ML20237K145
| ML20237K145 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 06/17/1987 |
| From: | NRC |
| To: | |
| References | |
| OLA-A-011, OLA-A-11, NUDOCS 8709040215 | |
| Download: ML20237K145 (7) | |
Text
e se - 2 75/3 23 -NA bl/7l77 PGandE Exhibit No. 11
/h ~ ((
003Eiil wp r APPENDIX D TO S'P SECTION 3.8.4 R
{Y' TECHNICAL POSITION ON SPENT FUEL POOL RACis7 AU3 26 P3 :33 Introduction The purpose of this appendix is to provide minimum requirements and criteria for review of spent fuel pool racks and the associated structures which would meet the design standards specified in subsection II'of this SRP section.
(1) Description of the Spent Fuel Pool and Racks Descriptive information including plants and sections showing the spent fuel pool in relation to other plant structures shall be provided in order to define the primary structural aspects and elements relied upon to perform the safety-related functions of the pool, the spent pool liner fuel, and the racks. The main' safety function of the spent fuel pool, including the liner, and the racks is to maintain the spent fuel assemblies in a safe configuration through all environmental and abnormal loadings such as earthquake, and impact due to spent fuel cask drop, drop of a spent fuel assembly, or drop of any other heavy object during' routine spent fuel handling.
The major structural elements reviewed and the extent o,f the descriptive information required are indicated below.
(a) Support of the Spent Fuel Racks: The general arrangements and principal features of the horizontal and the vertical supports to the spent fuel racks should be provided indicating the methods of transferring the loads on the racks to the fuel pool wall and the. foundation slab.
All gaps (clearance or expansion allowance) and sliding contacts should be indicated. The extent of interfacing between the new rack system and the old fuel pool walls and base slab should be discussed, i.e.,
interface loads, response spectra, etc.
If connections of the racks are made to the base and to the side walls of the pool such that the pool liner may be perforated, the provisions for avoiding leakage of radioactive water of the pool should be indi-cated.
(b) Fuel Handling:
Postulation of a drop accident, and quantification of the drop parameters are reviewed by the Accident Evaluation Sranch (AEB); Structural Engineering Branch accepts the findings of the AE3 review for the purpose of review of the integrity of the racks and the fuel pool including the fuel pool lines due to a postulated fuel handling accident.
Sketches and sufficient details of the fuel handling system should be provided to facilitate this review.
(2) Applicable Codes, Standards, and Specifications Construction materials should conform to Section III, Subsection NF of Ref. 3.1.
All materials should be selected to be compatible with the fuel pool environment to minimize corrosion and galvanic effects.
\\
8709040215 870617 y
o 00N 3.8.4-27 Rev. D - July 1981
RUCLEAR REQllA70#f M2/t3310N bY Dxksileo, h0 'UT'OO Off41al tsk. No.
V Cw E ca r pu,
- i. a..
\\/
O
_ REClWED Applitant _
. ggjtcigg Intervener ___
Cent's Ofri b"
~
DA71 Contextor Whness Othe'
'NT#4 OMNd Reporter i
O O
6
Design, fabrication, and installation of spent fuel racks of stainless O
steel material may be performed based upon Subsection NF requirements of i
1 Ref. 3.1 for Class 3 component supports.
(3) Seistic and Impact Loads For plants where dynamic input data such as floor responses spectr4'or ground response spectra are nut available, necessary dynamic analyres may be performed using the criteria described in SRP Section 3.7.
The ground response spectra and damping values should correspond to Regulatory Guides 1.60 and 1.61, respectively.
For plants where dynamic data are available, e.g., ground response spectra for a fuel pool supported by the ground, ficer response spectra for fuel pools supported on soil where soil-structure interaction we considered in the peal design or a floor response spectra for a fuel pool supported by the react 6r building, the design and analysis of the new rack system any be performed by using either the existing input parameters including the old damping values or new parameters in accordance with Regulatory Guides 1.60 and 1.61. The use of existing input with new damping values in Regulatory Guide 1.61 is j
not acceptable.
Seismic excitation along three orthogonal directions should be imposed simultaneously for the design of the new rack system.
The peak response from each direction should be combined by square root of the sum of the squares in at.cordance with Regulatory Guide 1.92.
