ML19242A278
| ML19242A278 | |
| Person / Time | |
|---|---|
| Site: | Vallecitos File:GEH Hitachi icon.png |
| Issue date: | 06/08/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Darmitzel R GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7908010257 | |
| Download: ML19242A278 (7) | |
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g EdCLEAR REGULATORY COMMISSION jj, g -l-2 j WASHINGTON, O. C. 20555
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June 8, 1979
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Docket No.:
50-70 Mr. R. W. Darmitzel, Manager Irradiation Processing Product Section General Electric Ccmpany Vallecitos Nuclear Center P. O. Box 460 Pleasanton, California 94566
Dear Mr. Darmitzel:
We currently expect to complete our safety evaluation of GETR, with respect to the October 24, 1977 Order to Show Cause, in August 1979.
This safety evaluation will be based on the geologic infomation currently available.
We have reviewed your report " Geologic Investigations - Phase II, General Electric Test Reactor Site, Vallecitos, California" submitted February 28, 1979, and have determined that the questions in the enclosure have not been adequately addressed.
We will consider your respense to any of these questions, received prior to issuance of our safety evaluation, in our evaluation.
Sincerely, 4Y Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosure:
-GETR Questions cc w/ enclosure:
See next page b)G ll 'I \\
7908010 9 p)
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General Electric Company cc w/ enclosure (s):
California Department of Health ATTN: Chief, Environmental Radiation Dr. Harry Foreman, Member a-Control Unit Atomic Safety and Licensing Board Radiologic Health Section Box 395, Mayo 714 P Street, Room 498 University of Minne ota Sacramento, California 95184 Mianeapolis, Minnesota 55455 Honorable Ronald V. Del'ums Ms. Barbara Shockley ATTN: Ms. Nancy Snow 1890 Bockman Road General Delivery, Civic Center San Lorenzo, California 94580 Station Oakland, California 94604 Advisory Committee on Reactor Safeguards Friends of t'he Earth U. S. Nuclear Regulatory Commission ATTN:
W. Andrew Baldwin, Esquire Washington, D. C.
20555 Legal Director 124 Spear Street San Francisco, California 94105 Jed Somit, Esquire 100 Bush S*reet Suite 304 San Francisco, California 94104 Edward Luton, Esquire, Chairman Atomic Safety and Licensing Beard U. S. Nuclear Regulatory Commission Washington, D C.
20555 Mr. Gustave A. Linenberger. Member Atomic Safet) and Licensing Board U. S. Nuclea' Regulatory Commission Washington, U. C.
20555 George Edgar, Esquire Morgan, Lewis t Backius 1800 M Street, N!
Washington, D. C.
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GENERAL ELEClda. TEST REACTCR (GETR) 1 1.
Inasmuch as the censultants caintain that the dislocations seen in the trenches are related to landsliding and not faulting, therefore, the relative stability of these so-called landslides is pertinent to GE's position en the safety of the reactor. The landslide stabili4y 2
analysis (ESA July 1978) was made before the information cn trenches B and H was available. What new arcs cf circles would be required to reflect the dislocations in these trenches? Are there any samples of ccmparable deformation reported in the literature?
In particular, are there any precedents for recurrent lands 1'de movement at a distance of 0010 feet from the base of the hill?
2.
Inase.uch as the censultants acmit (Ladslide ;nalysis, ESA 1973, p. 5) that no detailed ecgineering investigations of the static and dynamic strengtn of the Livermore Graels have been made, how can they affirm O.
- 1) that tk landslide that could affect GETR is stable under present geologic and climatic conditions?
3.
Referring to figure 3 in the ESA February 1979 report, the movement of landslide U :ks alcng the lines projected should result in bedcing dips that are considerably steeper than those in undisturbed bedrock.
Instead, the figure and attitudes in the field indicate that the dips are shallow. What is the explanation for tnis relaticnship?
4.
Inasmuch as the censulu.nts admit (ESA, 1979 p. IV-8) that there has been three feet of displacement of the stoneline in the last 10,000 years, and inasmuch as figure 9 shows multiple offsets that have no relation to any established geologic feature, what prcof exists that this so-called landslide will not break directly beneath the reactor next and break with a displacement of :everal feet'l 5.
ESA asserts (ESA,1979 p. IV-4) that the widespread occurrence of the buried paleosol expcsed in the trenches indicate, that no major disrupticn ef the present topograchy has hapcened in the last 10,0C0 years.
Yet, the consultants allege that thepostulated GETR landslide was significantly modified and the headscarp " pull away" structures largely eroded away during two " pluvial" episcdes which occurred within the last 70,C00 years (p. IV-2 thru IV-3). Substantial amount. of debris from the ereced landslide should have been shed westward across the GETR site during the period of alleged land-surface stability. Where is the debris?
5.
(ESA, 1979, p. IV-2) ESA argues that fault movements in the GETR site area "can be reasonably explained as minor adjustments of the remnants of the slide cceplex in response to seismic shaking from large earthquakes on the Calaveras fault." When did large prenistoric earthquakes cccur en
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the Calaveras fault zone, and hcw does their timing, location and size ccmpare with the record of f ault movements in the GETR site area?
