ML20155C205
| ML20155C205 | |
| Person / Time | |
|---|---|
| Issue date: | 10/26/1998 |
| From: | Birmingham J NRC (Affiliation Not Assigned) |
| To: | Mcphatter C FRAMATOME |
| References | |
| TAC-M99903, NUDOCS 9811020133 | |
| Download: ML20155C205 (4) | |
Text
_. . . ___ _ _ . . __ __ . _ _ _ _.
October 26, 1998 Mr. C. F. McPhatt:r, Man:gsr Framatome Cogema Fuels 3315 Old Forest Road P.O. Box 10935 Lynchburg, VA 24506-0935
SUBJECT:
Request For Additional Information For Topical BAW-10227P, " Evaluation of Advanced Cladding and Structural Material (MS) in PWR Reactor Fuel,"
Dear Mr. McPhatter:
By letter dated September 30,1997, Framatome Cogema Fuels submitted topical BAW-10227P, " Evaluation of Advanced Cladding And Structural Material (MS)in PWR Reactor Fuel" for NRC review. The staff has reviewed the report and determined a need for additional information. The enclosure to this letter identifies the information requested. Please address your response to the NRC Document Control Desk.
If you have any questions on this matter, please contact me by phone (301) 415-2829, or by email jlt'4@nrc. gov.
Sincerely, Original Signed By:
Joseph L. Birmingham, Project Manager Generic issues and Environmental Projects Branch Office of Nuclear Reactor Regulation
Enclosure:
Questions on topical BAW-10227P cc w/ encl: Mr. M. Schoppman, Manager Rockville Licensing Operations ,
Framatome Technologies, Inc.
1700 Rockville Pike, Suite 525 l Rockville, MD 20852-1631 DISTRIBUTION: E-mail:
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l Questions for M5 Topical Report BAW-10227P
- 1. The hydrogen pickup fraction used for M5 cladding (Sections 3.1 and A.4.2) appears to !
be low compared to the hydrogen pickup data above rod burnups of 10 GWd/MTU in Figures 3-3 and A-7. Please explain why this is acceptable. Have micrographs been taken of the hydrides in irradiated M5 cladding? What is their shape and orientation?
- 2. Please provide the yield strength (YS) and ultimate tensile strength (UTS) data along with uniform and total elongation data for irradiated and unirradiated M5 cladding. Please provide information on how the irradiated and unirradiated biaxial and axial-tensile specimens were tested (including strain rate) along with specimen sizes and shapes.
Please show how the lower bound yield strength in the hoop direction was determined (Table 3-3) based on this data. Please explain why there is a difference in the stress intensity limits under compressive and tensile conditions. Please provide the temperature range that the strength models will be applied.
I
- 3. Please provide the plant coolant outlet temperatures of the M5 cladding oxidation data in !
Figure 3-1 and identify the data by plant and burnup. Also, please provide a plot of measured-minus-predicted corrosion as a function of burnup, oxide thickness, maximum oxide-metal-interface temperature (also end-of-life oxide-metal-interface temperature), and coolant outlet temperature (if data are at more than one outlet temperature). Please provide the oxide-metal-interface temperature range that the M5 corrosion model will be applied. Also explain how the M5 maximum oxide thickness is determined from measured data.
- 4. There is a particular concern with the M5 predictions in Figure 3-4 because they do not exhibit any indication of accelerated corrosion while experience has shown that all zirconium based alloys examined to date show accelerated corrosion given high enough
- cladding temperatures and/or burnups. Please provide the assumed oxide-metal-interface temperature at beginning-of-life (BOL) and the interface temperature at maximum burnup for these predictions and relate them to an assumed coolant temperature. Also, please provide CORROSO2 code predictions of M5 cladding corrosion with a 10 C higher oxide-metal-interface temperature than assumed for Figure 3-4 and extend the predictions to 70 GWd/MTU.
- 5. For each of the new models for M5 cladding, e.g., growth, corrosion, hydriding, creep,
- thermal conductivity, high temperature oxidation, etc., in this submittal please provide the range of application of their independent variables For example, for the cladding rupture model what is the range of engineering hoop stress and heating rate for LOCA applications.
