RS-17-119, Byron, Units 1 and 2 - Full Action Request Report AR 1284054, Legacy Issues with Main Steam Tunnel Pressurization Calculation, Redacted

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Byron, Units 1 and 2 - Full Action Request Report AR 1284054, Legacy Issues with Main Steam Tunnel Pressurization Calculation, Redacted
ML17255A831
Person / Time
Site: Byron  Constellation icon.png
Issue date: 10/31/2011
From:
Exelon Generation Co
To:
Office of Nuclear Reactor Regulation
Shared Package
ML17255A838 List:
References
RS-17-119 AR 1284054
Download: ML17255A831 (6)
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Text

Go Back Print l New Search l Home AR Number: 01284054 Linked ARs Aff Fac: ByronAR Type: CRStatus:COMPLETEAff Unit: 00Owed To: A8852CAPDue Date:04/30/2012Aff System:

--Event Date:10/31/2011 CR Level/Class:

4/DDisc Date:10/31/2011 How Discovered:

H02 Orig Date:10/31/2011 Action Request Details

Subject:

LEGACY ISSUES WITH MAIN STEAM TUNNEL PRESSURIZATION CALCULAT

Description:

Originator:

Supv Contacted: Condition

Description:

The issue documented in this IR was previously identified in IR 789344.Calculation 3C8-0282-001 was found to contain errors and the original IRwas generated. Actions to revise the calculation were tied to IR 653093 for AF tunnel cover design deficiencies. The purpose of this IR is tocreate stand alone actions to improve the calculation. A brief history ofthe issue is included below;During preparation of engineering changes to correct deficiencies with theAF tunnel covers, it was determined that the main steam tunnelpressurization calculation prepared by Sargent & Lundy (calculation 3C8-0282-001) contained errors. At the time, operability was addressed aspart of Operability Evaluation EC 366685 which has since been closed after new AF tunnel covers were installed.The main issue affecting the calculation results was the configuration ofblowout panels in the main steam safety valve rooms. This issue was resolved through modifications (EC 375941 and 375942). Enhancements to thecalculation were added to actions tied to IR 653093. That IR dealt withdeficiencies in the design of the AF tunnel covers that have since been corrected. Actions to address the calculation weaknesses should have been stand alone.

Basis for operabilityCalculation 3C8-0282-001 determines the main steam tunnel pressurizationunder HELB conditions. The main issue with the calculation was that itassumed panels installed over dampers in the safety valve rooms would blowout under the HELB pressure. At the time of the original IR 789344, thepanels were found to be welded in place. Since that time, the panels have been replaced with blowout panels. The other issues identified in IR 789344 dealt with strengthening assumptions in the calculation. It isexpected that these assumptions are valid, but need better documentationto meet todays standards for technical rigor.Immediate actions taken:Research of open corrective actions to try to clarify what is needed toclose them.Page 1of 6 Full Action Request Report 8/31/201 7http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet Recommended Actions:1. Initiate a request for proposal to update calculation 3C8-0282-001.Once the proposal is obtained create a new action to obtain the necessaryfunding.2. Calculation 3C8-0282-001 takes input from main steam mass and energy release provided in EC 373119. It is also recommended to investigateissuance of a new mass and energy release calculation since an ECEvaluation does not replace a design basis calculation.What activities, processes, or procedures were involved?Review of aging CAs to determine actions left to complete them. This one didn't make sense since all of the actions from the original IR had been completed but a CA was still open.Why did the condition happen?Actions from several IRs were combined into one CA. The tie between the original issue and the corrective action was lost.What are the consequences?A aging CA could have been closed sooner.Were any procedural requirements impacted?

NoneWere there any adverse physical conditions?

NoneList of knowledgeable individuals:Repeat or similar condition?None that I am aware of.Operable Basis:

Reportable Basis:Does not meet any Reportability criteria per the Exelon Reportability Manual.SOC Reviewed by: 11/02/2011 09:37:20 CDTSOC Comments:Follow up to shift for operability/reportability. 110111 SOC 110111

  • Send to Design Electrical Engineering for actions. 11/01/11 SOC 110211 Reviewed by: 11/02/2011 01:46:09 CDTReviewer Comments:"The purpose of this IR is to create stand alone actions to improve thecalculation." This is an Admin action. There is no new issue in this IR.Functionality not affected. Shift review for Operability andReportability complete.Department review perf ormed by: 11/04/2011 08:01:32 CDTEvaluation Comments:Actions Completed/Created:The following assignment was created;Page 2of 6 Full Action Request Report 8/31/201 7http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet Initiate requests for proposals to update calculation 3C8-0282-001 and toprovide a revised mass and energy release calculation. Once the proposals are obtained create a new action to obtain the necessary funding.Manager review performed by: 11/07/2011 17:09:28 CSTManager Comments:I agree with the actions. Page 3of 6 Full Action Request Report 8/31/201 7http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet Assign #: 01 AR #: 01284054 Aff Fac: ByronAssign Type:TRKG Status:COMPLETEPriority:Assigned To:Due Date:11/11/2011Schedule Ref:Prim Grp:ACAPALLOrig Due Date:Unit Condition:Sec Grp:

Assignment DetailsSubject/Description:LEGACY ISSUES WITH MAIN STEAM TUNNEL PRESSURIZATION CALCULAT Assignment CompletionIn Progress Notes:Completion Notes:Page 4of 6 Full Action Request Report 8/31/201 7 http://eamgenco.ceco.c om/cap/servlet/ReportFullARServlet Assign #: 02 AR #: 01284054 Aff Fac: ByronAssign Type:ACIT Status:COMPLETE Priority:Assigned To:

Due Date:01/06/2012Schedule Ref:

Prim Grp:A8852NESDMOrig Due Date:12/02/2011Unit Condition:Sec Grp: Assignment DetailsSubject/Description:Initiate requests for proposals to update calculation 3C8 -0282-001 and to provide a revised mass and energy release calculation. Once the proposals are obtaine d create a new action to obtain the necessary fundi ng.

Assignment CompletionIn Progress Notes:

01.06.12 The scope of this ACIT has changed, with the concurrence of Jack Feimster,Design Engineering Manager. The revised scope it to initiate arequisition to revise the main steam tunnel mass and energy calculation.The original scope requested initiation of a request for proposal. Thegoal of a RFP is to then be able to initiate a requisition. Thus, thechange in scope is satisfactory, inconsequential, and expeditious.Requisition 01284479 has been initiated. This task is complete and may beclosed.This calc revision is not yet funded. However, it is being lumped into a mass engineering pot for 2012 resolution of legacy issues. A new ATI willbe cut to A8852NESDM to track approval of funding. This task will be anACIT and will be set far enough in the future to avoid future extensions.It will be task 03 of this AR.Completion Notes:Page 5of 6 Full Action Request Report 8/31/201 7http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet Assign #: 03 AR #: 01284054 Aff Fac: ByronAssign Type:ACIT Status:COMPLETE Priority:Assigned To:

Due Date:04/30/2012Schedule Ref:

Prim Grp:A8852NESDMOrig Due Date:04/30/2012Unit Condition:Sec Grp: Assignment DetailsSubject/Description:obtain funding for requisition 1284479, calculation 3C8-0282 Assignment CompletionIn Progress Notes:

Contract Requisition 1284479 was canc elled. The main steam tunnelpressurization issue is being addressed as part of the Design Issues Plan.Reference contract 470441-292Completion Notes:see in prog notes Page 6of 6 Full Action Request Report 8/31/201 7http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet

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