Background to the Project

Operational experience and performance of Shutdown and Low-Power Probabilistic Safety Analysis (SLP PSA) have highlighted that the risk from those operational modes is significant. Based on this consideration the OECD-NEA Principal Working Group 5 for Risk Assessment decided to form a Task Force (Task 13) to address these issues. It was decided that the Task Force should compile a report on plans, methods and experience in the area from the different OECD countries. 

As a result of this effort, the OECD-NEA issued a Report on Shutdown and Low-Power Safety Assessment - a Status Report in November 1993. This Report pioneered international work in this area. The Report was very successful in delineating topics highlighting the issues of concern and presenting the state of the art studies as available at the time. As such, it served an useful purpose to iirform wider audience of SLP PSA practitioners, but also regulators and utilities on issues relevant for Shutdown and Low-Power Safety Analysis. 

Considering the extent of activities on SLP PSA which have occurred since 1992/93, and from the today s perspective, the original Task Force 13 Report is outdated. In addition to specific SLP PSA studies, which are completed to-date, a number of studies have been initiated in several countries. Moreover, methodology has in the mean time matured. 

The results of several SLP PSAs became available, and are being implemented at plants to improve the safety during Shutdown and Low-Power operating modes. In the 1993 Report, those issues were not discussed as the information was not available. 

Considering the significance of the safety improvements in Shutdown and Low-Power operating modes, the extent of activity in the area over the last several years and the fact that methods are well profiled, the OECD-NEA Task Force 13 initiated an activity to develop an update of the 1993 report. The aim was to provide a compendium of practices on safety improvements/enhancements in Shutdown and Low-Power operation modes. In addition, this should be a continuation of efforts in compiling the plans, methods and experiences in the area from the different OECD countries. 

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In this chapter, we propose the creation of a new collaborative virtual environment for the development of the Coulson-Fischer method for molecular wave functions. It is proposed that this environment should be open. This chapter gives some background to the project. 

This paper is based on the work undertaken during the first year of a four year collaborative project entitled "Software Engineering Methods for Safe Programmable Logic Controllers". The project is part of the joint DTl/Serc "Safety Critical Systems Initiative". In the paper the background to the project is presented, and the principal objectives of the project are summarised. Whilst it is too early to present detailed results, the major issues are summarised. The principal conclusion to date is that the cross-sectoral background of project members has challenged many preconceived notions. 

There is a very wide range of condensate polishers available, and it is important to properly understand the background to the problem to make the correct selection and ensure the economic viability of the project. 

Table 2.8. Typical issues addressed when designing a clinical trial protocol. The trial objectives should clearly define what questions the trial should answer. The study design section should contain comprehensive information detailing trial size, criteria used to choose the study population, and enrolment procedures. Description of intervention section should give the background to the intervention itself, its therapeutic rationale and how it is to be administered. Measurement of response should detail the data to be collected, how it will be collected and analysed. The organization and administration section should give full details of all the investigators, where the trial is being run, and its project management details...

Introduction - including background to the proposed project, rationale for it and any work done to date. 

The Reference List (sometimes called Literature Cited or Bibliography) should only contain references that are cited in the text. A list of support literature, background or fiirther reading, contains literature not cited in the text that is also relevant to the project. 

The bottling and storage procedures followed those previously tested in the preliminary investigations (see section on background of the project). Acidified suprapure water contained in the LPE bottles was discarded. The volume of soaking liquid which remained in the bottles was observed to be minimal and therefore no rinsing step with sample was considered to be necessary. The bottles were filled directly using the peristaltic pump and closed with LPE caps. 

In this study, non-participant structured observation was employed to gain quantitative data such as the production processes of the products, the time-phased labour action, the resource constraints and the layout of production facilities and manufacturing workshops. As this project was based on industrial case studies, observation provided a deeper understanding of the backgrounds to the industries, the manufacturers operations, management strategies and the SC systems. 

Although the raw efficiency, or number of true coincidences acquired, is a basic determinant of the quality of a PET scanner, the complicating factors of scattered and random events and dead time have to be brought into the analysis. Details of the distribution of scattered events and correction methods can be found elsewhere, but for the present purposes it can be stated that scattered radiation (or scatter for short) produces a relatively flat background on the projection and image data, impairing contrast and reducing quantitative accuracy. The quantity of scatter detected, the scatter fraction (SF), is expressed simply in terms of the total true (unscattered -i- scattered) events (Tj j) and the scattered events S) by... 

Once the plan is complete, you will almost certainly need to submit it for final approval. Your company probably has well established approval processes. Make sure to understand these and adequately brief anyone who may present your project to project review committees or board meetings on your behalf. When preparing your plan for approval, it is important to briefly reiterate the history of the project. Although you have thoroughly prepared senior management through your various communication and consultation exercises, they will not recall all of the relevant background. 

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