GTG incident on 2020-12-05 — MI

Operator
Consumers Energy Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$208,000
Incident datetime
2020-12-05 07:23
Report number
Location
MI
Narrative
On december 5, 2020 at approximately 07:20 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 - dehydration system building). The consumers energy st. Clair compressor station is located in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant firegate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, scorch marks were discovered on insulation on the reboiler vent stack. The plant safety system identified a high heat signature on the thermal oxidizer which initiated the firegate activation. The equipment was taken off-line and physically inspected. Several cracked welds were identified on the exhaust line of the thermal oxidizer. The incident was reported to michigan public service commission on december 5, 2020 because the emergency shut-down system was activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $50,000. Once this was discovered, on december 10, 2020 a notification was made to the national response center. Additional investigation subsequent to the event has identified a concern relative to design/actual unit operating temperature, material temperature limits of the exhaust system components, and excessive thermal cycling caused by system programming. Further problem solving is required to determine the root cause of the failure. However with the concerns defined, consumers energy has taken action to remediate each concern through a decrease in the operating temperature of the system and a reduction in thermal cycling of the equipment. All damaged materials have been replaced and welds have been improved in the restoration process. Further analysis confirmed the system design and material supply of the thermal oxidizer superheater to the exhaust stack inadequately accounted for the stress levels present on the system due to the operating temperature range of the system. In addition to the initial remedial actions taken, the equipment was analyzed to determine fatigue and stress. The evaluation resulted in equipment design modifications to (1) reduce the stress present in the system and (2) provide access for inspections and repairs. Additionally, thermal cycles will be monitored and inspected at a predetermined cycle count to confirm system integrity.
Detailed record list
Report Received Date
2021-01-04 00:00:00
Iyear
2020
Report Number
20210002
Supplemental Number
35515
Report Type
Supplemental Final
Operator Id
Name
Consumers Energy Co
Operator Street Address
One Energy Plaza
Operator City Name
Jackson
Operator State Abbreviation
MI
Operator Postal Code
49201
Local Datetime
2020-12-05 07:20:00
Time Zone
Eastern
Daylight Savings Ind
Yes
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2020-12-10 08:40:00
Additional Nrc Report Numbers
1294029
Commodity Released Type
Natural Gas
Unintentional Release
15.5
Intentional Release
0
Accompanying Liquid
0
Fatality Ind
No
Fatal
0
Injury Ind
No
Injure
0
Status When Identified
Normal Operation, Includes Pauses During Maintenance
Shutdown Due Accident Ind
Yes
Shutdown Datetime
2020-12-05 07:24:00
Restart Datetime
2021-01-15 15:00:00
Communication State Fed Ind
No
Ignite Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2020-12-05 07:23:00
On Site Datetime
2020-12-05 07:23:00
On Off Shore
Onshore
Onshore State Abbreviation
Mi
Onshore Postal Code
48023
Onshore City Name
Ira
Onshore County Name
St. Clair
Designated Location
Not Applicable
Pipe Fac Name
St. Clair Compressor Station Plant 4 (Dehydration)
Segment Name
Dehydration System
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Inside A Building
Crossing
No
Pipe Facility Type
Intrastate
System Part Involved
Onshore Compressor Station Equipment And Piping
Item Involved
Dehydrator/drier/treater/scrubber
Installation Year
2018
Manufactured Year
2018
Material Involved
Material Other Than Carbon Steel Or Plastic
Material Details
Stainless Steel
Release Type
Other
Release Type Details
The Plant Safety System Identified A High Heat Signature On The Thermal Oxidizer Which Initiated The Firegate Activation.
