ML18100A813
| ML18100A813 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 01/12/1994 |
| From: | Stone J Office of Nuclear Reactor Regulation |
| To: | Miltenberger S Public Service Enterprise Group |
| References | |
| TAC-M85797, TAC-M85798, NUDOCS 9401180113 | |
| Download: ML18100A813 (7) | |
Text
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- Dc.cket Nos. 50-272 and 50-311 Mr. Steven E. Miltenberger Vice President and Chief Nuclear Officer Public Service Electric & Gas Company Post Office Box 236 Hancocks Bridge, New Jersey 08038 Dear Mr. Miltenberger
- ' January 12, a
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI), SPENT FUEL POOL RERACK, SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2, (TAC NOS. M85797 AND M85798)
The staff has reviewed certain portions of your application to rerack the spent fuel pools at Salem, Units 1 and 2, dated April 28, 1993.
During that review, the staff has determined that additional information is required in order for them to complete their review.
The additional information that is required is detailed in the enclosure to this letter.
In addition, the staff notes that draft Regulatory Guide 8.38 (RG 8.38),
"Control of Access to High and Very _High Radiation Areas in Nuclear Power Plants" was referenced in your application. Regulatory Guide 8.38 was issued as final in June 1993.
The staff requests this commitment be changed to the final version of RG 8.38 and to include RG 8.38, Appendix A, "Procedure for Diving Operations in High and Very High Radiation Areas", if diving operations are necessary.
In order to support an April 1, 1994 approval of the spent fuel pool rerack amendments, it is requested that you respond to this RAI by February 1, 1994.
This requirement affects 9 or fewer respondents and, therefore, is not subject to Office of Management and Budget review under P.L.96-511.
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Steven E. Miltenberger Vice President and Chief Nuclear Officer Public Service Electric & Gas Company Post Office Box 236 Hancocks Bridge, New Jersey 08038 Dear Mr. Miltenberger January 12, 1994
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI), SPENT FUEL POOL RERACK, SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2, (TAC NOS. M85797 AND M85798)
The staff has reviewed certain portions of your application to rerack the spent fuel pools at Salem, Units 1 and 2, dated April 28, 1993.
During that review, the staff has determined that additional information is required in order for them to complete their review.
The additional information that is required is detailed in the enclosure to this letter.
In addition, the staff notes that draft Regulatory Guide 8.38 (RG 8.38),
"Control of Access to High and Very High Radiation Areas in Nuclear Power Plants" was referenced in your application. Regulatory Guide 8.38 was issued as final in June 1993.
The staff requests this commitment be changed to the final version of RG 8.38 and to include RG 8.38, Appendix A, "Procedure for Diving Operations in High and Very High Radiation Areas", if diving operations are necessary.
In order to support an April 1, 1994 approval of the spent fuel pool rerack amendments, it is requested that you respond to this RAI by February 1, 1994.
This requirement affects 9 or fewer respondents and, therefore, is not subject to Office of Management and Budget review under P.L.96-511.
