ML20235C227
Text
{{#Wiki_filter:-_
- I REVISED DRAFT OF REPORT TO AEC REGULATORY STAFF SEISMIC EFFECTS ON BODEGA BAY REACTOR BY N. M. NEWMARK 17 SEPTEMBER 196h INTRODUCTION This report concerns the ability of the reactor facility proposed by the Pacific Gas .: nd Electric Company to resist an earthquake opposite Bodega Head of the intensity postulated. by the U. S. Geological Survey and the U. S. Coast and Geodetic Survey, including the faulting or relative displacements. Refer-ence is made in this report to the application by the Pacific Gas and Electric Company concerning this reactor, particularly Amendment No. 8.
The general description of the postulCced earthquake involves a pattern of ground motions similar to that recorded by the Coast and Geodetic Survey in the El Centro Earthquake of May 18,19ho, but with approximately twice ! the intensity, corresponding to a maximum acceleration of two-thirds gravity, a maximum velocity of 2.5 ft/sec. , and a maximum ground displace-ment of 3 feet, and with occasional intermittent pulses of acceleration up to 1.0 times the acceleration of gravity. The response spectrum for the earthquake without the additional acceleration pulses up to 1.0g vill be similar to that of the El Centro Earthquake. With the additional accelera-tions , the high frequency part of the spectrum vill be increased somewhat. { 8709240391 051217 PDR FOIA FIRESTOB5-665 PDR
1
~ ~
Li In addition, the structures are considered to be subjected to simult.aneous shear displacements ranging up to 3 feet , along lines extending under the containment structure or other parts of the plant, with motions in either horizontal or vertical directions along the f ault. It is assumed also that after-shocks of intensity equal to the El Centro quake might be suffered before mmedial action could be taken. Under these conditions , and with the design considerations described in Amendment No. 8 and in previous application amendments, it is my conclusion, i after study of the matter, that the structural integrity and leak tightness of the containment building can be maintained under the conditions postulated. However, certain precautions must be considered especially in the design of umbilicals and of penetrations to the containment building. These are described below. Similarly, the ability to shut down the reactor and maintain it in the shut-down condition would not be impaired, provided that the intensities of motion and the magnitudes of f ault slip do not exceed those postulated. Again, certain precautions are required as described mon fully below. The primary system, being contained in the massive reactor containment structure , vould remain intact up to fault movements not exceeding 3 feet , and under earthquake motions as described above, provided that the piping system carrying the main steam lines from the dry well to the turbine inlet is made sufficiently flexible to accommodate a relative movement of 3 feet without failure, and at the same time is damped to reduce its dynamic response to earthquake os cillations. All attachments and umbilicals must be arranged to prevent failure by shearing or crushing due to contact with walls , rock, earth, etc. in the event of major earthquake motions. Further l comment on these matters is made below.
(
.- The supply of power to the facility, from power lines crossing the major fault, might be interrupted, although the probability of such inter-ruption is probably fairly lov. In the event of such interruption, auxiliary power supplies are required. The sources of auxiliary power described appear to have adequate capability to resist the postulated earthquake effects.
i In general, the provisions for meeting the various requirements are l based on methods which in the light of analysis and study appear to be reasonably adequate. The earthquake motions, including acceleration and velocity as well , 1 as displacement, appear to be 2 to 3 times more intense than any that have been recorded in the United States , and probably about twice as intense as those experienced anywhere else in the world in the recent years for which i ve have fairly good records. Nevertheless , it appears that the design - objectives can be accomplished. A more detailed discussion of the various points described in Amend-ment No. 8 is contained in the following material. In addition , con-sideration is given to several points not specifically discussed in the
]
l amendment. J EFFECTIVENESS OF SAND LAYER IN SHO,CK ISOLATION The sand layer under the containment building is intended to act in two ways: (1) to isolate in part the containment structure from the high peaks of acceleration that might be transmitted to it from the ground beneath it; and (2) to permit either horizontal or vertical faulting to l l take place in the rock beneath the containment structure without damaging the structure. It vill be shown in the following discussion that the ; I effectiveness of the sand layer in reducing the peak accelerations may be questionable, but its effectiveness in reducing the effects of faulting is subst antial. ! l l
w.
' I 1 .
I .In the study of this problem I have had the benefit of discussion of the current state of knowledge of this aspect of the problem with Mr. R. A. Williamson of Holmes and Narver, a consultant to the AEC staff. The state-ments made herein reflect in general his views , es interpreted by me, and the final conclusions are based on ny views as well as his.