If response spectv-a are available for a vertical and horizontal directions enly, the same horizontal resp 6nse spectra may be saplied along the other e
horizontal direction.
rh Submergence in water may be taken into account, The effects af submergence are considered on case-by-case basis.
Due to gaps between fuel assemblies and the walls of the guide tubes, additional. loads will be generated by the impact of fuel assemblies during a postulate # seismic excitation. Additional loads due to this impact effect may be determined by estimating the kinetic energy of the fuel asstably. The sexison velocity of the fuel assembly may be estimated to be the spectial v61ocity ass 6ciated with the natural frequency of the submerged f.uel assembly.
Loads thus generated should be considered for local as well is overall etfacts on the wails of the rack and the support-ing framewr,rk.
It should be demonstrated that the consequent loads on the fuel assembly do not lead to a desage of the fue).
Loads generated front other postu'iated impact events may be acceptable, if the fellowing perameters are described:
the total mass of the impacting missile, the maximia velocity at the time of impact, and the ductility ratio of the turget material utilized to ahnsrb the kinetic energy.
(4) Loads and Load Combinations:
Any changa in the temperature distribution due to the proposed modification should be identified.
Information portaining to the applicable design loads and various combinations t. hereof should be provided indicating i
the thermal load due to the effect of the saaximum temperature distribution through 1.he pool walls and base slab. Yesperature gradient across the J
~
3.8.4-28 Rev. 0 - July 1981 6
9 m
m m.m
-aum
o m
rack structure due to differential heating affect between a full and an empty cell should be indicated and incorporated in the design of the rack structure. Maximum uplift forces available.f tam the crane should be indicated including the consideration of these forces in the design of the racks and tre analysis of. the existing pool floor, if. applicable.
~
The fuel pool racks,.the fuel pool r>tructure including the pool slab and fuel pool liner, should be evaluated for accident load combinations which include the impact of the spent fuel cask, the heaviest postulated load drop, and/or accidental drop of. fuel assembly from maximim height.
The acceptable limits (strain'or stress limits) in this case will be-reviewed on a case-by-case basis but in general the applicant'is required to demonstrate that the functional capability and/or the structural integrity of each component is maintained.
The specific loads and load combinations are acceptable if they are in conformity with the applicable portions of SRP Section 3.8.4, subsection 11.3, and Table 1.
(5) Design and Analysis Procedures Details of the mathematical model including a description of hr.w the important parameters are obtained should be provided ' including the follow-ing: The methods used to incorporate any gaps between the support systems and gaps between the fuel' bundles and the guide tubes; the methods used to lump the masses of the fuel bundles and the. guide tubes; the met. hods used to account for the effect of sloshing water on the pool walls; and, the effect of submergence on the mass, the mass distribution and the effective damping of the fuel bundle and the fuel racks.
The design and analysis procedures in accordance with SRP Section 3.8.4, subsection 11.4 are acceptable. The effect on gaps, sloshing water, and increase of effective mass and damping due tc submergence in water should be quantified.
When pool walls are utilized to provide lateral restraint at higher elevations, a determination of the flexibility of the pool walls and the capability of the walls to sustain such loads should be provided.
If the pool walls are flexible (having a fundamental frequency less than 33 Hertz),
the floor response spectra corresponding to the lateral restraint point at the higher elevation are likely to be greater than those at the base of the pool.
In such a case using the response spectrum approach, two separate analyses should be performed as indicated below:
(a) A spectrum analysis of the rack system using response spectra corresponding to the highest-support elevation provided that there is not significant peak frequency shift between the response spectra i
at the lower and higher elevations; and (b) A static analysis of the rack system by sub.jecting it to the maximum relative support displacement.
The resulting stresses from the two analyses above should be combined j
by'the absolute sua method.
3.8.4-29 Rev. 0 - July 1981
1 In order to detemine.the flexibility of the pool wall it is acceptable z
for t.he applicant to use equivalent mass and stiffness properties obtained
)
from calculations similar to those described in Ref. 4.1.
Should the funda-mental frequency of the pool wall model be higher than or equal.te 33 Hertz,
^
it may be assumed that the response of the pool vall and the corresponding lateral support to the new rack system are identical to these of the base slab, for which appropriate floor response spectra or ground response spectra may already axist.
(6) Structural Acceptan:e Criteria k
The structural acceptance criteria are those given in the Table 1.
When buckling loads are considered in the design, the stesetural acceptence criteria shall be limited by the requirements of Appendix XVII to Reference 3.1.
