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| {{#Wiki_filter:Chemistry Lab Pre-action System Clogging Wes Keller September 12, 2011 Background*Chemistry LabDrop CeilingLab Below Ceiling Cables Over Ceiling (Crowded) | | {{#Wiki_filter:Chemistry Lab Pre-action System Clogging Wes Keller September 12, 2011 |
| Ionization Smoke Detection Above Ceiling Pre-action Spray System (Tray Dedicated)
| |
| Pressurized with Air (Standby) 18 Month Surveillance for Flow TestingTested through a single, very accessible nozzleNo specification as to which nozzle(s) to flow test through35 Branch Lines283 Spray Nozzles (250º F Nozzles)
| |
| BackgroundAfter Test CompletionThe nozzle is reinstalledSystem is re-pressurized with compressed air. This causes an oxygen-dense environment. The piping in the Overlab System is galvanized, but the high-oxygen atmosphere combined with trapped water is a potentially corrosive environment.
| |
| System LayoutFP Water from Deluge ValveBL 19BL 17BL 15BL 13BL 11BL 9BL 7BL 5BL 3BL 2BL 1BL 4BL 16BL 14BL 18BL 20BL 22BL 6BL 8BL 10BL 12BL 29BL 31BL 33BL 30BL 32BL 34BL 24BL 26BL 28BL 21BL 23BL 25BL 27BL 35 Main Header Issue DescriptionOn October 1 st, 2010 at approximately 00:55 Preaction Spray System Function Test in the Chemistry Overlab A Mud like substance blocked all flow through the 1/2" ball valve attached to the hose that routes water to the floor drain during the testSystem was declared inoperable and associated time clocks and compensatory measures were established. A comprehensive investigation was performed for above the lab area and all 35 Branch Lines (BLs) were flushed. BLs 2 and 5 were found to have blockage. A mud like substance was found in BL 2 and a rag was found in BL 5. As an extent of condition Unit 1 and Unit 2 Cable Spreading Rooms and Unit 1 and Unit 2 D/G Corridors were immediately tested in accordance with procedure since they have similar pre-action spray system. No similar issues were found.Equipment Apparent Cause Evaluation (EACE) Performed Issue Description Issue Description Issue Description Sample of Mud-Like SubstanceA sample of the sediment was collected and sent to Powerlabs in Wilmington, IL for elemental
| |
|
| |
|
| analysis. Powerlabs stated that elemental analysis can be used to determine if the sediment is internal to the
| | === |
| | Background=== |
| | * Chemistry Lab |
| | * Drop Ceiling |
| | * Lab Below Ceiling |
| | * Cables Over Ceiling (Crowded) |
| | * Ionization Smoke Detection Above Ceiling |
| | * Pre-action Spray System (Tray Dedicated) |
| | * Pressurized with Air (Standby) |
| | * 18 Month Surveillance for Flow Testing |
| | Tested through a single, very accessible nozzle |
| | No specification as to which nozzle(s) to flow test through |
| | 35 Branch Lines |
| | 283 Spray Nozzles (250º F Nozzles) |
|
| |
|
| piping system (corrosion) or external to the piping | | === |
| | Background=== |
| | * After Test Completion |
| | * The nozzle is reinstalled |
| | * System is re-pressurized with compressed air. This causes an oxygen-dense environment. |
| | * The piping in the Overlab System is galvanized, but the high-oxygen atmosphere combined with trapped water is a potentially corrosive environment. |
|
| |
|
| system (sediment/silt/soil).