' Vibratory Effects The properties of sand under static loading have been studied for many years and are vell understood. The frictional resistance in natural beds of sand has been measured and compared with behavior of such beds under various conditions. Within recent years dynamic tests of the behavior of sand have been made by Dr. R. V. Whitman of MIT, Dr. H. B. Seed of the University of California at Berkeley, and by others. The results of these tests , and of the engineering experience for many years , indicate that the frictional resistance of sand, as measured by the angle of internal l
friction, changes very little for velocities of the order of 2 ft/sec.a and the change is not greater than about 20% for velocities slightly greater than 3 ft/sec. The coefficient of friction, as measured by the tangent of the angle of internal friction, corresponds to values ranging from about 0.5 or slightly greater up to about 0.9, and in general there appears to be no increase in the coefficient of friction for high contact pressures or for high loadings. The constancy of the angle of internal friction is dependent on the relative density of the sand. If it is in a condition corresponding to a density of the order of 90 to 95% of its maximum possible density, the friction angle does not increase with notion. For very low relative densities, or for loosely packed sand, the friction angle of dry sand vill increase with loading. On the other hand, this increase in friction
f* 1 i L
.6 t f angle' of loosely packed sand is accompanied by a reduction in volume, and this reduction in volume, under conditions of saturation, corresponds to a great increase in the pressure carried by the inter-granular water. g This results in a temporarily decreased effective frictional resistance,
\
and therefore it is quite reascoable to expect that under the conditions of 1
<' (
deposition of the sand layer, the fri.filonL1 resistance vill not effectively be increased over the value corresponding to the density achieved in place-ment, over a long period of time. However, after an earthquake has occurred, the conditions prior to the next earthquake vill have been slightly changed, if the swid is in a very loose condition to begin with. Nevertheless , a change 12 density of the sand would not be expected to occur unless l] relatively larger motions take ple.ce than those postulated. The skin friction angle between relatively smooth concrete and sand is generally slightly less than the friction angle in the sand itself; hence the resistance to sliding of a properly constructed structure on a sand bed can be made as low as that which corresponds to a coefficient of friction of the order of 0.6 to 0.8, and it can be expected with confidence that this coefficient of friction vill not increase with time pmvided that the sand is clean and the water inundating it does not contain cementing compounds. l l Earthquakes having accelerations less than that required to overcome the frictional resistance would not affect the behavior of the sand r.t all. It appears from the foregoing that the containment structure vill move with the ground for accelerations icou than about 2/3g and possibly even for accelerations as high as 0.9g to 1.0g. Only the very largest petts of acceleration, greater than the frictional resistance, can be attenuated { by the sand layer. Moreover, if the sand layer vere to slip at an I
.I 1
w_-_-.__-_-__. _ - - _ - - - - - --
.gs
.. (
> c I e
- 6- 5, acceleration of about 2/3g, a ground acceleration of 1.cg would involve a slip of the containment stbacture on the sand bef cf th'e.Iirder of 2-3 inches ,
- I which could reduce the gap provided for isolation purposes 'by this same amount. j
.Y '.l i
Faulting Effects q
- i ,
i ; The ro:k beneath the containment structure ra y suff-v a postulated si f r x.y 3 , fault displacement of magnitude up to 3 feet d either thtI vertical or
>>4 x l
\
,I horizontal direction. Whether Jr not the sand has become, partially cemented, it vill be much weaker than either tN rock or the con $ rete and vill, there-
~
lI
., j .
fore, not change or influened the fwlt notion immediately beneath the 'I t 4
/
st ructure. If the rock Nultd vertitaY1.y. the structurn vill tip. The
- ,1
,t
\
greatest angle of tipping would be that corresponding to a vertical fault ' 9 occurring at the center'of tae structure, in which case the a.igle vt/4d be approximately equal to the fault displacement divided by the radius of '4' 1 the containment building. Such tipping would partially close the gem ,left ! between the containment building and the surrounding rock and/or earth. This must be considered in evaluating the available space in whi h to ,
.accommo d ate concurrent horizont al faul; mutions. Both horizonia'. teld vertical motions must be taken into account in considering the intagrity of the contelument building, other vital structures or any attachments
. Or conneeti .na thereto.
