ML20235D088
Text
_ _ - _ _ _ - _ _ _ _ - _ - . .- ---
t I
i
, N A TH A N . M. N E W M A R K-I consut.rewo suomesame scamcas sis 4 cML ENGWEEMWG BUlt.DfM l - .m o.. . .:
i I "
'l I
REPGt7 TO AEC REGULATmf STAFT l
ADEQu4CY OF STRUCTURAL CRITERIA FGL
}
l WILLIAM H. ZIMMER NUCLEAR POWER STATION CINCINNATI GA5 AND ELECTRIC CetPANY, ET AL.
,' AEC Docket No. 50-358 I
l li l
by l !
i N. M. Newne rk
- s W. J. Hall y *"A
'l A. J. Hendron, Jr.
7 Septecter 1971 8709250122 870921'~ -
MENZ87-111 PDR 9f Q"&
' $T ri[ [ 1
1 ADEQUACY OF STRUCTURAL CAf TERI A FOR WILLIM M. 28MMER IfUCLEAA POWEA STATION 4
by W . M . Newsa rk , W . J . Mal l , and A. J . Hend ron , J r . .
iffTRODUCT f ON This report concerns the adeguacy of the containment structures and components of the Willf as N. Ilmeer Iluclear Poser Station for which application for a construction permit has been made to the U.S. Ataele Energy Cassission by the Cincinnati Ces and tiectric t in,, Columbus and Southern Ohio Electric Campany, and the 0syton Poner and Light Campany. W facility Is Iocatod 24 i
miles southeost of Cincinnati, Chlo en the Ohio side of the Ohio Alver, and approminately 1/2 mile north of Moscow, Chlo. This report is based on the i
]
Infoneatlere and criteria presented in the Preliminary Safety Analysis Report (PSAA) and' Amendesnts thereto as referenced herein. Additional Infoneation has been obtained through discussions with the AEC Aegulatory Staff. -
, DESCAIPfl0N OF FAC f LiTV l The Willlas M. Zlamer Nuclear Ponser Station is described in the P1AA as a single-cycle, forced-circulation, bolling water reactor producing stems L for direct use'in the steam turbine-generator unit designed for a not electrical power output of about 007 MWo.
i The primary containment, which houses the reactor vessel and other coeponents, consists of a steel-lined prestressed concrete pressure suppression system of the over-and-under configuration. The drywell, in the form of a cone, is located directly above the suppression chamber. The suppression chamber, I
which is cylindrical, is separated from the drywell by a reinforced concrete slab which functions as the drywell floor. In the event of an accident, the l
o
___,,__--------------v~ ^ ^ ^ ^ ' ' __ . _ _ .
- 6 t
- t drywell atmosphere is vented into the suppression chanber through a series of dounconer ~ pipes penetrating the drywell floor. The drywell has a base dieneter of approximately 80 f t. and a top dianster of about 30 ft.
The reactor building, elch comprises the secondary containment, will censIst of poured-in-place reinforcod concrete for the substructures and eaterIor wells 'of the building up to the refuellag floor, and above this level the building strweture will be steel-framed with Insulated metal siding. The siding will '
have sealed jo!nts, and entrance to the building will be through interlocked l j
double doors.
LOAp fmG5 AND 500Act$ OF STRf 55E5 I
The reactor containment structures will be designed for the following loadings and conditions: dead loads; live loads; design temperatures and
)
pressrtas for the drywell and suppression chanber of +45 psig Internal pressure
{
l and +2 psig external pressure, and temperatures of 290'F and 275% for the drywell
'{
1 and pressure suppression chenbers, respectively; test pressures of 52 psig for {
the drywII and prossure suppression chenbers; a maxlaum differential pressure of 25 ps! applied to the drywell side for the floor separating the drywell from the suppression chenber; a wind pressure ranging from 35 to 53 psf; and a tornado loading associated with a 300 mph horizontal peripheral tangential velocity with a transnational velocity of 60 mph, and an internal pressure drop of 3 psi, with associated missiles.
In addition, the design is to be made for a Design Basis Earthquake corresponding to a maximum horizontal ground acceleration of 0.20g (as rgeted in l
I Amendment 5) and for an Operating Basis Earthquake corresphding to a maximum horizontal ground acceleration of 0.109 The vertical acceleration is to bc taken as 2/3 of the horizontal value.
e 3
Mt0UACY OF DEstCN Foundations Sedrock formations in the sits area consist of limestone and shale, and are encountered at depths ranging from 83 to 88 ft. In the plant construction area, launediately above the bedrock for. a depth of roughly 80 ft., the soII consists af medium dense fine to medlue and fine to' coarse sand with varying amounts of sllt and gravel, and occasional gravelly layers. The nemt to to 30 ft. above that is characterized by dense to medium dense and stiff inte.rlayered sit ty fine sand, fine sand and clay, slit and fine sand. The top layer, up to -
12 ft. In thickness, consists of very selff clay and fine sandy slit with roots. -
The upper 30 to 35 ft. of soll is noted to be recent alluvial deposits and the underlying sands are believed to be of glaclofluvial origin of pleistocene age.
