Repository Development (RD) Southern Trench Cap Interim Membrane Replacement (STIM)

Tender description

LLW Repository Ltd trading as Nuclear Waste Services has a scope of work for the “Southern Trenches Interim Membrane (STIM) Contract”, which forms part of the Repository Development portfolio of work at the LLW Repository facility near Drigg Village in Cumbria, England.<br/><br/>The work consists of civil engineering works associated with installing an engineered interim trench cap over the Southern Trenches. In summary, the scope is to provide labour, equipment, materials, project management and supervision to complete the work. Work also includes establishment and maintenance of site offices, welfare and all associated temporary works. Lot 1: Repository Development is a long-term portfolio of works that will provide disposal capacity and protection of low-level nuclear waste over the next 107 years, or until the end life of the Repository Site. In the shorter term the portfolio, over the next 15 years will install closure engineering works for short and long-term environmental protection for wastes currently disposed in Vault 8 and the adjacent trenches. This scope of works has been previously referred to as Repository Development Programme – Tranche 1 Main Civils and has been communicated to the market in early 2022.<br/><br/>The works over the next 15 years have been considered, and optimised detailed designs completed. More recently, the delivery strategy for the works has been further developed and subsequently split into projects that deliver a key benefit to the closure of Vault 8 and adjacent trenches. Additional information: The original scope of works which was shared in January 2023 (via the following link: https://www.find-tender.service.gov.uk/Notice/001208-2023) included the following elements:<br/>- Site Clearance - Seasonal tree and root clearance for the subsequent package. Removal of existing weather station fence.<br/>- Soft spot removal - Topsoil strip, herringbone filter drains, connections to perimeter drain, managing/handling excavated topsoil and spoil. <br/>- Rail Deliveries - Supply of aggregates, trains, offload and storage, transport through site.<br/>- Drainage - Temporary Settlement Lagoon, Temporary drains, stockpile construction, haul road drainage, Establishment of borehole, pumping equipment and storage tank for dust suppression. General Earthworks.<br/>- Interim membrane - Sequential Construction of haul road ramp, screening bund and stockpile area. Placement of imported regulating layer, Geosynthetic Clay Layer (GCL) & Geotextile Composite Drainage Layer and engineering/subsoil layers above. Topsoil and seed in areas outside footprint of haul road, Stockpile and the screening bund.<br/>- Infrastructure Monitoring - Protect and extend existing boreholes, in advance of Interim membrane works or any surcharge and profile fill activities.<br/>- Haul Road - Chainage 950 to 1400 (mound 1); 1580 - 1800 ramp onto cap.<br/>- Stockpile Management - Temporary access onto the cap; Clear stockpiled soils in existing stockpile. Construct Stockpile A drainage swales and outfalls & reinforced aggregate running surface.<br/>- Earthworks - Excavate and process for suitable profile fill the existing stockpiled soils in Mound 1 and 2, profile fill to trenches for Interim membrane works and construct screening bund.<br/>- Materials Testing - Establish soils testing on-site Laboratory and gain UKAS accreditation; Offsite testing in the interim period until lab is ready.<br/>- Accommodation - Contractor accommodation for office and welfare facilities, including water main and power supplies.<br/><br/>In recent months this scope has been amended. Rail delivery of imported bulk aggregates and soils will be carried out by Nuclear Transport Services (NTS) on behalf of the Client. The Client will enter into a contract for rail deliveries with NTS, the scope of which will be limited to transport between the agreed loading point and unloading point at LLWR rail sidings. The Contractor shall have no contractual arrangements with NTS.<br/><br/>A copy of the draft scope is located in the documents area of the Atamis eSourcing system (https://atamis-2464.my.site.com/s/Welcome) and is subject to final approvals. You can find the scope by clicking on “View our live opportunities” and searching for "PIN for RD - South Trench Cap Membrane Replacement Project (Scope Amendment)" with the record reference C15697.<br/><br/>Subject to the final approvals, an Invitation to Participate (ITP) will be issued in the coming weeks. A separate Contract Notice will be published in relation to the ITP.