Enen horizental f aulting taxe s place under the containment structure , i there can be a tendency to rotate the containment structure. This rotation can result in somewhat larger movements of points on the circumference than the fault motions themselves , and must be taken into account in evaluating the e-ffects on both the structure and attachments thereto. If proper provision is made for the t ipping and rotation, and possible
+
w
i
! (
i [3 sliding, the containment structure and its associated attachments can be Iesigned to resist successfully a major earthquake with maximum effects as 11 postulated. However, if such an earthquake brings the structure nearly into is contact with the sides of the cavity in which it is placed, a second major L earthquake may involve the possibility of damage to the structure or the i
^
attachments :.hmto. since the gap providing isolation against fault motions Q: t i vill have been nearly closed. In other words , the amount of faulting in successive earthquakes cannot involve a greater combined fault motion than three feet in any one direction, and the amount of gap left after faulting must not be so small as to permit battering of the structure or of vital attachments against rock, earth, etc. adjacent to the structure, in after-shocks , or la the remainder of the earthquake following the faulting. DESIGN _ 0F PIPING. ETC. TO ACCOMMODATE RELATIVE MOVEMENT AND VIBRATORY EFFECTS 1 The amendment indicates that adequate anchors and bracing vill be pro- I vided to prevent large relative motions of the piping connecting the dry well to the vall of the reactor building. Beyond the anchor at the vall, and extending to the anchor near the turbine generator foundation, the I i piping vill be subject to the differential motions corresponding to fault displacements ranging up to tnree feet as well as the vibratory motions t induced by the earthquake accelerations. Since the time sequence of the assumed faulting and the oscillation is entirely a random matter, both of the effects must be considered as occurring at any time, even simultaneously. The precise strains in the pipe due to relative motions or due to earthquake vibrations are functions of the length of the pipe runs in the various directions and the method of ancnoring. The curvatures in the pipe, and hence the maximum strains in it, due to a slow relative motion of the ends of a pipe run, are primarily a function of the geometry of the system, l . . - - _ _ _ _ - _ _ _ _ _ _ . l
L ( l i
<j. and are nearly independent of the thickness of the pipe shell. The diameter of the pipe and the length of the runs in the various directions, as well as
. the conditions at the support, namely whether these are fixed or hinged to provide rotation, are the primary influences affecting the strains accompa-nying a given relative motion of the ends of the run. The maximum strain is in general of the order of h times the diameter of the pipe times the relative displacement divided by the square of the component of length of the run in the direction perpendicular to the displacement. This value of the strain corresponds to a condition of fixity at the ends of the run. If the ends are hinged, which is an extremely favorable condition that cannot be obtained except with flexible connections, then the strains are reduced to possibly two-thirds as much as those corresponding to fixed ends. The re-fore, the higher value vill be used in the estimates made herein.
Both the horizontal and vertical components of the pipe runs of the 20-inch main steam lines are approximately 80 feet. Since the pipe is 20 inches in diameter, the corresponding strain is approximately 0.003 in/in. This is about twice the strain at the yield point. There fore , without flexible connections , the strain in the pipe due to the postulated relative motion of slightly more than three feet would exceed the yield point, but only slightly, and by an amount that should not cause failure. To reduce the strains to yield point values vould require the introduction of flexi-bility at possibly two of the joints or elbows in the pipe, or one or more bellove connections at the ends of the pipe run. It does not seem necessary to increase the length of the pipe run from 80 feet to 115 feet , which would be the requirement to reduce the strain to the yield point value merely by increasing flexibility of the pipeline itself. The dynamic response of the piping depends on its fundamental period
'r I '.L c,f vibration and. can be obtained from the shock response spectrum. Since e
both the weight of the piping .and its stiffness depend linearly on its vall thickness, the deflection of the piping due to a given acceleration, which is proportional to weight divided by stiffhess , is independent of the vall thick-ness. Only the diameter of the pipe and the length of the pipe runs determine the frequency of a pipe not carrying additional load. For several different l configurations of pipe a fairly consistent relationship between maximum dynamic strain due to earthquake vibration and maximum strain due to movement of the supports can be obtained. The ratio of the maximum strain due to a spectral displacement, D for vibration at a given frequency, compared with the strain due to a relative D static displacement at the ends , A , is approximately 2 3. Hence , the earthquake strains which accompany earthquake motions will be of the same order as the strains for the three foot movement of the ends if the earth-quake displacement is approximately 1.5 feet. For the pipe runs considered, Mr. Williamson estimates a period of vibration of the order of 1 to 2 secs. assuming binged ends. $ calculations indicate a period of about 0.5 sec. j l for two fundamental modes, one primarily vertical and the other primarily horizontal, when the ends are fixed. These periods are about twice as long, or one sec. , for hinged ends. 'Ibe maximum combined stress when both modes l are excited is only slightly greater than the maximum stress for one of the modes. For a period of 0.5 sec , and for the PGE spectrum in Figure 1 of Amendment 8, for 0.5% damping, the displacement is of the order of 0.25 ! feet, and for twice this earthquake the displacement vill be about 0.5 feet. On this basis, it can be estimated that the strains due to the earthquake response are about one-third as gnat as those due to the 3 feet relative displacement of the supports. Hence, under combined earthquake and relative