Enclosure:
Request for Additional Information cc w/enclosure:
See next page Sincerely,
~~~
James C. Stone, Senior Project Manager Project Directorate I-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Mr. Steven E. Miltenlger Public Service Electric & Gas Company*
cc:
Mark J. Wetterhahn, Esquire Winston & Strawn 1400 L Street NW Washington, DC 20005-3502 Richard Fryling, Jr., Esquire Law Department - Tower SE 80 Park Place Newark, NJ 07101 Mr. Calvin A. Vondra General Manager - Salem Operations Salem Generating Stati9n P.O. Box 236 Hancocks Bridge, NJ 08038 Mr. J. Hagan Vice President - Nuclear Operations Nuclear Department P.O. Box 236 Hancocks Bridge, New Jersey 08038 Mr. Charles S. Marschall, Senior Resident Inspector Salem Generating Station U.S. Nuclear Regulatory Commission Drawer I Hancocks Bridge, NJ 08038 Dr. Jill Lipoti, Asst. Director*
Radiation Protection Programs NJ Department of Environmental Protection and Energy CN 415 Trenton, NJ 08625-0415 Maryland People's Counsel American Building, 9th Floor 231 East Baltimore Street Baltimore, Maryland 21202 Mr. J. T. Robb, Director Joint Owners Affairs PECO Energy Company 955 Chesterbrook Blvd., 51A-13 Wayne, PA 19087 Mr. S. LaBruna Vice President - Nuclear Engineering Nuclear Department P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Nucle,Generating Station, Units 1 and 2 Richard Hartung Electric Service Evaluation Board of Regulatory Commissioners 2 Gateway Center, Tenth Floor Newark, NJ 07102 Regional Administrator, Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Lower Alloways Creek Township c/o Mary 0. Henderson, Clerk Municipal Building, P.O. Box 157 Hancocks Bridge, NJ 08038 Mr. Frank X. Thomson, Jr., Manager Licensing and Regulation Nuclear Department P.O. Box 236 Hancocks Bridge, NJ 08038 Mr. David Wersan Assistant Consumer Advocate Office of Consumer Advocate 1425 Strawberry Square Harrisburg, PA 17120 Mr. J. A. Isabella MGR. - Generation Department Atlantic Electric Company P.O. Box 1500 1199 Black Horse Pike Pleasantville, NJ 08232 Carl D. Schaefer External Operations - Nuclear Delmarva Power & Light Company P.O. Box 231 Wilmington, DE 19899 Public Service Commission of Maryland Engineering Division Chief Engineer 6 St. Paul Centre Baltimore, MD 21202-6806
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION ON THE SPENT FUEL POOL STORAGE RERACK APPLICATION AT SALEM G.ENERATING STATION, UNIT NOS. 1 AND 2,
- 1.
The licensee, Public Service Electric and Gas (PSE&G) Company is requested to submit the following:
a)
Explain the physical meaning of the negative hydrodynamic pressures shown in Tables 6.8.4 and 6.8.10 of the submittal.
b)
If the negative pressure indicates a cavitation, discuss whether PSE&G expects the occurrence of such a phenomenon as part of the fluid-rack interaction in the spent fuel pool during an earthquake event. Also, discuss how the DYNARACK computer program accounts and/or assumes such an interaction in the codification of the computer code~
c)
Describe the procedure used in the analysis to calculate the hydrodynamic pressure.
d)
Provide the largest magnitude of the hydrodynamic pressure distribution along the height of the rack and pool wall during the fluid and rack interaction for each case of the 3-D single and whole pool multi-rack (WPMR) analyses.
e) Tables 6.8.4 and 6.8.10 show average dynamic pressures of -0.0038 psi to +0.0063 psi in x and y directions. Provtde the magnitude of the hydrodynamic pressure in the vertical direction used in the spent fuel pool concrete wall analysis. If PSE&G used an average hydrodynamic pressure, rather than the peak (largest) hydrodynamic pressure, in the concrete wall analysis, justify the use of such a small (almost zero) average dynamic pressure as a conservative approach.
f)
Indicate whether or not an analysis with the peak dynamic pressure would not alter the calculated safety margin of 1.22 for the East Wall with respect to the bending strength evaluation (Table 8.5.2).
If it alters the margin, what is the revised margin? Also, discuss its implication.
g)
The staff anticipates a smaller safety margin if an analysis is carried out with the maximum dynamic pressure. This margin also can be changed depending on analytical methodologies and other parameters, such as, material properties used in the analysis. Since it is very important to maintain the pool structural integrity during a critical loading combination, PSE&G is requested to submit both the input and output of the pool structural analyses of a slab and four walls including the upper, middle and lower sections of the walls for all four different critical loading conditions. Also provide the physical dimensions and reinforcement areas and l~cations for further staff review.
Any technical assumptions made during the analyses should be discussed in details.
h)
In addition to the average hydrodynamic load, identify any other loads included in E or E' terms of the four critical loading conditions used in the concrete wall analysis, and provide the magnitudes of those loads.
- 2.
PSE&G stated that four artificial time histories were generated from the design response spectra defined in the FSAR, and they were used for dynamic analyses.
PSE&G is requested to submit the digitized time histories representing the input motions at the spent fuel pool floor which correspond to the safe shutdown earthquake (SSE) and operating basis earthquake (OBE) in a 3.5-inch diskette for use by the staff in performing an independent analysis.
- 3.
PSE&G indicated that an analysis is performed for the pool liner using the ANSYS computer program.
