ML19337B482
| ML19337B482 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 04/12/1978 |
| From: | Mcmullen R Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19337B473 | List: |
| References | |
| NUDOCS 8010020604 | |
| Download: ML19337B482 (30) | |
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NUCLEAR REGULATORY C0 ~J4ISSION BEFORE THE ATOMIC SAFETY AND LICENSI!!G SOAP.D In the Matter of PG?.TLAND' GENERAL ELECTRIC COMPANY, )
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(Proposed Amendment to Facility
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Operating License NPF-1 to Permit rcjan Nuclear Plant)
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~ Storage Pool Modification) l AFFIDAVIT OF RICHARD B. McMULLEN STATE OF MARYLAND
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COUNTY OF MONTGOMERY
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, I, Rich'ard B. McMullen, being duly sworn, depose and state:
1.
I am a Geologist in the Geosciences Branch of the Office of Nuclear Reactor Regulation, U.S. fluclear Regulatory Ceranission, '!ashington, D.C.
20555.
2.-
I have prepared the statement of Professional Qualifications attached hereto, a' d, if called u,pon, would testify as set forth therein.
n 3.
I have prepared the a'ssessments on landslides and volcanism attached hereto in response to the Atomic Safety and Licensing Board's Order of January 9,1978 and I hereby certify that the statements made herein are true and correct to the best of my knowledge.
1 g/ J/i'7?A f %
Richard B. McMullen.
Subscribed & sowrn to tefere me this m* day of A;ril,1978
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PROFESSIONAL QUALIFICATIONS GEOSCIENCES BRANCll DIVISION OF SITE SAFETY AND ENVIRONMENTAL ANAf YSIS NUCLEAR RECULATORY CO:CIISSION 3
I am a geologist in the Geosciences Branch, Division of Site Safety and Environmental Analysis, Nuclear Regulatory Commission. My present duties in this position include:
(1) the evaluation of the geological aspects of sites for nuclear power generating facilities; (2) analyzing and interpreting the geological data submitted to the NRC in support of applications for construction and operation of nuclear facilities; (3) developing criteria; and acting as consultant to the Regulatory staff on e'ngineering and construction matters. After completion of three years in the Marine Corps I attended the University of Florida and graduated in 1959 with a B.S. degree in Geology. During my pro-fcssional employ =cnt, I completed correspondence courses in soils engineering and quarrying sponsored by the Army Engineer School at Ft. Belvoir, Va., and short courses in the effects of ground motions on structures, and airphoto interpreting.
I am a registered Geologist 4
and Engineering Ccologist in the State of California.
Af ter graduation I worked as a field geologist with the Corps of Engineers in Florido conducting field geological investigations for flood control structures, levees, canals, military installations, radar sLtes, and missile launching complexes.
I evaluated and wrote reports concerning the stratigraphy, geologic structure, groundwater conditions, and foundation engineering aspects regarding these facilities in Florida, Puerto Rico, Bahama Islands, several of the L* cst Indies Islands, and Panama.
In 1963 I was assigned to the Corps of Engineers Canaveral District of fice at Cape Kennedy, Florida, first as a staff engineering geologist, and later as District Geologist. My duties were to plan, direct and evaluate the results of geological and foundation studies for nissile launch pads and associated facilities for the NASA Manned Lunar Landing Program, the Air Force, and the Navy.
I acted as con-sultant to other government agencies and architectural engineers in developing design features of structural foundations, monitored the performance of foundations during and after construction, and recommended and monitored necessary foundation treatment techniques such as vibra-flotation, grouting, surcharging, dewatering and compaction. I wrote reports on the investigations, geology, foundation design, and construction regarding these projects.
In 1967 and 19681 spent 6 conths and 1 month respectively participating in the geological investigations for proposed sea level canal routes in Panama. The region investigated consisted of complex structures of volcanics and folded and faulted sedimentary strata. Among the tech-niques employed in this study were field geologic mapping, geophysical surveying, bore hole photography, and core borings.
