This annual report gives the results of the work conducted by the Pacific Northwest Laboratory in FY 1994 on Task 3 of the Ferrocyanide Safety Project, Ferrocyanide Aging Studies. Waste aging refers to the dissolution and hydrolysis of simulated Hanford ferrocyanide waste in alkaline aqueous solutions by radiolytic and chemical means. The ferrocyanide simulant primarily used in these studies Savannah River Operations Office PO. Box A

A b s t r a c tSteel materials, due to their numerous advantages -high availability, easiness of processing and possibility of almost any shaping are commonly applied in construction for carrying out basic carrier systems and auxiliary structures. However, the major disadvantage of this material is its high corrosion susceptibility, which depends strictly on the local conditions of the facility and the applied type of corrosion protection system. The paper presents an analysis of life cycle costs of structures installed on bridges used in the road lane conditions. Three anti-corrosion protection systems were considered, analyzing their essential cost components. The possibility of reducing significantly the costs associated with anti-corrosion protection at the stage of steel barriers maintenance over a period of 30 years has been indicated. The possibility of using a new approach based on the life cycle cost estimation in the anti-corrosion protection of steel elements is presented. The relationship between the method of steel barrier protection, the scope of repair, renewal work and costs is shown. The article proposes an optimal solution which, while reducing the cost of maintenance of road infrastructure components in the area of corrosion protection, allows to maintain certain safety standards for steel barriers that are installed on the bridge.

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In the past two decades economic considerations and very good mechanical parameters of polyethylene pipes contributed to more and more common use of the pipes for construction and repair of water distribution systems all over world. This paper presents the results of research into parameters of water collected from a polyethylene pipeline which was a part of an operational water supply network. We determined Total Organic Carbon (TOC) content and the content of organic compounds in the examined water samples using a multichannel gas chromatograph (Trace Ultra Thermo) coupled with a mass spectrometer (Polaris Q). We identified organic compounds bounded with antioxidants, added to polyethylene in the process of pipe production, in the water samples.

Water chlorination is one of the most popular ways of disinfection used in potable water distribution systems. Nevertheless, chlorinated water does influence mechanical properties, structure and characteristics of the surface of plastic water pipes forming the system. This paper presents tests of HDPE and PVC water pipes in different ageing solutions of specific chlorine concentration, pH and CaCO 3 content and in different temperatures. Strength, structure and the chemical stability of samples were determined following different immersion periods in ageing solutions. Static tensile strength tests have not indicated any significant changes in the selected mechanical properties of either HDPE or PVC pipes samples. Infrared spectrometry tests of the chemical structure, however, showed changes in the tested samples indicating material degradation caused by chlorinated water.

This research focused on a model setup fed with underground water pumped into a water supply network. The scope of the research included a long- and a short-term stagnation of water in the setup and a water flow of 0.1 m/s. The water supplied into the system gradually lost its corrosive properties and developed calcium carbonate precipitation capability. These processes indicated that cement components migrate from the lining into the water. Apart from the primary components, the presence of the following trace elements was found: iron (399.6 ppb), magnesium (17.8 ppm), zinc (26.9 ppb), barium (22.6 ppb), boron (21.6 ppb), sodium (10.8 ppm), gallium (2.1 ppb). At early stages of the operation, recorded quantities were not significant. Leaching of the trace elements from cement increased after water was chlorinated. In turn, the highest percent increases were observed in the case of zinc (217%), boron (19%) and gallium (12%), whereas the increase for sodium, iron, barium and magnesium in water was insignificant (reaching a few percent). A repeated analysis of samples of stagnant water in the setup showed that most of trace elements were below the detectability level. Final concentrations of all elements identified in the water after its contact with internal cement mortar lining were much lower than the limit values set out for drinking water.

As a part of the critical infrastructure, water supply systems must be characterized by an appropriate level of operational reliability and safety. One of the threats to this is the failure of the water supply network, influenced by many factors, among which we can distinguish internal factors related to the process of designing, construction and system operation, and external factors related to the impact of the environment. The paper presents the influence of negative daily temperature on the failure rate of the water supply network, taking into account the material of the pipes, their diameters, and the cause of failure. The research was carried out on operational data from the period 2004–2018 from the water supply network in a city located in south-eastern Poland. The relationship between the daily temperature and the failure rate of the water supply system has been shown. As the temperature values drop, the failure rate values increase. The biggest influence of the negative daily temperature on the water supply network failure rate is observed for cast iron pipes. PE and PVC pipes are more resistant to the influence of negative temperatures. The most common cause of failure is corrosion and unsealing of the pipes. Pipes with the diameters of 100, 150, 300, 350, and 400 mm in distribution and main networks turned out to fail most often. These results can be used by water supply companies to limit the influence of factors related to negative daily temperatures on the failure rate of the water supply network.

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