ML20036C173
| ML20036C173 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/08/1993 |
| From: | Edison G Office of Nuclear Reactor Regulation |
| To: | Sieber J DUQUESNE LIGHT CO. |
| References | |
| TAC-M84673, NUDOCS 9306150104 | |
| Download: ML20036C173 (5) | |
Text
..
June 8, 1993 Docket No. 50-334 Mr. J. D. Sieber, Senior Vice President and Chief Nuclear Officer Nuclear Power Division Post Office Box 4 Shippingport, Pennsylvania 15077-0004
Dear Mr. Sieber:
SUBJECT:
REQUEST FOR ADDITIONA'. INFORMATION RELATED TO CHANGE REQUEST NO. 202 (TAC NO. M84673)
On November 2, 1992, Duquesne Light Company (DLC) submitted an application to amend the Appendix A Technical Specifications (TS) for Beaver Valley Power Station, Unit 1.
The proposed change would revise the TS to permit an increase in spent fuel pool capacity. Our review of this application is underway, but for us to complete our review we require additional information.
The required additional information is described in the Enclosure.
DLC is requested to provide a response within 30 days of receipt of this letter so that the staff can continue its review on the schedule you have requested.
The questions in the enclosure were discussed with Mr. Vassello of your staff on June 8, 1993.
The requirements of this letter affect fewer than 10 respondents, and, therefore, are not subject to the Office of Management and Budget review under PL 96-511.
Sincerely,
/S/
Gordon E. Edison, Senior Project Manager Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
Request for Additional Information cc w/ enclosure:
See next page DISTRIBUTION:
Docket File JCalvo OGC JBagchi NRC & Local PDRs WButler ACRS (10)
PDI-3 Reading Slittle JLinville,RI SVarga GEdison JMa
- See previous concurrence
/J OFFICE LA:TM PM:PDI-3M
- D:PDI-3 KAME t]e G[djson:mW WButler D /8/93
[ /(//93 06/08/93
/ /
/ /
DATE OFFICIAL RECORD COPY FILENAME: BV184673.RAI
)
y0L 9306150104 930608 u, ;'
PDR ADDCK 05000334 f
p PDR L
.i
~
4 pm Rf g 6
'o UNITED STATES
~g l'
NUCLEAR REGULATORY COMMISSION n
5 E
WASHINGTON, D. C. 20555 S
June 8, 1993 4
~
Dock *eYNo.50-334 Mr. J. D. Sieber, Senior Vice President and Chief Nuclear Officer Nuclear Power Division Post Office Box 4 Shippingport, Pennsylvania 15077-0004
Dear Mr. Sieber:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION RELATED TO CHANGE REQUEST NO. 202 (TAC NO. M84673)
On November 2, 1992, Duquesne Light Company (DLC) submitted an application to amend the Appendix A Technical Specifications (TS) for Beaver Valley Power Station, Unit 1.
The proposed change would revise the TS to permit an-increase in spent fuel pool capacity. Our review of this application is underway, but for us to complete our review we' require additional information.
The required additional information is described in the Enclosure. DLC is requested to provide a response within 30 days of receipt of this letter so that the staff can continue its review on the schedule you have requested.
The questions in the enclosure were discussed with Mr. Vassello of your staff-on June 8,_1993.
The requirements of this letter affect fewer than 10 respondents, and, therefore, are not subject to the Office of Management and Budget review under PL 96-511.
Sincerely, Gordon E. Edison, Senior Project Manager Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
Request for Additional j
Information cc w/ enclosure:
i See next page j
i
Mr. J. D. Sieber Beaver Valley Power Station Duquesne Light Company Units 1 & 2 cc:
Jay E. Silberg, Esquire Bureau of Radiation Protection Shaw, Pittman, Potts & Trowbridge Pennsylvania Department of 2300 N Street, NW.
Environmental Resources Washington, DC 20037 ATTN:
R. Barkanic Post Office Bux 2063 Nelson Tonet, Manager Harrisburg, Pennsylvania 17120 Nuclear Safety Duquesne Light Company Mayor of the Borrough of Post Office Box 4 Shippingport Shippingport, Pennsylvania 15077 Post Office Box 3 Shippingport, Pennsylvania 15077 Comissioner Roy M. Smith West Virginia Department of Labor Regional Administrator, Region I Building 3, Room 319 U.S. Nuclear Regulatory Comission Capitol Complex 475 Allendale Road Charleston, West Virginia 25305 King of Prussia, Pennsylvania 19406 John D. Borrows Resident Inspector Director, Utilities Department U.S. Nuclear Regulatory Comission Public Utilities Comission Post Office Box 181 180 East Broad Street Shippingport, Pennsylvania 15077 Columbus, Ohio 43256-0573 Director, Pennsylvania Emergency Management Agency Post Office Box 3321 Harrisburg, Pennsylvania 17105-3321 Ohio EPA-DERR ATTN: Zack A. Clayton Post Office Box 1049 Columbus, Ohio 43266-0149
k
~
Enclosure REQUEST FOR ADDITIONAL INFORMATION ON THE SPENT FUEL POOL STORAGE RACK APPLICATION AT BEAVER VALLEY UNIT N0.1 1.
