Letter Sequence Approval |
|---|
|
|
MONTHYEAR05000328/LER-2011-001-01, For Sequoyah Nuclear Plant, Unit 2 Regarding Nuclear Instrumentation System Power Range Neutron Flux Trip Low Range Bistable Incorrectly Calibrated - Revision 12011-09-29029 September 2011
For Sequoyah Nuclear Plant, Unit 2 Regarding Nuclear Instrumentation System Power Range Neutron Flux Trip Low Range Bistable Incorrectly Calibrated - Revision 1
Project stage: Request
ML11307A3692011-10-31031 October 2011
NRR E-mail Capture - Sequoyah, Unit 1 - Acceptance Review of LAR Requesting to Add a One-Time License Condition to Conduct Heavy Load Lifts for Unit 2 SGRP
Project stage: Acceptance Review
ML12019A2642012-01-13013 January 2012
NRR E-mail Capture - Sequoyah, Unit 1 LAR - Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Approval
ML12034A2272012-02-0202 February 2012
NRR E-mail Capture - Sequoyah, Unit 1 LAR - Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Approval
ML12046A6462012-02-10010 February 2012
Response to NRC Request for Additional Information Regarding the Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Response to RAI
ML12089A4912012-03-0505 March 2012
Response to NRC Second Request for Additional Information Regarding the Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Request
ML12114A0612012-04-0505 April 2012
Technical Report, SQN2-SGR-TRI, Revision 3, Sequoyah Unit 2 Steam Generator Replacement Rigging and Heavy Load Handling
Project stage: Other
ML12114A0602012-04-0505 April 2012
Cover Letter - Revision to the Sequoyah Unit 2 Steam Generator Replacement Rigging and Heavy Load Handling Technical Report, SQN2-SGR-TR1, Submitted in TVAs Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Other
ML12121A2332012-05-0202 May 2012
Meeting Notice - Notice of Forthcoming Meeting Via Conference Call with Tennessee Valley Authority Regarding Sequoyah Nuclear Plant, Unit 1, Heavy Loads Amendment Request (TAC No. ME7225.)
Project stage: Meeting
ML12144A2972012-05-22022 May 2012
Response to Nuclear Regulatory Commission (NRC) Third Request for Additional Information Regarding the Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP
Project stage: Request
ML12136A5222012-07-0505 July 2012
Summary of Public Telephone Call with Tennessee Valley Authority Regarding Heavy Load Lifts License Amendment Request Risk Informed Request for Additional Information
Project stage: RAI
ML12213A0352012-07-30030 July 2012
NRR E-mail Capture - Sequoyah 1 - Heavy Loads LAR
Project stage: Other
ML12234A3812012-09-0606 September 2012
Issuance of Amendment Regarding the Proposed Operating License and Technical Specification Changes for Unit 2 Replacement Steam Generator Project to Conduct Heavy Load Lifts
Project stage: Approval
ML12263A1632012-09-20020 September 2012
Safety Evaluation Corrections for Amendment No. 330 Associated with Unit 2 Replacement Steam Generator Project to Conduct Heavy Load Lifts (TAC No. ME7225) (TS-SQN-2011-05)
Project stage: Approval
2012-04-05
[Table View] |
Text
1 NRR-PMDAPEm Resource From:
Lingam, Siva Sent:
Friday, January 13, 2012 5:42 PM To:
'cdmackaman@tva.gov' Cc:
Howe, Andrew
Subject:
Sequoyah, Unit 1 LAR - Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP (TAC No. ME7225)
Please, note the following official RAI from our PRA Branch (APLA), and provide your response within 30 days:
In the submittal, the licensee has identified the change in risk associated with the requested ERCW alignments as 7.2E-7/year (CDF) and 4.05E-8/year (LERF); this is the risk increase above the nominal risk of maintaining the normal ERCW alignment. Also, the licensee has identified the additional risk of performing heavy load lifts as 7.0E-9/year (CDF) and 5.0E-10/year (LERF), given that the ERCW is in its proposed special alignment.
The risk increase incurred due solely to the special ERCW alignment is two orders of magnitude greater than the heavy load lift risk increase. It is assumed by the NRC staff that if the ERCW is not aligned as described, then the risk increase associated with the heavy load lifts would be significant, or at least greater than the 7.2E-7/year (CDF) and 4.05E-8/year (LERF) reported for the ERCW alignment. However, the risk metrics associated with performing the same heavy load lifts with ERCW in its normal alignment was not provided in the submittal, which would permit the NRC staff to assess the relative risk impacts. Therefore, the NRC staff cannot conclude that the special ERCW alignment is necessary to avoid a more significant risk increase during the heavy load lifts.
The licensee is requested to justify the need for the ERCW alignment and the resulting risk increases incurred by providing the risk metrics associated with heavy load lifts if the normal ERCW alignment is maintained.
Hearing Identifier:
NRR_PMDA Email Number:
235 Mail Envelope Properties (BE1CC4A72435624D84F8699734202B3E7D6F76147A)
Subject:
Sequoyah, Unit 1 LAR - Heavy Load Lifts and UHS One Time Change in Support of Unit 2 SGRP (TAC No. ME7225)
Sent Date:
1/13/2012 5:42:03 PM Received Date:
1/13/2012 5:42:00 PM From:
Lingam, Siva Created By:
Siva.Lingam@nrc.gov Recipients:
"Howe, Andrew" <Andrew.Howe@nrc.gov>
Tracking Status: None
"'cdmackaman@tva.gov'" <cdmackaman@tva.gov>
Tracking Status: None Post Office:
HQCLSTR01.nrc.gov Files Size Date & Time MESSAGE 1583 1/13/2012 5:42:00 PM Options Priority:
Standard Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
Recipients Received:
