ML20207A879
| ML20207A879 | |
| Person / Time | |
|---|---|
| Site: | 07109268, 07201023 |
| Issue date: | 02/25/1999 |
| From: | Baskin J, Price W, Srinivasan R SIERRA NUCLEAR, INC. |
| To: | |
| Shared Package | |
| ML20136H802 | List: |
| References | |
| TSL01-10.06.70, TSL01-10.06.70-R01, TSL1-10.06.70, TSL1-10.06.70-R1, NUDOCS 9903050293 | |
| Download: ML20207A879 (24) | |
Text
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LlO CtIENT: Nix l
CLIENT NO.: TSL-01 f
SNC NO.: TSI51-10.06.70 REVISION:_
1 l
DESIGN CALCULATION i
TRANSTOR* CONCRETE CASK HYPOTHETICAL TIPOVER ANALYSES PREPARED BY SIERRA NUCLEAR CORPORATION APPROVED BY:
DATE:
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Engineering Manager APPROVED BY DATE:
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Project Manager 9903050293 990225 gDR ADOCK 07109268 PDR op,
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Title:
_T_rmStor" Concrete Cask Hvoothetical Tioover Analysis SNC No: TSL01-10.06.70 1
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RJEVISION CONTROL SHEEI h:
PAq Reason Affected Pares Preparer Checker Proi. Enc.
Affected Documents / Comments i
1-1 BAC TJW BAC None 0
2/97 Initialissue All(I{[lj#
' Rev, o'
((/2il9B pcEA T5L41-C48 j
Att gy 1
4 99.
Incorporate All h 03 h3 (2-15.o49) Anctech's u
Report (DLR/M T5tDI -02A)
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"ilGNATURES Name/ Title Initials Date i
Boris Checheinitsky/ preparer / PE k %awuw/wra 04 2 24.-99 wrgeea mes /cNecxee k '
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SNC I
Sierra Nuclear Corporation
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1.0 BACKGROUND
O ' The cask tipover accident is considered a beyond design basis cvent that would cause the TranStor cask to tipover. The accident analyses performed for the tomado wind and missiles, flood, earthquake and explosions show that the margin of safety against overtuming of the cask is greater than 1.1 (Reference 1). Also, as shown in Reference 1, one side of the cask must be raised more than 5 feet higher over the other to move the center of 1
l gravity over the comer and create a potential for tipover,. This condition is not possible because:
l a) the cask limiting conditions of operations (LCO) restrict the cask lifling height to no more than 18 inches, l
and b)' the bed of a heavy-haul trailer is only 2 feet above the ground so that, even if all axles or tires were to simultaneously fail on the same side, the angle would not be sufficient to cause a cask tipover.
Thus, it is highly unlikely ' hat the TranStor cask would tipover. However, the attached report by Anatech t
addresses the consequences of the low probability, beyond design basis accident of a cask tipover. A summary of the Anatech's report is provided in the following.
2.0.
SUMMARY
The eccident analyses address the following parameters important to the cask overturning event:
o. Cask overtuming energydissipation through deformation of the concrete cask, foundation pad and the
^
subgrade material Structural integrity of the concrete cask o
Structural integrity of the basket, failed fuel cans and the fuel debris cans o
2.1 Storage Cask Evaluation
. During the hypothetical tipover accident, the concrete storage cask will impact the concrete foundation pad, which in tum is supported by the foundation subgrade material. The impact area will initially be along a narmw longitudinal strip of the cask surface. The concrete material in the cask and the foundation ped would both crack and crush thus dissipating a part of the impact energy.
A 2D model of tne concrete cok was developed to assess the damage sustained by the concrete cask.~ This model accounted for the stiffness of the foundation slab and the subgrade material. 'Diree different cases were constructed to represent the variations in slab design and subgrade conditions. Plastic stress-strain
- relations were used to represent the concrete and reinforcing steel materials,,
l Static capacity calculations were performed to determine the deceleration forces experienced by the cask -
during impact. The static capacity method pmvides steady g-loads on the cask for a given drop height that i
. was factored by a dynamic ampli6 cation factor. A multiplier for the gravity load in the cask is Revision Prepared Date thchi
- Date Sheet F
T. _O
- TSL- 01 0
BAC 02/25/97 TJW 2/26/97 1
Suldect: TranStor* Concrete Cask Hypothetical Tipover Ann ysis 1
RS 2.l24Mq h)P 2M&J of 2
CalculationNumber 3L4110.06.70
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I Sierra Nuclear Corporation incrementally applied to allow concrete cracking and compressive yielding to develop with redistribution of
, O ta i 4 t ta i r 4 ta a=r 4 99ert.
