Compliance verification activity type: Field Inspection
Team:
Regulated company: Westcoast Energy Inc., carrying on business as Spectra Energy Transmission
Operating company: Westcoast Energy Inc., carrying on business as Spectra Energy Transmission
Province(s) / Territory(s):
Discipline(s):
Related events:
Rationale and scope:
To verify the methodology of the company in evaluating the performance of the EMAT ILI conducted in November 2018 on Segment 8BL2 related to INC2018-142. The information is important to the evaluation of Westcoast's upcoming Engineering Assessments for the NPS 36 Line 2 return to licensed MOP.
Compliance tool(s) used:
Facilities:
Facility Types
Regulatory requirements that apply to this activity:
Additional Project-specific requirements or conditions:
Observation 1 - Dig Site 8BL2- KP 15.312- GW 13390
Date & time of visit: 2019-03-13 11:30
Discipline: Integrity Management
Categories:
Facility:
Observations:
- NEB staff received Westcoast's safety orientation at the dig site.- The tailgate meeting, contractor safety orientation and the hot work permit were conducted and all forms reviewed (Field Level Hazard Assessment) and signed off.- All personnel and NEB Staff were provided with gas monitors.- The medical assistance and the Emergency Response Procedure were presented on site.- Proper signage to identify work on the pipeline was in place.- The Non-Destructive Examination (NDE) third party contractor on-site was Acuren. The technicians were CGSB Level II certified. The NDE equipment calibration was confirmed to be valid and current.- Westcoast staff confirmed with Gas Control that the safe working pressure was set at the excavation site. Westcoast confirmed that the safe excavation pressure implemented was the equivalent of 80% of the 60-day high pressure recorded prior to the date of the incident (i.e.: INC2018-142, occurring on 9 October, 2018). The NEB inspectors noted that this pressure was not in accordance with the safe excavation pressure indicated in the dig list spreadsheet provided by Westcoast in advance of the inspection (i.e. document 2019 8BL2 EMAT Dig List Issued Jan 25.2019.xlsx which requires pressure reduction to "80% of the pressure experienced at this location within the last 60 days" which is similar to the safe excavation pressure mentioned in Standard Operating Practice (SOP) - Ref No. 16.3 of 08/06/2011, also provided in advance. Westcoast representatives confirmed that a waiver to the SOP was approved by the Westcoast Integrity team. An electronic version of the waiver was presented to the NEB inspectors upon request. It was confirmed that the waiver is applied to all compressor discharge / excavation sites where the NPS 36 Line 2 pipeline is still operated at the Restricted Operating Pressure under NEB Inspection Officer Order NB-001-2018 (Amendment No. 3). The pressure measured at the discharge of Compressor Station 8B located 15.3 km upstream (U/S) of the excavation site was 615 psi (4240 kPa) - lower than the calculated safe excavation pressure of 623 psi (4295 kPa). The process for calculating the safe excavation pressure was presented to the NEB inspectors. Accounting for the pressure gradient between the U/S compressor station and the worksite, Westcoast estimated the at-site pressure to be 577 psi (3978 kPa). Westcoast also confirmed that the safe excavation pressure allowed for safely removing cracks up to 30% of the pipe wall thickness (WT) through buffing (grinding).- The excavation site was in good condition with proper ingress/egress points.- Westcoast staff confirmed that the targeted location for this anomaly (i.e. EMAT-reported crack field, 341 mm x 89 mm, 38% WT) was verified using the EMAT in-line inspection (ILI) reported GPS coordinates, exposing the U/S girth weld and measuring the distance to the anomaly, as well as confirming the orientation of the longitudinal weld on the excavated joint.- The pipe was exposed for approximately 5 m (which was not the full joint girth weld to girth weld) at the NEB inspectors arrival, with the Polyken tape coating removed, and pipe surface sandblasted. NEB inspectors noted that the exposed pipe surface was magnetic particle inspected (MPI) along its full circumference for approximately 4.8 m with all field-identified anomalies marked on the pipe, including the EMAT-reported crack-field feature. Inspectors also noted the presence of an additional fiber-type coating covering the Polyken tape coating. An area of 200 mm x 80 mm representing the EMAT tool tolerance box was also marked on the pipe around the EMAT-reported crack-field anomaly at approximately the 5 o'clock orientation. The minimum depth of cover (DoC) was confirmed to be 1.45 m.- The pipe was covered by sandy soil and sitting on river bed soil. Two minor potential corrosion and 13 SCC anomalies, including the single EMAT-reported crack-field feature, were identified and marked following MPI. Six scabs (i.e.: slivers) were also marked on the pipe. The remaining crack anomalies will be assessed and dimensions will be confirmed in the final NDE report.- Westcoast staff also said that feedback will be provided to the ILI vendor relating to all anomalies identified through NDE activities.- Westcoast also confirmed that in the case where false negatives are detected, they would contact the Westcoast Integrity team in order to determine next steps (e.g.: extend the excavation for further in-field verification on the joint).- The shear wave ultrasonic inspection (UT) was only performed on the U/S girth weld in the area of two field-identified crack anomalies.- Acuren confirmed they had measured and recorded the pH (5.5) and cathodic protection level in the vicinity of the pipeline. Soil characteristics were also recorded; however, joint geometry was not measured by Acuren.