i I 5 displacement due to faulting, the pipe vould be overstressed, but not beyond three times the yield strain. It should be noted that the dynamic displacement due to the postulated earthquake varies almost directly as the natural period in the range from about 0.h sec. to more than 3.0 secs. In other words, if the period of the pipe can be reduced, its displacement vill be decreased in the same pro-porti on. However, reducing the period of the pipe vould, in general, require ~ an increase in stiffness which would cause difficulties in resisting the relative displacement of the ends. Conversely, introducing flexible connections vill in general increase the period of the pipe which will increase the dynamic earthquake strains. The final design of the piping should take the foregoing considerations into account to insure that the piping can sustain both the earthquake vibrations and the relative fault motions without being overtrained. It might be pointed out in this regard that the maximum displacement of the pipe,should it become inelastic in an earthquake, would probably not be different from the maximum displacement were the pipe to remain elastic. Hence the pipe, under the most serious combination of conditions , will be strained to about 3 times the elastic limit strain at yielding for the proposed material (under the combined effects of the fault motion and earthquake motion). Whether this is acceptable depends on the details of the final design. A possible means of reducing the stress involves introduction of damping by artificial means. If dampers are used, care must be taken to avoid introducing additional disturbing forces in the pipe when relative motions of the ground or the containment structure take place. All umbilical connections to the reactor containment structure, including the main steam lines , should be designed to assum freedom from
l i t- - 11 r contact with other structures , valls , or earth and rock, by such a distance as to provide for the possibility of a three foot fault motion under the containment building and, in addition, the vibratory motion of the element considered. Also, all vital piping and other conr.ections must be arranged in such a way that a three foot fault motion occurring elsewhere in the area
)
vill not cause a failure of the vital element. The actual relative dis-placement in piping and other umbilical elements may exceed three feet because of rotation and/or tipping of the containment structure caused by the fault motion.
. The main steam lines and similar important lines should be designed to be locally stiffened by sleeves or doubler plates , at points where isolation valves or where anchors are attached, to prevent ovalling or distortion of the lines that would impair their behavior.
SAFETY OF AUXILI ARY EQUIPMENT The auxiliary equipment contained within the reactor containment building vill, in general, move as a unit within the containment structure. The fault displacement of three feet for which provision is made does not produce a similar displacement within the structure, although it may produce a rotation or tilting of the containment structure. However, the equipment described in Amendment 8 and elsewhere in the application can certainly be designed for the slight tipping or tilting and rotation, provided it is not rigidly attached to items which move either a different amount or do not move at all. It is stated in Amendment 8 that "where vital components of the 1 I emergency systems are located within the turbine generator foundation of the control building, the inner-connecting piping and cable vill be designed to withstand up to three feet of relative displacement between the reactor
t I: g
! containment structure and the turbine generator foundation, or control building." The provision of resistance to large relative displacement combined with resistance to oscillations seems capable of achievement for relatively small diameter pipes, or for wires, although it is more difficult for the 20-inch main steam lines.
SAFETY OF PRIMARY SYSTEM Comments have been made previously in this report regarding the main steam lines and the difficulties involved in providing the necessary resistance to relative motion and to earthquake vibrations. The statement is made in Amendment 8 that " accelerations experienced by the primary system during such a displacement would be less than the accelerations used in the design of the equipment". It is not clearly stated that the accelerations experienced by the primary system during the maximum earth-quake would be less than the acceleration used in the design of the equip-ment. Moreover, it is not clear, if the relative motion of faulting should exceed three feet , whether there vill not be a greater maximum acceleration than that provided during the earthquake, owing to a possible crashing or battering of the retaining valls outside the gap against the reactor containment structure. These could induce f airly large, but high frequency, accelerations. Because of the large mass to be moved, the inertia of this mass, and the possible weakness of the valls of the reactor 1 containment structure against a localized line loading from outside, it is not clear at all that a relative movement of more than three feet could be sustained without producing serious damage to the reactor containment structure or serious accelerations to the primary system within it. l Nevertheless , since fault motions greater than three feet are not considered ! credible, questions of this sort need not be considered.
o ( 1 POSSIBLE INTERRUPTION TO SUPPLY OF POWER
. The vulnerability of the overhead transmission lines has not been es tablishe d. These lines cross the San Andreas fault, and although they are supported on videly spaced towers , there is a possibility that one or more of the towers may be displaced by as much as 20 feet relative to a neighboring tower. It is possible that the towers can sustain such a motion without loss of all of the lines. However, further study of this problem is desirable if it is necessary to depend on this source of power.
