ML14160A781: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
 
(3 intermediate revisions by the same user not shown)
Line 3: Line 3:
| issue date = 06/04/2014
| issue date = 06/04/2014
| title = Part 21 - Defect Identified in Single Loop Operation Minimum Critical Power Ratio
| title = Part 21 - Defect Identified in Single Loop Operation Minimum Critical Power Ratio
| author name = Meginnis A B
| author name = Meginnis A
| author affiliation = AREVA, Inc
| author affiliation = AREVA, Inc
| addressee name =  
| addressee name =  
Line 15: Line 15:


=Text=
=Text=
{{#Wiki_filter:0610412014 U.S. Nuclear Reru torv Commission Overations Center Event ReDortPpoo IPart 21 (PAR) Event# 50172Rep Org: AREVA INC Notification Date / Time: 06/04/2014 15:22 (EDT)Supplier:
{{#Wiki_filter:0610412014                   U.S. Nuclear Reru torv Commission Overations Center Event ReDort                      Ppoo I Part 21 (PAR)                                                                                   Event#       50172 Rep Org: AREVA INC                                             Notification Date / Time: 06/04/2014 15:22     (EDT)
AREVA INC Event Date I Time: 06/04/2014 (PDT)Last Modification:
Supplier: AREVA INC                                                   Event Date I Time: 06/04/2014           (PDT)
06/04/2014 Region: 4 Docket #:City: RICHLAND Agreement State: YesCounty: License #:State: WANRC Notified by: ALAN B MEGINNIS Notifications:
Last Modification: 06/04/2014 Region: 4                                                   Docket #:
DEBORAH SEYMOUR R2DOHQ Ops Officer:
City: RICHLAND                                 Agreement State:           Yes County:                                                     License #:
CHARLES TEAL NICK TAYLOR R4DOEmergency Class: NON EMERGENCY PART 21 GROUP EMAIL10 CFR Section:21.21(d)(3)(i)
State: WA NRC Notified by:   ALAN B MEGINNIS                       Notifications: DEBORAH SEYMOUR                   R2DO HQ Ops Officer:   CHARLES TEAL                                           NICK TAYLOR                       R4DO Emergency Class:     NON EMERGENCY                                         PART 21 GROUP                     EMAIL 10 CFR Section:
DEFECTS AND NONCOMPLIANCE PART 21 -DEFECT IDENTIFIED IN SINGLE LOOP OPERATION MINIMUM CRITICAL POWER RATIOThe following is a synopsis of information received via facsimile from AREVA:AREVA identified a defect is in the calculation of the single loop operation (SLO) minimum critical power ratio(MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage ofnon-conservative inputs in the SLO pump seizure analyses for the three plants, which results in non-conservative limits for SLO.Individual informing the Commission:
21.21(d)(3)(i)     DEFECTS AND NONCOMPLIANCE PART 21 - DEFECT IDENTIFIED IN SINGLE LOOP OPERATION MINIMUM CRITICAL POWER RATIO The following is a synopsis of information received via facsimile from AREVA:
Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA 99354.  
AREVA identified a defect is in the calculation of the single loop operation (SLO) minimum critical power ratio (MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage of non-conservative inputs in the SLO pump seizure analyses for the three plants, which results in non-conservative limits for SLO.
-AREVA6/4/2014 3:22:25 PM PAGE1/003 Fax ServerAREVAREVAAREVA Inc.FAXTo: NRC Operations CenterCompany:
Individual informing the Commission:
U.S. NRCDate: 6/4/2014 Time in: 3:22 PMPages to follow: 2From: Alan B. MeginnisTelephone:
Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA 99354.
509-375-8266 MB: 36E] Original to be mailed [ Via fax onlyReceiving fax: 301-816-5151 Telephone:
 