The nearest known fault is the Maysville Fault located about 30 miles southeast of the f acili ty.
On page 2.5-81 (Anendment II), it is Indicated that major plant structures will be supported on mat foundations; the foundation elevations are given in Table 2.5-16. Foundation preparation will consist of densification of soils between foundation level and Elevation 450 by dowatering, excavating and recompacting existing solls. Also, as reported on page 2.5-87, sof t, loose or disturbed materials at the base of the excavation will be removed.
[ The applicant advises in Amendment 18 that a clay blanket will be installed on all slopes of the compacted fill upon which the Class I structures are founded, and a thin layer of clay will be placed under this compacted fill foundation. Further, af ter completion of the foundation and base structure, observations will be made of plezametric levels inside and outside of the structural fill zone, i.e., on either side of the clay blanket, and the rate of l
w - _ _ - - _ - - - - - - _ _ . _-----
4 change of waur levels under partial flood conditions will be studied to dstormine newther pumping under the foundations of the major facility structures will be needed later. Provisions are to be made in .the design so that i f pumps are amadad they can be installed, With the ' aforementioned technique of construction, and indication by j the appf Icant on page 12.2-13 that the foundation zone will be des igned to resist a horizontal acceleration of 0.20s, we believe the possibility of any ef fficut tles with liquefaction editch could af fect major plant structure is remote.
]
We believe the general method described for construction of the foundations to i
]
be adequate.
f As noted on page 12.2-13, the service water pipe located between the river intaba structure and the main building complex will be supported on a pile f
foundation. The description provided on page 12.2-13, in Appendix J, and 1 Amendment 18, Indicates that the pile foundation will resist all doww.ard, uplift and lateral loads for all conditions of static and dynamic loadings.
f The destyi will be made to provide for resistance against lateral forces in both the downhill and transverse directions; the forces for Alch the design is to be made are on the order of 360 kips per bent downhill and approximately 100 klps in the transverse direction. We believe the proposed design scheme for the l
service water piping to be adequate. '
I Figure 12.5 6 (Revised), as presented in Amendment 18, provides details 1
of the service water pump house and intake structure design. Earth pressures at !
rest and dynamic pressures are to be used in design of the bulkhead, and we are advised that th*; design of* the surrounding bank area will be revleved to insure that the stability of the area is maintained during the connal rise and fall of the river. We believe the design of the service water pump house and Intake structure is satisfactory.
l J
5 Selsmic Deslan The earthquake design critaria and earthquake hazard were discussed la meetfraps with the AEC/DR5/DftL staff and representatives of WO5 and U545.
As noted en page 12.2-13 (Anendeent 12), the hazard for which the plant is
' desiped is a Design Basis EartN>ake characterized by a maximum horizontal 3
l ground acceleration of 0.20g and an Operating Sasis Earthquake of 0.10g. We
]
concur in the design values selected. . The response spectra for the CSE and D8E are presented in Flps. 2.5-22 and 2.5-23 (Amendment 13) and w concur in use of the spectra presented.
Modull and soll damping values for the fourdation materials are presented in Table 2.5'-14. No specific values . ire >% ~3r the conpacted solls Alch ~will be employed under the facility structures. In Amendment 18, the. applicant confirms that a value not greater than 7 percent be taken for the soll damping values, except for retalning walls where a slightly larger value >
may be used. .We concur in this approach.
The methods of selsmic analysis to be employed are described generally In Section 12.3 of 'the PSAR. This section, and answers to many of the questions in Section 12, refer to Appendix 1. The analytical procedures outlined, and the denping values given for structural elements, are acceptable to us.
It is noted on page 1.1-1 that " separate reports will be developed for each major Class I structure on which a dynamic analysis must be performed, j These reports will cover the specific details of each analysis and will be completed by the time the FSAR is prepared". We interpre t this to mean that detailed descriptions of the methods of analysis actually employed and the significant a.pects of the design, including tabulations of critical stresses and deformations, will be provided for FSAR review. We concur in this approach.
L_-____-._--
{
, :j 6 I i
It is indicated on page 12.3-1 that the s tresses resul ting from the horizon.tal excitation will be conbined linearly with those resulting from the
'l wartical excitation. We agree with this approach.
3 Lead and Stress Criteria
'f ' The controlling load combinations and allowable . stresses for the l
{
i
. structural elements are swrierized in Table 12.2-2 and on the basis of the j 1
- infonnation presented, it app 6ars that all structural elements will be designed l j l to behave elastically (i.e.,' not escaed yleid) for the naminum loading conditions i
j considered. On this basis we concur in the critarla adopted.