Class Location Type
Class 3 Location
Could Be Hca
Yes
Determination Method
Method1
Pir Radius
680
Heat Damage Ind
No
Non Heat Damage Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
51
Est Cost Intentional Release
0
Est Cost Prop Damage
208000
Est Cost Emergency
125
Est Cost Other
0
Gas Cost In Mcf
3.3
Prpty
208176
Num Persons Hosp Not Ovnght
0
Num Injured Treated By Emt
0
Num Resident Building Affctd
0
Num Business Building Affctd
0
Wildlife Impact Ind
No
Accident Psig
1060
Gas Flow In Pipe In Mcf
1060
Mop Psig
1440
Mop Cfr Section
192.619(A)(2)
Maop Established Date
1969-10-27 00:00:00
Maop Reversal Flow Ind
Bi-Directional
Accident Pressure
Pressure Did Not Exceed Maop
Pressure Restriction Ind
No
Gas Required Odorized Ind
No
Pipeline Function
Transmission System
Scada In Place Ind
Yes
Scada Operating Ind
Yes
Scada Functional Ind
Yes
Scada Detection Ind
Yes
Scada Conf Ind
Yes
Accident Identifier
Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status
No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details
Control room operator responded as required when alarm was generated.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Failure Of Equipment Body (Except Compressor), Vessel Plate, Or Other Material
Eq Failure Type
Failure Of Equipment Body (Except Compressor), Vessel Plate, Or Other Material
Eq Additional Thermal Ind
Yes
Preparer Name
C******* K***
Preparer Title
Senior Engineering Technical Analyst Ii
Preparer Email
C************@c********.com
Preparer Telephone
989-280-2963
Local Contact Name
C******* K***
Local Contact Email
C************@c********.com
Local Contact Telephone
989-280-2963
Authorizer Name
J**** P****
Authorizer Title
Gas Compliance Manager
Authorizer Telephone
989-791-5749
Authorizer Email
J**********@c********.com
Narrative
On december 5, 2020 at approximately 07:20 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 - dehydration system building). The consumers energy st. Clair compressor station is located in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant firegate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, scorch marks were discovered on insulation on the reboiler vent stack. The plant safety system identified a high heat signature on the thermal oxidizer which initiated the firegate activation. The equipment was taken off-line and physically inspected. Several cracked welds were identified on the exhaust line of the thermal oxidizer. The incident was reported to michigan public service commission on december 5, 2020 because the emergency shut-down system was activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $50,000. Once this was discovered, on december 10, 2020 a notification was made to the national response center. Additional investigation subsequent to the event has identified a concern relative to design/actual unit operating temperature, material temperature limits of the exhaust system components, and excessive thermal cycling caused by system programming. Further problem solving is required to determine the root cause of the failure. However with the concerns defined, consumers energy has taken action to remediate each concern through a decrease in the operating temperature of the system and a reduction in thermal cycling of the equipment. All damaged materials have been replaced and welds have been improved in the restoration process. Further analysis confirmed the system design and material supply of the thermal oxidizer superheater to the exhaust stack inadequately accounted for the stress levels present on the system due to the operating temperature range of the system. In addition to the initial remedial actions taken, the equipment was analyzed to determine fatigue and stress. The evaluation resulted in equipment design modifications to (1) reduce the stress present in the system and (2) provide access for inspections and repairs. Additionally, thermal cycles will be monitored and inspected at a predetermined cycle count to confirm system integrity.
Report Received Date 2021-01-04 00:00:00
Iyear 2020
Report Number 20210002
Supplemental Number 35515
Report Type Supplemental Final
Operator Id 2748 PHMSA Enforcement
Name Consumers Energy Co
Operator Street Address One Energy Plaza
Operator City Name Jackson
Operator State Abbreviation MI
Operator Postal Code 49201
Local Datetime 2020-12-05 07:20:00
Time Zone Eastern
Daylight Savings Ind Yes
Location Latitude 42.71873 Google Maps OpenStreetMap
Location Longitude -82.71592 Google Maps OpenStreetMap
Nrc Rpt Num 1293954 NRC Report How to search
Nrc Rpt Datetime 2020-12-10 08:40:00
Additional Nrc Report Numbers 1294029
Commodity Released Type Natural Gas
Unintentional Release 15.5
Intentional Release 0
Accompanying Liquid 0
Fatality Ind No
Fatal 0
Injury Ind No
Injure 0
Status When Identified Normal Operation, Includes Pauses During Maintenance
Shutdown Due Accident Ind Yes
Shutdown Datetime 2020-12-05 07:24:00
Restart Datetime 2021-01-15 15:00:00
Communication State Fed Ind No
Ignite Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2020-12-05 07:23:00
On Site Datetime 2020-12-05 07:23:00
On Off Shore Onshore
Onshore State Abbreviation Mi
Onshore Postal Code 48023
Onshore City Name Ira
Onshore County Name St. Clair
Designated Location Not Applicable
Pipe Fac Name St. Clair Compressor Station Plant 4 (Dehydration)
Segment Name Dehydration System
Federal No
Location Type Operator-Controlled Property
Incident Area Type Aboveground
Incident Area Subtype Inside A Building
Crossing No
Pipe Facility Type Intrastate
System Part Involved Onshore Compressor Station Equipment And Piping
Item Involved Dehydrator/drier/treater/scrubber
Installation Year 2018
Manufactured Year 2018
Material Involved Material Other Than Carbon Steel Or Plastic
Material Details Stainless Steel
Release Type Other
Release Type Details The Plant Safety System Identified A High Heat Signature On The Thermal Oxidizer Which Initiated The Firegate Activation.