301-816-5100 Extra Distribution to:Sending fax: 434-382-5541 Fax verification:
-AREVA                          6/4/2014 3:22:25 PM         PAGE        1/003       Fax Server AREVA Inc.
509-375-8266 Message:Please see attached defect noticeAREVA Inc.2101 Horn Rapids RoadRichland, WA 99354-5102 Telephone:  
AREV AREVA FAX To: NRC Operations Center                    Date: 6/4/2014                 Time in: 3:22 PM Pages to follow: 2 Company:    U.S. NRC                        From: Alan B. Meginnis Telephone: 509-375-8266           MB: 36 E] Original to be mailed       [ Via fax only Receiving fax: 301-816-5151                   Sending fax: 434-382-5541 Telephone: 301-816-5100                      Fax verification: 509-375-8266 Extra Distribution to:
(509) 375-8100Operator:
Message:
Log No.:Ti me Sent:
Please see attached defect notice AREVA Inc.
AREVA 6/4/2014 3:22:25 PM PAGE 2/003 Fax ServerReportable Defect(i) Name and address of the individual or individuals informing the Commission.
2101 Horn Rapids Road                        Operator:
Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA99354.(ii) Identification of the facility, the activity, or the basic component supplied for such facility orsuch activity within the United States which fails to comply or contains a defect.The defect is in the calculation of the single loop operation (SLO) minimum critical power ratio(MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage of non-conservative inputs in the SLO pump seizure analyses for the threeplants, which resulted in non-conservative limits for SLO.(iii) Identification of the firm constructing the facility or supplying the basic component whichfails to comply or contains a defect.AREVA Inc.(iv) Nature of the defect or failure to comply and the safety hazard which is created or could becreated by such defect or failure to comply.This issue is a defect as defined in 10 CFR 21.3. The calculated MCPR is used to confirm that thecore is operated within the required Operating Limit MCPR (OLMCPR).
Richland, WA 99354-5102 Telephone: (509) 375-8100                    Log No.:                 Ti me Sent:
The OLMCPR isestablished to ensure that the Technical Specification Safety Limit MCPR (SLMCPR) is notviolated during anticipated operational occurrences (AOOs). The defect in the SLO pump seizureanalyses produced a non-conservative prediction of MCPR. If a SLO pump seizure occurred inany of the three Browns Ferry Units, and that reactor was operating on the specified OLMCPR,the technical specification MCPR safety limit could have been violated.
 
Therefore, the issue isconsidered a defect.(v) The date on which the information of such defect or failure to comply was obtained.
AREVA                             6/4/2014       3:22:25 PM           PAGE   2/003       Fax Server Reportable Defect (i) Name and addressof the individualor individuals informing the Commission.
The issue was first documented in the AREVA Inc. Corrective Action Program on April 15, 2014.Page 1 of 2  
Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA99354.
-AREVA6/4/2014 3:22:25 PM PAGE3/003 Fax Server(vi) In the case of a basic component which contains a defect or fails to comply, the number andlocation of these components in use at, supplied for, being supplied for, or may be supplied for,manufactured, or being manufactured for one or more facilities or activities subject to theregulations in this part.The defect exists in the calculation of SLO MCPR for the following reactors:
(ii) Identification of the facility, the activity, or the basic component suppliedfor such facility or such activity within the United States which fails to comply or contains a defect.
Browns Ferry Unit 1Browns Ferry Unit 2Browns Ferry Unit 3(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be takento complete the action.As the responsible organization, AREVA Inc. has provided recommended compensatory actionsto all affected plants. The compensatory actions involve restricting the range of core power,core flow, and margin to thermal limits during single loop operation to compensate for the non-conservative prediction of SLO OLMCPR. The operability analyses used as a basis for thecompensatory operating restrictions will be formally reviewed per AREVA's approved qualityassurance process which complies with the criteria set forth in 10 CFR 50 Appendix B. AREVAInc. will provide TVA the formal operating restrictions on core power, core flow, and margin tothermal limits applicable to Browns Ferry Unit 1 Cycle 10, Browns Ferry Unit 2 Cycle 18 andBrowns Ferry Unit 3 Cycle 17. The schedule for completion of the formal documentation is July31, 2014. Analyses and documentation for future operating cycles for the three units which arelicensed by AREVA Inc. will occur on the normal reload schedules for cycle specific milestones.
The defect is in the calculation of the single loop operation (SLO) minimum critical power ratio (MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage of non-conservative inputs in the SLO pump seizure analyses for the three plants, which resulted in non-conservative limits for SLO.
(viii) Any advice related to the defect or failure to comply about the facility,  
(iii) Identification of the firm constructing thefacility or supplying the basic component which fails to comply or contains a defect.
: activity, or basiccomponent that has been, is being, or will be given to purchasers or licensees.
AREVA Inc.
This defect only had the potential to violate the SLMCPR during SLO. The Browns Ferry plantsnever operated in SLO while they were supported by the supplied limits. Therefore, the plantsnever operated where SLMCPR could have been violated.
(iv) Nature of the defect orfailure to comply and the safety hazardwhich is createdor could be createdby such defect orfailure to comply.
Additionally, the current licensing methodology used by AREVA Inc. is believed to be overly conservative in determining thermalmargins specific to the SLO pump seizure event. AREVA Inc. currently has a new high fidelitytransient methodology under review by the USNRC referred to as AURORA-B.
This issue is a defect as defined in 10 CFR 21.3. The calculated MCPR is used to confirm that the core is operated within the required Operating Limit MCPR (OLMCPR). The OLMCPR is established to ensure that the Technical Specification Safety Limit MCPR (SLMCPR) is not violated during anticipated operational occurrences (AOOs). The defect in the SLO pump seizure analyses produced a non-conservative prediction of MCPR. If a SLO pump seizure occurred in any of the three Browns Ferry Units, and that reactor was operating on the specified OLMCPR, the technical specification MCPR safety limit could have been violated. Therefore, the issue is considered a defect.
Scoping andpreliminary SLO pump seizure analyses with this new method have demonstrated that thermallimits would not have had the potential to be violated if AURORA-B had been used for thelicensing calculation.
(v) The date on which the information of such defect orfailure to comply was obtained.
AURORA-B is not yet approved for licensing calculations, but does providesupport that the current method is overly conservative.
The issue was first documented in the AREVA Inc. Corrective Action Program on April 15, 2014.
Page 1 of 2
 
