ML082840542
| ML082840542 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/22/2008 |
| From: | Farideh Saba Plant Licensing Branch II |
| To: | Young D Florida Power Corp |
| Saba F, NRR/DORL/LPL2-2, 301-415-1447 | |
| References | |
| TAC MD8919 | |
| Download: ML082840542 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 October 22, 2008 Mr. Dale E. Young, Vice President Crystal River Nuclear Plant (NA1B)
ATTN: Supervisor, Licensing & Regulatory Programs 15760 W. Power Line Street Crystal River, Florida 34428-6708
SUBJECT:
CRYSTAL RIVER UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION, REGARDING LICENSE AMENDMENT REQUEST NO. 303, REVISION TO FINAL SAFETY ANALYSIS REPORT, SECTIONS 5.4.3 AND 5.4.5.3 (TAC NO. MD8919)
Dear Mr. Young:
By letter dated June 3, 2008, the Florida Power Corporation (the licensee) submitted License Amendment Request No.303 that would revise the analysis methodology in Final Safety Analysis Report, Section 5.4.3, "Structural Design Criteria," and Section 5.4.5.3, "Missile Analysis." The amendment would allow the licensee to use the yield line theory methodology to qualify the east wall of the Auxiliary Building for wind and tornado missile loading. The Nuclear Regulatory Commission (NRC) staff has reviewed the information the licensee provided and determined that additional information is required in order to complete the evaluation. The NRC staff's request for additional information is enclosed.
Please respond to the enclosed questions within 30 days of the date of this letter. Please contact me at 301-415-1447, if you have any questions on this issue.
Sincerely, Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-302
Enclosure:
As stated cc w/encl: See next page
October 22, 2008 Mr. Dale E. Young, Vice President Crystal River Nuclear Plant (NA1B)
ATTN: Supervisor, Licensing & Regulatory Programs 15760 W. Power Line Street Crystal River, Florida 34428-6708
SUBJECT:
CRYSTAL RIVER UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION, REGARDING LICENSE AMENDMENT REQUEST NO. 303, REVISION TO FINAL SAFETY ANALYSIS REPORT, SECTIONS 5.4.3 AND 5.4.5.3 (TAC NO. MD8919)
Dear Mr. Young:
By letter dated June 3, 2008, the Florida Power Corporation (the licensee) submitted License Amendment Request No.303 that would revise the analysis methodology in Final Safety Analysis Report, Section 5.4.3, "Structural Design Criteria," and Section 5.4.5.3, "Missile Analysis." The amendment would allow the licensee to use the yield line theory methodology to qualify the east wall of the Auxiliary Building for wind and tornado missile loading. The Nuclear Regulatory Commission (NRC) staff has reviewed the information the licensee provided and determined that additional information is required in order to complete the evaluation. The NRC staff's request for additional information is enclosed.
Please respond to the enclosed questions within 30 days of the date of this letter. Please contact me at 301-415-1447, if you have any questions on this issue.
Sincerely, IRA!
Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-302
Enclosure:
As stated cc w/encl: See next page Distribution:
PUBLIC LPL2-2 R/F RidsNrrDorlLpl2-2 RidsNrrPMFSaba RidsOgcRp RidsNrrLACSola (Hard Copy)
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NAME FSaba CSoia KManoly TBoyce DATE 10/21/08 10/21/08 10/03/08 10/22/08
- by Memorandum OFFICIAL RECORD
Florida Power Corporation Crystal River Nuclear Plant, Unit 3 cc:
Mr. James W. Holt Plant General Manager Crystal River Nuclear Plant (NA2C) 15760 W. Power Line Street Crystal River, Florida 34428-6708 Mr. William A. Passetti, Chief Department of Health Bureau of Radiation Control 2020 Capital Circle, SE, Bin #C21 Tallahassee, Florida 32399-1741 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304 Mr. Daniel R. Westcott Supervisor, Licensing &Regulatory Programs Crystal River Nuclear Plant 15760 W. Power Line Street Crystal River, FL 34428-6708 Additional Distribution via ListServ
REQUEST FOR ADDITIONAL INFORMATION CRYSTAL RIVER UNIT 3 LICENSE AMENDMENT REQUEST TO REVISE FINAL SAFETY ANALYSIS REPORT, SECTIONS 5.4.3 AND 5.4.5.3 DOCKET NO. 50-302, LICENSE NO. DPR-72
- 1. One of the limitations of the yield line method of analysis for slabs is an "upper bound" approach based on postulated collapse mechanisms, and consequently the failure load calculated for a slab may be higher than the true collapse load. Therefore, it is necessary to investigate all possible failure mechanisms (yield-line patterns) for any given slab and loading to confirm that the correct solution, giving the lowest failure load, has been found. Please explain how the above limitation was addressed in the application of the yield line theory to the east wall of the Auxiliary Building to ensure that the correct solution, giving the lowest failure load, has been found.
- 2. The licensee, under "Basic assumptions of the Yield Line Theory methodology," on Page 4 of Attachment 1 of the submittal, states that "Concrete is assumed to be ductile (linear stress distribution)." However, the Nuclear Regulatory Commission (NRC) staff does not believe that concrete is ductile and that the stress distribution in concrete for application of yield line analysis is linear. In fact, concrete is a brittle material, the reinforced concrete element (slab) section is assumed to be ductile and it is the strain distribution that is considered linear. Please clarify/correct this assumption.
- 3. The application of yield line analysis to reinforced concrete slabs is predicated upon available rotation capacity at the yield lines to attain the predicted ultimate loads. Please explain how it was ensured that the necessary ductility is present in the application of the yield line theory to the east wall of the Auxiliary Building. In the response, please include information on the tensile steel ratios in comparison to balanced design value for the wall.
- 4. The licensee, under "Basic assumptions of the Yield Line Theory methodology," on Page 4 of Attachment 1, states that "The structure is collapsing because of the moment, not by other failure mechanisms such as shear or bend." The NRC staff notes that the terms "moment" and "bend" represent the same response behavior of a structural element to loading. Please define each term as it is used in the submitted license amendment request (LAR). The NRC staff notes that the intended assumption in the above statement should be that the yield line analysis focuses entirely on the flexural capacity of the slab and it is presumed that earlier failure will not occur due to shear or torsion. Given that the east wall of the Auxiliary Building at Crystal River is 2 feet thick, please explain how the above assumption of the yield line theory was verified in the LAR. In the response, please include information on parameters such as wall dimensions, span to depth ratio and boundary conditions used in the application of the yield line analysis to the east wall of the Auxiliary Building for the loads and load combinations considered.
Enclosure
- 2
- 5. Please provide a summary of the results of the yield line analysis of the east wall of the Auxiliary Building. Include a comparison of the predicted ultimate capacity of the wall to the applied load for the tornado wind, pressure drop and missile loads and load combinations considered. Please confirm if the yield line analysis was used for checking only the global (as opposed to local) response of this wall.
- 6. Based on the submittal, it is the NRC staff's understanding that the yield line analysis methodology was used to check and qualify an as-constructed configuration of the east wall of the Auxiliary Building for tornado wind and tornado missile loads and load combinations, that was already designed (sizing the wall thickness and reinforcement) using the America Concrete Institute (ACI) standard, ACI 318-63. The language used in the proposed Final Safety Analysis Report (FSAR) markup of Sections 5.4.3 and 5.4.3.2.2 gives the impression that this wall was "designed" using Yield Line methodology and that the yield line theory was also used for earthquake loads, which appears to be misleading. Please clarify the language of the markup of FSAR Sections 5.4.3 and 5.4.3.2.2 to accurately reflect application of the yield line analysis methodology for the east wall of the Auxiliary Building, which is to check/qualify the wall design for tornado wind and tornado missile loads as well load combinations.