GTG incident on 2022-10-01 — NE

Operator
Northern Natural Gas Co
Cause
Equipment Failure
Commodity
Natural Gas
Program
GTG
Damage and Injuries
0 fatalities 0 injuries
Property damage (nominal)
$500
Incident datetime
2022-10-01 20:40
Report number
Location
NE
Narrative
At 20:40 on saturday october 01, 2022, northern received a call from the operations communication center (occ) stating that a passerby heard a loud noise from chancellor ethanol tbs. The local technician was sent to the station to investigate. The technician contacted gas control and discovered that no alarms were reporting, and scada was not communicating. Northwestern (the ldc) was onsite and reported that gas was blowing. Northern's technician arrived on scene at approximately 21:15 and found the relief valve reliving stacks half open. The technician checked pressures from the electronic flow measurement (efm) and noticed that no displays were working. He also noticed the efm was not being powered. The technician corrected the relief venting by lowering the set point of the secondary pneumatic valve controller. The primary regulator is controlled with a digital valve controller which is powered with 24 volts. When the power was lost to the digital valve controller, the regulator failed open causing the relief to vent due to the secondary regulator being set slightly higher than the relief. If the relief was set higher than the secondary regulators, the relief may not have opened. On october 3, 2022, further investigation was conducted concerning the power failure to the station. It was discovered that the solar panels were not wired correctly to charge the batteries. The batteries were only getting 19 volts to charge 24-volt batteries. The batteries were fully charged when the station was put into service on september 28, 2022. The batteries slowly depleted from not being charged correctly. Upon further review of the regulator, this model regulator has a low voltage protect function that disconnects all the load once the batteries reach 23 volts. Northern natural gas sets a low voltage alarm at 22 volts. Due to the voltage regulator disconnecting power at 23 volts, no alarms were received, nor could any other monitoring be performed remotely.
Detailed record list
Report Received Date
2022-10-25 00:00:00
Iyear
2022
Report Number
20220112
Supplemental Number
37313
Report Type
Supplemental Final
Operator Id
Name
Northern Natural Gas Co
Operator Street Address
1111 South 103rd Street
Operator City Name
Omaha
Operator State Abbreviation
NE
Operator Postal Code
68124
Local Datetime
2022-10-01 20:40:00
Time Zone
Central
Daylight Savings Ind
Yes
Location Latitude
Location Longitude
Nrc Rpt Num
Nrc Rpt Datetime
2022-10-01 22:25:00
Additional Nrc Report Numbers
1348928
Commodity Released Type
Natural Gas
Unintentional Release
5200
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
No
Shutdown Explain
Able To Maintain Service
Communication State Fed Ind
Yes
Party Initiated Communication
Local/state/federal Emergency Responder
Initial Responder Com Datetime
2022-10-01 21:15:00
Ignite Ind
No
Num Pub Evacuated
0
Incident Identified Datetime
2022-10-01 20:40:00
On Site Datetime
2022-10-01 21:15:00
On Off Shore
Onshore
Onshore State Abbreviation
Sd
Onshore Postal Code
57013
Onshore City Name
Not Within A Municipality
Onshore County Name
Lincoln
Designated Location
Milepost
Designated Name
77.26
Pipe Fac Name
Chancellor Ethanol
Segment Name
78367
Federal
No
Location Type
Operator-Controlled Property
Incident Area Type
Aboveground
Incident Area Subtype
Typical Aboveground Facility Piping Or Appurtenance
Crossing
No
Pipe Facility Type
Interstate
System Part Involved
Onshore Regulator/metering Station Equipment And Piping
Item Involved
Regulator/control Valve
Installation Year
2022
Manufactured Year
2021
Material Involved
Carbon Steel
Release Type
Other
Release Type Details
Battery-Operated Equipment Failed When Power Was Lost.