- NEB inspectors observed buffing activities on the pipe. Acuren explained that prior to buffing, straight probe UT examinations are conducted to confirm the absence of sub-surface anomalies which could impact the safe removal of the defect. NEB inspectors noticed the absence of firefighting equipment in the ditch, or references to ignition hazards in any of the site hazard assessments in spite of the generation of sparks being a potential source of ignition. The concern of a potential fire hazard during buffing activities was raised with Westcoast personnel. NEB inspectors also asked Westcoast why “N/A” was entered under Fire Watch Personnel in the Safe Work Permit. Westcoast explained that they consider the need for a fire watch whenever forest fire activity is present in the vicinity of the work area; therefore, due to the lack of fire activity at the time, a fire watch was not required. Westcoast also indicated that fire extinguishers were available in all onsite company vehicles. Westcoast responded by placing a fire extinguisher in the ditch in proximity to the Acuren technicians.- NEB inspectors observed Acuren technicians conducting crack buffing activities in increments of 0.2 mm and recording wall thickness measurements using a straight probe UT technique. By the time NEB inspectors were preparing to leave the site, it appeared that the crack targeted for assessment was almost entirely removed by buffing below the 30% WT criterion required by Westcoast. Westcoast personnel confirmed that following crack removal by buffing, a metal loss assessment (i.e. RSTRENG calculations) of the area will be performed followed by the selection of an appropriate repair method. It was also confirmed that in the event crack depths extends beyond the 30% WT limit, an engineering calculation would be performed for further decisions on mitigation, along with new safe working pressure calculations.
Compliance tool used: Information Request (IR)
Regulatory requirement:
Relevant section(s):
Company action required:
Provide a copy of the waiver for the Standard Operating Practice - Reference No.: 16.3, Revision date: 2011-06-08 which was applied at this excavation site. Provide the following information:1. Explain the conditions under which a waiver to the safe excavation pressure specified in Standard Operating Practice 16.3 (SOP) is required.2. Any internal documentation, procedure, etc. allowing the issuance of a waiver for deviations from the safe excavation and inspection pressure calculation methods defined in SOP 16.3.3. All three detailed calculation options as defined in SOP 16.3 for the safe pressure during excavation and inspection required at dig site 8BL2-KP 15.312- GW 13390, including rationale for the pressure selected.4. Explain why EMAT tool tolerances were not applied in safe pressure calculations for excavation and inspection in addition to the SCC anomaly growth values, since the “Safety Issues" on page 4 of 18 in SOP 16.3 notes that measurements by current ILI technologies shall not be relied on to provide an accurate assessment of maximum depth/length but should be considered when calculating minimum depths/lengths. 1. Confirm whether the Standard Operating Practice (SOP) provided - i.e. Reference No.: 16.3, Revision date: 2011-06-08 which references CSA Z662-07 and CSA Z662-11, is still in accordance with the current edition of CSA Z662-15.2. Confirm when the SOP will be updated to reference the current CSA Z662-15 edition. Explain whether any hazards due to fires have been identified by Enbridge at excavation site 8BL2-KP 15.312-GW 13390 for the activities conducted during the pipe surface inspection and repair. Confirm whether any firefighting equipment (i.e. fire extinguisher) was required to be made available in the ditch during these activities.
Due date: 2019-04-05
Date closed: 2019-04-12 Note: the date closed is the date that the inspector completed their review of the company corrective actions for adequacy and determined that no further actions are required.
Reason closed: Requirement met
Compliance achieved: Yes
Observation 2 - Non-destructive examination (NDE) report - IR
Date & time of visit: 2019-03-13 17:00
- Westcoast committed to provide the final NDE report for this site when it becomes available as requested by the NEB inspectors.
Provide a copy of the final non-destructive examination (NDE) report for dig site 8BL2-KP 15.312- GW 13390.
Due date: 2019-04-15
Observation 3 - Fire hazard identification - CNC
Date & time of visit: 2019-03-13 12:00
NEB inspectors noticed the absence of firefighting equipment in the ditch during buffing activites. The concern of a potential fire hazard was raised with Westcoast personnel. A fire extinguisher then was placed in the ditch in proximity to Acuren technicians.An information request was submitted to Westcoast to explain whether hazard due to fire associated with buffing activites have been identified at the excavation site and to confirm whether firefighting equipment was required in the ditch.Westcoast confirmed that it did not adequately identify fire hazards associated with the use of a grinder. Westcoast also confirmed that it will improve its hazard identification process for hot work activities to ensure that all combustible materials within 11m of the activity are identified. Two fire extigushers will be strategically placed near the excavation access/egress areas during similar activities in the future.The response to the information request confirms that the fire extinguisher was properly placed at the excavation site only after inspectors' observation. The non-compliance was corrected during the inspection.
