Abstract
Reactor operators have to judge the state of the reactor. In the operator room they see the panels displaying data on the state of the reactor and decide on the action to be taken to operate safely and economically. A reactor surveillance system is complex enough to encounter errors, failures, or malfunctions. The present chapter deals with disturbances and anomalies: how to discover them, what are the possible consequences of the disturbances and anomalies. The investigation focuses on early anomalies which are often hard to detect. Because of their safety implications, we deal with coolant flow anomalies, small changes in the flow pattern, possible errors in the technical side, like an erroneous follower enrichment data or a false measurement. Our investigations are based on the techniques having discussed throughout the previous chapters. It is possible to exploit disturbances when we study the consequences of a known anomaly to characterize the reactor.
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Notes
- 1.
In many cases it suffices to know that the ratio of the temperatures should be constant in time.
- 2.
This is the case when the core map is symmetric. Since symmetry offers additional check on the measured values usually the map is symmetric.
- 3.
Figure 7.10 is not included as details of the cleaning process are out of our scope.
- 4.
As to activity, see the Appendix.
- 5.
Non-metered assemblies are light yellow colored.
- 6.
Non-metered assemblies are light salmon colored.
- 7.
Non-metered assemblies are light salmon colored.
- 8.
\(E\{\varDelta T\}\) is the average \(\varDelta T\) of the measured assemblies.
- 9.
The average is zero, only one number is negative in position 218.
- 10.
For example assembly No. 65 is involved in seven microsectors and it has also a measured value. Its maximum and minimum value as well as the measured value is given in Table 7.3.
- 11.
Just look at the positions of control rods in the core and remember, around 30 control rods are capable of shutting down the energy production in the entire core.
- 12.
Reactor operators measure control rod position from the bottom.
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Makai, M., Végh, J. (2017). Detection of Disturbances and Anomalies. In: Reactor Core Monitoring. Lecture Notes in Energy, vol 58. Springer, Cham. https://doi.org/10.1007/978-3-319-54576-9_7
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