The results of the analyses, for all three site conditions considered, indicate that the cask tolerates the impact loads without significant distonion. The ovalizing deformations are not significant and, based on the static calculations, would appear to be mostly recoverable since the liner remains clastic. The cask sustains cracking and local crushing but has adequate reserve strength for operaticas to extract the canister after a hypothetical tipover accident.
2.2 Basket Evaluation TheTranStor baskets are designed by analysis to withstand the drop loads of 124g in the axial direction and 44g in the lateral direction. The hypothetical cask tipover accident analyses presented in the attached report resulted in basket loads that in all cases were below the design value of 44g. The loads in the axial directions would result from a vertical drop of the cask. The maximum credible vedical drop is estimated to be 18 inches. Tlie basket acceleration due to the 18-inch drop is bor.nded by the !?4g design value. The actual maximum acceleration from such drop can be calculated as follows:
F f'c A 4,000 2,640 1
i g=
g = 33g a=
=
Mcask Weask 320,000 1
Thus it is concluded that, following a hypothetical cask drop accident, the structural integrity of the
' Q concrete cask would be maintained and that the et t' action of the basket with the f achievable.
3.0 REFERENCES
' t. Calc. TSL01-10.06.64, Rev.1, TranStor* Concrete Cask Tornado, Flood, Earthquake, and Explosion Analysis, Revision 1.
I CL :.7+t TSL-01 Revision Prepared Date Checked Date Sheet I
Subject:
TranStor" Concrete Cask Hypothetical 0
BAC 02/25/97 TJW 2/26/97 2
1 (l4 2.Pt41%
Nr
- 2psh, of Tipover Analysis 2
Calculation N----'-n* TSL01 10.06.70
SNC Sierra Nuclear Corporation ATTACIIMENT ANATECll REPORT Structural Evaluation Of The BNFL TranStor" Spent-Fuel Storage Cask for Tipover Onto Concrete Storage Slabs O
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. r%
3o pojes AM'E Chent/ Project: TSL 01 Revision Pregu ed I Date Checked Date Sheet
Subject:
TranStor" Concrete Cask Hypothetical 0
BAC 02/25/97 TJW 2/26/97 A1 Tipover Analysis 1
9.,9, 7.l241 %
Nf" 2AsQ Calculation Nwnber: TSL01-10.06.70
ANATECH consuitino engineers Linking Theory and Practice ANA-99-0266 Structural Eva!aation of the BNFL TranStor*
Spent-Fuel Storage Cask for Tipover onto Concrete Storage Slabs BNFL Fuel Solutions 1 Victor Square Scotts Valley, CA 95066 l
P.O.99-005 Prepared by Q
ANATECH Corp.
San Diego, CA
,Oa-ehe/Pr Pre' pared and% proved by Program Manager Date
$I Wed anl Certified by Pdncipal in Charge Dat$
d i7 fh lpprov"ed andleleased by QA Manager Date
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February 1999 ANA-QA-150 Revision 3 5435 Oberlin Drive, San Diego, CA 92121 Far (619) 455-1094 Phone: (619) 455-6350 ""
REVISION EFFECTIVE NUMBER PURPOSE OF REVISION DATE O
Draft 01/29/99 1
Final Report 02/02/99 1
2 Customer Comments 02/17/99 1
3 Remove Proprietary References at Customer Request 02/19/99 i
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Rev. 3 Page 2 of M l
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l TABLE OF CONTENTS l
Page 1 INTRODUCTION 1.1 Backg ro u n d and Desc ription............................................................. 4 1.2 Objectives and Scope....................................................................... 4 2 ANALYSIS METHODS
~ 2.1 Analysis P rocedu re........................................................................... 6 2.2 S oftwa re O ualification..................................................................... 7 2.3 Evalu ation C rite ria............................................................................. 7 3 ANALYSIS RESULTS 3.1 Model Description.............................................................................. 10 3.2 Case.1 Results.................................................................................. 12 3.3 C ase 2 Res ults.................................................................................. 13 P
3.4 C ase 3 Results.................................................................................. 14 4.
SUMMARY
AND CONCLUSIONS 4.1 Summary of Results.......................................................................... 29 4.2 Conclusions..................................................................................... 29 5 R E FE R E N CE S................................................-............................................