Class Location Type
Class 1 Location
Could Be Hca
No
Pir Radius
241
Heat Damage Ind
No
Non Heat Damage Ind
No
Did Occur In Mca Ind
No
Est Cost Oper Paid
0
Est Cost Unintentional Release
29120
Est Cost Intentional Release
0
Est Cost Prop Damage
500
Est Cost Emergency
250
Est Cost Other
0
Gas Cost In Mcf
5.6
Prpty
29870
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
448
Gas Flow In Pipe In Mcf
3300
Mop Psig
800
Mop Cfr Section
192.619(A)(2)
Maop Established Date
2022-09-15 00:00:00
Maop Reversal Flow Ind
No
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
No
Scada Functional Ind
No
Scada Detection Ind
No
Scada Conf Ind
No
Accident Identifier
Notification From Public
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
Controllers did not receive any alerts or alarms due to the power loss.
Employee Drug Test Ind
No
Contractor Drug Test Ind
No
Cause
Equipment Failure
Cause Details
Malfunction Of Control/relief Equipment
Eq Failure Type
Malfunction Of Control/relief Equipment
Power Failure Ind
Yes
Additional Installation Ind
Yes
Io Not Installed Properly Ind
Yes
Io Wrong Equipment Ind
Yes
Preparer Name
J*** G******
Preparer Title
Sr Pipeline Safety Specialist
Preparer Email
J***********@n****.com
Preparer Telephone
4026811574
Preparer Fax
4023987313
Local Contact Name
M**** G********
Local Contact Email
M**************@n****.com
Local Contact Telephone
4025303305
Authorizer Name
T** C******
Authorizer Title
Vp Pipeline Safety And Rist
Authorizer Telephone
14023987715
Authorizer Email
T*************@n****.com
Narrative
At 20:40 on saturday october 01, 2022, northern received a call from the operations communication center (occ) stating that a passerby heard a loud noise from chancellor ethanol tbs. The local technician was sent to the station to investigate. The technician contacted gas control and discovered that no alarms were reporting, and scada was not communicating. Northwestern (the ldc) was onsite and reported that gas was blowing. Northern's technician arrived on scene at approximately 21:15 and found the relief valve reliving stacks half open. The technician checked pressures from the electronic flow measurement (efm) and noticed that no displays were working. He also noticed the efm was not being powered. The technician corrected the relief venting by lowering the set point of the secondary pneumatic valve controller. The primary regulator is controlled with a digital valve controller which is powered with 24 volts. When the power was lost to the digital valve controller, the regulator failed open causing the relief to vent due to the secondary regulator being set slightly higher than the relief. If the relief was set higher than the secondary regulators, the relief may not have opened. On october 3, 2022, further investigation was conducted concerning the power failure to the station. It was discovered that the solar panels were not wired correctly to charge the batteries. The batteries were only getting 19 volts to charge 24-volt batteries. The batteries were fully charged when the station was put into service on september 28, 2022. The batteries slowly depleted from not being charged correctly. Upon further review of the regulator, this model regulator has a low voltage protect function that disconnects all the load once the batteries reach 23 volts. Northern natural gas sets a low voltage alarm at 22 volts. Due to the voltage regulator disconnecting power at 23 volts, no alarms were received, nor could any other monitoring be performed remotely.
Report Received Date 2022-10-25 00:00:00
Iyear 2022
Report Number 20220112
Supplemental Number 37313
Report Type Supplemental Final
Operator Id 13750 PHMSA Enforcement
Name Northern Natural Gas Co
Operator Street Address 1111 South 103rd Street
Operator City Name Omaha
Operator State Abbreviation NE
Operator Postal Code 68124
Local Datetime 2022-10-01 20:40:00
Time Zone Central
Daylight Savings Ind Yes
Location Latitude 43.373715 Google Maps OpenStreetMap
Location Longitude -96.710057 Google Maps OpenStreetMap
Nrc Rpt Num 1348816 NRC Report How to search
Nrc Rpt Datetime 2022-10-01 22:25:00
Additional Nrc Report Numbers 1348928
Commodity Released Type Natural Gas
Unintentional Release 5200
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 No
Shutdown Explain Able To Maintain Service
Communication State Fed Ind Yes
Party Initiated Communication Local/state/federal Emergency Responder
Initial Responder Com Datetime 2022-10-01 21:15:00
Ignite Ind No
Num Pub Evacuated 0
Incident Identified Datetime 2022-10-01 20:40:00
On Site Datetime 2022-10-01 21:15:00
On Off Shore Onshore
Onshore State Abbreviation Sd
Onshore Postal Code 57013
Onshore City Name Not Within A Municipality
Onshore County Name Lincoln
Designated Location Milepost
Designated Name 77.26
Pipe Fac Name Chancellor Ethanol
Segment Name 78367
Federal No
Location Type Operator-Controlled Property
Incident Area Type Aboveground
Incident Area Subtype Typical Aboveground Facility Piping Or Appurtenance
Crossing No
Pipe Facility Type Interstate
System Part Involved Onshore Regulator/metering Station Equipment And Piping
Item Involved Regulator/control Valve
Installation Year 2022
Manufactured Year 2021
Material Involved Carbon Steel
Release Type Other
Release Type Details Battery-Operated Equipment Failed When Power Was Lost.
