High Pressure Washing for Radiological Decontamination of Concrete Surfaces

The Department for Environment, Food and Rural Affairs (Defra) is commissioning small-scale research to investigate the viability of high-pressure washing for decontaminating UK concrete building materials following a major radiation incident. Defra is the designated Lead Government Department in England for coordinating the recovery from Chemical, Biological, Radiological and Nuclear (CBRN) incidents in England. To that end, Defra facilitates UK access to decontamination capabilities for buildings, environment, and infrastructure following a CBRN incident. When not recovering from a CBRN event, Defra develops recovery policy and operational capability by working closely with cross government colleagues, academia, and industry.

The aim of this project is to test the suitability of high-pressure washing procedures to decontaminate UK concrete surfaces contaminated with 85Sr, 137Cs, and 152Eu. This project consists of 2 stages.

The objectives of stage 1 of this project are:

• Source suitable concrete samples from the UK built environment and then contaminate with 85Sr, 137Cs, and 152Eu under laboratory conditions (Objective 1).

• Measure radionuclide depth profiles after aging the contaminated samples for a maximum of 2 months. This aging period is considered representative of decontamination operations after a significant radiation incident (Objective 2).

The objectives of stage 2 of this project are:

• Determine the effect of three different water pressures (between 2,000 and 7,000 psi) on the radionuclide removal rates from contaminated concrete samples (Objective 3).

• Examine the potential for high pressure washing to induce aesthetic and/or physical damage to the decontaminated materials by visual inspection and appropriate microscopy technique(s) (Objective 4).

It is important to note that the duration of stage 1 of the project is 5.5 months. A 6-month extension to the project is available for stage 2, subject to satisfactory completion of stage 1. It is acceptable for Tenderers to submit a tender for stage 1 of the project only.