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ANA-QA 150 Rev. 3 Pese 3 of 30 s
O1 INTRODUCTION 1.1 Background and Description The TranStor" cash, developed by BNFL Fuel Solutions, is designed for dry storage of spent-fuel. The spent-fuel assemblies, supported in baskets, are sealed in al canisters and loaded into these storage casks, which are then placed on concrete slabs. The cyhndrical casks are stored upright to facilitate convective airflow. The U.S. Nuclear Regulator Commission (USNRC) has recently published Standard Review Plans [1,2] describing the licensing requirements for these spent-fuel storage systems. The regulations require, among other things, that the casks remain stmeturally intact enough so that the realed canisters can be safely extracted after a hypothetical tipover accident. In addition, it must be demonstrated that the tipover event does not deliver g-loads to the fuel canister shell and basket such that their integrity is compromised.
t RHDAC"HD 1.2 Objectives and Scope MHDAC"HD o
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O RHDAC"HD The scope of this current work is limited to 2-D static calculationi, using the longest TranStor* cask. A 2-D slice of the cask at midspan is employed with the assumption that the tipover is bounded by an equivalent side drop. This provides a good approximation for the average g-load delivered to the cask internals and for the structural integrity evaluation of the cylindrical portion of the cask away from the cads. The following site conditions are considered; Case 1.
' An 18" thick,3000 psi concrete slab on 24" of engineered fill on top of bedrock Case 2.
A 36" thick,3000 psi concrete slab on deep soil with a subgrade modulur of 480 psi /in.
Case 3.
A 36" thick,4000 psi concrete slab on deep soil with a subgrade modulus of 288 i
psi /in.
These generic sites have similar values of target hardnest, which is a function of the slab strength and ultimate bending moment capacity and the subgrade modulus.
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ANALYSIS METHODS 2.1 Analysis Procedure 1
O MHDAC"HD Dese calculations use 2-dimensional modeling and static capacity analyses to determine the deceleration forces experienced by the cask during the impact. Detailed modeling of the cask is needed to establish the damage level sustained by the cask. A multiplier for the gravity load in the cask or a g-load, is'incrementally applied to allow concmte cracking and compressive yielding to develop with' redistribution of the loads to reinforcement and subgrade support. The total energy due to the incremental loading is accumulated through integration of the incremental strain energy density in the clements at any point in the loading. De total intemal energy is used to calculate the equivalent drop height by equating the total intemal energy,to the potential energy, which is defined by the cask weight times the drop height. Dus, a relation for the steady g-load vs. drop heigl1Ith constructed by plotting tie intemal energy divided by cask weight against the level of g-load applied to the cask. Because this is a static calculation, the calculated g-load is the average or steady force over the time of impact, and a j
dynamic amplification factor is needed to establish the peak g-load that the cask will experience during O the impact.' For heavy steel casks impacting concrete slabs, this factor has been verified from tests a having a value in the range of 1.27 to 1.47., From dynamic calculations of concrete casks impacting ma$l?$E
r-concrete slabs [4), the dynamic amplification factor on the static steady g-load has been found to be in O the range of 1.1 to 1.3. Therefore, the factor of 1.3 is used in the present analyses.
2.2 Software Qualification i
RHDAC"HD i
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2.3 Evaluation Criteria 1
As discussed above, the peak g-load experienced by the cask can be determined by applying a dynamic amplification factor to the steady g-force resulting from the static calculations for the drop height of j
interest. This amplified steady g-force would be the appropriate force to apply to the basket. However, i
the strains and stresses in the cask's structural elements obtained in the static analysis for the C. G. over h comer drop height cannot simply be amplified by a factor because the cask materials are responding in 3
1 nonlinear regime. Herefore, the procedure adopted for the evaluation of the cask integrity is first to detennine the steady g-load on the cask associated with the drop height that is equivalent to C.G. over corner. Den, the static calculations are continued beyond that drop height until the ultimate capacity of the slab or a force equivalent to the dynamic peak load is reached which ever came first. Incremental
- application of the additional g-loads in the static calculation allow the nonlinear cask response to develop. Imd redistribution to the steel components occurs as damage develops in the concrete. Full plasticity models are included for the steel components to account for load limitations on these materials. Hus, the cask integrity is evaluated at the " amplified" g-load by continuing the static capacity calculations. This procedure is intended to account for additional cask defonnations that may occur during the post-pulse dynamic response. However, the capeity of the slab and s'ubgrade system may not allow the continuation of the static calculations to the amplified g-load. In this case, the cask integrity is evaluated at a level of loading near the static capacity of the slab. The diametric deformation across the liner is calculated for evaluation of the ability to extract the fuel basket / canister after the tipover. The liner and cask reinforcement are also evaluated as a measure of the cask integrity.
