Structure of This Report

The report focuses on an international outlook on the risk issues related to Shutdown and Low-Power conditions, including approaches used in the OECD countries to reduce the risk during Shutdown operating mode. Further, the application of those approaches to enhance the safety during shutdown and low power operation and specific measures undertaken at various plants are discussed  

This report encompass seven Chapters. Chapter 1 in Introduction. 

Chapter 2 summarises the international experience on the use of different approaches to the assessment of risk during shutdown operating mode. It focuses on three main approaches 1) Full-Scope SEP PSA models, 2) Barrier Analysis Approach and 3) Configuration control tools. 

Chapter 3 focuses on specific modelling issues related with the SLP PSA. It provides an in-depth overview of international experience on modelling issues of interest, and experience in the use of a full-scope SLP PSA. 

Chapter 4 summarises the NEA member countries activities in the area of shutdown and low power safety assessment, with focus on PSA. 

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The introduction (Chapter 1) describes the background and identifies the objectives, the scope and the structure of this report. 

A chiral titanium complex with 3-cinnamoyl-l,3-oxazolidin-2-one was isolated by Jagensen et al. from a mixture of TiCl 2(0-i-Pr)2 with (2R,31 )-2,3-0-isopropyli-dene-l,l,4,4-tetraphenyl-l,2,3,4-butanetetrol, which is an isopropylidene acetal analog of Narasaka s TADDOL [48]. The structure of this complex was determined by X-ray structure analysis. It has the isopropylidene diol and the cinnamoyloxazolidi-none in the equatorial plane, with the two chloride ligands in apical (trans) position as depicted in the structure A, It seems from this structure that a pseudo-axial phenyl group of the chiral ligand seems to block one face of the coordinated cinnamoyloxazolidinone. On the other hand, after an NMR study of the complex in solution, Di Mare et al, and Seebach et al, reported that the above trans di-chloro complex A is a major component in the solution but went on to propose another minor complex B, with the two chlorides cis to each other, as the most reactive intermediate in this chiral titanium-catalyzed reaction [41b, 49], It has not yet been clearly confirmed whether or not the trans and/or the cis complex are real reactive intermediates (Scheme 1.60). 

The toxin is less effective on oats and wheat and does not have the specificity reported for the toxin from Hehmnthosporium vic-toriae for oats. A metabolite isolated from another strain of H. sativum in Japan by Tamura et al. (15) has a marked elongation effect on the shoots of rice seedlings. The structure of this metabolite is closely related to that described here. 

Bis(diazo)-l,2,4,5-cyclohexanetetraone (4.5) may be regarded as a derivative of a double 1,2-quinone diazide. Its X-ray analysis was reported by Ansell (1969). The synthesis, properties, and structure of this interesting compound will be discussed in the forthcoming book on aliphatic diazo compounds (Zollinger, 1995, Secs. 2.3 and 5.2). 

Next, the CD spectra of the backbone 2 aPNA Ac-Cys -Lys-Ser -Ala-Ala-Lys-Ser -Ala-Ala-Lys-SerhAla-Ala-Lys-Ser -Ala-Ala-Lys-Ser -Gly-Lys-NH2, was measured as a function of pH in phosphate buffer. At pH 7, the secondary structure of this aPNA was largely random coil. However, the a-hehcity of this aPNA increased with the pH until it reached a maximum at pH 11. Analogous pH-depen-dent secondary structure has also been reported for the amphipathic KALA peptide Trp-Glu-Ala-Lys-Leu-Ala-[Lys-Ala-Leu-Ala]2-Lys-His-Leu-Ala-Lys-Ala-Leu-Ala-Lys-Ala-Leue-Lys-Ala-Cys-Glu-Ala-OH [53]. In our case however, maximum a-helicity... 

