Zeinab A. Sabri

Analysis of gross error rates in operation of commercial nuclear power stations

Abstract Experience in operation of US commercial nuclear power plants is reviewed over a 25-moth period. The reports accumulated in that period on events of human error and component failure are examined to evaluate gross operator error rates. The impact of such errors on plant operation and safety is examined through the use of proper taxonomies of error, tasks and failures. Four categories of human errors are considered; namely, operator, maintenance, installation and administrative. The computed error rates are used to examine appropriate operator models for evaluation of operator reliability. Human error rates are found to be significant to a varying degree in both BWR and PWR. This emphasizes the import of considering human factors in safety and reliability analysis of nuclear systems. The results also indicate that human errors, and especially operator errors, do indeed follow the exponential reliability model.

Operating procedure automation to enhance safety of nuclear power plants

Abstract Use of logic statements and computer assist are explored as means for automation and improvement on design of operating procedures including those employed in abnormal and emergency situations. Operating procedures for downpower and loss of forced circulation are used for demonstration. Human-factors analysis is performed on generic emergency operating procedures for three strategies of control; manual, semi-automatic and automatic, using standard emergency operating procedures. Such preliminary analysis shows that automation of procedures is feasible provided that fault-tolerant software and hardware become available for design of the controllers. Recommendations are provided for tests to substantiate the promise of enhancement of plant safety. Adequate design of operating procedures through automation may alleviate several major operational problems of nuclear power plants. Also, automation of procedures is necessary for partial or overall automatic control of plants. Fully automatic operations are needed for space applications while supervised automation of land-based and offshore plants may become the thrust of new generation of nuclear power plants.

Desalting in Saudi Arabia—demand, production, management, associated power generation and future plans

Abstract Patterns of water demand and consumption in the Kingdom of Saudi Arabia are analyzed to extrapolate the extent of actual future desalination activities. Methods sought for supplementing the present water supply by means other than desalination are reviewed. Current production of desalted water and future plans are given. Expansion in the construction of desalination plants is intended to increase the installed capacity by more than a hundred fold within the next decade. The largest plant is 757 thousand m3/d (200 mgd)/2000 MWe dual-purpose plant, which will be installed on the East Coast. Electric power generation activities associated with water desalting are also considered to examine the role of dual-purpose plants. Patterns of power demand, production and consumption are discussed. The present management procedure of major desalting plants is presented and analyzed. Finally, long-term plans are examined in relation to the present economic and social structure.

Nuclear desalination for Saudi Arabia: an appraisal

Abstract The viability of using nuclear energy in desalting seawater in Saudi Arabia is considered. On the basis of recent plans to expand in the capacity and distribution of power and desalination plants, scenarios are developed to examine the economics of nuclear systems within the frame of present development. Merits of employment of nuclear energy are discussed and regional factors which may affect future plans are presented.

Selection for desalination processes for dual-purpose nuclear plants

Abstract The various aspects of combining desalination processes with nuclear heat generation systems are explored with emphasis on MSF and RO technologies. Comparisons between nuclear desalination plants based on each technology are made and analysis of the difficulties which may be encountered are examined. Considering the impact of reliability, availability and safety of the desalination processes on the nuclear steam supply system (NSSS), integration of the power production and the desalination stages is studied and necessary improvements on the desalination processes are sought to assure compatibility of the nuclear energy source and the desalting phase.

Reliability analysis of reverse osmosis plant

Abstract The increasing complexity of desalting plants demands consideration of operational and maintenance factors in the design phase. Applications of the fault tree techniques to RO sea water desalination systems are illustrated; critical failure problem areas are identified and methods of improving the performance of the RO desalination plants are recommended. Failure data has been extracted from operation and maintenance reports of the operating RO desalination plants in Jeddah, Saudi Arabia. An assessment is also made of the impact of failures and outages on the availability of the plant.

Performance evaluation of MSF plants, the case of Jeddah plants

Abstract The objectives of the work reported here is to review the performance of Jeddah Desalination plant during a period of 8 years of operation to provide insight into actual plant experience. Data have been extracted from plant monthly reports and maintenance orders. The analysis provided here is based on objective evaluations of operations data and experience and is directed towards assessment of problems that can be mitigated in new designs of MSF plants and recommendations for improvement or modifications of existing designs or procedures.

A Data Bank for Human Related Events in Nuclear Power Plants

The authors introduce a comprehensive survey and evaluation of presently available data sources in nuclear power plants. A newly developed classification format for human related events is proposed. The format presents all necessary information in a coded form to support human reliability analysis and the assessment of performance shaping factors. Recommendations are given for improving data sources to facilitate the evaluation of man-machine interfaces and human performance in nuclear power plants.

Reliability of MSF processes based on operation history

Abstract Reliability of MSF processes are estimated using time-dependent fault tree analysis of major critical systems. Failure data are obtained from the operation records of Jeddah I since it is one of the oldest plants still in operation in a relatively harsh environment. Industrial failure data are also used to complement historic data. The analysis shows areas where design improvements can be made to enhance MSF processes availability.

A comprehensive formal approach to the evaluation of bids for desalination plants using verbal judgment

Abstract Evaluation of competitive bids for large engineering projects such as desalination plant construction requires careful consideration of several factors other than pure economic merits; namely, technical characteristics of bids, the socio-political situation, safety merits, environmental aspects, public acceptance and other non-financial aspects. A method is developed here based on verbal judgment and fuzzy set theory to allow for comprehensive and systematic formal evaluation of bids. The method is applied to a case study and can be directly used by the technical team to make the final conclusion. The method is implemented in the form of a computer code (MAFDA) which is suitable for interactive computer facilities.