For impact leading, the ductility ratios utilized to absorb kinetic energy in the tensile, flexural, compressive, arid shearing modas should be quanti-3 fled. When considering the effects of seismic loads, hetors of safety against gross sliding and overturning of racks and rack medulus under all probable service conditions shall be in accordance with SRP Section 3.8.5, subsection 11.5. This position on factors of safety against sliding and tilting need not be met provided any one of the following conditions is met:
(a) it can be shown by detailed nonlinear dynamic analyses that the ampli-O tudesofslidingmotionareminimal,andimpactbetweenadjacentrack modules or between a rack module and the pool walls is prevented w;
provided that the factors of safety against tilting are within the Uj b
values permitted by SRP Section 3.8.5, subsection 1I.5.
i 1
(b) it can be shown that any sliding and tilting motion will be contained within suitable geometric constraints such as themal clearances, and that any impact due to the clearances is int.orporated.
The fuel pool structure should be designed for the increased loads due to the new and/or expanded high density racks. The fuel pool liner leak tight integrity should be maintained or the' functional capability of the fuel 1
pool should be demonstrated.
(7) Materials, Quality control, and Special Construction Techniques The materials, quality contec1 procedures, and any special construction
)
techniques should be described. The sequence of installation of the new fuel racks, and a description of the precautions to be taken to prevent damage to the stored fuel during the construction phase should be provided.
1
- if connections between the rack and the pool liner are made by welding, ll the welder as well as the welding procedure for the welding assembly sha I
i be qualified in accordance with the applicable code, O
~
i
.)
i 3.8.4-30 Rev. 0 - July 1981
T TABLE 1 u
LOAD COMBINATION ACCEPTANCE LIMIT D+L Level.A service limits D+L+T, D+L+T
+E o
D + L + T, + E Level a service limits D + L + T, + Pf D4 L + T, + E' Level D service limits D+L+F The functional capability d
of the fuel racks should be demonstrated Limit Analysis:
1.7 (D + L)
XVII 4000 of ASME ASME Code Section III 3.3 (D + L + T,)
1.7 (D + L + E) 1.3 (D + L + E + T,)
~
1.3 (D + i. + E + T,)
1.3 (D + L + T,+ P )
f 1.1 (D + L + T,+ E')
Notes:
1.
The abbreviations in the table above are those used in subsection II.3.a of this SRP section where each term is defined except for T, postulated which is defined here as the highest temperature associated with the abnormal design conditions.
2.
Deformation limits specified by the Design Specification limits shall be satisfied, and such deformation limits should preclude damage to the fuel I
assemblies.
3.
The provisions of NF 3231.1 of Reference 3.1 shall be amended by the requirements of paragraphs c.2.3 and 4 of Regulatory Guide 1.124 entitled
- Design Limits and Load Combinations for Class 1 Linear-Type Component Supports."
4.
F is the force caused by the accidental drop of the heaviest load from d
the maximum possible height and P is upward force on the racks caused by postulated struck fuel assembly. f g
3.8.4-31 Rev. 0 - July 1981 L
3
\\
VI. REFERENCES
[
O.
Regulatory Guides i
1 Seismic Design Classification 1.29 Design kesponse Spectra for Seismic Design of Nuclear Power' 1.60 Plants Damping values for Seismic Design of Muclear Power Plants 1.61 l'.76 De. sign Basis Tornado for Nuclear Power Plants Combining Modal Responses ~and Spatial Components in Seismic 1.92 Response Analysis 1.124 -
Design Limits and Loading Combinations for Class 1 Linear-Type Components Supports 2.
Standerd Review Plan Section Seismic Design 3.7 3.8.4 -
Other Category I Structures
~
3.
Industry Codes and Standards 1.
American Society of Mechanical Engtneers, Boiler and Pressure sr-Vessel Code,Section III, Division 1 s
2.
American National Standards Institute, N210-76 3.
American Society of Civil Engineers, Suggested Specification for Structures of Aluminum Alloys 6061-T6 and 6067-T6 4.
Tr.e Alueinium Association, Specification for Aluminum Structures 4.
Other 1.
Esriggs, John M., " Introduction to Structural Dyannics," McGraw-Hill Book Co., New York,1964.
i 3.8.4-32 Rev. 0 - July 1981 9
.