| | System Layout FP Water from Deluge Valve BL 13 BL 9 BL 5 BL 3 BL 1 BL 15 BL 11 BL 7 BL 35 BL 33 BL 31 BL 29 BL 27 BL 25 BL 23 BL 21 BL 17 BL 19 Main Header BL 4 BL 2 BL 20 BL 10 BL 8 BL 6 BL 22 BL 18 BL 12 BL 16 BL 14 BL 34 BL 32 BL 30 BL 28 BL 26 BL 24 |
| Substance FoundNearly a 50/50 split of Zinc Oxide and Iron Oxide Sample of Mud-Like Substance Immediate Corrective ActionsProcedural & PM ChangesEngineering: Provide necessary guidance for system flush plan on a periodic basis to operations department
| |
|
| |
|
| to revise the procedureProvided a method of performing an entire system flush IAW NFPA 13A Section 5-4.2Method includes flushing the most remote locations in each of the 35 Branch Lines on a periodicity that essentially flushes the entire systemOperations: Revise the procedure as appropriate following guidance given from EngineeringRevision in progress. It is to be implemented prior to the next performance Future ActionsSystem ModificationsLow Point DrainsPressurize the Overlab System with Nitrogen instead of airCompressed air causes a higher Oxygen content to exist in the pipe, leading to accelerated corrosion in the presence of raw waterGuidance from Nexus Engineering suggests that going to Nitrogen will eliminate the need for low point drains and potentially eliminate the need for extensive flushing as prescribed by the EACE Corrective Actions Overlab Flushing Questions?}} | | Issue Description |
| | * On October 1st, 2010 at approximately 00:55 |
| | * Preaction Spray System Function Test in the Chemistry Overlab |
| | * A Mud like substance blocked all flow through the 1/2 ball valve attached to the hose that routes water to the floor drain during the test |
| | * System was declared inoperable and associated time clocks and compensatory measures were established. A comprehensive investigation was performed for above the lab area and all 35 Branch Lines (BLs) were flushed. |
| | * BLs 2 and 5 were found to have blockage. A mud like substance was found in BL 2 and a rag was found in BL 5. |
| | * As an extent of condition Unit 1 and Unit 2 Cable Spreading Rooms and Unit 1 and Unit 2 D/G Corridors were immediately tested in accordance with procedure since they have similar pre-action spray system. No similar issues were found. |
| | * Equipment Apparent Cause Evaluation (EACE) Performed |
| | |
| | Issue Description Issue Description Issue Description Sample of Mud-Like Substance |
| | * A sample of the sediment was collected and sent to Powerlabs in Wilmington, IL for elemental analysis. |
| | * Powerlabs stated that elemental analysis can be used to determine if the sediment is internal to the piping system (corrosion) or external to the piping system (sediment/silt/soil). |
| | |
| | Sample of Mud-Like Substance |
| | * Substance Found |
| | * Nearly a 50/50 split of Zinc Oxide and Iron Oxide |
| | |
| | Immediate Corrective Actions |
| | * Procedural & PM Changes |
| | * Engineering: Provide necessary guidance for system flush plan on a periodic basis to operations department to revise the procedure |
| | * Provided a method of performing an entire system flush IAW NFPA 13A Section 5-4.2 |
| | * Method includes flushing the most remote locations in each of the 35 Branch Lines on a periodicity that essentially flushes the entire system |
| | * Operations: Revise the procedure as appropriate following guidance given from Engineering |
| | * Revision in progress. It is to be implemented prior to the next performance |
| | |
| | Future Actions |
| | * System Modifications |
| | * Low Point Drains |
| | * Pressurize the Overlab System with Nitrogen instead of air |
| | * Compressed air causes a higher Oxygen content to exist in the pipe, leading to accelerated corrosion in the presence of raw water |
