Letter Sequence RAI |
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Administration
- Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance, Withholding Request Acceptance
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MONTHYEARRS-05-061, Response to Request for Additional Information for Review of Quad Cities Replacement Steam Dryer2005-05-12012 May 2005
Response to Request for Additional Information for Review of Quad Cities Replacement Steam Dryer
Project stage: Response to RAI
ML0518100572005-07-14014 July 2005
Withholding from Public Disclosure, Updated Responses to DNPS and QCNPS EPU RAIs 3B & 7, August 14, 2003 (GE Proprietary Information)
Project stage: RAI
ML0518200102005-07-18018 July 2005
Continuum Dynamics, Inc., Request for Withholding Information from Public Disclosure
Project stage: Withholding Request Acceptance
ML0528704802005-12-0707 December 2005
Report of Project Manager Site Visit- Dresden Steam Dryer Licensing Issues
Project stage: Other
RS-06-015, Commitments and Plans Related to Extended Power Uprate Operation2006-01-26026 January 2006
Commitments and Plans Related to Extended Power Uprate Operation
Project stage: Request
ML0604507082006-03-0808 March 2006
General Electric Company, Request for Withholding Information from Public Disclosure for Dresden, Units 2 and 3 and Quad Cities, Units 1 and 2
Project stage: Withholding Request Acceptance
ML0604002722006-03-16016 March 2006
Request for Withholding Information from Public Disclosure
Project stage: Withholding Request Acceptance
ML0610805702006-04-10010 April 2006
Dryer Inspection Results
Project stage: Request
ML0610806102006-04-13013 April 2006
Request for Additional Information - Dryer Inspection, Start-up and Power Ascension Plan
Project stage: RAI
05000254/LER-2006-002, Automatic Reactor Scram from Turbine/Generator Load Reject Due to Degraded Current Transformer Wiring on the Main Power Transformer2006-04-14014 April 2006
Automatic Reactor Scram from Turbine/Generator Load Reject Due to Degraded Current Transformer Wiring on the Main Power Transformer
Project stage: Request
RS-06-058, Operational Plan Commitments2006-04-14014 April 2006
Operational Plan Commitments
Project stage: Request
ML0610406142006-04-20020 April 2006
Dryer Inspection Results Decision
Project stage: Other
ML0610102872006-04-28028 April 2006
General Electric Company, Request for Withholding Information from Public Disclosure for Dreden Nuclear Power Station, Units 1 and 2 (TAC Nos. MC0875, MC0876, MC0877 and MC0878
Project stage: Withholding Request Acceptance
ML0609603942006-04-28028 April 2006
GE Request for Withholding Information from Public Disclosure Dresden and Quad by Letter Dated May 13, 2005
Project stage: Withholding Request Acceptance
ML0610200462006-04-28028 April 2006
General Electric Company, Request for Withholding Information from Public Disclosure for Dresden Nuclear Power Station, Units 2 and 3, and Quad Cities Nuclear Power Station, Units 1 and 2
Project stage: Withholding Request Acceptance
ML0611604452006-04-28028 April 2006
RAI Related to Unit 2 Steam Dryer Inspection
Project stage: RAI
ML0609603632006-05-0101 May 2006
General Electric, Withholding from Public Disclosure, GE-NE-0000-0032-1827P, Quad Cities Replacement Steam Dryer Instrumentation Acceptance Criteria, Dated April 2005
Project stage: Other
ML0608905262006-05-0101 May 2006
GE Request for Withholding Information from Public Disclosure for Dresden, Units 2 and 3 and Quad, Units 1 and 2
Project stage: Withholding Request Acceptance
ML0610202772006-05-19019 May 2006
General Electric Company, Request for Withholding Information from Public Disclosure for Dresden Nuclear Power Station, Unit 2 and 3, and Quad Cities Nuclear Power Station, Units 1 and 2
Project stage: Withholding Request Acceptance
ML0608201332006-07-0505 July 2006
GE, Request for Withholding Information from Public Disclosure
Project stage: Withholding Request Acceptance
ML0614401352006-07-0505 July 2006
General Electric Company, Request for Withholding Information from Public Disclosure
Project stage: Withholding Request Acceptance
ML0614406092006-07-0505 July 2006
GE, Request for Withholding Information from Public Disclosure
Project stage: Withholding Request Acceptance
ML0614402522006-07-25025 July 2006
GE Company, Request for Withholding Information from Public Disclosure for Dresden and Quad Cities - Quintana Ltr
Project stage: Withholding Request Acceptance
ML0615301212006-08-17017 August 2006
Continuum Dynamics, Inc. Request for Withholding Information from Public Disclosure, Bilanin Letter
Project stage: Withholding Request Acceptance
ML0507701992006-09-0505 September 2006
Withholding from Public Disclosure, C.D.I. Proprietary Report No. 04-09P, Rev. 5 and Presentation Entitled, Methodology to Determine Unsteady Pressure Loading on Components in Reactor Steam Domes, Dated January 25, 2005