Amendment 8 states , however, that if the external sources are unavailable, the engine generator, located within the reactor containment structure, will be capable of handling the load required to shut down the plant safely. A further supply of power is available in the battery contained within the reactor cante.inment structure and control building. It must be regarded as possible that the main overhead transmission line would be severely impaired in its functioning where it crosses the main fault. ABILITY OF STRUCTURES AND EQUIPMENTS __T_0 RESIST EARTHQUAKE OSCILLATIONS The procedure described for the design of critical and non-critical structures , on pages 19-25 of Amendment 8, appears in general to be i satisfactory, with minor exceptions. On page 21, the second paragraph ! indicates that "the design of the plant vill be checked to assure that all critical structures, equipment and systems vill be capable of with-standing earthquake ground motions corresponding to spectrum...(values)... two times as great as shown on Figure 1 without impairment of functions..." This means an earthquake of maximum acceleration of 0.67g, but not with acceleration spikes ranging up to 1.0g. The difference is not important for items having periods of vibration greater than about 0.5 sec. , but it _D
Jo. ( 1.-
, yg ,
ia3 can be substantial for elements having' shorter periods or higher frequencies , f . ..
. and the discrepancies become progressively larger as the frequency becomes higher or the period becomes lower. A clear and unequivocal statement cbout
' this point would be desirable.
In ' general, there is a reserve margin in almost every element beyond the point at which yielding begins, even in items of equipment, control rods , fuel assemblies , etc. Dr. Housner's study of the reserve capacity of structural. elements , in Appendix II of Amendment 8, is sound. Nevertheless , for items of equipment which are not designed for yielding at all, but which have to satisfy certain criteria such as clearance or magnitude of displacement , it is essential to consider the higher spikes of acceleration in their design in order to provide the necessary reserve margin to assure operation of these items under the extreme maximum conditions. In this regard, it should be noted that the design spectrum in Figure 1 is not quite as large' as the values that correspond to the extume peaks of the El Centro spectrum. The values in Figure 1 are in general those that correspond to the mean of the oscillations for the rather jagged peaks
)
in the individual response spectrum curves for various earthquakes , l I especially in the high frequency region. An envelope through the spikes would generally lie about a factor of 2 above the smoothed spectrum, particularly for the lov values of damping. This is not regarded as an important discrepancy, however, as there are indications that the mean of the oscillations in the spectrum is a much more significant value than the magnitude of the spikes. Calculations and measurements that have been made and that are reported for equipment mounted on submarines , and i calculations for response of buildings to earthquakes, in general { j indicate that the measured responses are more nearly consistent with the 1
o j ( , f mean of the oscillations of the spectral values rather than with the peaks. Hence appropriate smoothing of a design spectrum is a rational and reasonable procedure. The accelerations transmitted to the reactor containment structure vill not exceed the acceleration that will cause sliding on the sand layer, which may be from 2/3g to 0.9g, depending on the characteristics of the sand, until first contact is reached with the side of the cavity. ; Since this contact will occur after a three foot fault movement, or possibly slightly less if some sliding occurs on the sand, a design level of 1.0g for proper functioning of equipment should be used. SUITABILITY OF PROPOSED DAMPING COEFFICIENTS The damping coefficients listed on page 23 of Amendment No. 8 appear ! in general to be reasonable. The degree of precision implied in the selection of damping coefficients to two significant figures seems somewhat unwarrante d. However, the values are in general reasonable for the stress levels implied in the design of the individual elements , or for the con-ditions which are involved in their behavior. The damping for the reinforced concrete reactor containment structure vould be considered high for a structure supported directly on the rock, but appears to be reasonable considering the fact that the structure is supported on a sand bed. EFFECTIVENESS OF SAND LAYER IN CLIP _ PING PEAK ACCELERATIONS In view of the comments on the behavior of the sand layer, it can be concluded that the sand layer vill act to clip high peaks of horizontal acceleration that exceed its frictional capacity to transmit force to the reactor containment structure. It vill not clip vertical acceleration peaks.
