Contaminated site clean-up

16.1.3 Regulation

Decommissioning represents a current challenge to the UK nuclear indus­try because many of the UK’s reactors have reached the end of their useful life.

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Nuclear site licence holders are required to prepare strategies for decom­missioning of nuclear infrastructure. The Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations 1999 (EIADR99) as amended by the Nuclear Reactors (Environmental Impact Assessment

for Decommissioning) (Amendment) Regulations 2006 (EIADR06) require that nuclear reactor decommissioning is accompanied by an Environmental Impact Assessment (EIA) in addition to other requirements. The purpose of EIADR is to require assessment of the potential environmental impacts of projects to decommission nuclear power stations and nuclear reactors. In addition, the intention is to make the decision-making process open and transparent. EIADR require that the public and other relevant stakehold­ers be consulted from an early stage, regarding the environmental impacts of the options being considered for a proposed decommissioning project.

An Environmental Statement containing details of potential environ­mental impacts must be submitted to the Health and Safety Executive before any decommissioning work can be carried out, and once they have consulted with various bodies, i. e. the environment agencies, conservation bodies, local authorities and stakeholders, permission may be granted.

HSE have developed policy (HSE, 2005) and guidance (HSE, 2008) on the criteria to be satisfied for sites to be de-licensed. The basis is the dem­onstration of ‘no danger’ remaining from the presence of any remaining contamination on the site. The requirement is ‘to show that any such remain­ing radiological hazard will not pose a significant residual risk to any person, for all reasonably foreseeable uses to which the site may be put and not just for its next future use. Based on the reasoning laid out in the HSE publication “Reducing Risk and Protecting People”, HSE believes that the annual risk of a fatality of one in a million to an individual is regarded by society as “broadly acceptable”.’

HSE (2008) also refers to the need to show that risks are ALARP (as low as reasonably practicable). HSE’s preferred method for demonstrating that the risk criterion has been met is the application of derived concentra­tion levels for the clearance and exemption of radioactive substances (IAEA, 2004). These values are calculated on the basis of a dose criterion of 10 qSv/y and a set of exposure scenarios.

The management of radioactively contaminated land on a nuclear licensed site is carried out by ONR. ONR regards radioactively contami­nated land and emplaced radioactive substances on nuclear licensed sites as accumulations of nuclear matter, unless they are, or arise from, author­ised disposals, and it requires licensees to manage it as such. The licence conditions require that licensees control or contain nuclear matter, to record the amount of radioactive material and its location, and justify and demonstrate the arrangements to maintain safety by means of a safety case.

For radioactively contaminated land that is not on a nuclear licensed site, a different set of regulations apply. Part IIA of the Environmental Protec­tion Act 1990 provides a regulatory regime for the identification and reme­diation of contaminated land that is causing unacceptable risks to human health or the wider environment. In 2006 and 2007 this was extended to cover radioactivity and to cover land contaminated with radioactivity origi­nating from nuclear installations (different regulations were enacted in England and Wales and in Scotland). The objectives for the extension of Part IIA to radioactive contamination remain the same: to provide a system for the identification and remediation of land where contamination is causing lasting exposure to radiation for human beings and where ‘interven­tion’ is liable to be ‘justified’. A key aspect is that the land should be ‘suit­able for use’. The criteria for designating land as ‘radioactively contaminated land’ are based on a probability weighted annual dose of 3 mSv from the contamination. In the case of contamination in the form of discrete radioac­tive particles that could give rise to doses above 50 mSv if encountered, decisions on whether the land should be designated as radioactively con­taminated land are based on a number of factors.

In the context of new development of land, radioactive contamination may also be deemed a material planning consideration under the relevant Town and Country Planning Act.

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