Compliance tool used: Corrected Non-compliance (CNC)
Identify fire hazards associated with the use of a grinder and assess the need of fire extinguisher at the excavation site.
Due date: 2019-03-13
Observation 4 - Follow-up on response to information request
In the information request dated 20 March 2019, Westcoast was required to explain why EMAT tool tolerances were not applied in safe pressure calculations for excavation and inspection in addition to the SCC anomaly growth values, since the “Safety Issues" on page 4 of 18 in SOP 16.3 notes that measurements by current ILI technologies shall not be relied on to provide an accurate assessment of maximum depth/length but should be considered when calculating minimum depths/lengths. In the response to the information request, Westcoast confirmed that tool tolerances were not applied in the safe pressure calculations for excavation and inspection in addition to considering crack anomaly growth. Westcoast explained that data on newer generation tools demonstrate that field findings are generally smaller than what the EMAT tool is calling. Westcoast would apply the tool tolerance only when the data indicates that this approach is warranted. Westcoast states that the third calculation option for safe pressure - i.e. 80% of failure pressure calculation based on tool-reported dimensions is not used as it is much higher than the other two safe pressure calculations outlined in SOP 16.3 Table 2. Westcoast provided the explanation as requested. The response refers to the comparison between field data and EMAT tool calls. However, because the purpose of the excavation involves validating EMAT-reported anomaly dimensions, NEB inspectors consider it prudent to ensure increased safety when determining safe excavation pressures. This may be accomplished in part through the addition of tool tolerances to EMAT-called anomaly dimensions in safe excavation pressure calculations while tool validation investigations are concluded. Further clarification on this topic is therefore required.
1. Provide the 80% of failure pressure calculation (i.e.: Calculation 3), applying EMAT tool tolerances to demonstrate that the safe excavation pressure remains higher (i.e.: inapplicable) in comparison to Calculations 1 and 2 outlined in SOP 16.3 Table 2.2. Confirm if Westcoast will include EMAT tool tolerances in Calculation 3 (i.e. 80% of failure pressure calculation) in future EMAT tool validation excavations.
Due date: 2019-04-23
Date closed: 2019-04-25 Note: the date closed is the date that the inspector completed their review of the company corrective actions for adequacy and determined that no further actions are required.
Observation 5 - Follow-up on IR response of 23 April 2019
On 23 April 2019, Westcoast responded to IR2 of the Inspection Report Observation “Follow-up on response to information request”. The IR2 required Westcoast to confirm if it includes EMAT tool tolerances in the safe pressure Calculation 3 (i.e. 80% of failure calculation) for its future EMAT tool validation excavations.
Westcoast responded that it does not plan to include EMAT tool tolerances in Calculation 3 for its future EMAT tool validation excavations and explained the rationale.
NEB inspectors understand that in its response, Westcoast refers to the selection of crack features for excavation (i.e. for EMAT tool validation purposes), and does not refer to the evaluation of safe excavation pressures. Westcoast explained the criteria for excavation is based on a grown feature’s predicted failure pressure multiplied by a Class Location Safety Factor; therefore, not including EMAT tool tolerances of 1.1 mm to depth and 10% to length (which was explained in the response to IR1 of the same Inspection Report Observation).
In addition, Westcoast confirmed in its response to IR2 that for this excavation, the Safety Factor was determined to be 1.39 based on a Class 1 Location.
According to the dig schedule provided by Westcoast prior the inspection, this excavation site occurred in a Class 2 Location; therefore, the Safety Factor used in the calculation should be 1.67.
1. Confirm whether the 1.67 Safety Factor based on Class 2 Location was used at excavation site 13390. If not, provide the safe pressure calculation using a Safety Factor based on Class 2 Location as per considerations listed hereafter (for the remaining validation digs).2. For each of the remaining EMAT tool validation digs scheduled for 2019 on the T-South Mainline 2 (NPS36), provide the following tabulated calculations demonstrating that Westcoast will choose the safest excavation pressure: a. Predicted failure pressure using EMAT feature dimensions accounting for growth (depth and length) without tool tolerances of 1.1 mm to depth and 10% to length. b. 80% of the predicted failure pressure determined in 2.a. c. Predicted failure pressure using EMAT feature dimensions accounting for growth (depth and length) and tool tolerances of 1.1 mm to depth and 10% to length. d. 80% of the predicted failure pressure determined in 2.c. e. 80% of the highest pressure in the 60 days before the incident (i.e. Calculation 1).
Due date: 2019-05-02
Date closed: 2019-05-03 Note: the date closed is the date that the inspector completed their review of the company corrective actions for adequacy and determined that no further actions are required.
Identified non-compliances to company plans or procedures are non-compliances either to:
- the condition of an authorization document that requires the implementation of that plan or procedure; or
- the relevant section of the regulations that requires implementation of that plan or procedure including those sections that require implementation of plans or procedures as a part of a Program
