In-Service Inspection of Nuclear Power Plants - gnssn - International ...

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Please see http://www-ns.iaea.org/standards/
According to the written procedure or a detailed specification, the component/
system or part of it should be prepared as follows:
— configuration of the tested component/system section;
— preparation of the pressurizing or evacuating equipment;
— preparation of the calibrated testing equipment;
— accident precautions;
— in the case of a liquid pressure test, correct venting of components/systems.
The specified pressure retention time depends on the component/system,
temperature, test sensitivity, leak rate, etc. If component/system insulation is not
removed, a longer pressure retention time should be applied. In the case of leakages
during pressure tests, make-up by pumping may be used to hold specified test
pressure.
5.4.5. Evaluation of results
— Leak testing: In the case of leakage the leak rate, pressure drop, etc., must not
exceed the specified values, otherwise the acceptance standard is exceeded. If
inside leakages (e.g. from valve seats) are allowed and can be deducted from
the total leakage, they have to be carefully located and quantified.
— Pressure testing: In the case of unspecified leakages or different alterations
(e.g. deformations, damage) the acceptance standard is exceeded.
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