.o
(
- )
DETAILED DYNAMIC ANALYSIS OF' EQUIPMENT The nethod described on pages 23 and 2h for handling the response of equipment within the building appears reasonable, although for sensitive items near the upper part of the building, the approximate method may not be adequate. A detailed dynamic analysis, such as described near the bottom of page 2h, vill be desirable for all extremely sensitive and critical items of equipment. The method of analysis described can take into account the interaction with the reactor containment structure itself. However, the ground accelerations or ground input motions considered should correspond to the maximum postulated earthquake, and not the 0.33g earthquake for which Figure 1 of the amendment is drawn. The statement en page 3h implies that double the seismic loads corresponding to Figure 1 vill be considered, but this does not take into account the spikes of acceleration ranging up to lg for the higher frequency components. A further clarification of this point is desirable. ADDITIONAL COMMENTS The effect of the water in the annulus surrounding the reactor contain-ment structure should not, in general, cause accelerations to be transmitted directly to the structure through the water because of the fact that the water has a free surface. However, it vould be desirable to have a study by the applicant or this problem to insure that the surging of the water will not introduce additional oscillations within the structure. This does not seem likely and it appears most reasonable to expect that the water contained in the annular space vill damp the motion of the structure. Nevertheless , no specific data on this topic are available. c_____
I___ MEMO ROUTE SLIP _ 5" '"*
- u'""*- F c aacw"*'- For actica-3 IN>rTTI Al:Ca93 (Rev. May 14, toen Note and return. For elenature. For information.
( TC) (Name and unit) INITIAL 5 REMARR$ g Att. ached is the_nrisid_dratt of Newmark's nuort on REG ^ 'E leissle Effecta_otLBodega_Bar_.EeactoruThis report una vevin.M in meenvMnnea with w letter of Sentember TO (Name and unet) INITI ALS REMARKS Lto Dr. Newmmek anLdiacussions with him and 0^TE W1114 ama nn in htheada on September 17. I proposa_to_
*s manA thfe Av nM wannv+
+n the AN far enna4 Aavatt nn TO (Name and unit) INITIALS REMARKS at its_ meeting rm Getnhor 7 on the Radena protect.
D^IE
'Ph 4 m vSport_.wi11 al e n sa n an the haain fo P Dr. Newmatic's testimony at the public hearing on this FROM (Name and unit) RLM ARKS E. G. Case RL gestions you may have prior to October 15 on this l
draft _ report when_considend in that ligit. PHONE NG DATE 3hl 9/22 USE Uf HER SIDE FOR ADDifichAL REMARKS u 5 GovtRNMEh? PRINTING 0FTICE 2 1 422007 1
*vw l
i I h _--._____._m. _ _ _
4 . , V V
?
v October 20, 1964 Honorable Glenn T. Seaborg Chairman U. S. Atomic Energy Cc= mission Washington, D. C.
Subject:
REPORT ON BODEGA BAY ATOMIC PARK - UIIIT NO.1
Dear Dr. Seaborg:
At its fifty-fifth meeting on May T-9,1964 at Argonne, Illinois, and at its fifty-eighth meeting en October 7-10, 1964, the Advisory Com-mittee on Reactor Safeguards again considered the proposal of Pacific Gas & Electric Company to construct and operate a 1008 MW(t) boiling water reactor en Bodega Head north of San Francisco, California. The Committee had the benefit of oral discussion with representatives of Ae applicant and its consultants, with the AEC Regulatory Staff and its consultants, including staff members of the U. S. Geological Survey (USGS) and the U. S. Coast and Goodetic Survey (USC&GS) and of the reports cited below. Subcommittee meetings were held July 31, 1962 and March 20, 1963 and members of the Committee again visited the excavated site on June 3, 1964 Numerous information meetings were held with the applicant, the AEC Regulatory Staff, and with consultants. This proposal had been considered at the Co=mittee's forty-seventh meeting and reported en in its letter of April 18, 1963 which stated:
" Tentative exploration indicates that the reactor and turbine buildings will not be located on an active fault line. The Co=mittee believes that if this point is established, the design criteria for the plant are adequate from the standpoint of hazards associated with earthquakes. Careful examination of the quartz-diorite rock belov should be made during building excavation, to confirm this point. Furthermore, the Cc=mittee suggests that, during design, careful attention should be given to the ability of emergency shutdown systems to operate
,_ properly during and subsequent to violent earth shocks, and to the stress effects that might be introduced because the reactor building and the turbine building are to be anchored in different geological formations. The need for earthquake-induced shutdown and isolation of the primary system can be considered e.t a later time."