On page 6-9 it is stated that "In the fuel rack simulations, the coulomb friction interface between rack support pedestal and liner is typical of a nonlinear spring." Please state the mathematical formulation of this nonlinear spring and describe the physical meaning of this formulation.
2.
On page 6-10 it is stated that "The fuel rack structure is very rigid."
What is the fundamental frequency of the rack ?
3.
On page 6-11 it is stated that " Fluid coupling between rack and fuel assemblies, and between rack and wall, is simulated by appropriate inertial coupling in the system kinetic energy."
Provide sketches to indicate the physical model of the inertial coupling and describe how the model was represented mathematically.
4.
On page 6-11 it is stated that " Potential impacts between rack and fuel assemblies are accounted for by appropriate compression-only gap elements between masses involved." Please illustrate how the gap elements actually accounts for the potential impacts between the rack and. fuel assemblies (use sketches and descriptions).
5.
On page 6-11 it is stated that " Local pedestal spring stiffness accounts for floor elasticity and for local rack elasticity just above the pedestal." Describe the mathematical formulation of the local pedestal spring stiffness in general, and of the floor elasticity and local rack elasticity in particular.
6.
On page 6-13 it is stated that rack-to-rack gap elements can be found in Figure 6.4.3.
However, the title of Figure 6.4.3 is " rack-to-rack impact springs" and the designation of the springs in the Figure is labeled as " typical impact element". Are " gap element", " impact spring", and " impact element" the same thing ?
7.
Table 6.4.2 contains numbering system for gap elements and friction elements. Provide a drawing of the model that shows the gap and friction elements as stated in Table 6.4.2.
8.
On page 6-16 it is stated that "It is noted that sliding will occur at the pedestal-bearing pad interface before it occurs at the bearing pad-liner interface. This can be assured by the use of dissimilar material constitution between pedestal and pad, whereas the same material constitution is used in the bearing pad and liner." Do the analysis results in Beaver valley show that any bearing pad slides against the liner ?
If not in this case, could it happen in other cases where seismic movements are relatively higher than this case ?
9.
On page 6-22 it is stated that " Stress results are presented in dimensionless form.
Dimensionless stress factors are defined as the
jg
~
ratio of the actual developed stress to the specified limiting value.
Stress factors are only developed for the single rack analysis. The limiting value of each stress factor is 1.0 for OBE and 2.0 (or less) for the SSE condition." Provide reasons to justify the criterion which allows the limiting value of stress factors exceeding 1.0 or the actual stress exceeding the specified limiting value.
10.
On page 6-27 it is stated that " Local cell wall integrity is conservatively estimated from peak impact loads.
Plastic analysis is used to obtain the limiting impact load." Should the word " limiting" be replaced by " peak" ? Describe the procedures of this plastic analysis that were used to obtain the limiting, or peak, impact load.
11.
On page 6-28 it is stated that " This upper bound value is obtained by using the highest rack-to-fuel impact load from Table 6.7.5 (for any simulation), and multiplying the result by 2 (assuming that two impact locations are supported by every weld connection). Justify the assumption that two impact locations are supported by every weld connection.
12.
On page 3-1 it is stated that "The storage cells are connected to each other by austenitic stainless steel corner welds which leads to a honeycamb lattice construction. The extent of welding is selected to "detuae" the racks from the seismic input motion (OBE and SSE) "
Expla n how the welding was selected to detune the racks from the seismic input motion.
13.
What are the clearances between the racks during plant operation ?.
Desr. ribe inspection procedures for fuel racks after being subjected to OBE level earthquakes and corrective procedures for those racks which ha/e been moved or shifted as a result of earthquakes.
14.
The nonlinear computer program DYNARACK has been used to analyze the rack responses during earthquakes. Has the program been validated against test data from free standing racks emerged in the water and subjected to seismic loads, if any ? As applicable, discuss the extent and key features of the verification and justify that the types of verification implemented would assure obtaining of correct results from nonlinear DYNARACK analysis.
.