7.
(ESA, 1979) ESA implies on page III-20 that the faulting seen in trenches A-1 ar.d A-2 could be part of a northwest-trending extension-of the Williams fault. This continuation of the Williams fault would strike about N25W (ESA, 1979, fig. 3), extending.through the pass en California Highway 34 east of the GETR. However, the faults seen in trenches A-1 and A-2 strike generally N65W to N8CW, rather than N25W.
Moreover, the alleged northwest-trending fault wculd have to cut Liver ore Gravel Horizens near highway 34 that ESA previcusly reported (ESA, 1973a,
- p. IV-15) are "unfaulted." Mcw are these ccaflicting data ccmoatible?
3.
The Livermore Gravels stratigraphic section in the Vallecitos-La Costa Ridge northeast of the GETR thins rapidly southward by several thousand feet toward California Highway 84 The abrupt cht. ge in section was explained previously (ESA,1978b, p. 4-5) as.a result of depositional thickening toward the north. With.he discovery scuth of Highway 84 in the trencnes of a major fault across aich there is no stratigra1 hic. continuity, how is the southward stratigraphic thinning in the Liver ore Gravels now exclained?
9.
In the description of the mcdern solum in trenches.3-1, 3-2, and E (ES 1979, A-13 thru A-15), the soil is described as having All, A12, A13, A2 (Ae), 31, and St horizcn. The soil is developed in colluvium mantling a stoneline unconfomity asserted to be at least 17,CCO-20,CC0 years old. The St horizon reportecly famed "in latest Pleistocene time" (p. A-15), between 10,C00 (end of the Holocene) and 17,CCO-20,000 3.P.
The albic horizcn (A2 or A3 horizen), however supposedly developed after the St horizcn, in the early Holocene (?), after 10,0C0 3.P.
Raciocarbon ages (ESA,19-), p. A-10) detemined for carben collected frem the 3t, A2, and 31 horizens were all less than 46C0 C-la years. The true age (when corrected fcr mcdern carbcn contaminaticn) of these horizers is rescrted to be " greater than about ECCO years, and more likely in the range of 12,000-15,0C0 years" (Earth Sciences Asscciates, 1979, p. A-23).
In a typical soil, humidified crganic matter accumulates in the Al horizons.
In the A2 or Ae horizcn, clay, ircr. or aluminum is. leached cut by dcwnward-percolating groundwater.
In the B her e ns, an alluvial concentration of. silicate clays, iron, aluminum, or hun.'s results frcm the dcwnward movement of leachable ions and particulate mutter frcm the A hon zcns. The growth of all horizons is simultaneous;.tr.' horizcns are interrelated. With time, the horizons beccme better develowed and grew to greater cepths. At the GETR site, however, the St horizo? is sucposed to have formed before the A2 horizon, like an accumulating st: Ttigraphic sequence. This might be explained if the 3t horizon were part af a buriec soil profile, separatec frcm the overlying Al or A2 horizont Hcweve", no erosicnal uncenfomity is describec or recognized between the horizcns; in figure A-7, they are inseparable.
Mcreover, the St horizon yielded radiccarben qes indistinguishable frca those Cetermined en the A2 horizon. Hcw are thi.se discrepancies explained?
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- 10. All radiccarben ages obtained for sar',u frca the colluvium arco the j
stoneline in trenches 3-1 and 3-2 were less than 5C00 C-14 years.
Without direct radiometric control, how can it be proved that the stoneline dates to isotope stage 2 (17,000-20,000 years ago), and that it is not time transgressive?
- 11. The establishment of the true ace of the faulted soil horizons at the 2
GETR site is of critical importance to defining tu recency of faui ing.
Modern carbon contamination admittedly causes younjet apparent C-14 ages.
On page A-23, it is ccncluded that "(althcugh) the e.ccunt of acdern contamination in the GETR samples is ccnjuctural...the true age of these horizons is probably greater than abcut 30C0 years; and more likely in the range of 12,cco-lb,000 years." How was this age correction calculated, and can it be proved that these horizons are really that old?
- 12. Un page IV-10, tSA as;erts that "(since) no offset of the Livermore Gravels d'd project beneath the reactor... no faulting has cccurred in the foundation area of the reactor fer at least a millicn years."
Units are unlabeled in the log of Trench 3-1; secaration of Livemore Gravels frca younger alluvium and colluvium is incassible. Was Livemore Gravel seen in the area of trench 3-1 adjacent to the reactor? What proof exists that the.Livermore Gravels at the GETR site are 1,000,'CC0 years in age?
- 13. ESA attempts to restrict the northeast-trending Las Positas f ault to the southeast corner of Livermore Valley.
In the only area where they have conducted field work near the Las Positas fault (at its southwest end), the ESA geologic map is practically identical to tnat of Herd (1977). Yet, ESA maintains th.t " field examination of the southern ma::ced trace of the Las Positas fault scuth of Arroyo del Valle confi mec Hall's (1958) interpretation that the Cierbo/ Live mcre Gravels contact in this area represent an enlap unconformity..." (p. III-3 and III-4).
