ISSN:
1573-8205
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Physics
Notes:
Conclusions Thus, we suggested an engineering approach for evaluating the strength of cylindrical vessels containing cracks and for determining the approximate magnitude of the possible depressurization. Fatigue growth of a technological (an already existing) crack or a cracklike defect nucleated during the service period forms the principal mechanism determining the destruction process (damage) of the reactor vessels right up to the stage of loss of tightness. The detrimental effect of the factors such as radiation embrittlement, hydrogenation, or stress corrosion requires additional studies. In the case of the vessels of NHP, realization of the criterion of ‘prefacture flow’ (and not catastrophic fracture) is expected, during crack growth through the reactor wall. Basically, depressurization appears to be highly improbable since growth of an elliptical crack from the initial sizes (0.1S) up to the final sizes (0.8S) is possible only when the number of loading cycles is large (N〉106). If cyclic crack growth occurs through the wall, the magnitude of depressurization of the reactor vessels of NHP is insignificant (M=1·10−5 m2). The large reserve (safety factor) with respect to the number of cycles to realization of the criterion of ‘prefacture flow=rs makes it possible to indicate, in advance, the loss of integrity of the reactor vessel using the available methods of nondestructive control and the small magnitude of depressurization forms a basis for working out the variations of localization of the consequences of the anticipated accident without compulsory use of complex and costly structures such as special (insured) vessels.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01153718
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