The chemistry and the structures in this report have been organized by the main-group/chalcogen building block units (Fig. 14.1). At the start of 2000, we were beginning to understand aspects of the chemistry of chalcophosphates both as selenophosphates and thiophosphates. The thesis of Dr. Carl Evenson [14] and his subsequent papers discuss the composition phase diagrams of Y,... 

Over the last decade, the chemistry of the carbon-carbon triple bond has experienced a vigorous resurgence [1]. Whereas construction of alkyne-con-taining systems had previously been a laborious process, the advent of new synthetic methodology based on organotransition metal complexes has revolutionized the field [2]. Specifically, palladium-catalyzed cross-coupling reactions between alkyne sp-carbon atoms and sp -carbon atoms of arenes and alkenes have allowed for rapid assembly of relatively complex structures [3]. In particular, the preparation of alkyne-rich macrocycles, the subject of this report, has benefited enormously from these recent advances. For the purpose of this review, we Emit the discussion to cychc systems which contain benzene and acetylene moieties only, henceforth referred to as phenylacetylene and phenyldiacetylene macrocycles (PAMs and PDMs, respectively). Not only have a wide... 

Apart from the determination of the structures of stannylenes by diffraction methods (X-ray or electron diffraction) many other physico-chemical techniques can be exployed to characterize these compounds more completely. Besides the classical methods such as IR-, Raman-, PE-, UV- and NMR-spectroscopy, MoBbauer-119 m-tin spectroscopy is widely used for the determination of the oxidation states of tin atoms and of their coordination 1n8-12°-123>. jt is not in the scope of this report to study the dependence of MoBbauer constants such as isomer shift and quadrupole splitting on structural parameters. Instead, we want to concentrate on one question Which information can we deduce from the structure of stannylenes to evaluate their reactivity ... 

However, the formation of these products does not appear to play a critical role in the decision as to whether the 425 nm and 480 nm maxima are due to different states of the same molecule or to different compounds. It was reported that special care was taken to ensure the purity of luminol and of 3-aminophthalate 109>. In commercially available 3-amino-phthalic acid a yellowish impurity exhibiting brilliant green fluorescence was detected 109> this substance also formed in neutral solutions of pure 3-amino phthalic acid and crystallized from these solutions in yellow crystals. The structure of this substance was determined to be 53 its absorption spectrum has a maximum at 388 nm the fluorescence maximum is at 475 nm, with a fluorescence quantum yield of about 0.75 in DMF i 9). 

A compound known as nitrosyl azide, N40, has been reported. Draw the structure of this unusual compound and discuss the bonding. What would be a different arrangement of atoms for a compound having this formula Comment on its stability. 

The stated objective of this report was to present sufficient data about aromatic carbenes to permit the forecast of their properties directly and reliably from their structures. This has been accomplished to a reasonable degree. Coupling of the theoretical framework with the experimental measurements allows confident prediction of the outcome of many chemical reactions. The rates of the important processes controlling aromatic carbene behavior can be estimated, and thus even yields can be forecast in many... 

A further report dealt with the synthesis, variable temperature magnetic susceptibility measurements, and crystal structure determination at various temperatures (115, 136, 140, 150 and 231 K space group P-1) of [Fe(isoxa-zole)6][Fe(isoxazole)4(H20)2](BF4)4 [73]. The molecular structure of this well-defined double salt consists of two mononuclear Fe(II) dications,... 

The first structures of this kind were reported in 1993 pectate lyase G from Erwinia chrysanthemi (Yoder et al, 1993) and alkaline protease from Pseudomonas aeruginosa (Baumann et al, 1993). Based on consideration of these crystal structures, the term parallel //-helix was introduced for a fold containing three //-strands per coil, and parallel //-roll for a fold with two //-strands per coil (Baumann etal, 1993 Yoder andjurnak, 1995 Yoder et al., 1993). The epithet parallel was intended to emphasize the distinction between these folds and the previously observed helical structure of the antibiotic gramicidin which contains both l- and D-amino acids and... 

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