ML12054A134
| ML12054A134 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/19/2011 |
| From: | Meena Khanna Plant Licensing Branch 1 |
| To: | Patrick Boyle, Martin R Plant Licensing Branch II |
| References | |
| FOIA/PA-2011-0357 | |
| Download: ML12054A134 (4) | |
Text
From: Khanna, Meena To: Boyle, Patrick; Martin, Robert
Subject:
FW: Database Draft Date: Monday, September 19, 2011 12:35:00 PM Attachments: NRC O&R Database.doc Fyi...let me know what you think, pls..thanks From: David Sommers [1]
Sent: Monday, September 19, 2011 11:50 AM To: Khanna, Meena
Subject:
Database Draft For your consideration as a database that can be used to encompass status of questions CONFIDENT ILITY NOT)iC: This electro i message co ation whT'e1may be legally conjVdential and/yr privileged and es not in anyase represent a firl/ENERGY COMMODitY bid or offer relating there which binds $be sender without at additional express w/itten confi7 'at"-ion to that eff-ct. The inform ýion is intended so lely for the individ*al or entity amed above agh access by an ne else is unauth rized. If you e not the e~nded rec9fent, any discl re, copying,,dfstribution, or use the contei of this infrmation istrohibited and ay be unlawf. If you have rec i ed this ele onic trfnsmissioi nnerror, pleaa reply im-meie tely to the sendee at you have received the
,/mnessag
- error, and dprete it. Thank you.
NRC Questions/RAls on North Anna Seismic Event NRC Docketed Dominion Dominion Branch & NRC Response Responsible Response date Comments ST / LT QuestionslRAls Yes/No Department & Serial N Designation YsN Dam &_SerialNo.
Fuels .
NRC letter dated September 14, 2011 .
1.FANP Topical Report, BAW-10239(P)(A), Revision 0 (Reference 2),
Fuels provides an evaluation of the Advanced Mark-BW fuel assembly in a Yes NA&F sample reactor against the criteria defined in the Section 4.2 of the Standard Review Plan (SRP). Section 5.3.4. of the topical report discusses fuel assembly structural damage from extemal forces, such as the operating basis earthquake (OBE), the safe shutdown, earthquake (SSE), as well as SSE + loss-of-coolant-accident (LOCA) loads. The evaluation of faulted conditions also addresses both horizontal (LOCA and seismic) and vertical LOCA effects. Based on the availability of information to date from VEPCO's presentation and the Advanced Mark-BW fuel mechanical design report, the Nuclear Regulatory Commission (NRC) staff is unable to verify the operability condition for the core internals, specifically for the fuel assemblies (grids, fuel rods, guide tubes) and control rods.
ST a)Please provide a comprehensive strategy and qualifying criteria for determining the operability of these components.
ST b) Provide a comparison of the predicted design basis loads (e.g., local acceleration) on the core internals and fuel assemblies against the predicted loads derived from the measured ground motion data during the seismic event. In addition, compare these predicted loads against the measured yielding load and deflection from the fuel assembly grid crush testing.
ST c) Describe all sources of technical information considered in determining the operability and integrity of the fuel, including involvement of the fuel vendors.
2.Describe the extent of fuel assembly inspections which will be performed Yes NA&F Fuels to confirm the structural integrity of the fuel. Provide specific information on how the inspections will determine that there is no distortion of the ST fuel lattice array or rod cluster control assembly (RCCA) guide tubes that occurred as a result of the seismic event. Also provide information on guide tube drag and rod drop testing.
3.Describe the extent of fuel assembly inspections and supporting Yes NA&F Fuels analyses which will be performed to confirm the thermal-hydraulic performance of the fuel. Provide specific information on how the inspections will determine that there is no deflection of any fuel grid ST mixing vanes or any other component that will alter the thermal-hydraulic performance of the fuel bundle as a result of the seismic event. If any deficiencies are detected, provide information on the impact on the fuel departure from nucleate boiling ratio (DNBR).
- 4. Describe the extent of inspections and testing which will be performed Yes Station Fuels to demonstrate the operability of the control element drive mechanisms. Engineering
NRC Questions/RAIs on North Anna Seismic Event NRC Docketed Dominion Dominion Branch & NRC Response Responsible Response date Comments ST I LT Questions/RAIs Yes/No Department & Serial No.
Designation ST
- 5. Provide any nuclear fuel related information that has been gathered Yes Station Fuels considering the Electric Power Research Institute (EPRI) guidance and Engineering recommendations found in EPRI report NP-6695 (reference 3). Specific ST information of interest is control rod drive mechanism operability as related to changes in core instrumentation readouts; changes in primary coolant radiation monitor values; changes in other parameters such as primary coolant flow, temperature, and pressure; loose parts monitoring equipment noise signatures; and primary coolant chemistry sample results.
Fuels 6. Explain the rationale and extent of the operability determinations for the ST core components (fuel and control rods) and their support systems.
Fuels 7. Provide the final root cause analysis report on the cause of the reactor Yes Station ST trips. Engineering Fuels 8. Describe the extent of inspections on the core shroud to investigate Yes Station ST possible changes in local flow conditions (e.g., baffle jetting, change in Engineering core bypass flow).
9.Third-burned fuel assemblies are generally located along the core Yes NA&F Fuels periphery in locations where seismic loading may be limiting. These assemblies are at end-of-life and would be discharged to the spent fuel ST pool (SFP) (no reinsertion). Are there any plans to do detailed investigations and measurements (including rod pulls, dismantling, hot cell examinations) on any of the third-burned fuel assemblies located at the core periphery of Unit 2?
Reactor Systems . .
NRC letter dated September 14, 2011 ,..
Reactor 1. Describe the evaluations, inspections and analyses of the steam Yes Station Systems generators (SG) to ensure SG tube integrity? Engineering ST Reactor 2. Discuss provisions to ensure that system pressure relief capabilities are Yes Station Systems maintained. Engineering ST Reactor 3. Discuss measures to verify overall reactor coolant system (RCS) Yes Station Systems pressure boundary integrity. Engineering ST
- 4. Describe the inspections, examinations and evaluations of the Yes Station Reactor emergency core cooling systems (ECCS) that have been or will be Engineering Systems performed to show that the ECCS will continue to perform as designed, ST especially under simultaneous design basis earthquake loading and ECCS design basis seismic requirements.
- 5. Were there any complications in residual heat removal (RHR) following Yes Station Reactor the earthquake? Did all RHR equipment perform as intended? Enginering Systems ST
NRC Questions/RAIs on North Anna Seismic Event NRC Docketed Dominion Dominion Branch & NRC Response Responsible Response date Comments STi LT QuestionsiRAls Yes/No Department & Serial No.
Designation