derive confidence in the construction conformance of the anchorages to the SRP roof trusses.
The anchorages are important for the structural integrity of the SRP roof.
The anchorages comprise high strength Macalloy bar anchorage assemblies that are required to be cast in to the reinforced concrete superstructure. There are 88 anchorage assemblies containing a total of 880 Macalloy bars.
The concreting around the anchorage assemblies needs to be done in stages in order to allow for full strength to be developed in the anchorages before casting the SRP roof slab. Access for concrete placement and compaction will be physically restricted and it is judged that an inspection is warranted in order to derive confidence in the contractor's application of RGP and that the licensee is applying adequate construction planning and supervision pursuant to its obligations under LC19 (Construction and Installation of New Plant).
Furthermore, in recognition of the conformance risks associated with the procurement and installation of the Macalloy bars specifically, this inspection will sample the licensee's implementation under LC 17 (Management Systems). Sampling under LC17 will take account of the status of the constriction works and will be confined to the roof truss anchorages.
Subject(s) of inspection
- LC17 - Management systems - Rating: Green
- LC19 - Construction or installation of new plant - Rating: Green
Key findings, inspector's opinions and reasons for judgement made
The specific purpose of this inspection was to gain confidence in the construction conformance of the anchorages to the Sellafield Product and Residue Store Retreatment Plant (SRP) roof trusses. This inspection follows a previous readiness inspection on the readiness for installation of the roof trusses. The anchorages are important for the structural integrity of the SRP roof. The anchorages comprise high strength Macalloy bar anchorage assemblies that are required to be cast in to the reinforced concrete superstructure. Whilst not a novel undertaking, the proposed installation and subsequent concreting operations present a conformance challenge due to a confluence of practical risk factors.
This inspection comprised a proportionate sampling of the licensee’s construction management arrangements. During this inspection, I examined relevant documentary evidence, inspected the ongoing preparatory works and interviewed directly those personnel responsible for planning and supervising its construction.
On the basis of the above, I judge that the licensee is currently manging the works pursuant to its duty under License Condition (LC) 19 (Control of Construction) and LC 17 (Management Systems).
I made one observation pertaining to the merit of undertaking a visual inspection of the anchorages for serviceability cracking after completion of the upper slab pour when the trusses are subjected to substantial dead load.
I have rated this inspection as GREEN in accordance with the ONR Integrated Intervention Strategy.
No outstanding matters or regulatory issues were identified.
Conclusion
Based on the evidence gathered, I judge that the licensee is adequately managing the works pursuant to its duty under Licence Condition (LC) 19 (Control of Construction) and LC 17 (Management Systems).