| | * Guidance from Nexus Engineering suggests that going to Nitrogen will eliminate the need for low point drains and potentially eliminate the need for extensive flushing as prescribed by the EACE Corrective Actions |
| | |
| | Overlab Flushing Questions?}} |
|
---|
Category:Slides and Viewgraphs
MONTHYEARML24029A1742024-01-30030 January 2024 Constellation Pre-Application January 30, 2024, Meeting Slides - Proposed Alternative to Utilize Code Case N-932, Alternative Requirements for Acceptance of Containment Base Metal Corrosion or Erosion ML23317A0712023-11-14014 November 2023 NRC Pre-Submittal Meeting on November 14th, 2023 - TSTF-591 and Selected 50.69 License Condition Updates (EPID L-2023-LLM-0098) (Slides) ML23255A1042023-08-11011 August 2023 Slides - Constellation - Pre-Application EP 9/18/2023 Draft CEG Presubmittal SG Performance Monitoring Plan Meeting Handout NEI 99-01, Slides - Constellation - Pre-Application EP 2/23/2023 Meeting Slides2023-02-21021 February 2023 Slides - Constellation - Pre-Application EP 2/23/2023 Meeting Slides ML22311A5112022-11-0707 November 2022 Pool Swell License - Amendment Request ML21314A4472021-11-10010 November 2021 Slides for Presubmittial Meeting for Proposed Alternative to Adopt ASME Code Case N-921 to Extend the Inservice Inspection Interval ML21194A1582021-07-13013 July 2021 and Lasalle Nuclear Generating Stations 2020 Annual Assessment Meeting Slides ML21162A3322021-06-11011 June 2021 BWR Fleet Relief Request Associated with RPV Instrument Nozzle Repairs ML21141A0102021-05-21021 May 2021 La Salle County Station, Units 1 and 2, May 27, 2021 Pre Submission Public Meeting Slides (EPID-L-2021-LRM-0052) ML20261G7322020-09-16016 September 2020 Pre-Submittal Slides Extend 120-month Isi/Ist Interval Under 50.55a ML20238B8662020-08-25025 August 2020 Hq Online EOC Slides ML20178A4202020-06-30030 June 2020 NEI Slides for June 30, 2020, Public Meeting on COVID-19 Response ML20170B0212020-06-23023 June 2020 NRC Pre-Submittal Meeting Byron Unit 2 One-Time Deferral of Reactor Pressure Vessel Head Penetration Nozzle (Rpvhpn) Inspections ML20163A6552020-06-16016 June 2020 6-16-20 Byron Unit 2 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections ML20169A5592020-06-16016 June 2020 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections (Rev 1) ML18347B3142018-12-19019 December 2018 Bwrvip/Asme Relief Request Discussion December 19, 2018 ML18334A2162018-11-30030 November 2018 Presentation Slides: Exelon BWR MSIV (Boiling-Water Reactor - Main Steam Isolation Valve) Leakage Optimization for NRC Pre-Submittal Meeting of December 6, 2018 ML18319A1272018-11-19019 November 2018 Slides for 11/19/18 Public Meeting - Exelon Fleet LAR for Common Language for TS 5.7 High Radiation Areas ML18054B3592018-02-27027 February 2018 Slide: NRC Pre-Submittal Meeting for Exelon Fleet LAR to Relocate TS Unit Staff Qualification ANSI Requirements to the QATR, February 27, 2018, Profile Info: Submitted by Frank Mascitelli ML17339A1812017-12-0707 December 2017 NRC Hq Pre-Submittal LaSalle CSCS LAR 12-7-2017 Final ML16194A0062016-07-12012 July 2016 Pre-Application Meeting Presentation Regarding LaSalle County Station License Amendment Request for Revision of Suppression Pool Swell Design Analysis ML16077A1562016-03-22022 March 2016 Fleet: Pre-application Teleconference with Exelon to Discuss a Potential License Amendment Request Regarding Operating Training Standards ML16077A3492016-03-17017 March 2016 NRC Briefing Slides for LaSalle Dseis Public Meeting March 22, 2016 ML15062A3642015-03-0303 March 2015 Environmental Scoping Briefing for March 10th Meetings ML15058A6322015-02-27027 February 2015 LSCS Scoping Briefing Prepared 2-27-15 for March 10th Meeting ML13212A3372013-07-31031 July 2013 NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting NEI 