Accidents quality assurance

Planned changes should be documented as part of a formal change monitoring process (for example via a quality assurance system). Unplanned changes should be identified during the accident investigation process. 

All surveyors need a database of technical information, which should include reports of accidents or of defects that could lead to accidents derived from other sources. He also needs a regular supply of technical documentation from his head office that keeps him abreast of technical developments. If his company operates an effective quality assurance system, they will periodically check that he is keeping these data properly and they may control the indexing of them. 

Technical systems which contain material representing a hazard potential must be treated under controled, safe conditions. A respective design of the facility and its operational modes is checked by different kinds of safety considerations. In addition to the consequences of normal operation, the system behavior under accident conditions has to be considered in terms of sufficient measures for controling accidents. Assumptions are being made based upon experience which has been achieved in the course of the technical development and which has resulted in a system of laws, regulations, rules, guidelines, and recommendations, e.g., for the design of components, for quality assurance, for fire protection and also for accident prevention measures. 

When operating at elevated levels of risk, the only question is which of many potential events will trigger the loss. Before the Columbia accident, NASA manned space operations was experiencing a slew of problems in the orbiters. Ihe head of the NASA Manned Space Program at the time misinterpreted the fact that they were finding and fixing problems and wrote a report that concluded risk had been reduced by more than a factor of five [74]. The same unrealistic perception of risk led to another report in 1995 recommending that NASA restructure and reduce overall safety, reliability, and quality assurance elements [105]. 

In the context of process safety, quality assurance is more concerned with problems that lead to accidents rather than product quality in the customer satisfaction sense. However, there is generally a close relationship between the two. 

Consequently, there were some very spectacular accidents and the engineering disciplines of reliability and quahty control were tasked to provide a greater measure of mission success through elaborate quality assurance and reliability analyses and testing. Despite this, accidents continued at a higher rate than was considered acceptable and the new discipline of system safety was developed to bring the accident preventive experience into the systems engineering processes. 

Limitations in the Soviet manufacturing capacity for specialist equipment such as electronics and control, and the lack of a comprehensive quality assurance system, linked to the pressure to design and build plant that could be manufactured, constructed and commissioned quickly, led to a design which, in both concept and detail, has features which impaired ultimate plant safety. Among the features of the design which appear to be questionable, some of which contributed to the initiation and development of the accident at the Chernobyl 4 reactor, the following merit noting ... 

In this period up to the TMI accident, three other facts influenced nuclear safety technology defence against non-natural external events the preparation of the Rasmussen report, WASH 1400 and the introduction of Quality Assurance (QA) in design, construction and operation of plants. 

This class does not require the same conservative design provisions required by DBAs (high safety margins for mechanical strength, strict quality assurance requirements, etc.). However, substantial core integrity is required as a consequence of the implementation of accident management measures. 

Static factors refer to the properties of the procedure and are not expected to change during the accident event. In ADS-IDAC, static factors include procedure type, step objectives, and step complexity. In the U.S., quality assurance program requirements require that plant operators to specify the manner in which procedures are to be executed (ANS3.2/ANSIN18.7,1976). 

AIMS is used in over 50% of the hospitals in Australia and in 2005 it was adopted by the New Zealand Accident Compensation Corporation. The AIMS data remains confidential and is protected from legal actions under the Australian Commonwealth Quality Assurance legislation. 

Auspicious safety culture includes some overwhelming characteristics such as transparency, quality assurance and priority of safety. Transparency means, among other things, that the obligation to protect individuals and society is written in legislation. It also means that the safety objectives are well formulated and that mass media and individuals have access to safety-related materials etc. The experts must have preparedness to explain to the public even the difficulties and problems of nuclear safety and radiation protection, such as the very low probability of severe accidents and low probability of cancer due to low doses. Good safety culture also means that all the relevant problems are properly solved and no major elements are pushed aside to the unknown future. 

The MARS safety concept provides for retaining of radionuclides in the fuel both in normal operation and accidents, so that radiation exposure of the personnel and population around the NPP falls within the limits prescribed by the regulations. Barriers to the release of fission products from fuel are provided primarily by the coatings applied to each fuel particle. The required retention of radioactivity is ensured by the long-term operability of the fUel elements, which maintain their performance at temperatures up to 1250 C with the fast neutron (E>0.18 MeV) fluence to the coatings of up to 2.2 10 cm, and by quality assurance during fuel fabrication. 

All accident analyses are based on a valid data base such as geometrical data, material properties, physical and thermohydraulic data including boundary conditions of plant operational status. Every accident analysis needs a plant model which must be constructed on the basis of valid data. This data base is subject to quality assurance programme. It is essential that plant owners obtain reliable and verifiable data on the plant as-built and modified over the plant lifetime and validate them appropriately. 

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