Decontamination and Demolition work in Building 3 MFB Facility in Lucas Heights

This document details the details the scope of work for the decontamination and dismantling of the Material Fabrication Bay (MFB) of the Institute of Materials Engineering at ANSTO, Lucas Heights.

The MFB is a large space being approximately 35 m (L) x 15 m(W) x 9 m(H) the length being on a North South axis.

It is equipped with a ventilation exhaust system comprising of 2 main rectangular ducts running along each side of the length of the building at floor level and rising on the North wall and passing through to an external plant room. There are a number of smaller subfloor ducts which run transversely partly across the building in service trenches and rise into the main ducts. The service trench arrangement comprises of a central trench along the building axis with 7 intersecting lateral trenches which run to the building walls.There are also several ducts feeding into the top off the main ducts from fume cupboards and the like.

The MFB has been formerly known as the Fuel Element Development Bay (FED Bay) and as the Nuclear Materials Fabrication Laboratory.

The MFB was used to examine and develop fabrication techniques for nuclear fuels. Samples were made using uranium and thorium in the form of metals and oxides. Sample sizes ranged from a few grams to many kilograms and consisted of pellets, rods, clad bars, bars, ingots, etc. Non-radioactive materials associated with nuclear fuel fabrication were also used here e.g. zirconium alloys, aluminium, stainless steel, beryllium, cadmium, lead. Asbestos was also present as an insulating material on a high pressure hot water system reticulated via the service trenches and which was removed many years ago. It is expected that there are still areas of asbestos contamination in the trenches.

Uranium metal was machined in a former workshop area that has since been removed. Some of the equipment was removed in 2002 and others have been decontaminated and retained for installation at a later date to give the bay some metal machining capabilities.

Much of the equipment associated with the FED era has been removed, though staff should be aware that there is the potential for residual contamination within e.g. ductwork, older equipment, floor service ducts, old crucibles, samples, etc. Only the central floor duct and glass wall to the exterior of the building has been decontaminated during the refurbishment of 1998 – 2000; other ducting throughout the bay still possesses some risk and has been labelled where appropriate.

The contractor shall undertake the following works and services (refer also to the following figure) which are listed in indicative order of execution:

·Remove large equipment such as, but not limited to fume cupboards, scrubber systems, glove boxes benches and alike (note that it shall be the Tenderers responsibility to make them themselves as to the scope of these works during the tender process).

·Temporarily relocate Hot Isostatic Press (HIP). Note HIP isolation and disconnection and subsequent reconnections by others. HIP to be reinstalled at conclusion of works (see below)

·Place protective plastic over existing previously cleaned or non-contaminated surfaces i.e. glass walls

·Remove internal room structures (except room 0049)

·Strip and remove floor coverings ready for recovering (note recovering by others)

·Remove trench covers (to be reused)

·Temporarily seal significant existing air leakage paths from outside the building into trenches and elsewhere as identified during works.

·Disconnection, removal and disposal of subfloor services as indicated:

oPower cabling ( refer Section

oWater piping

oDrainage piping

oCompressed air

oIT cabling

oVentilation ducts (refer also to the point regarding ventilation below)

·Removal electrical distribution panels

·Remove main ventilation ducts along walls. Duct sections shall be separated in such a way as to minimise or prevent the disturbance and redistribution of internal contaminants. Duct section ends to be securely sealed with plastic sheeting after cleaning of external surfaces. All removed ductwork shall be transferred to a storage container supplied by ANSTO.

·Reinstall HIP in the temporary room built by others so as to allow HIP operations to be able to continue if required during the decontamination project period. (Note: HIP re-commission by others)

·Paint trenches (all surfaces)

·Cover trench lids with plastic and provide protection from point load damage to prevent recontamination

·Removal of active and non-active contaminants including asbestos, beryllium, lead.

·Remove surface contamination on floors, covers, in trenches, and other surfaces within the building both prior to and during dismantling. ANSTO will provide training and advice on the radioactive contaminants and the disposal of materials which are identified as being radioactively contaminated. Decontamination is to be carried out throughout the demolition process to ensure that minimal amounts of contaminated material are transferred out of the work area and which would require further treatment by ANSTO

·Removal of concrete and components found to contain embedded contamination above acceptable levels. An allowance of 1 m³ concrete (100 mm thick x 10 m²) should be made for this as a PC item

·Prevention of recontamination of areas already decontaminated to levels deemed satisfactory by ANSTO by the use of appropriate controls and provision of temporary coverings on surfaces until the completion of the works

·All floor surfaces shall be sealed with Bond create (or similar) after surfaces have been deemed clear by ANSTO HPS, this is shall encapsulate any minor loose Asbestos dust.

·Provision of all protective coverings