assessment and modelling

Staff from Aurora have carried out several environmental and radiological impact assessments to determine the radiation dose and risk to members of the public arising from residual radioactivity remaining on remediated facilities and land where a change of use is planned and disposals of radioactive material via environmental pathways (land, sewage, river and airborne).

Aurora uses a combination of methodologies for the impact assessments, utilising regulatory documents, industry standard guidance documents and both commercial and bespoke software tools.

Examples of regulatory and guidance documents and tools used are given below:

• The Radioactive Substances Act 1993 (RSA93) and current Exemption Orders.
• The Radioactive Contaminated Land (Enabling Powers)(England) Regulations 2005.
• Guidance on the Characterisation and Remediation of Radioactively Contaminated Land, Environment Agency.
• Methodology for Estimating the Doses to Members of the Public from Future use of Land Previously Contaminated with Radioactivity, NRPB-W36.
• HSE Criterion for Delicensing Nuclear Sites.
• HSE Nuclear Safety Directorate Guidance for Inspectors on Decommissioning of Nuclear Licensed Sites.
• Clearance and Exemption Principles, Processes and Practices for Use by the Nuclear Industry, A Nuclear Industry Code of Practice, 2005.
• Multi Agency Radiation Survey and Site Investigation Manual (MARSSIM), US Environmental Protection Agency, 2000.
• Application of the Concepts of Exclusion, Exemption and Clearance, RS-G-1.7, IAEA.
• Radcontab software, BNFL.
• PC Cream software, HPA/EC.
• RESRAD software suite, Argonne National Laboratory.
• In-house developed spreadsheets and software tools.

Under RSA93 Aurora staff have undertaken several radiological impact assessments for clients discharging radioactive waste to the environment in airborne, solid and liquid waste streams.