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Rigid Cask 36" Slab,#14 Bers E E E._EZ EE EEE nusuas.n a.-ls mis e.s, s$Id. N
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SUMMARY
AND CONCLUSIONS 4.1 Summary of Results Simulation of a tipover event for a TranStor* spent-fuel storage cask is considered for three site conditions. The calculations are based on 2 dimensional modeling and the static capacity methodo'ogy used in the EPRI target hardness methods. The 2D slice at mid-cask assumes the tipover is boundtd by a side drop from a height equivalent to the CG over comer distance and provides a good approximation for the average impact loads along the cylindrical portion of the cask. The static capacity method provides steady g-loads on the cask for the given drop height that must be factomd by a dynamic amplification factor. The structural integrity of the center portion of the cask is evaluated by
- considering liner deformations and stress and hoop rebar strains at a factored level of g-loading.
oO RHDAC7HD In all cases, the cask appears to tolerate the impact loads without significant distortion. The ovalizing defonnations are not significant and, based on these static calculations, would appear to be mostly :ecoverable since the liner remains elastic. The cask sustains cracking and local crushing at the line of impact, but has adequate reserve strength for operations to extract the canister after a tipover. Hoop reinforcement remains intact and is not in jeopardy of reaching ultimate strains. The basket loads are within the basket design value of 44g for all cases.
4.2 Conclusions e-ee-MHDAC"HD O
ANA4A 150 mev.3 rese 29 ef 30
o5 REFERENCES 4
i 1.
" Standard Review Plan for Dry Cask Storage Systems," Draft, NUREG-1536, February,1996.
i 2.
" Standard Review Plan for Spent-Fuel Dry Storage Facilities," Draft, NUREG-1567, October 1996.
3.
" Storage Pad Design for Cask Tipover for the Trojan Nuclear Plant Independent Spent-Fuel l
Storage Facility," Report ANA-97-0212 to Portland General Electric Company, ANATECH Corp.,
San Diego, CA., April,1997.
4.
" Verification of Storage Pad Design for Cask Tipover for the Trojan Nuclear Plant Independent Spent-Fuel Storage Facility," Report ANA-98-0233 to Portland General Electric Company, ANATECH Corp., San Diego, CA, January,1998.
5.
Y. R. Rashid, "The Effects of Target Hardness on the Stmetural Design of Concrete Storage Pads for Spent-Fuel Casks," EPRI Report NP-4830, October,1986.
6.
Y. R. Rashid et. al., " Validation of EPRI Methodology for Analysis of Cask Drop and Tipover Accidents at Spent-Fuel Storage Facilities," Proceedings of ICONE-5, 5* Intemational Conference on Nuclear Engineering, Nice, France, May 26-30,1997.
7.
ANACAP User's Manual, Version 2.1, ANATECH Corp., San Diego, CA., September,1997.
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REVISIONS TO THE RAI-2 RESPONSES for the TRANSTOR" STORAGE CASK SYSTEM INSTRUCTIONS FOR REPLACEMENT PAGES INSERT REPLACE B-22 B-22 B-26 8-26 B-27 B-27 i
B-74 B-74 B-79 B-79 B-80 B-80 3
c
SNC/BNFL Fuel Solutions Transtor 10CFR72 SAR-Docket 72-1023 SECTION B31/3-21 NRC Questions (February,1999) TAC No. L22307 QUESTION:
l 3-9 RE: Calculation TSL01.10.06.65 Revision 1 (a)
Re-verify the seismic stresses using the rssolution of RAI-2, Question 3-7 above,for Calculation TSL01.10.06.64, Revision 0.