01-01, NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting2013-07-31031 July 2013 NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting ML13211A3782013-07-30030 July 2013 7/31/2013 NRC Public Meeting Presentation on NEI 01-01 NEI 01-01, 7/31/2013 NRC Public Meeting Presentation on NEI 01-012013-07-30030 July 2013 7/31/2013 NRC Public Meeting Presentation on NEI 01-01 ML13164A3792013-06-24024 June 2013 Summary of Public Meeting with Exelon Generation Company, LLC, Regarding the Proposed Extended Power Uprate License Amendment Request for LaSalle County Station, Units 1 and 2 ML12200A3652012-07-27027 July 2012 County Station UHS Pre-Application Mtg 6-28-12 - Final ML12188A5122012-07-0606 July 2012 IEMA HAB Lessons Learned_rev1 ML12159A2662012-06-11011 June 2012 County Generating Station Pre-Application Meeting Extended Power Uprate: Replacement Steam Dryers. June 11, 2012 ML12130A0442012-06-0707 June 2012 Summary of Public Meeting with Exelon Generation Company, LLC, Regarding Proposed Extended Power Uprate License Amendment Request for LaSalle County Station, Units 1 and 2 ML1209306162012-04-0202 April 2012 Enclosure - 04/04/2012 Exelon Nuclear Meeting Presentation LaSalle Count Station Pre-Application Meeting Extended Power Uprate. ML1209006542012-03-30030 March 2012 Slides for April 4 Public Meeting on LaSalle Extended Power Uprate ML1208701402012-03-27027 March 2012 Licensee Slides for Exelon Fleet Pre-Submittal Public Meeting 4-10-12 Licensed Operator Eligibility Requirements LAR ML1208806542012-03-27027 March 2012 Non-Proprietary Slides for LaSalle Prnm Meeting ML1200303212012-01-19019 January 2012 12/7/2011 - Summary of Public Meeting with Exelon Regarding the Proposed Extended Power Uprate License Amendment Request for LaSalle, Units 1 and 2 ML13014A1002011-09-12012 September 2011 Sprinkler Clogging LaSalle Exelon - Presentation During September 2011 NEI Fire Protection Information Forum ML11201A2132011-07-20020 July 2011 Summary of Public Meeting to Discuss Exelon'S Plans for Implementing an Electronic Document Control System (Edocs) for Use by NRC Inspectors with U.S. Nuclear Regulatory Commission (NRC) Region III Staff ML1100502552011-01-17017 January 2011 December 29, 2010, Summary of Public Conference Call with Exelon Generation Company, LLC, Regarding LaSalle Netco Insert Request ML1100503592010-12-29029 December 2010 NRC Meeting Slides for December 29, 2010, Public Conference Call with Exelon Generation Company Regarding LaSalle Netco Insert Request ML1030704842010-11-19019 November 2010 Summary of Public Meeting with Exelon Generation Company, LLC Regarding LaSalle Netco Insert Request ML1030903782010-11-19019 November 2010 Licensee Handouts for LaSalle Meeting with Exelon to Discuss Netco Inserts ML1032601422010-11-10010 November 2010 Handouts for November 10, 2010 Public Conference Call with Exelon Regarding LaSalle Insert Request ML0929400522009-10-22022 October 2009 Meeting Power Uprate Meeting Slides ML0917502262009-07-0707 July 2009 Summary of Pre-Application Meeting with Exelon Generation Company, License Amendment Request for LaSalle and Limerick Measurement Uncertainty Recapture Power Uprates ML0911102662009-04-16016 April 2009 LaSalle Summary Meeting Slides ML0909005022009-04-0909 April 2009 Meeting Summary of Pre-application Meeting with Exelon on License Amendment Request for Automatic Depressurization System for LaSalle 2024-01-30
[Table view] Category:Meeting Briefing Package/Handouts
