ML19256D330
| ML19256D330 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 08/05/1970 |
| From: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Morris P US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910170836 | |
| Download: ML19256D330 (9) | |
Text
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AUG 5 B70 J
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Peter A. horris, Director Diviaicn of Reactce Licensing 20 TEE MILE IS1AND, WIT fl, DOCEF NO. 50-289 Adequate respcnses to the <~TM request for additional infer-matica are requued before we can cocplete our review of the subject applicaticn. *lhase requests, prepared by the DRS Structural Engineering Branch, and DRS Seim:ir Cmsultants, Netanark, and Hall, and J. F. Proctor, cmcern the ocntainment and Class I structural design material presented in Secticos 2, 5, 5A, and SB of the applicatim.
Original signed by E. G. Case Edsal G. Case, Director Divinicn of Reactor Standards
Enclosure:
Request for Additirmal Infomation for Diree Milm Island il oc w/ enc 1:
R. C. DeYoung, DRL R. Boyd, IRL m
Dis tribution:
u D. Skzwholt, DRL o uppl R. R. Maa:ary, IRS DRS RF C. Iong, IRL DR RF A. Iktmerick, DRS SEB RF D. Ross, IRL bec:
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- r. Se, Iss R. Shesansar, DRS 1454 290 G. Arndt, IRS f
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t REQUEST 10R ADDITICIIAL INICPyM ION
'IHFEE MILE ISLMID UiIT NO.1 DOCKET NO. 50-289
- 1.
'Ihe material presented in Section 2 of the FSAR suggests that all the critical Class I structures are founded en bedrock, since bedrock is quite near the surface. Provida for each of the principal structures at the site a tabulation of the type of foundation employed for the structure, the elevation of the foundation, the foundation medium, and other pertinent in.fon::aticn.
- 2.
Uvennessing or excessive deformation may arise from differential translational or rotational motion of major structures and connecting elements, or at points where piping or tunnels enter buildings.
Indicate the special provisions that were emplcyed fcr protection of Class I ele:aants traversing between buildings, such as piping or tunnels.
- 3.
The stress analysis of the buttresses for the containment is presented in Appendix 5B. The maximum s..a.aring stress ccr:per.ent of maxi:mrn and minimum principal stresses for a ntrier of different loading conditicns has been omitted. Provide the sizing criteria applied for designing the reinforcing steel and the associated shearing stresses.
"LRS denc Consultant, hewnarx S nall, requests for additional informaticn.
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x *4.' The structural integrity testing of the reactor containnent structure is described in Appendix SB.
It is not apparent what measurements-will be made at and in the vicinity of the prestressing anchorages to indicate their adequacy. In view of the high stresses already existing in these areas by virtue of the prestressing, the additional stre." and strains arising fm1 internal pressure loading may not be highly significant. Nonetheless,nonitoring might M appropriate, coupled with visual observations and inspections, to attempt to lend validity to the analysis and understanding of the behavicr.
Provide a discussion which addresses this area as well as preposed monitoring program which is planned for the test.
- 5.
A summary of the aircraft impact design is contained in Appendix 5A of the FSAR. Ecwever, the combined effect of separate consideration of simultaneous or not simultaneous localized engine impact and the plane impact of Case D is not examined explicitly. Mcre precisely certain assumptions are made regarding loss of engines, cuter pertions of wings, and fuel which are open to question. If the airemft remains whole (no loss of weight) the peak load would be 6
18 x 10 lb. The area under the load-time curve (impulse) would be equal to the initial ::r. mentum of the 200,000 Ib. airtraft with a 200 knot velocity. The curw of Fig. 5A-1 and Table SA-1 cf FSAR 6
shows a peak lead of 15 x 10, assuming loss cf engines, fuel, and
- rnece mformation requests were prepared by ERS Ccasultant J. F. Prectcr of Naval Orc.ance labcra cry.
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. wing structure :(nich is inconsistent with the peak load of 16.2 x 106 lb.
specified in Table SA-6.
Explaia this inconsistency and indicate the correct load, e
Since no criteria are presented to show when these pieces would break away fraa the main aircraft, it is not clear how this lost weight is handled nor how these now free pieces of the aircraft are treated as additional colliding masses en the containment structure at scm locatica removed from the main fuselage loading.' Provide additional discussion and infomation en the impact of the aircraft remaining whole anc on the effect of ccabined impact of aircraft without engines, fuel, and outer pcMiens of wings, and of the impact of detached parts c f the aircraft, including the investigation of:
(a) Impact of the vinole aircraft (b) Simultaneous impact of the partially disabled aircraft and the detached elecents (engines, wings, tips, etc.) on separate locaticns of the structures.
(c) Irpact of the partially disabled aircraft en the structure daraged by previous irpact of detached elements.
Provide the criteria used to detemine when the outbcarx! engines, outer portion of wings, and fuel break away during i:: pact. The dis-cussica requested for the contain:ent should be expanced to include all harxiened structures listed further balcw.
- 6.
The methcd of calculating the fundam2ntal frequency discussed in Sectica 3.2.1 of Appendix 5A is questiened. Tne frequency of a linear elastic 1454 293
4 flexural system such as that assumed varies directly with the square root of the modulus of elasticity E.
Normal E for concrete is taken at low stresses. Actually this is an approximation of the intial slope of the non-linear stress-strain curve for concrete.