[
(b)
Venfy the tipover load with the resolution ofRAl-2, Question 3-13 below,for Calculatien TSL01.10.06.70, Revision 0.
(c)
Perform design acceptability calcidation in accordance with the requirements ofthe ACI349 Code.
Section 5.7 of the calcidation incorrectly references allowabla stresses given in AC:349. This code does notprovide allowable stresses. Rather, the code requires that the design strength at every section of the concrete cask be at least equal to the required strength for the greatest load combination. To i
meet the AC1349 code, theforces and moments fr each load combination must be calculated and be shown to be less than the design strength.
RESPONSE
a) The stresses have been verified. Please note that the seismic loads for this analysis have i
not changed as stated in the response to Question 3-8 (a), (b), and (c) above.
b) As discusse~d in the response to Question 3-13, the SAR has been revised to provide an evaluation of the consequences of a hypothetical non-mechanistic cask tipover event. As stated in that response, the loads on the cask due to the tipover accident are bounded by the design values of 124g (vertical) and 44g (horizontal).
I c) Calculation TSIMI.10.06.65 has been revised to evaluate the concrete cask based on the forces and mon. nts rather than allowable stresses. Please see Revision 2 of this document in Section D, Calculations. As shown in the calculation, forces and moments due to all load combinations are less than the design strength as specified by ACI 349.
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I B-22
SNC/BNFL Fuel Solutions TranStorm 10CFR72 SAR - Docket 72-1023 L
SECTION B3-1/3-21 NRC Questions (February,1999) TAC No. L22307 l
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QUESTION:
i 3-13 ^ RE: Calculation TSL01.10.06.70, Revision O Revise this calculation package to take into account thefollowing:
1 Include in the SAR an analysis ofcask drop and tipover accidents. Also, provide the l
derivation of the design envelopes of 44g and 124gfor the respective horisontal and
}
vertical decelerationforces stated in the SAR. The analysis should beperformed with
^
a validated methodology.
The staffhas demonstrated that results oflow-velocity impact tests ofsteel billets can be effectively used to validate afinite element analysis approach on the basis of a cask-pad-sollinteraction system.
Because the TranStor application isfor a certificate ofcompliance under the general licenseprovisions ofPart 72, limiting conditions ofoperations must be established to ensure that users ofthe TranStor design meet the criteria given in the SAR. A user of the TranStor design must, under 10 CFR 72.212, determine and verify that its design I
decelerations due to a drop and tipover at its site do not exceed the cask design envelop of44g horizontally and 124g vertically, as stated in the SAR. To do this, the
'l user must demonstrate that the site-specific pad / soil design conditions at its ISFSI result in decelerations which are within the design envelop.
Note: This calculation wasprepared to address RAl-1, Questions 1-29 through 1-38.
RESPONSE:-
-l Calculation TSL01.10.06.70 has been revised (Revision 1). The revised calculation j
includes an evaluation of the concrete cask and the basket due to a hypothetical cask tipover accident. The analysis takes into account dissipation of the energy from the j
cask overturning through deformation of the concrete cask, foundation pad and the subgrade material. The methodology has been validated as documented in Appendix.
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B of EPRI Report NP-7551 and further in a paper by Rashid, James, and Ozer,
" Validation of EPRI Methodology for Analysis of Cask Drop and Tipover accidents at Spent Nuclear Facilities," published in the Proceedings of the 5" International Conference on Nuclear Engineering, May 1997, Nice, France. The methodology is shown to be conservative when compared to drop tests.
Three different cases were constructed to represent the variations in slab design and subgrade conditions. The results of the analyses, for all three site conditions L
. considered, indicate that the cask tolerates the impact loads without significant l
- distortion.- The ovalizing deformations are minor (the peak diametrical deformations i
are calculated to be about 0.4") and, based on the static calculations, would be recoverable since the liner remains clastic. The cask sustains cracking and local crushing but has adequate reserve strength to allow the canister to be extracted after a hypothetical tipover accident. The hypothetical cask tipover accident analyses i
1 B 26
SNC/BNFL Fuel Solutions
. TranStor" 10CFR72 S AR - Docket 72 1023 SECFION B3-1/3-21 NRC Questions (February,1999) TAC No. L22307 presented in the attached report result in basket loads that in all cases were below the design value of 44g. The loads in the axial directions would result from a vertical drop of the cask. The maximum credible vertical drop is estimated to be 18 inches.