MONTHYEARML24029A1742024-01-30030 January 2024 Constellation Pre-Application January 30, 2024, Meeting Slides - Proposed Alternative to Utilize Code Case N-932, Alternative Requirements for Acceptance of Containment Base Metal Corrosion or Erosion ML23317A0712023-11-14014 November 2023 NRC Pre-Submittal Meeting on November 14th, 2023 - TSTF-591 and Selected 50.69 License Condition Updates (EPID L-2023-LLM-0098) (Slides) ML23255A1042023-08-11011 August 2023 Slides - Constellation - Pre-Application EP 9/18/2023 Draft CEG Presubmittal SG Performance Monitoring Plan Meeting Handout ML22311A5112022-11-0707 November 2022 Pool Swell License - Amendment Request ML21314A4472021-11-10010 November 2021 Slides for Presubmittial Meeting for Proposed Alternative to Adopt ASME Code Case N-921 to Extend the Inservice Inspection Interval ML21194A1582021-07-13013 July 2021 and Lasalle Nuclear Generating Stations 2020 Annual Assessment Meeting Slides ML21141A0102021-05-21021 May 2021 La Salle County Station, Units 1 and 2, May 27, 2021 Pre Submission Public Meeting Slides (EPID-L-2021-LRM-0052) ML20261G7322020-09-16016 September 2020 Pre-Submittal Slides Extend 120-month Isi/Ist Interval Under 50.55a ML20238B8662020-08-25025 August 2020 Hq Online EOC Slides ML20178A4202020-06-30030 June 2020 NEI Slides for June 30, 2020, Public Meeting on COVID-19 Response ML20170B0212020-06-23023 June 2020 NRC Pre-Submittal Meeting Byron Unit 2 One-Time Deferral of Reactor Pressure Vessel Head Penetration Nozzle (Rpvhpn) Inspections ML20169A5592020-06-16016 June 2020 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections (Rev 1) ML20163A6552020-06-16016 June 2020 6-16-20 Byron Unit 2 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections ML19318F9512019-11-20020 November 2019 Presentation Slides for November 20, 2019, Pre-Application Meeting - Request for Revision to Quality Assurance Program Internal Audit Frequency ML19161A2572019-06-0404 June 2019 BWR Fleet Msv/Srv - Testing Frequency Relief Request NRC Pre-Application Meeting June 4, 2019 ML19151A6602019-05-31031 May 2019 BWR Fleet Mssv/Srv Testing Frequency Relief Request NRC Pre-Application Meeting June 4, 2019 ML19022A2002019-01-23023 January 2019 Request for Use of ASME Code Case N-879 for Exelon Nuclear Power Plants ML18347B3142018-12-19019 December 2018 Bwrvip/Asme Relief Request Discussion December 19, 2018 ML18334A2162018-11-30030 November 2018 Presentation Slides: Exelon BWR MSIV (Boiling-Water Reactor - Main Steam Isolation Valve) Leakage Optimization for NRC Pre-Submittal Meeting of December 6, 2018 ML18319A1272018-11-19019 November 2018 Slides for 11/19/18 Public Meeting - Exelon Fleet LAR for Common Language for TS 5.7 High Radiation Areas ML18054B3592018-02-27027 February 2018 Slide: NRC Pre-Submittal Meeting for Exelon Fleet LAR to Relocate TS Unit Staff Qualification ANSI Requirements to the QATR, February 27, 2018, Profile Info: Submitted by Frank Mascitelli ML17142A2382017-05-25025 May 2017 OEDO-17-00280 - Briefing Package for Drop-In Visit on June 9, 2017, by Senior Management of Exelon Generation Company, LLC with Chairman Svinicki, Commissioner Baran, and Commissioner Burns ML16194A0062016-07-12012 July 2016 Pre-Application Meeting Presentation Regarding LaSalle County Station License Amendment Request for Revision of Suppression Pool Swell Design Analysis ML16077A1562016-03-22022 March 2016 Fleet: Pre-application Teleconference with Exelon to Discuss a Potential License Amendment Request Regarding Operating Training Standards ML16077A3492016-03-17017 March 2016 NRC Briefing Slides for LaSalle Dseis Public Meeting March 22, 2016 ML16075A3292016-03-16016 March 2016 OEDO-16-00165 - Briefing Package for Drop-In Visit on March 23, 2016, by Senior Management of Exelon Generation Company, LLC with the NRC Executive Director for Operations ML15062A3642015-03-0303 March 2015 Environmental Scoping Briefing for March 10th Meetings ML15058A6322015-02-27027 February 2015 LSCS Scoping Briefing Prepared 2-27-15 for March 10th Meeting ML13212A3372013-07-31031 July 2013 NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting NEI 01-01, NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting2013-07-31031 