Thus frequency based on such an E would hold only for relatively low stress levels. As concrete is loaded nearer its compressive capability or 'is cracked, the slope of the stress-strain curve is substantially changed; therefore, it would be expected that the fundamental freque-cy of a concrete slab or wall would vary with the magni ude of the load. This together with the unknowns of treat-ing a wall or a roof of a complex structure as a single degree of freedom system could lead to significant shif ts in response frequency.
Thus it would seem more prudent and certainly more conservative to assume the maximum DLF in designing exterior walls and roofs, of structures to withstand aircraft impact. Indicate the actual values of E used in frequency calculations.
Provide an evaluation of the influence of variation in fundamental frequencies on the response of the st, ucture and on DLF (see also
- 7(c)) and a discussion of the influence of changes in assumed edge conditions.
- 7.
Section 2 of the Appendix 5A indicates that a single-degree-of-freedom analysis approach was employed. On the other hcnd, in the analysis for Case C, impact loading, there is an indication that a rodal analysis procedure involving multiple-degree-of-freedom censiderations was employed.
It is not clear whether the dynamic 1454 294
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load factors originally referred to were employed with that analysis technique or whether some other approach was used, since the forcing functions are not defined. Submit the following additional infor-mation to permit an evaluation of the analysis carried out and the significance of the results.
(a) The justification for the adequacy of modeling a multiple-degree-of-freedom system as a single-degree-of-freedom system for con-centrated load considerations, as indicated at the beginning of of Appendix SA.
This justification should also, include the structure-soil interaction, especially when the impact occurs near an edge. Indicate to what degree the use of a single-degree-of-freedom system affects the natural frequency and the DLF.
(b) A further explanation of the technical analysis employed for Case C and any correlations between the findings there and those reported in the earlier sections of Appendix 5A.
(c) A discussion of the variation of parc=eters investigated as a part of the analysis, and the sensitivity of the analysis and evaluation to the variation of parameters.
For instance, depending on the loading-time curve used, differences of the order of 10% may occur in the calculation of DLF. Coupled with variation of peak loads, this might indicate response or stress differences of 30 to 40%. The discussion should include a study of the influence of possible variation of t presented in Table SA-1 and similar consideration, such as a variatica of the crushing load of tha fusclage cnd of the inpact velocity.
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% (d)
The applicability of the penetration femulas should be discussed especially with respect to the empirical material coefficients and the varicticn in these +b ; might be expected to be applicable in.this case; and, the interaction of the penetration with the overall flexural respcnse.
Indicate how these were considered to be interrelated.
(e)
The impact effects on equipment and ccupnents within the structure subjected to shock. Any significant shock effects carried thrcugh the structures should be identified, and the provisions employed to alleviate damage and effects of the shock should be described.
- 8.
The following structures are listed en page 5-11 as designed for aircraft impact:
Pcactor building Fuel handling building Portiens of auxiliary building as shown in Fig. 5-42 Pcrtions of interrediate building as shown in Fig. 5-42 Control building Intake screen house and pu::p. house Heat exchancer vault Ait intake structure Access kunnel--vault to auxiliary building 1454 296
w 7-Identify for all these structures, those equipment, inserts, instnrents, hangers, brackets, lighting fixtures, etc., attached to the walls and Icofs which may became missiles and could damage the Class I equipment located in these structurns sufficiently to pmelude safe shutdown of the plant, or impair the function of a vital ccrnponents in safety systems. Indicate the design criteria and quality centrol procedures used to ascertain that these elements will not become missiles, even in the case where excessive spalling of the concrete will occur. Discuss the possibility of such spalhng and explain hcw it is prevented. In the discussien of possible spalling censider possible concentration of dynamic ccepassion, tensica, cr shear stresses.
- 9.
Additional consideration should be given to liner anchcrs in the dome region, to counter possible spalling effects. Among others, the following items should be discussed:
Possible 1ccal concentration of dynamic stresses due to elastic a.
shock wave in concrete, including shear stresses.
b.
AdequJcy of liner anchors when located in parts of the structure where concrete is subject to tensile stresses er cracks.
Possible ruptum of the liner plate itself.
c.
A discussion of design c-iteria, quality contml and safety nargins should be included.
m<*Ihese Inquests for adc1tional informtica were i.itially transmitted to the applicant by DRL letter of April 7,1953, but the respenses by the applicat dere inadequate.
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. ***10.
Additional consideration should be given to the likelihood and consequences of loss of prestress tendons er anchors during the
.-7 impact in view of the fact that concrete under the anchor bearing plates is in tension and very likely to be completely cracked. The following possibilities should be discussed:
a.
Increased tensile stresses under the bearing plates which am additive to the bursting force and te:rperature stresses.
b.
Additional shear stresses.
- 11.
Provide additional details of flat-slab wall and roof reinforcing in-cluding:
a.
The design criteria fer this reinforcing, specifically the design basis for the main reinforcing, the shear reinforcing, the previsiens for anchcrage of reinferr.ing bars, and the allowable bond stresses, b.
An explanation of whether welding has been used to i:rprove the anchorage of bars, er any other means such as anchor plates located in concrete under tensien, etc.
c.
A descripticn of qmlity centrol precedures applied to all special constructica methods, if any.
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