Reference to Chapter

CORROSION OF ALUMINIUM COUPONS IN THE FUEL STORAGE BAY OF PINSTECH, ISLAMABAD, PAKISTAN 

This chapter reports the work carried out at the Pakistan Institute of Nuclear Science and Technology (PINSTECH) under the CRP, the aims of which were to  

The IAEA distributed racks 2 and 3, containing aluminium and stainless steel coupons, during the second RCM, in March 1998, to participants of the CRP, along with the test protocol. As the Pakistani representative could not attend the second RCM, the racks and the relevant literature were sent by mail by the IAEA and were received in July 1998. These racks were handled according to the test protocol and were immersed in the fuel storage bay in October 1998. Rack 1, received at the first RCM, had been immersed in the same bay since November 1996. 

In this chapter the procedures used for preparing the racks and coupons, for immersion and corrosion evaluation (after exposure) of the coupons of rack 2, for pool water chemistry determinations, for periodic inspections and for determination of radiation levels near the racks are described. Rack 2 contained eight aluminium alloy coupons and two stainless steel coupons. 

Aluminium and its alloys have low thermal neutron capture cross-sections, and good tensile strength and thermal conductivity. They are commonly used as fuel cladding and as construction materials in water cooled research reactors. Aluminium owes its excellent corrosion resistance in most environments to the protective barrier oxide film that forms and strongly bonds to its surface. This oxide film is relatively inert and tends to resist further oxidation. During wet storage of aluminium clad spent fuels, a number of corrosion mechanisms 

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T being the boiling temperature (Kelvin) and S being tbe standard specific gravity (15.6°C/15.6°C). Refer to Chapter 4. 

The Reid vapor pressure characterizes the light petroleum products it is measured by a standard test (refer to Chapter 7) which can be easily simulated. 

There also exist relatively simple correlations between the heating value of motor fuels and certain characteristics such as density and composition by chemical family supplied by FIA analysis. Refer to Chapter 3. 

Calculational methods. Associating the analysis, the knowledge of the property-structure relationships, and the calculation methods has made possible the replacement of costly and arduous test methods by quicker tests whose results are linked by calculations to the characteristic under study. Some examples are the cetane number, in some cases, the octane number, or the characteristics of LPG (refer to Chapter 3). 

We note here that the qiiantnm levels denoted by the capital indices I and F may contain numerous energy eigenstates, i.e. are highly degenerate, and refer to chapter A3.4 for a more detailed discussion of these equations. The integration variable in equation (A3.13.9) is a = 7 j / Ic T. 

This section describes briefly some of the basic concepts and methods of automatic 3D model builders. However, interested readers are referred to Chapter II, Section 7.1 in the Handbook, where a more detailed description of the approaches to automatic 3D structure generation and the developed program systems is given. 

The explicit definition of water molecules seems to be the best way to represent the bulk properties of the solvent correctly. If only a thin layer of explicitly defined solvent molecules is used (due to hmited computational resources), difficulties may rise to reproduce the bulk behavior of water, especially near the border with the vacuum. Even with the definition of a full solvent environment the results depend on the model used for this purpose. In the relative simple case of TIP3P and SPC, which are widely and successfully used, the atoms of the water molecule have fixed charges and fixed relative orientation. Even without internal motions and the charge polarization ability, TIP3P reproduces the bulk properties of water quite well. For a further discussion of other available solvent models, readers are referred to Chapter VII, Section 1.3.2 of the Handbook. Unfortunately, the more sophisticated the water models are (to reproduce the physical properties and thermodynamics of this outstanding solvent correctly), the more impractical they are for being used within molecular dynamics simulations. 

Interested readers are referred to Chapter X, Section 4 in the Handbook, dealing with drug design. 

Suitable inlets commonly used for liquids or solutions can be separated into three major classes, two of which are discussed in Parts A and C (Chapters 15 and 17). The most common method of introducing the solutions uses the nebulizer/desolvation inlet discussed here. For greater detail on types and operation of nebulizers, refer to Chapter 19. Note that, for all samples that have been previously dissolved in a liquid (dissolution of sample in acid, alkali, or solvent), it is important that high-purity liquids be used if cross-contamination of sample is to be avoided. Once the liquid has been vaporized prior to introduction of residual sample into the plasma flame, any nonvolatile impurities in the liquid will have been mixed with the sample itself, and these impurities will appear in the results of analysis. The problem can be partially circumvented by use of blanks, viz., the separate examination of levels of residues left by solvents in the absence of any sample. 

In general, the methods of synthesis and reactions of oxiranes and thiiranes fused to ordinary or large rings are not particularly affected by the ring fusion. The reader is referred to Chapters 5.05 and 5.06, and reviews cited there, many of which include fused-ring examples. 

In addition to the information presented in this chapter, refer to Chapter 3, Equipment Configuration and Layout, for further discussions on shared vent and drain systems. 

