Abstract
The operation and safety automation systems of the new nuclear power plant offered for Finland are proposed to be realized with new programmable digital technology. This seems to be the longest technological leap in the otherwise quite customary plant concepts. In the existing four plant units it may also become necessary to extend or replace old analog systems with digital ones in the future. The safety assessment of a programmable digital system can not be based on conventional probabilistic methods because of the difficulties in quantification of the reliability of the software as well as the hardware. In the case of the software it is widely acknowledged that quantification is difficult. The hardware has equal problems due to the dependence of the effect of a hardware failure on the instruction being executed at the time of failure. The difficulties stem from the complexity, non-continuous behaviour and tendency to common mode failures of the programmable systems. The reliability assessment has to be based on qualitative arguments linked to a claim limit. These qualitative arguments are based on sound engineering judgement and present deterministic as opposed to probabilistic criteria. Due to the uncertainty of the quantitative reliability estimate other means shall be
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Haapanen, P;
[1]
Haell, L E;
Lucander, A;
[2]
Manninen, T
[3]
- Technical Research Centre of Finland, Espoo (Finland). Lab. of Electrical and Automation Engineering
- Teollisuuden Voima Oy, Helsinki (Finland)
- Imatran Voima Oy, Vantaa (Finland)
Citation Formats
Haapanen, P, Haell, L E, Lucander, A, and Manninen, T.
Licensing practices for programmable automation systems; Ohjelmoitavan automaation hyvaeksymiskaeytaennoet.
Finland: N. p.,
1993.
Web.
Haapanen, P, Haell, L E, Lucander, A, & Manninen, T.
Licensing practices for programmable automation systems; Ohjelmoitavan automaation hyvaeksymiskaeytaennoet.
Finland.
Haapanen, P, Haell, L E, Lucander, A, and Manninen, T.
1993.
"Licensing practices for programmable automation systems; Ohjelmoitavan automaation hyvaeksymiskaeytaennoet."
Finland.
@misc{etde_10152803,
title = {Licensing practices for programmable automation systems; Ohjelmoitavan automaation hyvaeksymiskaeytaennoet}
author = {Haapanen, P, Haell, L E, Lucander, A, and Manninen, T}
abstractNote = {The operation and safety automation systems of the new nuclear power plant offered for Finland are proposed to be realized with new programmable digital technology. This seems to be the longest technological leap in the otherwise quite customary plant concepts. In the existing four plant units it may also become necessary to extend or replace old analog systems with digital ones in the future. The safety assessment of a programmable digital system can not be based on conventional probabilistic methods because of the difficulties in quantification of the reliability of the software as well as the hardware. In the case of the software it is widely acknowledged that quantification is difficult. The hardware has equal problems due to the dependence of the effect of a hardware failure on the instruction being executed at the time of failure. The difficulties stem from the complexity, non-continuous behaviour and tendency to common mode failures of the programmable systems. The reliability assessment has to be based on qualitative arguments linked to a claim limit. These qualitative arguments are based on sound engineering judgement and present deterministic as opposed to probabilistic criteria. Due to the uncertainty of the quantitative reliability estimate other means shall be used to gain confidence on the system safety. These means include evidence on the excellence of manufacture supported by deterministic features and confidence building measures. (29 refs., 6 figs., 1 tab.).}
place = {Finland}
year = {1993}
month = {Feb}
}
title = {Licensing practices for programmable automation systems; Ohjelmoitavan automaation hyvaeksymiskaeytaennoet}
author = {Haapanen, P, Haell, L E, Lucander, A, and Manninen, T}
abstractNote = {The operation and safety automation systems of the new nuclear power plant offered for Finland are proposed to be realized with new programmable digital technology. This seems to be the longest technological leap in the otherwise quite customary plant concepts. In the existing four plant units it may also become necessary to extend or replace old analog systems with digital ones in the future. The safety assessment of a programmable digital system can not be based on conventional probabilistic methods because of the difficulties in quantification of the reliability of the software as well as the hardware. In the case of the software it is widely acknowledged that quantification is difficult. The hardware has equal problems due to the dependence of the effect of a hardware failure on the instruction being executed at the time of failure. The difficulties stem from the complexity, non-continuous behaviour and tendency to common mode failures of the programmable systems. The reliability assessment has to be based on qualitative arguments linked to a claim limit. These qualitative arguments are based on sound engineering judgement and present deterministic as opposed to probabilistic criteria. Due to the uncertainty of the quantitative reliability estimate other means shall be used to gain confidence on the system safety. These means include evidence on the excellence of manufacture supported by deterministic features and confidence building measures. (29 refs., 6 figs., 1 tab.).}
place = {Finland}
year = {1993}
month = {Feb}
}