- AREVA                            6/4/2014 3:22:25 PM             PAGE      3/003       Fax Server (vi) In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, suppliedfor, being suppliedfor, or may be suppliedfor, manufactured,or being manufacturedfor one or more facilities or activities subject to the regulationsin this part.
The defect exists in the calculation of SLO MCPR for the following reactors:
Browns Ferry Unit 1 Browns Ferry Unit 2 Browns Ferry Unit 3 (vii) The corrective action which has been, is being, or will be taken; the name of the individual or organizationresponsiblefor the action;and the length of time that has been or will be taken to complete the action.
As the responsible organization, AREVA Inc. has provided recommended compensatory actions to all affected plants. The compensatory actions involve restricting the range of core power, core flow, and margin to thermal limits during single loop operation to compensate for the non-conservative prediction of SLO OLMCPR. The operability analyses used as a basis for the compensatory operating restrictions will be formally reviewed per AREVA's approved quality assurance process which complies with the criteria set forth in 10 CFR 50 Appendix B. AREVA Inc. will provide TVA the formal operating restrictions on core power, core flow, and margin to thermal limits applicable to Browns Ferry Unit 1 Cycle 10, Browns Ferry Unit 2 Cycle 18 and Browns Ferry Unit 3 Cycle 17. The schedule for completion of the formal documentation is July 31, 2014. Analyses and documentation for future operating cycles for the three units which are licensed by AREVA Inc. will occur on the normal reload schedules for cycle specific milestones.
(viii)Any advice related to the defect orfailure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasersor licensees.
This defect only had the potential to violate the SLMCPR during SLO. The Browns Ferry plants never operated in SLO while they were supported by the supplied limits. Therefore, the plants never operated where SLMCPR could have been violated. Additionally, the current licensing methodology used by AREVA Inc. is believed to be overly conservative in determining thermal margins specific to the SLO pump seizure event. AREVA Inc. currently has a new high fidelity transient methodology under review by the USNRC referred to as AURORA-B. Scoping and preliminary SLO pump seizure analyses with this new method have demonstrated that thermal limits would not have had the potential to be violated if AURORA-B had been used for the licensing calculation. AURORA-B is not yet approved for licensing calculations, but does provide support that the current method is overly conservative.
Page 2 of 2}}
Page 2 of 2}}

Latest revision as of 03:40, 4 November 2019

Part 21 - Defect Identified in Single Loop Operation Minimum Critical Power Ratio
ML14160A781
Person / Time
Site: Browns Ferry  Tennessee Valley Authority icon.png
Issue date: 06/04/2014
From: Meginnis A
AREVA
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14160A781 (4)
v • d • e


Text

0610412014 U.S. Nuclear Reru torv Commission Overations Center Event ReDort Ppoo I Part 21 (PAR) Event# 50172 Rep Org: AREVA INC Notification Date / Time: 06/04/2014 15:22 (EDT)

Supplier: AREVA INC Event Date I Time: 06/04/2014 (PDT)

Last Modification: 06/04/2014 Region: 4 Docket #:

City: RICHLAND Agreement State: Yes County: License #:

State: WA NRC Notified by: ALAN B MEGINNIS Notifications: DEBORAH SEYMOUR R2DO HQ Ops Officer: CHARLES TEAL NICK TAYLOR R4DO Emergency Class: NON EMERGENCY PART 21 GROUP EMAIL 10 CFR Section:

21.21(d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 - DEFECT IDENTIFIED IN SINGLE LOOP OPERATION MINIMUM CRITICAL POWER RATIO The following is a synopsis of information received via facsimile from AREVA:

AREVA identified a defect is in the calculation of the single loop operation (SLO) minimum critical power ratio (MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage of non-conservative inputs in the SLO pump seizure analyses for the three plants, which results in non-conservative limits for SLO.

Individual informing the Commission:

Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA 99354.

-AREVA 6/4/2014 3:22:25 PM PAGE 1/003 Fax Server AREVA Inc.