h hk'
= r
;4 - --
v N i l W F' $ i Honorable Glenn T. Seaborg October 20, 1964 l w The exploration suggested in the above comment has been completed, and the geologic features discovered have led to further structural considerations in the design. These geologic features include frac-tures in the underlying rock. One has been identified as the so-called " shaft fault". The character, extent, and age of the most recent activity of this fracture are controversial. Nevertheless, the applicant has considered its significance in the proposed struc-tural protection. Proximity of the site to the San Andreas fault system has been given careful consideration. The Co=mittee has been advised by several , consultants that, during the life of the proposed reactor, there is ) a high probability that the reactor site vill experience at least one major earth shock. There is associated with such an earthquake a remote possibility that the plant will be subjected to the effect of a shearing motion in the rock on which it would be built. The USGS and USC&GS have proposed values for the intensity and accompany-ing earth motions, including shear, which could be anticipated during the worst earthquake. Determination of these values has been hampered s~ by lack of authoritative historical records and reliable measurements. The applicant and his consultants believe that lower values are more realistic. The Committee considers that the USC&GS and USGS values are conservative. The applicant has proposed methods for mechanical and structural deci6n to meet the predicted seismic occurrences. The applicant also has proposed to design the building to withstand up to three feet of shear displacement along any plane at the site. The Occ=1ttee believes . that the engineering principles and general design proposed to incorpo-rate them are sound. These considerations afford that degree of assur-ance required for protection of the reactor in the unlikely event of the predicted maximum earthquake. The USC&GS has recommended a design height for tsunami run-up at Bodega , Head. The applicant stated that the facility design and safeguard pro-cedures vill be such the plant would withstand such a tsunami safely. The Committee is of the opinion that the applicant's design objectives may be accomplished within the scope of present engineering knowledge. Many details of the proposed design have not yet been co=pleted. It is understood that the applicant vill continue to give careful attention to the following items during design and construction: limitations on the maximum reactivity of individual control rods; provisions to acco==o-date possible seismic earth movements and shear displacement; consideration
/*
r.
^
w Y 1 l + - l l
'l Honorable Glenn T. Seabors -
3- october 20, 1964 v of testing or other experimental verification of structural design f j features associated with earthquake protection; provisions to assure adequate cooling water in case of damage to normal and emergency supply systems; core behavior during earthquakes; design and tests of critical plant components such as instrumentation, isolation valves, and control rod operating mechanisms to withstand earthquate damage; additional considerations which may be needed if zirconium clad fuel is to be used. The Committee recognizes that the applicant has accepted very conserva-tive values for earth shear movement, earthquake magnitudes, and tsunami heights as desi6n criteria. These criteria should not be con-strued as precedents for use elsewhere. With due consideration being given to the items discussed above, the Advisory Committee on Reactor Safeguards is of the opinion that the power reactor facility as proposed may be constructed at this site with reasonable assurance that it may be operated without undue hazard .
' to the health and safety of the public.
Sincerely yours,
/s/HerbertKouts Herbert Kouts Chairman References Attached.
e _ _ _ _ _J
m ---- 1 ar t . 4
,. v
) '
^
":k'~l
.~
~
, .= '
, i l
~ Honorable Glenn T. Seaborg October 20, 1964 -{ e (BodegaBay)
References:
- 1. . Amendment No. 2, Pacific Gas & Electric Company, Bodega Bay Atomic Park - Unit No.1,' dated April 5,1963 ,
- 2. U. S. . Department of the Interior letter to Dr. Glenn T. Seaborg, .
dated May 20, 1963, with attachments. 3 . Amendment No. 3, Pacific Gas & Electric Company, Bodega Bay Atomic Park, dated June 13, 1963
- 4. Amendment No. 4, Pacific Gas & Electric Company, dated August 9,1963 '
5 U. S. Department of the Interior letter dated September 25, 1963.to Dr. Glenn T. Seaborg with attached report, TE-837, " Geological and Seismic Investigations of a Proposed Nuclear Power Plant Site on Bodega Head, Sonoma County, California", dated September 1963 .
- 6. U. S. Department of the Interior letter dated January 16, 1964 to v Dr. Glenn T. Seaborg, with attached report, TEI-844, " Engineering
. Geology of the Proposed Nuclear Power Plant Site on Bodega Head, Sonoma County, California", dated December 1963 7 Amendment No~. 5, Pacific Gas & Electric Company, Bodega Bay Atomic Park, dated January 22, 1964.
