Environmental Engineering Reference
In-Depth Information
Table 5.12
Change of the mechanical properties of base metal of
pipeline DN 500 of the main circulation pipeline during operation
T
test
= 20
o
C
T
test
= 300
o
C
Grain
size
Melt
TS,
MPa
YS,
MPa
TS,
MPa
YS,
MPa
RA,
%
EL, %
RA, %
EL, %
Initial state
534
534
240
240
53.5
54.0
52.0
54.5
215
211
161 944
-
-
-
5
519
524
284
284
51.5
56.0
52.0
56.5
235
240
160 666
-
-
-
2
52.0
54.0
60.0
63.5
235
240
160 679
519
269
-
-
-
5
100 000 hours of operation
266
385
370
212
196
187
29.0
30.5
22.0
65.0
64.0
62.5
529
527
253
238
54.4
56.8
65.5
65.2
161 944
-
568
549
509
284
274
250
58.0
61.0
57.0
62.0
60.0
62.0
160 666
-
-
-
-
-
560
545
550
358
304
348
52.5
58.5
57.0
63.0
63.0
63.0
160 679
-
-
-
-
-
100 000 of operation + austenitizing and tempering
478
490
214
218
45.3
57.7
61.2
67.1
160 666
-
-
-
-
-
5.3.8 Initial data for calculating the probability of
destruction of equipment and pipelines of NPP
All information necessary to determine the probability of failure can be
found at the NPP and the organisations that support operation, construction
and design of NPPs.
For example, the power operating conditions are defined by regulations
for operation and may be made more accurate by NPP documentation. In
recent years, nuclear power plants in Russia and abroad have been using
automated inspection systems for the residual life of the type SAKOR in
Russia or Famos in Germany, in which the entire history of thermal force
loading of equipment and pipelines of NPPs is inspected.
The characteristics of the scatter of strength properties can be
determined according to the certificate data or appraisal reports. In the
first approximation, these regulations can be used, taking the variance to
be equal to zero. In this case, the estimates will be the greatest error in
the margin of safety.
The baseline data for evaluation of residual defects discussed above are
in sections 3.2.1 and 3.2.3. These data can be obtained from the results of
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