.I Plolna. Pressure Vessels. Heat Emchances, and foulomont .
t '
l The seismic design criteria for piping, pressure vessels, heat
{
[. sachanges, and egulpraent are described in Appendia A, Appendia C, Appendim O,
- and Appendix f.
The method of dynamic anelysis for piping and equipment supplied by the General Electric Company is described in detail in Appendix 0 (Anendment 4) on page 0.6 1 (et seq.). The allowable stresses for this particular pip *ng .
correspond - to code allowable s tresses. The approaches described for the
, s recirculation piping and primary stemn piping are satisfactory.
For equipment, it is indicated on page 0.6-1 that for the Design Basis Earthquake the horizontal coefficient will be taken as 1.59 and the vertical coefficient as 0.149 The applicant advises in Anendment 18 that the adequacy of the equipment to meet the specified floor response spectra will be checked in all cases and appropriate design modifications made if required.
We concur in this approach.
It is our understanding that all other piping and equirnent will bc designed in accordance with the criterla presented in Appendix i and we are In agreement with the approach described there. With respect to allowable
m f
t- 7 stresses, on pages A.3-2 and A.3-3, f or Group 8 piping, It is Indicated tha t p f p i ng i s t o rema in f unc t i ona l e i t he r by keep i ng t he s um of t he l ong i t ud i na l stresses less than the maximum specified yleid stress, or by allowing stresses above yleid, provided a plastic analysis shows no foss of function. The detalls of the amaner In which the latter stress criterlon will be employed, and the limitations on deformation, strain limits, or deflections are not presented.
Should any of the pfplog be designed to stresses above yleid, it is our recommendation that the specific location of such overstressing, as wel' as description of the pipe runs, be carefully dellneated and that the stress analysis In such cases be reviewed as a follow-on item. We are advised that the applicant will confirm in Amendment 19 that plastic analyses will not be employed unless supporting data are submitted for evaluation by the AEC staf f.
We concur in this approach.
The applicant advlses (to be documented in a later Amendment) that in developing floor response spectra a synthetic time-history base input will be employed; and, the spectra corresponding to this time history will envelope t'<. $lte design bests spectra. We concur In t his approach.
The seismic design of the reactor Internals is described in paragraph 3 3.5.5 of the PSAR and In the answer to Question 12 3. I-1 (Amendment 4).
The appreach described is satisfactory with one exception. It is Indicated that for closely spaced frequencies the peak modal responses may occur at practically the same time, and normally the sum of the absolute values of the contributions f rom each mode Is taken. Because of the Interaction wIth the f luid , t he moda l responses are coupled. For this case, the approach Indicated by the appilcant of using the square root of the sum of the squares of all the modal responses is generally acceptable. In Amendment 3, page 3.3-18, the appilcant advises that for the ZImer plant a time-blstory analysis of reactor
l 8
In te rnal s wil l: he made. We concur in this approach.
- The' poneral. stress criteria described for buried piping (Section A.3.I.I.3) and Appendle J, which will incorporate the effects of the ground
' notions, are acceptable. Careful attention should be given to points Are piping enters or leaves structures or other points _of constrelats to lasure that the piping does not undergo excessive focal strain in these regions. l l
C ri t i cal Con t rol s and l a s t evnen t a t i on 1'
The salamic deste criterio applic.able to critical controls and Instrumentation are described briefly la the p5AA on page 0.6-3 (et seq.)
(Amenesent 7). Analysis and vibration test procedures are to be used to demonstrate the capability and adequacy of the equipment items. The results -
1 tabulated in the PSAR Indicate that for items with reasonable enounts of l
\
dmping, the performance exhibited meets the plant deste criteria. For l
other items, which are covered by procedures outlined in Appendla I, it is noted that the seismic analysis and/or test results subeltted by vendors will l be ommelned in detall for acceptability. We believe the criteria outlined are satisfactory.
CONCLUDINC COMMEarTS As a result of our study of the PSAA and re1ated materials, we conclude that the seismic analysis and criterla to be employed in the design of the Wi l l i am H . Z iesme r Nucl e a r Powe r S t a t ion are in accordance with the present. state of the art and give reasonable assurance to provide structures with an adequate reserve of strength and ductility to resist selsmic loadings L_
j, combined with other applicable loadings.
l .
1 l
l l
'l 9
lif f fit ENCIS f.
'frellainery Safety Analysis Itaport", Vols. I-5, and "=. ' :,,rs I, 4, 5, 6, 7, 9,-11, 12, 83 , 14, 15, 16, 18, will f as. N. ZIsener Nuc lea r Pcaser Station, the Clancf masti Gas and Electric company, et al.,19M and 1971.
- 2. ' Procedures for the Seismic Analysis of Critical klaar Power Plant Structures, Systems and Igvlpment", Report SL-2690, Serpent & Lundy Engineers, Chicago,13 Nov.19M (Proprietary).
'