Class Location Type Class 1 Location
Could Be Hca No
Pir Radius 241
Heat Damage Ind No
Non Heat Damage Ind No
Did Occur In Mca Ind No
Est Cost Oper Paid 0
Est Cost Unintentional Release 29120
Est Cost Intentional Release 0
Est Cost Prop Damage 500
Est Cost Emergency 250
Est Cost Other 0
Gas Cost In Mcf 5.6
Prpty 29870
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 448
Gas Flow In Pipe In Mcf 3300
Mop Psig 800
Mop Cfr Section 192.619(A)(2) View CFR 49 §192
Maop Established Date 2022-09-15 00:00:00
Maop Reversal Flow Ind No
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 No
Scada Functional Ind No
Scada Detection Ind No
Scada Conf Ind No
Accident Identifier Notification From Public
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 Controllers did not receive any alerts or alarms due to the power loss.
Employee Drug Test Ind No
Contractor Drug Test Ind No
Cause Equipment Failure
Cause Details Malfunction Of Control/relief Equipment
Eq Failure Type Malfunction Of Control/relief Equipment
Power Failure Ind Yes
Additional Installation Ind Yes
Io Not Installed Properly Ind Yes
Io Wrong Equipment Ind Yes
Preparer Name J*** G******
Preparer Title Sr Pipeline Safety Specialist
Preparer Email J***********@n****.com
Preparer Telephone 4026811574
Preparer Fax 4023987313
Local Contact Name M**** G********
Local Contact Email M**************@n****.com
Local Contact Telephone 4025303305
Authorizer Name T** C******
Authorizer Title Vp Pipeline Safety And Rist
Authorizer Telephone 14023987715
Authorizer Email T*************@n****.com
Narrative At 20:40 on saturday october 01, 2022, northern received a call from the operations communication center (occ) stating that a passerby heard a loud noise from chancellor ethanol tbs. The local technician was sent to the station to investigate. The technician contacted gas control and discovered that no alarms were reporting, and scada was not communicating. Northwestern (the ldc) was onsite and reported that gas was blowing. Northern's technician arrived on scene at approximately 21:15 and found the relief valve reliving stacks half open. The technician checked pressures from the electronic flow measurement (efm) and noticed that no displays were working. He also noticed the efm was not being powered. The technician corrected the relief venting by lowering the set point of the secondary pneumatic valve controller. The primary regulator is controlled with a digital valve controller which is powered with 24 volts. When the power was lost to the digital valve controller, the regulator failed open causing the relief to vent due to the secondary regulator being set slightly higher than the relief. If the relief was set higher than the secondary regulators, the relief may not have opened. On october 3, 2022, further investigation was conducted concerning the power failure to the station. It was discovered that the solar panels were not wired correctly to charge the batteries. The batteries were only getting 19 volts to charge 24-volt batteries. The batteries were fully charged when the station was put into service on september 28, 2022. The batteries slowly depleted from not being charged correctly. Upon further review of the regulator, this model regulator has a low voltage protect function that disconnects all the load once the batteries reach 23 volts. Northern natural gas sets a low voltage alarm at 22 volts. Due to the voltage regulator disconnecting power at 23 volts, no alarms were received, nor could any other monitoring be performed remotely.

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