National requirements on inspection

Section XI of the ASME Boiler and Pressure Code [6.1] is the standard for operation and in-service inspection of nuclear power plant facilities. Examination Category B-N-3 of Section XI, Subsection IWB, provides requirements for the visual examination of core support structures. These requirements refer to the relevant conditions defined in IWB-3520.4 which include loose, missing, cracked, or fractured parts, bolting, or fasteners. 

Examination categories for BWR vessel internals may be found in Table IWB-2500-1, Section XI of the ASME Code [6.1]. Accessible welds in integrally welded core support structures (Item B13.40) must be visually inspected (VT-3). Accessible surfaces of removable core support structures (Item B13.70) and accessible welds must be visually inspected (VT-3). The acceptance standard for the core support structure is provided in IWB 

Welds in CRD housings (Item B14.10) can have a volumetric or surface examination. The acceptance standard for the CRD housing is provided in IWB-3523. 

ASME Code and other programme inspections are valid and effective for verifying component structural integrity. These inspections are performed unless an exemption was authorized by the appropriate regulatory body on a plant specific basis. 

Other internal components not covered by ASME Code Section XI requirements are addressed by various national regulatory requirements and GE Service Information Letters (SILs). 

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