1　General

1.0.1　This code is developed to unify technical requirements for surveying nuclear power stations and their ancillary facilities，improve accuracy of surveying and mapping results and ensure nuclear power stations are constructed in a safe，appropriate，advanced，economical and reliable manner.

1.0.2　This code applies to engineering surveying of land-based stationary commercial nuclear power stations of various reactor types in their planning，design，and construction phases.

1.0.3　For the purpose of this code，root-mean-square error（RMSE）is used for assessing surveying and mapping accuracy，whereas twice the RMSE is used as maximum permissible error.

1.0.4　Surveying instruments and associated devices shall be checked，tested，and calibrated before use.Measuring gauges shall bear calibration certificates and shall be used within their calibration validity periods.Software to be used for surveying shall be tested or validated as required.

1.0.5　The survey data available from previous surveys，when applied，shall be verified for accuracy.The original survey records shall be authentic and correct.

1.0.6　The electronic versions of relevant observation data，digital diagrams and technical documents that are the outcome of various surveying and mapping activities and are valuable to maintain shall be sorted，backed up，and filed by category and shall be maintained permanently along with their hard copies.

1.0.7　The state-of-the-art and proven techniques，processes or equipment shall be employed for various surveying activities，provided that they meet the intended accuracy for the project construction and as required in this code.

1.0.8　In addition to this code，the surveying of nuclear power station shall comply with relevant national standards in force as well.