Using probabilistic methods for solving the problem of ensuring leak tightness of heat exchanger tubes of nuclear power plant steam generators - Probabilistic Safety Assessment for Optimum Nuclear Power Plant Life Management (PLiM) - page 309

1.1. Chemical composition

1.2. Microstructure
1.3. Macrostructure

1.4. Mechanical means
1.5. Ageing

2.1. NOC
2.2. Hydraulic testing

2.3. Deviation from NOC,
cooling at 60 o C/h
2.4. Water discharge level
2.5. Long-term deactivation
of MCP followed by start-up

2.6. Wedging of HET in working range

2.7. Stress concentration

Episodic short-
term disruption of
WCR accelerating
corrosion damage

2.8. Vibrostresses
2.9. Fretting corrosion
3.1. Short-term

4.1. Short-term

Condensate-feed
circuit, suction, S
and possibly other
elements

5.1. Short-term

Penetration and
long-term storage
of corrosion-active
products, suction (S)
and corrosion (Cu)
from condensate-feed
circuit

7.1. Confirmed by chemical
analysis results

￿ ￿ ￿ ￿ ￿

8.1. Confirmed by
chemical analysis and
crevices under Cu deposits

Condensate-feed
circuit, suction,
corrosion products,
Cu and possibly other
elements

Stage 3. Analysis of factors
affecting damage

Stage 4. Factors
affecting damage

Stage 5. Primary
reason for damage

9.26 Analysis of causes of damage by the method of retrospective
network modelling.