- 6. What is the strength difference between the new M5 guide thimbles and guide tubes and the strength of previous Zircaloy-4 guide thimbles and guide tubes at beginning-of-life (BOL); and, if significam, how does this impact the seismic-LOCA analyses?
Enclosure
p Ctg l O % UNITED STATES 3
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NUCLEAR REGULATORY COMMISSION l WASHINGTON, D.C. 20066 0001 l
\,...../ October 26, 1998 1
Mr. C. F. McPhatter, Manager Framatome Cogema Fuels 3315 Old Forest Road P.O. Box 10935 Lynchburg, VA 24506-0935
SUBJECT:
Request For Additional Information For Topical BAW-10227P, " Evaluation of Advanced Cladding And Structural Material (MS)in PWR Reactor Fuel,"
Dear Mr. McPnatter:
By letter dated September 30,1997, Framatome Cogema Fuels submitted topical BAW-10227P, " Evaluation of Advanced Cladding And Structural Material (MS)in PWR Reactor Fuel," for NRC review. The staff has reviewed the report and determined a need for additional information. The enclosure to this letter identifies the information requested. Please address your response to the NRC~ Document Control Desk.
If you have any questions on this matter, please contact me by phone (301) 415-2829, or by email jlb4@nrc. gov.
Sincerely,
,AM h l
Joseph L. Birmingham, Project Manager Generic Issues and Environmental Projects Branch Office of Nuclear Reactor Regulation
Enclosure:
Questions on topical BAW-10227P cc w/ encl: Mr. M. Schoppman, Manager Rockville Licensing Operations Framatome Technologies, Inc.
1700 Rockville Pike, Suite 525 Rockville, MD 20852-1631
O
- 7. Please provide example fuel melting (at limiting low burnups),1 % cladding strain, rod pressure (including the rod pressure limit), and fuel rod shoulder to upper tie plate gap analyses for the new M5 material along with similar analyses with low tin Zircaloy-4.
Please provide the code input parameters in order that an audit calculation can be performed. ;
- 8. The interpretation of Figure 3-6 is somewhat confusing. Please provide a better explanation / definition of the limiting pressures and minimum collapse delta pressures plotted on this figure. One interpretation of this figure would conclude that cladding collapse will occur above a given cladding temperature on this plot.
- 9. The upper bound model predictions for M5 shoulder gap closure in Figure 3-8 do not reflect that the statistical uncertainty of the model should be proportionately larger with increasing burnup in the burnup regime where there is little or no data. Please justify this lack of conservatism in the model where there is little or no data. Please identify the plants l by legends or tabular form along with coolant outlet temperatures for each of the rod growth data provided in Figures 3-8 and 3-9. j
- 10. Please provide the thermal conductivity equation used for M5 material.
- 11. Please provide the data used to estimate the M5 alpha-beta and beta transformation I temperatures because there seems to be some differences on the start and completion of these phase transformations based on proprietary data available to NRC. What is the uncertainty in the a-p transformation temperatures? Also provide any assumptions used in applying these data to LOCA analyses.
i
- 12. Please provide the M5 modulus of elasticity data.
- 13. What are the consequences of overpwJicting M5 cladding Meyer-Hardness for the fuel melting analysis at BOL? Are there any other analyses at BOL that could be impacted due to an overprediction of Meyer-Hardness? Are there any other applications of Meyer-Hardness other than for contact conductance?
- 14. Please provide information on power ramp testing of rods with M5 cladding.
- 15. Please provide the M5 creep data (identify source of data and relevant conditions such as stress, temperature and fluence) from which the effective creep multiplier was developed for the M5 material. Are there any independent fuel rod creep data from one and two cycles of operation with M5 cladding that can be used to verify that TACO 3 with the M5 creep model can satisfactorily predict creep for the M5 cladding? Also, please provide those data and plots that demonstrate that the assumed stress, temperature and fast fluence dependencies of the creep model are applicable to the M5 cladding. What is the uncertainty in the M5 creep model as a function of fast fluence, temperature, and stress?
, , - . . .,