Project stage: Other
ML0615001032006-09-0505 September 2006
GE, Withholding from Public Disclosure, GENE-0000-0038-6481-01-R1-P, Exelon Steam Dryer Dynamic Time History Analyses: Dresden Unit 2 2004 Repair & Dresden Unit 3 2003 & 2004 Repair Dryer Configurations Using Loads from Plant Measurements,
Project stage: Other
ML0610103752006-09-21021 September 2006
General Electric Company, Request for Withholding Information from Public Disclosure for Dresden Nuclear Power Station, Units 2 and 3, and Quad Cities Nuclear Power Station, Units 1 and 2
Project stage: Withholding Request Acceptance
2006-04-14
[Table View] |
Text
April 13, 2006 Request for Additional Information Quad Cities Unit 2 Dryer Inspection, Start-up and Power Ascension Plan
- 1. Please provide the following information to the NRC staff:
(a) the steam dryer inspection results and analysis, including metallurgical reports; (b) the steam dryer failure root cause report; (c) the steam dryer stress analysis report; (d) licensee's justification for the steam dryer repair, including the extent of the repair, impact of the repair on steam dryer structural characteristics, and evaluation of remaining steam dryer, and (e) the licensee's description, analysis, and justification for the ERV modification in support of EPU operation, including evaluation of the shaker table test failure?
The NRC staff would like to have sufficient time to review these documents prior to Quad Cities Unit 2 startup.
- 2. Please provide the following information to the NRC:
MSL strain gage and accelerometer data, and walkdown information, during the power ascension.
The NRC staff would like to have sufficient time to review the data to determine if any safety concerns exist with continued power ascension.
- 3. In the Quad Cities Unit 2 Power Ascension Test Procedure TIC-1402, what is the power ascension intervals for Test Condition steps and hold times above OLTP (TC 12 to 18)?
- 4. Provide the basis for the vibration acceptance criteria for Levels 1 and 2 in Attachment 9.2 of TIC-1402.
- 5. Provide the basis for the MSL strain gage data acceptance criteria for Levels 1 and 2 in.3 of TIC-1402.
- 6. Provide the scope and objectives of the walkdowns that are planned at specific Test Condition steps.
- 7. Provide the basis and justification for remaining at the EPU power level while resolving the uncertainties surrounding the structural capability of the steam dryer and ERVs under EPU conditions.
- 8. Provide the extent of and the justification for leaving the small cracks in service during operation, especially at EPU.
- 9. For the large dryer crack in the skirt base metal at 135-degree location, provide the following information and documentation supporting your responses.
(a) What may be the magnitude of plastic strains and residual stresses introduced by the reported installation difficulty?
(b) What may be the corresponding reduction in the fatigue stress limits?
(c) What may be the stresses acting at the crack location?
(d) What is the stress intensity at the crack tip?
- 10. In the stress analysis submitted by Exelon in August 2005 (Report # GENE-0000-0043-5391-01-P), the maximum stress intensity in the skirt was high (24,285 psi) when 2% damping was assumed. Then damping in the skirt was increased to 4% and the corresponding maximum stress intensity was reduced to about 9,000 psi. Explain whether the damping in the skirt could be lower than 4% and what may be the role of resulting higher stresses in causing the large dryer crack?
- 11. Explain why some small fatigue cracks in several vane assemblies are not repaired. Did initial installation introduce any residual stress at the crack locations? What may be the magnitude of this stress? What may be the driving force for these cracks? How does this driving force compare with the one acting on the large crack at 135-degree location? How much these small cracks may grow during the next fuel cycle?
- 12. Are the MSL strain gage data at 2957 MWt available? How does this data compare with the corresponding data at 2,885 MWt and at pre-EPU condition? Provide similar comparison for RPV level sensor data.
- 13. What may be the magnitude of the weld residual stresses at the repaired crack location?
What may be the effect of these residual stresses on the fatigue stress limits? Explain why the repaired crack location may not be susceptible to fatigue cracking?
- 14. Address how the magnitude of residual stresses created as a result of highly constrained weld repair is determined. How do these residual stresses affect the fatigue life for the material?
- 15. Discuss the potential for loose parts resulting from the failure of the backing bar.