If these (ESA-Herc) "ps are nearly identical, how has faulting been disproved?
la. What is the character of the Verona f ault and what is its.relaticn to other faults and folds of the scuthwestern part of the Liver cre Valley depressicn.
Include in this discussion a censideraticn of the possibility that the Vercna fault zone is a detach ent structure and known faults (at 3-1, B-2, H, Maguire Peak, etc.) may be separate structures in a ccmplex decoupled or detached zone of related taults and tolds that may not have a direct ccnnection.
If the Verona faul-a detachment structure is the true basement disclacement the cumulative offsets less drag? Discuss reascns why the Williams
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fault and the Verona fault are not scissors faults as was suggested in tSA July 1973 rescrt IV-18. This would explain the lack of surface expressicn along the California Highway 34 readcuts.
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15.
Based on the character of the.'lerona fault zone as determinea by I
your response to question 14, and assLming surf ace displacements, what is the maximum probable earthquake that could occur en the
'/erona fault?
16.
Provice further Marification on the characteristics at depth of thel 2
faults that have been located in the trenches at the site. Estimate at what depth the fault mapped in the H trench passes beneath the GETR site and whether cr not these faults connect at depth.
- 17. The statement is made in the ESA February 1979 report p. I'/-t indicating that one line of evidence supporting a landslide origin of the shears is that base:.1ent rock in the Livermore Valley to the east is icwer than it is beneath the site, or on the >ast side of the fault zone. Provide a discussion of all evidence that demonstrates that basement rock is Icwer east of the fault cne than west of it.
13.
In the ESA February 1979 repcrt it is ccncluded that the shear offsets exposed in trenches are the result of 3 separate displacements of about 1 meter each in the last 70,CCO. years.
Based on the data available, could the total cumulative movement en all of the shears be related to larger offsets on a single. fault plane at depth where they connect. Discuss in detail and provide the basis for your repense.
- 19. The structure shown within the southernmost uart or geologic secticn of the ESA February, 1979 report (Figure No. 7) is interpreted to be that of a syncline and an anticline in the Sricnes Sandstene. A note en the drawing indicates that those structures are based on a projecticn of surface outcrops.
Are the cutcrops of 3ricnes sandstone, wnicn led to the structural interpretaticn illustrated here, of sufficient cuality ano procer distribution to rule out faulting as an alternative interpretation to folding?
2C. As stated in your February 23, 1979 submittal, it is the censicered opinion of GE and its consultants that the most probable crigin (of the shear like structures in trencnes 3-1, 3-2, 5-3, H, H-1 and H-3) is larce-
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scale landsliding. The staff and its consultants believe that the date of last movement along these shears cci.d be ycunger than the 10,CCO
- / ears B.?. reported in your landslide stability analysis (ESA July 1975).
ihere is general agree.7ent that multiple movements have taken place cn these shears since the last 70,CC0 to 125,CCO ;o to lest than 10,CCC years ago.
The ;otential for landslide is reviewed at sites whe~e the existence of historic landslides or topograonic relief or geology incicate sucn a candition may be present at the site.
The staff re;uires geologic acping, core borings as well as ccmplete geotechnical analysis of any landslide potential. Clearly the GETR site falls into this categcry. Ycur July, 19/3 report, Landslide Stability is a curscry trea=ent of this ;ctential
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. It is the staff's position that although evidence strongly supports tectonic origin of the shear like structures seen at the site, there is still a potential landslide hazard at the GETR site.
Provide a detailed investigation and complete geotechnical analysis to demons _trate the stability of the hillside deposits.
21.
It is strcngly inferred en pp. III-12-14 of the ESA 1979 report that evidence for a northeast-southwest trending Las Positas fault is questionable. On p. III-15 the referenced Wright, Harding, and Yadon abstract acknowledges the presence of~this fault although a subsidence origin is argued. Please explain this apparent discrepancy.
22.
The discussion of faults in the Livermore Valley in the ESA February 1979 report (P. LLL 4) neglects to discuss the fact that the Corral
. Hollow-Carnegie f ault system and Tesla faults have s,ubstanti al c:cponent of reverse movements.
In addition the Ramp thrust rault is not discussed. Please provide a cccolete descriotion of the direction of net slip and the amount of displacement on these faults, based on available information.
- 23. Referring to p. III-21 in the.ESA report, reference is made to a " mince obli;ue. slip comconent" of movement. Please provice the lccation at wnich this movement was coserved alcng with the amount of cblique slip which.vas measured.
Please provide a tabulation of all measurements or estimates at oblique slip which have been made during these investigaticn including the locations at wnich these observaticns were made.
22 It is noted on p. III-24, that, "expressicns cf the "S-2" shear
'4ere not observed in any of the remaining trenches located ncrtbeast and northwest of Trench 3-215," Sased cn a Icwer sun angle aerial overflight it appears that these trenches could be lccated ncrtheast of the actual strike of a linear feature in this area. Has an attemot been made to review available aerial photography to see if these trenches were croperly located?
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