BS ISO 20890-3 pdf free download
BS ISO 20890-3-2020 pdf free download.Guidelines for in-service inspections for primary coolant circuit components of light water reactors Part 3: Hydrostatic testing.
This document gives guidelines for in‑service system pressure tests of the reactor coolant circuit olight water reactors.
This document specifies the test technique, the requirements for measuring equipment and additional devices, the preparation and performance of the test as well as the recording and documentation, for the purpose to ensure the reliability and comparability of tests.
NOTE Data on (test) pressure, (test) temperature, scope of testing, rates of change of pressure and temperature, test schedule and inspection intervals can be obtained from the applicable national nuclear codes.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8596, Ophthalmic optics — Visual acuity testing — Standard and clinical optotypes and their presentation
ISO 18490, Non-destructive testing — Evaluation of vision acuity of NDT personnel
EN 837‑2, Pressure gauges — Part 2: Selection and installation recommendations for pressure gauges
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1 test medium
<pressure testing> reactor coolant or deionate
3.2 test temperature
temperature to which the pressure‑retaining boundaries of the reactor coolant system and the test medium (3.1) are to be heated
3.3 test pressure
overpressure to which the reactor coolant system is exposed during the test
3.4 maximum operating pressure
design pressure
overpressure for which the reactor coolant system is designed with regard to safety, operational and constructional requirements
4 Test system
4.1 General The system pressure test provides a global statement of integrity regarding the reactor coolant system and, as a safety measure for monitoring the consequences of alleged operationally induced damage mechanisms, is a part of the concept for assuring component integrity during operation. A general test procedure shall be prepared. Annex A contains the items of the general test procedure.
4.2 Standard system The system pressure test is an integral test covering pressure retaining components of the reactor coolant system. After filling the reactor coolant system with the test medium, the system is pressurised in accordance with a pressure temperature schedule to the test pressure, which shall be applied continuously during a defined holding time. The pressure is then reduced to the operating pressure and a visual (inspection) examination of the pressure
retaining components is performed for leakages. When planning and performing the visual (inspection) examination, aspects of minimising the radiation exposure shall be considered. 5 Requirements
5.1 Personnel requirements The test personnel shall have the skills to perform the work they are to carry out. In particular, they shall possess adequate experience in performing and evaluating system pressure tests on pressurised containers and piping and relevant knowledge about the reactor coolant system and about operationally induced damage. Those personnel, using qualified procedures and equipment, should be qualified through one or any combination of the following:
— certification through a national personnel certification scheme;
— theoretical and/or open trials
— assessment based on the procedure set by testing organization Any personnel certification requirements invoking relevant national personnel certification schemes should be validated according to Table 1. Any additional personnel training requirements should also be specified in the qualification dossier. If no relevant scheme exists or if extra personnel qualification is needed, the qualification body should determine the additional practical and theoretical examinations needed beyond those in the national certification scheme, include these in the qualification procedure and ensure that the test procedure also includes the necessary requirements. The qualification procedure should describe the proposed system.BS ISO 20890-3 pdf download.
