The Nuclear Decommissioning Authority

Last Updated: 26 November 2011

Approximately one quarter of NDA landholdings are subject to a designating direction under the Energy Act 2004.  Where a designating direction gives NDA the responsibility to clean up a site, we must set out the condition to which that site needs to be restored.  This is commonly known as the Site End State (SES), and NDA must take all steps that it considers appropriate to achieve it.  Consequently a SES is defined for each NDA site, which describes the physical condition of above or below ground structures and infrastructure (e.g. buildings, roads, pipelines) and land quality.

 Site End States - Preferred Option - March 2011 (1Mb)

Objective

To define credible objectives for the restoration of each site (or part of a site).

Scope and Boundaries

The SES strategy does not define how or when the SES will be achieved; this is covered by other topic strategies, e.g. other topics in the Site Restoration theme.  The Site End State is linked to but distinct from the end use. The end use describes the way in which the land will be used after NDA has completed its mission.  It is not for NDA to define the end use of a site; the end use will be defined by the next land owner in consultation with stakeholders, particularly the relevant planning authority.

Once a Site End State has been achieved and the land has ceased to be designated it will then be managed according to NDA's Land and Property Management topic strategy, along with other land owned by the NDA that is not subject to a designating direction.

Interfaces

The SES strategy interfaces with a number of other Topic Strategies including:

• Land and Property Management strategy is relevant because it could affect and be affected by plans for the next use of NDA land and property;
• Decommissioning strategy and Land Quality Management strategy are related because the SES represents objectives for all site restoration activities
• Integrated Waste Management, Spent Fuels and Nuclear Materials strategies are relevant because of the potential implications of and for on-site management facilities.

Credible Options

The strategic options that apply to the selection of a preferred SES are to:

1.1       Rely on institutional controls rather than restoration to manage risks to people and the environment

1.2       Restore site (or part of a site) to a condition suitable for next planned use

1.3       Restore site (or part of a site) to a condition suitable for any foreseeable future use

1.4       Restore site (or part of a site) to its pre-industrial state (background)  

2.1       Site End State reflects local requirements only

2.2       Site End State reflects national requirements only

2.3       Site End State balances both national and local requirements  

3.1       Site End State definition is a fixed articulation of site restoration objectives

3.2       Site End State definition articulates site restoration objectives but remains flexible to change

3.3       Site End State and Interim State definitions together articulate site restoration objectives (Interim States are natural milestones and decision points within the restoration programme, typically marked by a stepped reduction in risk or hazard)

Current Position

The 2006 NDA Strategy introduced our plan to review SES through a consultation exercise which comprised four main stages:

• Stakeholder consultation to understand preferences for the end use of each site
• Definition of a set of site end states that meet the preferred end use
• Stakeholder consultation to understand which SES would be acceptable
• Reconciliation of solutions with policy, regulatory requirements and other strategic issues to take account of the national perspective.

The SES definitions resulting from the consultation exercise have been embedded in site Lifetime Plans to provide overall strategic direction for site restoration activities.

There is a risk that as decommissioning progresses (and a site moves towards implementation of the SES), the declared SES will no longer represent the optimum solution.  Consequently, the current declared SES will be kept under review and revised when appropriate (as indicated in the 2006 NDA Strategy).

Our preferred option expressed in NDA Strategy is for restoring sites to a condition suitable for their next planned use because the level of intervention and the volume of waste are appropriate (no more and no less than required) to release the site for other uses.  However, where the next planned use does not need a nuclear site licence, the regulatory framework requires proof that radioactive contamination is reduced to a level suitable not just for the next planned use but for any foreseeable use.

It is NDA's preference that the SES and Interim State definitions together articulate site restoration objectives.  The SES definition provides overall direction for site restoration and remains flexible until planning commences for the final stages of restoration.  The Interim State definition provides the site restoration objective whilst there is discernable potential for the SES to change.

The SES that represents the greatest value will vary between sites and perhaps also within a site, and should be a balance both national and local requirements.