AREV AREVA FAX To: NRC Operations Center Date: 6/4/2014 Time in: 3:22 PM Pages to follow: 2 Company: U.S. NRC From: Alan B. Meginnis Telephone: 509-375-8266 MB: 36 E] Original to be mailed [ Via fax only Receiving fax: 301-816-5151 Sending fax: 434-382-5541 Telephone: 301-816-5100 Fax verification: 509-375-8266 Extra Distribution to:

Message:

Please see attached defect notice AREVA Inc.

2101 Horn Rapids Road Operator:

Richland, WA 99354-5102 Telephone: (509) 375-8100 Log No.: Ti me Sent:

AREVA 6/4/2014 3:22:25 PM PAGE 2/003 Fax Server Reportable Defect (i) Name and addressof the individualor individuals informing the Commission.

Alan B. Meginnis, AREVA Inc., 2101 Horn Rapids Road, Richland, WA99354.

(ii) Identification of the facility, the activity, or the basic component suppliedfor such facility or such activity within the United States which fails to comply or contains a defect.

The defect is in the calculation of the single loop operation (SLO) minimum critical power ratio (MCPR) operating limits for Browns Ferry Units 1, 2, and 3. Specifically, the defect is associated with the usage of non-conservative inputs in the SLO pump seizure analyses for the three plants, which resulted in non-conservative limits for SLO.

(iii) Identification of the firm constructing thefacility or supplying the basic component which fails to comply or contains a defect.

AREVA Inc.

(iv) Nature of the defect orfailure to comply and the safety hazardwhich is createdor could be createdby such defect orfailure to comply.

This issue is a defect as defined in 10 CFR 21.3. The calculated MCPR is used to confirm that the core is operated within the required Operating Limit MCPR (OLMCPR). The OLMCPR is established to ensure that the Technical Specification Safety Limit MCPR (SLMCPR) is not violated during anticipated operational occurrences (AOOs). The defect in the SLO pump seizure analyses produced a non-conservative prediction of MCPR. If a SLO pump seizure occurred in any of the three Browns Ferry Units, and that reactor was operating on the specified OLMCPR, the technical specification MCPR safety limit could have been violated. Therefore, the issue is considered a defect.

(v) The date on which the information of such defect orfailure to comply was obtained.

The issue was first documented in the AREVA Inc. Corrective Action Program on April 15, 2014.

Page 1 of 2

- AREVA 6/4/2014 3:22:25 PM PAGE 3/003 Fax Server (vi) In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, suppliedfor, being suppliedfor, or may be suppliedfor, manufactured,or being manufacturedfor one or more facilities or activities subject to the regulationsin this part.

The defect exists in the calculation of SLO MCPR for the following reactors:

Browns Ferry Unit 1 Browns Ferry Unit 2 Browns Ferry Unit 3 (vii) The corrective action which has been, is being, or will be taken; the name of the individual or organizationresponsiblefor the action;and the length of time that has been or will be taken to complete the action.

As the responsible organization, AREVA Inc. has provided recommended compensatory actions to all affected plants. The compensatory actions involve restricting the range of core power, core flow, and margin to thermal limits during single loop operation to compensate for the non-conservative prediction of SLO OLMCPR. The operability analyses used as a basis for the compensatory operating restrictions will be formally reviewed per AREVA's approved quality assurance process which complies with the criteria set forth in 10 CFR 50 Appendix B. AREVA Inc. will provide TVA the formal operating restrictions on core power, core flow, and margin to thermal limits applicable to Browns Ferry Unit 1 Cycle 10, Browns Ferry Unit 2 Cycle 18 and Browns Ferry Unit 3 Cycle 17. The schedule for completion of the formal documentation is July 31, 2014. Analyses and documentation for future operating cycles for the three units which are licensed by AREVA Inc. will occur on the normal reload schedules for cycle specific milestones.

(viii)Any advice related to the defect orfailure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasersor licensees.

This defect only had the potential to violate the SLMCPR during SLO. The Browns Ferry plants never operated in SLO while they were supported by the supplied limits. Therefore, the plants never operated where SLMCPR could have been violated. Additionally, the current licensing methodology used by AREVA Inc. is believed to be overly conservative in determining thermal margins specific to the SLO pump seizure event. AREVA Inc. currently has a new high fidelity transient methodology under review by the USNRC referred to as AURORA-B. Scoping and preliminary SLO pump seizure analyses with this new method have demonstrated that thermal limits would not have had the potential to be violated if AURORA-B had been used for the licensing calculation. AURORA-B is not yet approved for licensing calculations, but does provide support that the current method is overly conservative.

Page 2 of 2

Retrieved from "https://kanterella.com/w/index.php?title=ML14160A781&oldid=2048187"