- 8. Amendment No. 6, Pacific Gas & Electric Co=pany, dated March 16, 1964.
9 Amendment No. 7, Pacific Gas & Electric Company, dated March 31, 1964.
- 10. Amendment No. 8, Pacific Gas & Electric Company, dated July 20, 1964.
- 11. Amendment No. 9, Pacific Gas & Electric Company, dated September 16, 1964.
- 12. U.S. Coast & Geodetic Survey report " Seismicity and Tsunami Report, Bodega Head, California" dated October 1964.
13 U. S. Department of the Interior, Geological Survey report " Engineering , Geology of'the Proposed Nuclear Power Plant on Bodega Head, Sone =a l v County, California", dated October 1964.
_ , . _ - - . = - _ - - - - _ _ _ - _ . - _ - - - - - - - - - _ - - c' I DATE RECEIVED NO.i
., g g ggg DATE OF DOCUMENI>
10/28/614 5062 1 r in /w /n OfMERr
' " ' ' 'REMO: RET LTR.
[ CCi OfMER.
/
ORIG.: I
/ ACitON NECESSARY O CONCURRENCE O DATE AN$WERED ev, NO ACllON NECESSARY Q COMMENT O Post OFFICE FILE CODE.
/55tF., I REG. NO.
DATE RECEIVED BY DATE REFERRED 10 ESCRIPilON (Must Be Unclassified
#1 hL.D&N 10/28 # fio- km, i n/M gYhYON D@EM SE ATOE PARK-UNIT # 1 C
a/ ~ nevrov en m f
~ ~~ ~
ENCio5uREs,
/
i l
. .i
~ REMARK $i u
Vv
' u.s. Aiowc encRoy comissio" MAIL CONTROL FORM FORM AEC 1840) 326!
w-_ __-_m._ _ _
, gf' i. ,
- . llW5 . , I/A{ Q!jk.k . y lC .'F y n, .
.. p l ._
Q. ( '. x ,4 w .cr
'(" s 4 '
l v l
,/ g ~ UNCLASSIFIED AEC-R 80/10
.I h .c^ .
October 27, 1964 COPY No.' N .
%y,{ ,
J ATOMIC ENERGY COMMISSION ~ ..-. h..,.: .. , " Mw 4 A. _
- [,.Ifb...h}
6... . -
- .t.
i! ACRS REPORT y+, ; v," . C
'a
.u)$,(.4
,g 3
. 'i . < ON w n .
. A..?- ug 4.%'S r BODEOA BAY ATOMIU~'PIRK .-
Ci ~y, UNITNO.
%L,";. ~ ,
Q6' *L .3d,!.: .i ' . - Note by the Se$$e'ta'ry ?' ' i h!?UN M , 'i Mi
- e. :p ggs.
.~ % r, f,l:: .
1.Theattachedletterfromthe[W Chairman, Advisory [ g f 1 Committee on Reactor Safeguards, is circulated for the- - .s u c-W
.y. jp . : c. , -
y information of the Commission.. 'k'" ' a .-.
- 2. The public announcement on t'he ACRS report and the;AEC..
Regulatory Staff's Summary Analysis en; Bodega Bay was circulated to the Commissioners by the Director of Regulation's memorandum of October 23, 1964 W. B. McCool Secretary DISTRIBUTION COPY NO, y Secretary 1,44-51 Commissioners 2 - 6,52 Dir. of Regulation 7-9 General 1hnager 10 - 11 Deputy Dir. of Regulation 12.'<- Asst. Dir. of Regulation 13 Deputy Gen. Egr. 14 Asst. Gen. Par. 15 Asst. OM-Plans & Prod. 16 Asst. Gen. Pgr. R&D 1 General Counsel 18 7 22 Congr. Liaison 2 Public Information 24 3 25 ' Inspection 26 Operational Safety 27 - 28 . : t r.x Plans and Reports 29 .30 ,. 8.1, ~, '; Reactor Development
-c . , ,' "
31 Manager, Naval Reactors .. ; 4 0 . '.
' 39 ' '~ y~ ~. ~
NOU335llVW. i!- - A801vint3B " Reactor Licensing 41 - 42 'WWC3 ADb3N3 0!WD1V ,S T' San Francisco Oprns. 43 Q.g {t D Nd S? 100 MS -
'**h
. < -e. .
.* ll :p a : 9 &h4 :. $' ,
y, r ty -
, .y ,,. IFJ i 4 03,Al333d ' ]' g*)7
., g IL ,
q.' i
. .. s. ..
. , . 3 ,g M C O F r%}}