The basket acceleration dae to the 18-inch drop is bounded by the 124g design value.
J The 44g and 124g accelerations are stated to be the horizontal and vertical design loads for the TranStor* basket. These are termed the design loads simply because they are the maximum accelerations values for which BNFL Fuel Solutions has structurally qualified the basket (see calculation TSL01.10.06.61).
The cask tipover analyses included in Calculation TSL01.10.06.70, Revision I were based on three typical site conditions. The acceptability of a specific site would be established based on calculating the hardness of the foundation pad and the stiffness of the subgrade material. If the site-i.pecific hardness and stiffness values are within the range of values considered in the generic analyses, the site would be deemed acceptable. Site-specific analysis would be perfonneet by the user if the hardness and stiffness of the foundation and subgrade fall outside the range.
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SNC/BNFL Fuel Solutions Transtor 10CFR72 SAR - Docket 72-1023 SECTION B3-1/3-21 NRC Questions (Febmary,1999) TAC No. L22307 i
RESPONSE
a) The TranStor Part 72 Storage C ofC application is not intended to encompass plants without an operating fuel pool and Part 50 License and does not address the use of the shipping cask. Therefore, under the C of C, all lifts of the transfer cask will occur inside 1
the user's fuel building and be done underjurisdiction of the Part 50 License. At the sites where the building crane is single failure proof, no additional analysis is required. At the other sites where the building crane is not single failure proof, site-specific impact limiting pads will be used to keep the canister load withia its design values. This is the i
same design basis as currently used for the VSC-24 system.
l As discussed in the response to Question 3-13, the basket design loads are selected as 124g vertically and 44g horizontally. The drop loads may be limited to be within these values by a number of methods, such as use of the site-specific impact limiters, restricting the lift height, showing analytically that the target structure is son enough without additional impact limite s, etc. Then transportation impact limiters are not required for i
storage purposes and no reference to their use is made in the TranSter* Part 72 Storage SAR. However, the TranStor* Part 72 Storage SAR does refer to the potential for a site-specific heavy loads evaluation of a crane that does riot meet the single-failure proof criteria. These evaluations may require the use of impact limiting pads, which are j
different than impact limiters required for transportation.
The only handling outside of the fuel building is that of the storage cask. The storage cask is lifted vertically using either air pallets (3 inch lin) or a cask transporter (~12 inch lin). As discussed between the NRC reviewers and BFS on September 23,1998, the TranStor* SAR Limiting Condition of Operations (Chapter 12}has been revised to limit I
the lin height to no more than 18 inches. Since the TranStor baskets have the design vertical acceleration of 124g, a drop from that height would be inconsequential (see Section 11.2.10 in the SAR). Furthermore, horizontal drop or a tipover of the cask are not credible events because the cask is always vertical and never lifted by more than 18 inches. A heavy-haul trailer, which may also be used to move the cask between the fuel building and the ISFSI Pad, has a bed that is no more than 2-feet off the ground. Even if all axles of the trailer were to fail on one side, the cask would not tip over because a much largr angle is required to bring its CG over the corner (see Figure 11.2-2 of the TranStor SAR). See also the response to RAl2 3-13 relating to the analysis of a hypothetical cask tipover accident.
b) As stated in (a) above, this TranStor* Part 72 Storage C ofC application does not address the use of the shipping cask. For plants without a Part 50 License, this operation will be covered by a site-specific Part 72.
l B-74 i
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SNC/BNFL Fuel Solutions TrenStor 10CFR72 SAR - Docket 72-1023 SECTION B3-l/3-21 NRC Questions (February,1999) TAC No. L22307 l
t QUESTION:
l 11-3 RE Calculation BNFL1.10.06.34, Revision 1 i
(a) laplain the basisfor the deceleration loads of 44 g and 50 gfor the horizontal and vertical drop cases respectively, for the accident conditions, which existfor the storage license.
Reference 3 in Calculation BNFLL10.06.34, Revision 1 refers to the transportation application for TranStor. In the reference, as well as the calculation, the storage basket is assumed to have impact limitersfor the 30-i fact drop accidentsfor 10 CFR Part 71. For 10 CFR Part 72, on-site transfer and handling operations will not involve use ofimpact limiters. Therefore, a basisfor the design criteria must be established which does not assume the use ofimpact limitersfor storage purposes. This question may be considered in conjunction with RAl-1, Question 11-1, above.
