Irradiated flooring

Moistened filter paper (Whatman No 541) was found to be optimum for collecting the residues from floor surfaces. The filter paper squares containing the powder residues were dried at 50° to remove moisture prior to reactor irradiation. Ba and Sb standards were also prepd to match the geometry of the test samples, and were irradiated under identical conditions... 

Wiggins et al. [456] used neutrons from the thermal column of a 10 kW pool-type research reactor and from a 120 pg Cf source to study the prompt photon emission resulting from neutron capture in magnesium nodules (ter-romanganese oxides) from the ocean floor. Spectra were recorded with a Ce(Ii) detector and a 1024-channel analyser. Complex spectra were obtained by irradiation of seawater, but it was possible to detect and estimate manganese in nodules in a simulated marine environment by means of the peaks at 7.00, 6.55, 6.22, and 6.04 pV. 

The electrical cables between the control room, the modulator room, and the irradiation cell are in pipes below the floor. A cable trough is being installed in the labyrinth to increase the cable capacity between the cell and the control room. 

Red Oak is the wood most used for the production of irradiated acrylic-wood parquet flooring,however acrylic Aspen chip board and acrylic particle board are finding their way into the flooring market. Smaller amounts of maple, ash and black walnut have been used. The polymer loading of red oak is about 40% which makes the acrylic-wood flooring quite expensive, approximately three times that of ordinary red oak parquet flooring. 

Nelson, J.R., Eckman, J.E., Robertson, C.Y., Marinelli, R.L., and Jahnke, R.A. (1999) Benthic microalgal biomass and irradiance at the sea floor on the continental shelf of the South Atlantic Bight spatial and temporal variability and storm effects. Cont. Shelf Res. 19, 477-505. 

All patients from the site of an irradiator attack should be evaluated for radiation sickness, and a health physicist or medical physicist should be consulted to attempt to determine the radiation dose to each patient. If the patient is conscious, it is essential to get as much information as possible about their exact location, travel paths, and the amount of time they spent in each place near the site of the irradiator. For example, if an irradiator is placed in an elevator, persons working on the 50th floor of a high-rise will generally receive more radiation dose than patients on lower levels. On the other hand, a person who has a nonstop ride to an upper level may receive fewer doses than one whose trip to the 10th... 

Other important products include radiation cross-linked foamed polyethylene which is used for thermal insulation, floor mats, crash padding, floating jackets, and wood/plastic composites cured by gamma irradiation. These have been used successfully for flooring in places such as department stores, airports, hotels, and churches where their excellent abrasion resistance, the beauty of the natural grain, and low maintenance costs are important. This latter technique is also being used in the conservation of objects made of stone and wood of interest to our cultural heritage. 

Even more difficult task is to protect the polymeric structural materials in nuclear installations, such as electrical cables or decontaminable flooring in a nuclear power station or industrial gamma irradiator. The required dose-tolerance here can be as high as 1 MGy and a risk-increasing factor is here the low dose rate, sensitizing even the cross-linked polymers against radiation degradation. The warranted life time span here is typically 30 years, and safety aspects are extremely important. 

In most Nordion irradiators the pencils of cobalt-60 are mounted vertically in a source rack. The configuration is formally described as laminar. The source rack is suspended from a hoist mechanism on the roof of the cell such that it is movable between two locations. One of these locations is in the center of the cell in a position where product can be moved around the source during its irradiation. The other location is below floor level. This is for safe storage of the source when product irradiation needs to be interrupted for loading or maintenance work within the cell. 

The lead factor in surveillance specimens for upper floor assemblies is lower than 1 and therefore such results cannot be used for prediction of irradiation embrittlement of RPVs. 

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