The Nuclear Industry

This industry has most of the corrosion problems of other industries and some that are all of its own. Right from the start, the potential for disaster was recognized and tackled by using high-grade materials in many parts of the systems. Zirconium alloys were needed, which had their own corrosion problems and solutions. Growing worldwide demands for acceptable environmental performance have alienated others to the cause of nuclear power, in particular, after events at Three Mile Island and Chernobyl. 

This industry too had its share of corrosion costs. For boiler reactors capacity factor losses because of corrosion problems averaged over 6% between 1980 and 1991, reaching a peak value of 18% in 1982. It is estimated that corrosion problems have cost the nuclear utility industry more than 5 billion since 1980. In addition, repairs and mitigation cost the average US light water reactor 0.5 billion in the industry with radiation exposures of about 100 rem per year. 

---

The system has been in full use during the shutdown periods of 1996 and 97 in the nuclear industry in Sweden. Performed tests have produced excellent results under sometimes difficult conditions... 

The system has proven to be a powerful tool for inspections in the Nuclear industry with the potential of reducing the radiation doses for a highly qualified group of personnel and at the same time ensure a high quality and reproducibility of testing... 

The pulsed-plate column is typically fitted with hori2ontal perforated plates or sieve plates which occupy the entire cross section of the column. The total free area of the plate is about 20—25%. The columns ate generally operated at frequencies of 1.5 to 4 H2 with ampHtudes 0.63 to 2.5 cm. The energy dissipated by the pulsations increases both the turbulence and the interfacial areas and greatly improves the mass-transfer efficiency compared to that of an unpulsed column. Pulsed-plate columns in diameters of up to 1.0 m or mote ate widely used in the nuclear industry (139,140). 

In the North American HF market, approximately 70% goes into the production of fluorocarbons, 4% to the nuclear industry, 5% to alkylation processes, 5% to steel pickling, and 16% to other markets (41). This does not include the HF going to aluminum fluoride, the majority of which is produced captively for this purpose. 

In addition, solvent extraction is appHed to the processing of other metals for the nuclear industry and to the reprocessing of spent fuels (see Nuclearreactors). It is commercially used for the cobalt—nickel separation prior to electrowinning in chloride electrolyte. Both extraction columns and mixer-settlers are in use. 

Hydrogen sulfide is also used in the production of heavy water for the nuclear industry (84). 

D. Cubicciotti, R. L. Jones, and B. C. Syrett in D. G. Franklin, ed.. Zirconium in the Nuclear Industry, ASTM Special Technical PubUcafion 754, American Society for Testing and Materials, Philadelphia, Pa., 1982. 

Because boron compounds are good absorbers of thermal neutrons, owing to isotope B, the nuclear industry has developed many appHcations. High putity bode acid is added to the cooling water used in high pressure water reactors (see Nuclearreactors). 

Human error probabilities can also be estimated using methodologies and techniques originally developed in the nuclear industry. A number of different models are available (Swain, Comparative Evaluation of Methods for Human Reliability Analysis, GRS Project RS 688, 1988). This estimation process should be done with great care, as many factors can affect the reliability of the estimates. Methodologies using expert opinion to obtain failure rate and probability estimates have also been used where there is sparse or inappropriate data. 

General In comparison with design information on blowdown drums and cyclone separators, there is very httle information in the open technical hterature on the design of quench tanks in the Chernies industry. What is available deSs with the design of quench tanks (Sso called suppression pools) for condensation of steam or steam-water mixtures from nuclear reactor safety vSves. Information and criteria from quench tanks in the nuclear industry can be used for the design of quench tanks in the chemicS industry. There have been sev-... 

Annual Reports of Gumulative System and Gomponent Reliability for Period from July 1, 1974, through December 31, 1982,serves as a source of engineering and failure statistics for the nuclear industry. It contains data for most components used in nuclear power plants. 

The acronym for chemical process quantitative risk analysis. It is the process of hazard identification followed by numerical evaluation of incident consequences and frequencies, and their combination into an overall measure of risk when applied to the chemical process industry. It is particularly applied to episodic events. It differs from, but is related to, a probabilistic risk analysis (PRA), a quantitative tool used in the nuclear industry... 

Data Acquisition and Parameter Estimation determines frequencies of the initiating events, component unavailability and probabilities of human actions were estimated from plant history. If insufficient, generic values were used including generic data from the nuclear industry (IAEA, 1988). In addition meteorological data and data on the population distribution around the plant were gathered and processed. 

There is considerable interest in developing a database on human error probabilities for use in chemical process quantitative risk assessment (CPQRA). Nevertheless, there have been very few attempts to develop such a database for the CPI compared, for example, with the nuclear industry. Some of the reasons for this are obvious. The nuclear industry is much more highly integrated than the CPI, with a much greater similarity of plant equipment... 

In some organizations, designated individuals have specific responsibility for eliciting detailed information from operational staff on the immediate and underlying causes of incidents. An example is the Human Performance Evaluation System (HPES) developed for the nuclear industry, which is described in Bishop and Larhette (1988). These coordinators provide a certain level of guaranteed irrununity from sanctions which allows individuals to be frank about the contributory causes that they may not be willing to discuss in an open forum. As discussed earlier, the need for this approach is a consequence of the fact that in many organizations a blame culture exists which is likely to inhibit a free flow of information about the causes of accidents. 

The generic data sources used in the BRP data base originate from the nuclear industry. 

Probabilistic Risk Assessment (PRA) A conunonly used term in the nuclear industry to describe the quantitative evaluation of risk. 

Probably about 50000 tonnes of HF are used worldwide annually to make inorganic compounds other than UF4/UF6 for the nuclear industry. Prominent amongst these products are ... 

The behaviour of uranium has been well characterised for a variety of environments of importance in the nuclear industry. The corrosion is governed by the constitution and physical character of the solid reaction products which in turn are determined mainly by the oxygen potential of the environment, the temperature and the presence of water. The mechanisms of attack are known in broad outline. A major area in need of more detailed study is the influence of irradiation both prior to and during oxidation. 

Special correlations have also been developed for liquid metals, used in recent years in the nuclear industry with the aim of reducing the volume of fluid in the heat transfer circuits. Such fluids have high thermal conductivities, though in terms of heat capacity per unit volume, liquid sodium, for example, which finds relatively widespread application, has a value of Cpp of only 1275 k.l/ni1 K. 

Development efforts in the nuclear industry are focusing on the fuel cycle (Figure 6.12). The front end of the cycle includes mining, milling, and conversion of ore to uranium hexafluoride enrichment of the uranium-235 isotope conversion of the enriched product to uranium oxides and fabrication into reactor fuel elements. Because there is at present a moratorium on reprocessing spent fuel, the back end of the cycle consists only of management and disposal of spent fuel. 

---