However, it did not provide detailed quantitative information related to the integrity of the pool liner in the submittal.
PSE&G is requested to provide the following:
a)
Analytical approaches or methodologies, b)
Loading conditions, analysis model and assumptions used, c)
Liner failure (tear and rupture) criteria, d)
Material properties used including concrete bearing strength and friction coefficient used between the rack pedestal and liner, and e)
Provide complete summary of the analytical results.
- 4.
Provide complete gap sizes among racks, and between the racks and the spent fuel pool walls shown in Figure 6.1.1.
- 5.
Describe plan and procedure for the post-OBE inspection of spent-fuel-rack gap configurations.
- 6.
Summaries of the worst results are shown in Tables 6.7.2 and 6.7.3 for the SSE and OBE single rack analyses, respectively. All worst results of the maximum displacements and stress factors for the SSE analyses are obtained when single rack runs are carried out assuming in-phase motion of adjacent racks, while all worst results for the OBE analyses are obtained when single rack runs are carried out assuming out-of-phase motion between the adjacent racks.
Describe the factors attributable to such findings.
- 7.
The WPMR analysis indicated that there is no rack-to-pool wall impacts although impacts are found to occur at rack top corners among the racks during an SSE event as well as during an OBE event. Describe the factors attributable to the no rack-to-pool wall impacts (e.g., boundary condition effects, any DYNARACK program limitations, etc.). The WPMR analysis shows a small magnitude of impact force between rack-to-rack impact considering the rack.corner displacements (0.9 to 1.2 inches) and heavy weight of the rack and fuel assemblies (more than 200,000 lbs.).
Provide the parameters involved in calculation of the impact force with discussion of the procedure to determine those parameters. Also, describe the analytical approach used in the analysis to calculate the impact force.
- 8.
Table 6.8.19 shows large difference between the results (maximum displacements, pedestal vertical loads and stress factors) of the single rack and the WPMR analyses.
Discuss the factors attributable to those differences, and provide a rationale for concluding that these results are accurate and reasonable.
- 9.
Was the rack design controlled mainly by the results of the simple rack analysis? If yes, was there any physical rack design change necessitated by the results of the WPMR analysis? As applicable, describe the change(s).
- 10.
Provide detailed information regarding the analytical simulation of the rattling fuel assembly impacting against the cell wall including the following:
a)
How you calculated the magnitude of the largest impact force and location of the impact in the fuel assembly and cell wall, b)
How you determined and analyzed the fuel assembly and cell wall integrity, c)
Discuss the considerations given regarding the effects of the fluid between the fuel assembly and cell wall during the interactions, and d)
Provide available experimental studies that verify the reasonableness of the numerical simulation adopted to represent the fuel assembly and cell wall interaction.
- 11.
PSE&G stated laboratory experiments were conducted to validate the multi-rack fluid-coupling theory.
Provide informa_tion related to these experiments, and discuss the basis for how the Fritz's two-body fluid-coupl ing model was extended to the multi-body applications.
- 12.
PSE&G stated that all computer programs utilized in performing the rerack analysis were verified in accordance with Holtec International's nuclear Quality Program (QP).
Indicate whether the QP was reviewed and approved by the NRC staff, and provide pertinent references. Also, indicate whether or not the QP documentation is available for staff audit.
With respect to the QP, provide results of any existing experimental study that verifies the correct or adequate simulation of the fluid coupling utilized in the numerical analyses. Since the experimental study mentioned in the reference section does not fully reflect realistic rack configuration, boundary conditions, rack and fluid interaction, and dynamic input loading conditions, PSE&G is requested to provide any other available results of experimental study in addition to the experimental -
study indicated in the reference section of the submittal or provide justification that the current level of the DYNARACK code verification is adequate for engineering application, and thus, should be accepted without further experimental verification work.
- ~ '
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i L 13.
Discuss the basis for selecting storage locations for newly discharged spent fuels versus the spent fuels which have been stored for some periods (i.e., the fuel storage location plan and the associated load distribution patterns as well as their effect on pool stress distribution and permanent deformations due to the previous spent fuel loadings, etc.).
- 14.
Provide the complete locations of the leak chase systems with respect to Figure 6.1.1, which shows the locations of the racks and pedestals.