July 2013 NRC NEI-01-01 Meeting Presentation on 7/31/13 Digital I&C Meeting ML13211A3782013-07-30030 July 2013 7/31/2013 NRC Public Meeting Presentation on NEI 01-01 NEI 01-01, 7/31/2013 NRC Public Meeting Presentation on NEI 01-012013-07-30030 July 2013 7/31/2013 NRC Public Meeting Presentation on NEI 01-01 ML13164A3792013-06-24024 June 2013 Summary of Public Meeting with Exelon Generation Company, LLC, Regarding the Proposed Extended Power Uprate License Amendment Request for LaSalle County Station, Units 1 and 2 ML12159A2662012-06-11011 June 2012 County Generating Station Pre-Application Meeting Extended Power Uprate: Replacement Steam Dryers. June 11, 2012 ML12130A0442012-06-0707 June 2012 Summary of Public Meeting with Exelon Generation Company, LLC, Regarding Proposed Extended Power Uprate License Amendment Request for LaSalle County Station, Units 1 and 2 ML1209306162012-04-0202 April 2012 Enclosure - 04/04/2012 Exelon Nuclear Meeting Presentation LaSalle Count Station Pre-Application Meeting Extended Power Uprate. ML1209006542012-03-30030 March 2012 Slides for April 4 Public Meeting on LaSalle Extended Power Uprate ML1208701402012-03-27027 March 2012 Licensee Slides for Exelon Fleet Pre-Submittal Public Meeting 4-10-12 Licensed Operator Eligibility Requirements LAR ML1208806542012-03-27027 March 2012 Non-Proprietary Slides for LaSalle Prnm Meeting ML1200303212012-01-19019 January 2012 12/7/2011 - Summary of Public Meeting with Exelon Regarding the Proposed Extended Power Uprate License Amendment Request for LaSalle, Units 1 and 2 ML13014A1002011-09-12012 September 2011 Sprinkler Clogging LaSalle Exelon - Presentation During September 2011 NEI Fire Protection Information Forum RS-11-096, Intent to Submit License Amendment Request to Install Power Range Neutron Monitor (Prnm) in Accordance with Interim Staff Guidance, Digital I & C-ISG-062011-06-0707 June 2011 Intent to Submit License Amendment Request to Install Power Range Neutron Monitor (Prnm) in Accordance with Interim Staff Guidance, Digital I & C-ISG-06 ML1100502552011-01-17017 January 2011 December 29, 2010, Summary of Public Conference Call with Exelon Generation Company, LLC, Regarding LaSalle Netco Insert Request ML1100503592010-12-29029 December 2010 NRC Meeting Slides for December 29, 2010, Public Conference Call with Exelon Generation Company Regarding LaSalle Netco Insert Request ML1030903782010-11-19019 November 2010 Licensee Handouts for LaSalle Meeting with Exelon to Discuss Netco Inserts ML1030704842010-11-19019 November 2010 Summary of Public Meeting with Exelon Generation Company, LLC Regarding LaSalle Netco Insert Request ML1032601422010-11-10010 November 2010 Handouts for November 10, 2010 Public Conference Call with Exelon Regarding LaSalle Insert Request ML0919803632009-08-20020 August 2009 Summary of Licensing Counterparts Meeting with Exelon Generation Company, to Discuss Licensing Practices and Processes ML0917502262009-07-0707 July 2009 Summary of Pre-Application Meeting with Exelon Generation Company, License Amendment Request for LaSalle and Limerick Measurement Uncertainty Recapture Power Uprates ML0911102662009-04-16016 April 2009 LaSalle Summary Meeting Slides 2024-01-30
[Table view] |
Text
Chemistry Lab Pre-action System Clogging Wes Keller September 12, 2011
=
Background===
- Cables Over Ceiling (Crowded)
- Ionization Smoke Detection Above Ceiling
- Pre-action Spray System (Tray Dedicated)
- Pressurized with Air (Standby)
- 18 Month Surveillance for Flow Testing
Tested through a single, very accessible nozzle
No specification as to which nozzle(s) to flow test through
35 Branch Lines
283 Spray Nozzles (250º F Nozzles)
=
Background===
- The nozzle is reinstalled
- System is re-pressurized with compressed air. This causes an oxygen-dense environment.
