255.931 Confirmatory direct assessment (CDA).

An operator using the confirmatory direct assessment (CDA) method as allowed in section 255.937 of this Part must have a plan that meets the requirements of this section and of sections 255.925 (ECDA) and 255.927 of this Part (ICDA).#

An operator may only use CDA on a covered segment to identify damage resulting from external corrosion or internal corrosion.#

An operator's CDA plan for identifying external corrosion must comply with section 255.925 of this Part with the following exceptions.#

(1)The procedures for indirect examination may allow use of only one indirect examination tool suitable for the application.#

(2)The procedures for direct examination and remediation must provide that:#

(i)all immediate action indications must be excavated for each ECDA region; and#

(ii)at least one high risk indication that meets the criteria of scheduled action must be excavated in each ECDA region.#

An operator's CDA plan for identifying internal corrosion must comply with section 255.927 of this Part except that the plan's procedures for identifying locations for excavation may require excavation of only one high risk location in each ICDA region.#

If an assessment carried out under subdivision (b) or (c) of this section reveals any defect requiring remediation prior to the next scheduled assessment, the operator must schedule the next assessment in accordance with NACE SP 0502 (as described in section 10.3 of this Title), section 6.2 and 6.3. If the defect requires immediate remediation, then the operator must reduce pressure consistent with section 255.933 of this Part until the operator has completed reassessment using one of the assessment techniques allowed in section 255.937 of this Part.#