BS ISO 9978:2020 Radiation protection – Sealed sources – Leakage test methods.
test source
sample used in the performance tests, having the same material and construction as sealed sources of the model for which classification is being established
Note 1 to entry: A test source may be a simulated sealed source, a dummy sealed source or production source. Note 2 to entry: The performance tests are described in ISO 2919.
4 Requirements
The tests described in this document are all designed to test and verify that the sealed source is leaktight. However not all tests are applicable in all circumstances. Correct application and choice of test method and testing media is critically important in designing an effective leak test programme. Factors to be considered include:
— the chemical form of the active material if leak test is by radioactive means;
— the type of test liquid used in immersion tests;
— the number of encapsulations;
— the internal void volume when tests are carried out by volumetric means;
— the temperature of the sealed source;
— the suitability of the test method for the environment in which it is being performed;
— the reason for performing the test (integrity testing of a test source, production leakage tests, routine in service testing);
— the required sensitivity and acceptance criteria.
The test programme for test and production sealed sources should be considered as part of the design process and validated or justified as appropriate to demonstrate its effectiveness and sensitivity. This process may include the analysis of historic data.
The tests described in this document shall be designed, validated and carried out by competent and qualified persons who have demonstrable appropriate training in the applied test methods. For test methods by radioactive means, the persons shall also have appropriate training in radiation protection and measurement.
NOTE 1 Qualification and certification methods for non-destructive testing personnel can be found in
ISO 9712[21.
An evaluation should be made of uncertainty in the case of non-binary test results (e.g. radiation measurements on immersion test samples) and taken account of in sentencing the result.
Guidance for choosing suitable tests are specified in Annex A.
According to the test type and the sealed source type, at least one of each of the tests described in Clauses 5 and should be carried out [see Annex A for the choice of the test(s)].
It should be noted that it is best practice to carry out more than one type of leakage test and also to perform a final wipe as a contamination check.
The tests described in this document do not form an exhaustive list, and other test methods may be I developed. However, in the case where a special test, which is not described in this document, is carried out (see Clause 1), the organisation shall validate that the applied method is at least as effective as the corresponding method(s) given in this document in order to be able to claim compliance with this document.BS ISO 9978 pdf download.