Class Location Type Class 3 Location
Could Be Hca Yes
Determination Method Method1
Pir Radius 680
Heat Damage Ind No
Non Heat Damage Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 51
Est Cost Intentional Release 0
Est Cost Prop Damage 208000
Est Cost Emergency 125
Est Cost Other 0
Gas Cost In Mcf 3.3
Prpty 208176
Num Persons Hosp Not Ovnght 0
Num Injured Treated By Emt 0
Num Resident Building Affctd 0
Num Business Building Affctd 0
Wildlife Impact Ind No
Accident Psig 1060
Gas Flow In Pipe In Mcf 1060
Mop Psig 1440
Mop Cfr Section 192.619(A)(2) View CFR 49 §192
Maop Established Date 1969-10-27 00:00:00
Maop Reversal Flow Ind Bi-Directional
Accident Pressure Pressure Did Not Exceed Maop
Pressure Restriction Ind No
Gas Required Odorized Ind No
Pipeline Function Transmission System
Scada In Place Ind Yes
Scada Operating Ind Yes
Scada Functional Ind Yes
Scada Detection Ind Yes
Scada Conf Ind Yes
Accident Identifier Scada-Based Information (Such As Alarm(S), Alert(S), Event(S), And/or Volume Or Pack Calculations)
Investigation Status No, the operator did not find that an investigation of the controller(s) actions or control room issues was necessary due to: (provide an explanation for why the operator did not investigate)
Investigation Status Details Control room operator responded as required when alarm was generated.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Equipment Failure
Cause Details Failure Of Equipment Body (Except Compressor), Vessel Plate, Or Other Material
Eq Failure Type Failure Of Equipment Body (Except Compressor), Vessel Plate, Or Other Material
Eq Additional Thermal Ind Yes
Preparer Name C******* K***
Preparer Title Senior Engineering Technical Analyst Ii
Preparer Email C************@c********.com
Preparer Telephone 989-280-2963
Local Contact Name C******* K***
Local Contact Email C************@c********.com
Local Contact Telephone 989-280-2963
Authorizer Name J**** P****
Authorizer Title Gas Compliance Manager
Authorizer Telephone 989-791-5749
Authorizer Email J**********@c********.com
Narrative On december 5, 2020 at approximately 07:20 hours consumers energy gas control received an alarm notification which indicated a possible fire at the st. Clair compressor station (plant 4 - dehydration system building). The consumers energy st. Clair compressor station is located in ira, michigan (st. Clair county). A station mechanic at the site was notified and confirmed activation of the plant firegate system occurred due to the fire detection alarm. Following the event, the plant was removed from service and the scene was made safe. Additional personnel were dispatched to the station to determine the potential cause of the activation. During the incident investigation, scorch marks were discovered on insulation on the reboiler vent stack. The plant safety system identified a high heat signature on the thermal oxidizer which initiated the firegate activation. The equipment was taken off-line and physically inspected. Several cracked welds were identified on the exhaust line of the thermal oxidizer. The incident was reported to michigan public service commission on december 5, 2020 because the emergency shut-down system was activated, and gas released. However, a more in-depth visual inspection confirmed additional equipment damage anticipated to exceed PHMSA reporting criteria of $50,000. Once this was discovered, on december 10, 2020 a notification was made to the national response center. Additional investigation subsequent to the event has identified a concern relative to design/actual unit operating temperature, material temperature limits of the exhaust system components, and excessive thermal cycling caused by system programming. Further problem solving is required to determine the root cause of the failure. However with the concerns defined, consumers energy has taken action to remediate each concern through a decrease in the operating temperature of the system and a reduction in thermal cycling of the equipment. All damaged materials have been replaced and welds have been improved in the restoration process. Further analysis confirmed the system design and material supply of the thermal oxidizer superheater to the exhaust stack inadequately accounted for the stress levels present on the system due to the operating temperature range of the system. In addition to the initial remedial actions taken, the equipment was analyzed to determine fatigue and stress. The evaluation resulted in equipment design modifications to (1) reduce the stress present in the system and (2) provide access for inspections and repairs. Additionally, thermal cycles will be monitored and inspected at a predetermined cycle count to confirm system integrity.

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