- The piping in the Overlab System is galvanized, but the high-oxygen atmosphere combined with trapped water is a potentially corrosive environment.
System Layout FP Water from Deluge Valve BL 13 BL 9 BL 5 BL 3 BL 1 BL 15 BL 11 BL 7 BL 35 BL 33 BL 31 BL 29 BL 27 BL 25 BL 23 BL 21 BL 17 BL 19 Main Header BL 4 BL 2 BL 20 BL 10 BL 8 BL 6 BL 22 BL 18 BL 12 BL 16 BL 14 BL 34 BL 32 BL 30 BL 28 BL 26 BL 24
Issue Description
- On October 1st, 2010 at approximately 00:55
- Preaction Spray System Function Test in the Chemistry Overlab
- A Mud like substance blocked all flow through the 1/2 ball valve attached to the hose that routes water to the floor drain during the test
- System was declared inoperable and associated time clocks and compensatory measures were established. A comprehensive investigation was performed for above the lab area and all 35 Branch Lines (BLs) were flushed.
- BLs 2 and 5 were found to have blockage. A mud like substance was found in BL 2 and a rag was found in BL 5.
- As an extent of condition Unit 1 and Unit 2 Cable Spreading Rooms and Unit 1 and Unit 2 D/G Corridors were immediately tested in accordance with procedure since they have similar pre-action spray system. No similar issues were found.
- Equipment Apparent Cause Evaluation (EACE) Performed
Issue Description Issue Description Issue Description Sample of Mud-Like Substance
- A sample of the sediment was collected and sent to Powerlabs in Wilmington, IL for elemental analysis.
- Powerlabs stated that elemental analysis can be used to determine if the sediment is internal to the piping system (corrosion) or external to the piping system (sediment/silt/soil).
Sample of Mud-Like Substance
- Nearly a 50/50 split of Zinc Oxide and Iron Oxide
Immediate Corrective Actions
- Engineering: Provide necessary guidance for system flush plan on a periodic basis to operations department to revise the procedure
- Provided a method of performing an entire system flush IAW NFPA 13A Section 5-4.2
- Method includes flushing the most remote locations in each of the 35 Branch Lines on a periodicity that essentially flushes the entire system
- Operations: Revise the procedure as appropriate following guidance given from Engineering
- Revision in progress. It is to be implemented prior to the next performance
Future Actions
- Pressurize the Overlab System with Nitrogen instead of air
- Compressed air causes a higher Oxygen content to exist in the pipe, leading to accelerated corrosion in the presence of raw water
- Guidance from Nexus Engineering suggests that going to Nitrogen will eliminate the need for low point drains and potentially eliminate the need for extensive flushing as prescribed by the EACE Corrective Actions
Overlab Flushing Questions?