Managing Higher Activity Radioactive Waste
Source: gov.uk (2025-11-13)

This page explains how Nuclear Waste Services (NWS) is working to achieve safe management and disposal of Higher Activity Waste (HAW) in the UK.

Managing HAW (https://www.gov.uk/government/publications/an-overview-of-nda-higher-activity-waste) in the UK involves NWS, waste packagers and regulatory bodies working together to provide permanent answers to our country’s nuclear waste inventory. More information on NWS’ role can be found on the NWS mission page (https://www.gov.uk/government/organisations/nuclear-waste-services/about).

Lifecycle of a waste package

The lifecycle of a typical waste package has five main stages:

Manufacture

The waste is containerised and conditioned (where required) to produce a waste package.

Interim storage

The waste package is taken to an interim storage facility where it is stored and monitored until disposal.

Transport

Waste packages will be transported by road, rail, sea or inland waterway to the GDF (https://www.gov.uk/guidance/gdf-geological-disposal-facility). The expectation is that road and rail will be used.

Emplacement

At the GDF the waste package will be transferred underground and placed in a disposal vault.

Post Closure

After the GDF has been filled the vaults will be backfilled and permanently sealed, approximately 150 years after GDF operations begin. The waste packages must remain safe after closure of the GDF.

The diagram above shows the five key stages in the lifecycle of a waste package, including manufacturing, interim storage, transport, emplacement and post closure.

The figure above shows the core activities when managing radioactive waste packages intended for geological disposal.

Ahead of selection of a site for a GDF and development of detailed Waste Acceptance Criteria (https://www.gov.uk/guidance/creating-standardised-waste-packages), NWS use Disposability Assessment to minimise the risk of HAW packages being unsuitable for transport and geological disposal in the future. This allows waste to be packaged and stored in the decades before a GDF is available, reducing the hazards on UK nuclear sites. The Waste Package Specifications (WPS) are a key input to this process.

NWS carries out Disposability Assessments of proposed waste packages using information supplied by the waste packager in a ‘submission’. Before producing this submission, the waste packager holds early engagement meetings with NWS. This helps to identify potential risks and/or aspects requiring special attention, encouraging an efficient approach to producing the submission.

If the Disposability Assessment finds that the proposed waste package is expected to meet the WPS, NWS will issue a Letter of Compliance (LoC). The waste packager may then produce waste packages and the related package records.

The waste packages may be stored for decades before disposal. Package Assurance confirms that waste packages remain disposable, managing risks and ensuring records are maintained.

Engagement with NWS should commence early and be sustained throughout the Assurance of Disposability process.

WPS are a key input to disposability assessment, which is illustrated through the diagram above. Package Assurance ensures package records remain valid for later geological disposal. Engagement between NWS and waste packagers is key throughout.

See next: Managing Higher Activity Radioactive Waste: Engagement (https://www.gov.uk/guidance/managing-higher-activity-radioactive-waste-engagement)