Each electric motor and connected control gear is grounded separately at least two points. The ground resistance should be checked to ensure continuity of ground conductors. Refer to Chapter 21 for more details on grounding requirements. 

MCC - motor control centre. For details refer to Chapter 1.4. 

Number of power cables running together and their configuration. For more details refer to Chapter 16, Appendix 1. The cooling of the cables is affected by the number of cables and their formation. This detail... 

For more details on groiindinc and the grounding practices, refer to Chapters 21 and 22. 

For a general discussion of bearings and seals refer to Chapter 5. The coverage at this point will be limited to the identification of the various types used on the screw compressor. 

The bearings used in axial compressors are the same journal and thrust type used in the centrifugal compressor. Refer to Chapter 5 for a complete description of these bearings. 

Pressure is defined as foree per unit area. (It may be expressed in a variety of units refer to Chapter 18.) So, pressure x area = foree. 

The provision and use of properly selected personal protective equipment is normally regarded as back-up for the previous measures. Refer to Chapter 13. In some situations it is the only reasonably practicable measure to ensure personal safety and its use may be a legal requirement. Examples are ... 

With flammable gases, eliminate all ignition sources (refer to Chapter 6). Possibly provide additional high/low level ventilation background gas detectors to alarm, e.g. at 40% of the LEL. With toxic gases, possibly provide additional local ventilation monitors connected to alarms appropriate air-fed respirators. (The flammable/toxic gas detectors may be linked to automatic shutdown instrumentation.)... 

The medical background of workers must be considered for work involving certain chemicals, e.g. radioactive substances, sensitizers. (Refer to Chapter 5.)... 

The use of any of the above techniques demands knowledge, experience, and flexibility. No prescriptive set of questions or key words or list is sufficient to cover all processes, hazards, and all impacted populations. As a research chemist reviews a chemistry and its potential application, there are advantages to maintaining an open mind when applying the various techniques designed to open up avenues of thought. The reader is referred to Chapter 7 for additional information and direction on the choice of process hazard review techniques. 

Disposable PPE should be removed, and the workers should thoroughly wash and rinse themselves. Anything contaminated should be left on site and disposed of in the proper manner. In this case, the worker and equipment would leave the site only after having been thoroughly cleaned. Refer to Chapter 10 for detailed decontamination activities. 

Training requirements should be addressed in the site-specific HASP. For larger, more complicated sites, training matrices may be used so that different levels of training can be appropriate for different phases of work activity. Refer to Chapter 8. 

The safety professional should always be inviting ideas to make sure that site workers are working smarter and not harder. Refer to Chapter 9 for more information on PPE. 

On July 17, 1990, OSHA issued a proposed rule for the management of hazards assoeiated with proeesses using highly hazardous ehemieals. This rule, ealled the Proeess Safety Management Standard, was finalized on February 24, 1992. In an appendix to the proposed rule, OSHA diseussed several methods of proeess hazard analysis. That diseussion may be helpful for those doing job hazard analyses. Refer to Chapter 4 for these methods. 

All pressure vessels should be equipped with one or more pressure safety valves (PSVs) to prevent overpressure. This is a requirement of both the ASME Code and API RP 14C (refer to Chapter 14). The PSV should be located upstream of the mist extractor. If the PSV is located downstream of the mist extractor, an overpressure situation could occur when the mist extractor becomes plugged isolating the PSV from the high pressure, or the mist extractor could be damaged when the relief... 

The applieation of lattiee models in eomputer modeling of ehemieal reae-tions at solid surfaees is beyond the seope of the present ehapter the reader is referred to Chapter 8 by E. Albano for a detailed diseussion of this area of researeh. 

Explain why a plant accident is more likely to happen during startup of a new plant or a retro-fit process. Refer to Chapter 20 and careful review the presentation or tlie bathtub curve tliat is represented by the Weibull distribution. 

The measure used to describe the potential for noncarcinogenic toxicity to occur in an individual is not expressed as tlie probability of an individual suffering an adverse effect. The EPA does not at tlie present time use a probabilistic approach to estimate tlie potential for noncarcinogenic healtli effects. Instead, tlie potential for non carcinogenic effects is evaluated by comparing an exposure level over a specified time period (e.g., lifetime) witli a reference dose derived for a similar exposure period. Tliis ratio of exposure to toxicity is called a liazard quotient and is described below. (The reader is referred to Chapter 11 for additional details on tlie material tliat follows). The noncancer liazard quotient assumes tliat tliere is a level of exposure (i.e., RfD) below which it is unlikely for even sensitive populations to experience adverse healtli effects. 

Exempt wastes are usually disposed of on location following permission from the state oil and gas division. Liquid wastes, if not evaporated or fixated on location, are usually injected into Class II injection wells—refer to Chapter 6, Environmental Considerations. Solid wastes, if not acceptable to local landfills, are remediated onsite or buried in some instances. Table 4-175 shows exempt and nonexempt waste [234]. 

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