4.1 Neutron radiation effects are considered in the design of light-water moderated nuclear power reactors. Changes in system operating parameters may be made throughout the service life of the reactor to account for these effects. A surveillance program is used to measure changes in the properties of actual vessel materials due to the irradiation environment. This practice describes the criteria that should be considered in evaluating surveillance program test capsules.
4.2 Prior to the first issue date of this standard, the design of surveillance programs and the testing of surveillance capsules were both covered in a single standard, Practice E 185. Between its provisional adoption in 1961 and its replacement linked to this standard, Practice E 185 was revised many times (1966, 1970, 1973, 1979, 1982, 1993 and 1998). Therefore, capsules from surveillance programs that were designed and implemented under early versions of the standard were often tested after substantial changes to the standard had been adopted. For clarity, the standard practice for surveillance programs has been divided into the new Practice E 185 that covers the design of new surveillance programs and this standard practice that covers the testing and evaluation of surveillance capsules. A future standard is planned which will recommend procedures for modifying and supplementing existing surveillance programs both in terms of design and testing.
4.3 This standard practice is intended to cover testing and evaluation of all light-water moderated reactor pressure vessel surveillance capsules. The practice is applicable to testing of capsules from surveillance programs designed and implemented under all previous versions of Practice E 185.
4.4 The radiation-induced changes in the properties of the vessel are generally monitored by measuring the Charpy transition temperature, the Charpy upper shelf energy and the tensile properties of specimens from the surveillance program capsules. The significance of these radiation-induced changes is described in Practice E 185. The application of this data is the subject of Guide E 900 and other documents listed in Section 2.
4.5 Alternative methods exist for testing surveillance capsule materials. Some supplemental and alternative testing methods are available as indicated in Practice E 636. Direct measurement of the fracture toughness is also feasible using the To Reference Temperature method defined in Test Method E 1921 or J-integral techniques defined in Test Method E 1820. Additionally hardness testing can be used to supplement standard methods as a means of monitoring the radiation response of the materials.
4.6 The methodology to be used in the analysis and interpretation of neutron dosimetry data and the determination of neutron fluence is defined in Practice E 853.
4.7 Guide E 900 describes the bases used to evaluate the radiation-induced changes in Charpy transition temperature for reactor vessel materials and provides a methodology for predicting future values.
View Less