(b) Identify the specific calculation number referred to in Section 2.1 as the "BWR TranStor basket structural analysis ".
(c) In Table 4.2-1, correct the allowable stress value in the XM-19 column and 750 F rowfor 1.5 Sm.
(d) Provide node and element maps of the models as well as all computer input and output files to verify the results as listed in Table 2-1 for the PWR horizontal drop case.
(e) Table 2-1 presents stress intensity results, which cannot be verified without the location of the nodes and elementsfor the models, as well as the input and outputfiles. The data given in Tables 6.4-3 through 6.4-5for the 3-dimensional analysis does not appear to support the results in Table 2-1.
The data given in Tables 6.4-6 through 6.4-8 does appear to support the results in Table 2-1for the 2-dimensional analysis; however, without the maps and computerfiles it is notpossible to verify.
RESPONSE
a) The deceleration loads of 44g horizontally and 50g vertically used in this calculation were derived from the impact limiter analysis, which addresses a 3&. foot drop of a loaded L
shipping cask equipped with impact limiters.' As discussed in the responses to Questions 3-13 and 11-1, the basket design loads for storage are 44g horizontally and 124g vertically. The storage contiition stresses are calculated by scaling of the transportation stresses by the ratio oflodi.
B-79 I
i SNC/BNFL Fuel Solutions TranStor 10CFR72 SAR - Docket 72-1023 SECTION B3-1/3-21 NRC Questions (February,1999) TAC No. L22307 l
As also stated in the response to Question 3-13, the basket design loads of 44g (horizontal) and 124g (vertical) bound the maximum expected deceleration loads from a hypothetical cask tipover accident.
As discussed in response to Question 11-1, the qualification of the basket to the design loads is without the use of impact limiters that are required for transportation. Such impact limiters are not required for storage purposes and no reference to the use of impact limiters for transgortation are made in the TranStor* Part 72 Storage SAR.
However, the TranStor' Part 72 Storage SAR does refer to the potential for a site-l specific heavy loads evahtation of a crane that does not meet the single-failure proof criteria to satisfy an existing 10 CFR 50 License. These evaluations may require the use of impact limiting pads, which are different than impact limiters required for transportation.
The purpose of the specified design loads is to assist the plants without a single-failure proof crane in their Part 50 drop evaluations and impact limiting pad design. The impact limiting pads mus'. curb the drop loads within the stated design values.
b) The referenced calculation is BNFLI.10.06.46, MPB BWR Structural Analysis 30-foot End Drop Accident Condition. The editorial change to include this reference in Sections 2.1 and 5.0 of calculation BNFLl.10.06.34 will be incorporated into the next revision of the calculation.
c) The Allowable Design Stress Intensity Sm for Type XM-19 stainless steel at 750 F is 28.5 ksi and 1.5 Sm is 42.75 ksi. Calculation BNFLl.10.06.34, Table 4.2-1 has been corrected in Revision 3 of calculation BNFLI.10.06.34. Please note that XM-19 stainless steel is no longer an option for the basket material, so the identified discrepancy has no impact on the analysis.
l d) Due to a large number of nodes used in both 2-D and 3-D models for basket analysis, the printed map with node numbering would not be legible.. To assist the reviewers, the current revision of the calculation BNFLI.10.06.34 also includes printouts of the stress listings and stress contour plots in the basket shell. This calculation has been recently submitted in support of the PGE application.
l e) The values in Tables 6.4-3 through 6.4-8 of BNFLI.10.06.34, Revision 3, have been reviewed and found to support the summary of results in Table 2-1. As stated above, to assist the reviewers, the current revision of the calculation BNFLI.10.06.34 also includes printouts of the stress listings and contour plots in the basket shell.
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SAFETY ANALYSIS REPORT for the TRANSTOR STORAGE CASK SYSTEM REVISION D INSTRUCTIONS FOR REPLACEMENT PAGES INSERT REPLACE 3-7 3-7 3-11 3-11 3-39a new 3-39b new 4-6 4-6 11-41 11-41 11-42 11-42 11-43 11-43 11-45 11-45 4**
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