Provision of Specialist Technical Ventilation Services

BACKGROUND TO THE PROJECT 1.1 The XXXXXXXXXXXXXXXXXXX at Sellafield support the Magnox Operating Programme (MOP) by producing XXXXXXX powder from the nitric acid based XXX feed liquor arising from the Magnox Reprocessing Plant (MRP). There are a number of individual facilities incorporating old redundant XXXXXX to relatively modern XXXX storage facilities. 1.2 ONR Inspections have revealed serious issues with the ventilation system fitted to the original build facility which is considered to be in an unacceptable condition.

These issues are amplified by the presence of a highly contaminated area in the heart of one of the facilities that has fragile containment. ONR has engaged pro-actively with the licensee to derive a number of improvements to restore these facilities to an adequate state, however this involves significant modifications to the original design intent of ventilation systems that have already been extensively modified for decommissioning. 1.3 If the intended modifications to the system are inadequately conceived or implemented there is a significant risk that the containment of the decommissioning area, which is heavily contaminated, could be compromised.

Assessments of the resulting consequences indicate the potential for a significant onsite release and the probability of an offsite release. The decommissioning of the facility would be delayed by years by the resulting clean-up operations and there would be reputational risk to ONR. 1.4 ONR mechanical specialist inspectors have reviewed these projects and require detailed design level technical knowledge to underpin the assessment. This is not available within ONR and this specification details the scope and content of the required technical support below for tender to suitable external contractors.