Method for deterministic safety analysis in non-stationary high risk system, control method and control system using thereof

• US 8,566,139 B2
• Filed: 11/20/2007
• Issued: 10/22/2013
• Est. Priority Date: 05/20/2005
• Status: Active Grant

• Current Assignee: Diakont Advanced Technologies, Inc.
• Original Assignee: Diakont Advanced Technologies, Inc.
• Inventors: Fedosovskiy, Mikhail Evgenievich, Dunaev, Vadim Igorevich, Kopiev, Yurii Vladimirovich, Sherstobitov, Alexander Evgenievich
• Primary Examiner(s): Choi, Peter
• Assistant Examiner(s): Gills, Kurtis
• Application Number:
  US11/943,531
• Publication Number:
  US 20080288121A1
• Time in Patent Office: 2,163 Days
• Field of Search: 705/7.28
• US Class Current: 705/7.28
• CPC Class Codes: G05B 23/0243 model based detection method, e.g. first-principles knowledge model
• CPC Class Codes: G05B 23/0291 Switching into safety or degraded mode, e.g. protection and supervision after failure
• CPC Class Codes: G06F 2111/08 Probabilistic or stochastic CAD
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
• CPC Class Codes: G06Q 10/0635 Risk analysis of enterprise or organisation activities

Abstract

A method and systems of safety analysis of engineering processes for safety analysis of nuclear power stations are disclosed. A distribution of risk factors is analysed on different stages of the engineering process, and safety intervals are determined where safety conditions remain invariable. The method further includes analysis of failure transitions from one safety interval into another by means of cause-effect analysis. Based on the results of this analysis, deterministic safety models are created for possible scenarios of transition of failures from one safety interval into another. The method and systems provide quantitative safety analysis and evaluation for engineering processes in variable safety conditions and enable creating valid safety requirements to perform optimization of an engineering processes control system.

Claims

1. A computer-implemented method of control of a high risk engineering process, the engineering process involving non-stationary objects, wherein the method comprises:

measuring with measurement devices a plurality of process parameters Pi (1<

i<

n) on the objects involved in the engineering process;

defining a maximum permissible value of the process parameter P.ipermitted;

comparing each actual measured process parameter Pi with the respective permitted process parameter P.ipermitted in order to determine failures Fi=f(Pi) of the engineering process, when Pi>

P.ipermitted;

wherein for each determined failure Fi=f(Pi>

P.ipermitted), defining a plurality of process parts, which are affected by the said failure, and

dividing the process into a plurality of safety intervals Rj={F1, F2, Fi . . . Fm} (1<

j<

m) and (1<

n<

m), wherein each safety interval is associated with a subset of the process parts and wherein a combination Sum.i=1.n. Fi of the said failures remains invariable for all intervals;

wherein each safety interval Rj is subject to;

analyzing, by a computer executing software, of transitions of failures Fi=f(Pi>

P.ipermitted) in the engineering process from one to another safety interval based on analysis of cause-effect relations;

modeling by construction of deterministic safety models based on an analysis of possible scenarios of the transitions of failures Fi=f(Pi>

P.ipermitted) of the engineering process from one to next safety interval, and

defining a failure probability of the equipment used for the engineering process based on constructed models of each safety interval Rj, and

correspondingly modifying the engineering process to reach the required safety parameters.

2. A method of claim 1, further comprising creating deterministic models of the safety intervals R_j based on analysis of possible scenarios of the transitions of failures of the engineering process from one to next safety interval R_j+1.

3. A method of claim 1, wherein the engineering process is divided into safety intervals with account of each failure F_i=f(P_i>

P_ipermitted) in each part of the engineering process for each chosen safety parameter P_imax.

4. A method of claim 1, further comprising construction of logical or logical-probabilistic models for each failure F_i=f(P_i>

P_imax).

5. A method of claim 4, wherein the logical or logical-probabilistic models are constructed based upon analysis of possible impacts P_i, which result in respective failures F_i=f(P_i>

P_imax) of the engineering process, and combinations of the impacts.

6. A method of claim 1, wherein the non-stationary object is selected from at least one of the following:

an engineering process as a whole, at least one stage or part of an engineering process or any combination thereof, products, devices, units, in which process, stage, product, device or unit the safety conditions vary depending on time and allocation of the product, device or unit, in particular depending on which stage or part of the engineering process the product, device or unit is located.

7. A method of claim 6, wherein switching from consideration of non-stationary engineering process to consideration of stationary parts of engineering process, based on analysis of distribution of areas affected by the determined failures F_i=f(P_i>

P_imax) in different parts of the engineering process.

8. A method of claim 1, wherein switching to stationary conditions based on analysis and safety evaluation of each safety interval R_j of the engineering process.

9. A method of claim 1, wherein an analysis and a safety evaluation of the engineering process are performed by plotting diagrams of partition into safety intervals R_j.

10. A method of claim 1, further comprising creating deterministic models of the safety intervals R_j based on analysis of possible scenarios of the transitions of failures of the engineering process from one to next safety interval R_j+1.

11. A method of claim 1, further comprises a step of creating a deterministic-probabilistic safety model of the whole engineering process.

12. A method of claim 11, wherein the deterministic-probabilistic safety models of the whole engineering process are created using the obtained deterministic models of the safety intervals R_j.

13. A method of claim 11, wherein the deterministic-probabilistic safety models of the whole engineering process are created using obtained logical-probabilistic models of occurrence of failures F_i=f(P_i>

P_imax).

14. A method of claim 11, wherein the deterministic-probabilistic safety models of the whole engineering process are created using obtained deterministic models of the safety intervals R_j and logical-probabilistic models of occurrence of failures F_i=f(P_i>

P_imax) of the engineering process.

15. A method of claim 1, wherein the analysis of failure transitions in engineering process is performed based on cause-effect relations of failures F_i=f(P_i>

P_imax), possible failures F_i=f(P_i) of the engineering process and malfunction of protectors or locks on each stage of the engineering process.

16. A method of claim 1, wherein an analysis of distribution of an areas affected by a sources of danger is performed by analysis of each unit part of an engineering process stage, in order to determine particular source of danger, which could result in overrun of any one acceptable impact P_imax.

17. A method of claim 1, wherein the engineering process is divided into safety intervals with account of each failure F_i=f(P_i>

P_ipermitted) in each part of the engineering process for each chosen safety parameter P_imax.

18. A method of claim 1, wherein the acceptable impacts P_imax are normative impacts, specified in normative documentation on safety.