Surveillance Tests on Structural

The need for a material surveillance testing program to monitor changes in the properties of ferritic materials in the reactor vessel beltline region has been recognized since the beginning of the commercial nuclear power industry. In 1961, the American Society for Testing and Materials provisionally introduced ASTM E 185, Surveillance Tests on Structural... 

ASTM E 185-61T (1961), Tentative Recommended Practice for Surveillance Tests on Structural Materials in Nuclear Reactors , American Society for Testing and Materials. 

In 1959, an American Society for Testing and Materials task group made recommendations on test procedures for evaluating radiation effects on materials, which led to recommended practices for surveillance tests on structural materials in nuclear reactors. As part of their safety analysis review, the AEG ensured that each plant conducted a reactor vessel irradiation surveillance program per American Society for Testing and Materials standards to evaluate the shift in RTnot over the plant life, especially in the beltline region opposite the core midplane where the reactor vessel sees the largest neutron flux. 

In Japan, the Japan Electric Association Code, JEAC 4201, Method of Surveillance Tests for Structural Materials of Nuclear Reactors (JEAC 4201, 2007), specifies the design for a surveillance program to monitor radiation-induced changes in mechanical properties of beltline materials in light-water moderated nuclear power reactor vessels testing and evaluation of the test results. The JEAC 4201 was developed based on the ASTM E 185 for nuclear power RPVs for which the predicted maximum neutron fluence at the end of the operating period (usually 32 EFPY unless otherwise identified) exceeds 1 x 10 n/cm" E > IMeV) at the inside surface of the reactor vessels. 

This restart criteria requires demonstration that structural integrity of the CWS is maintained under normal and abnormal load conditions using applicable codes, standards and analysis methods, including those specified in the seismic section of the SER. Components which are part of the CWS shall be subject to (1) periodic inspection and testing of areas important to safety to assess their leak tight integrity, and (-2) periodic evaluation based on surveillance of the condition of the material. 

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