_In 1968, I was l
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a transferred to the Huntsville, Alabr.=a Corps of Engineers Division which uns responsitic for the siting, design and constructica of 15 to 20 (later reduced to 4) safeguard antibalistic =issile installations throughout the U.ited States. :!y duties there were to plan, direct and participate in intestigations to determine the suitability of these sites for construction of the m',sile ccmplexes.
I performed geological studies and sonc soil mecha.iics work to develop design parameters for fcundations :.:d excavations.
I also served as technical consultant during design and construction to other government agencies.
architectural engineers, and contracters.
I have been a member of. the Regulatory staff since January 1971 and have participated in licensing activities for at least twenty-five nui. lear facilities including Sumer, Nine-Mile Point, Washington Ntelear 2, Feb*cle Springs, and Indian Point.
These activities con-
.sisted of review of the geological aspects of the sites as presented by applicants and usually an indepe.; dent evaluation conducted by a i
review of the most pertinent literature, site visits, and conversations with knowledgeable individuals or agencies.
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Landsli n 1.
- RC Posit ions Af ter CF And 01. Reviews In its.c fety Evaluation Report (SER) for. the Trojan site dated CCto-a ber 19,1970, the staff concluded that " Based on the evidence provided by the applicant and field observations of our geologists and our geologien1 co6sultants, we have concluded that the existing geological st ructur e is acceptable for the construction and operation of the proposcil plant at the Trojan site."
The U. S. Geological Survey concluded that, i'the applicant propt ses to found all. major plant structures in the volcanic rocks.
Boring logs and test data indicate that the rocks are sound and will provide an adequate foundation for the proposed facility." In its SER following the OL review, the staff reaffirmed its originaleconclusions.
2.
Dyrent Staff Positions It is the staff's position that landsliding in the site area does not present a threat to the Trojan plant.
This conclusion is based on our review of several recent publications on landsliding in the region and the results of geological investigations in the site area including horings, scismic profiling, surface geologic mapping and the geophysical investi-gations that were supervised and evaluated by the Trojan Geophysical Mvisory Poard compriscil of Dr. Peterson, Dr. L'hite and Mr. Dodd. The results of these studies indicate that the immediate site area does not have the characteristics which typify large landslides along the Columbia River.
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f !..trm. I :nnl.. i.h s in t he Col or.ibia River Cor ce Palmer (1977) studied several large landslides that have occurred within the Columbia River Gorge. These slides were in an area characterized by steep terrain with relief on the order of 1200 meters, high rainfall (:00 cn/yr.), exposure of water saturated plastic clay layers under permeable rock masses, and regional dips of rock strata from 5 to 30' into the gorge.
A thick stratigraphic section of the Eocene to Oligocene Chanapecosh formation underlies the area studied by Palmer.
This formation is made up of varied claystone to pebble conglomerate of both sedimentary and volcanic materials. Portions of this rock have been weakened by weathering.
An angular unconformity in the Miocene caused the develop-ment of a zone of soft clay rich saprolite on top of the Chanapecosh formation.
The Miocene Eagle Creek formation overlies the Chanapecosh.
The Eagle Creek is similar in composition to the Ohanapecosh'but is less weathered an.d contains larger rock fragments.
On the k'ashington side of the river, the strata within these formations dip toward the Columbia Gorge, while on the Oregon side they dip away from it.
Basalt overlies the Eagle Creek formation.
River banks were overst eepened as the Columbia River cut through the basalt into the weak Eagic Creek and Chanapocosh formations.
Most large scale Pleistocene and Holocene landsliding occurred on the
!.'ashington shore vhern oversteepened' slopes intersected the bedding planes of eiposed inconpetent rock, which dip to the south into the gorge.
- i. esser slides are found on the Oregon shore where several thousand feet of l
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basalt overlie the clay of the Eagle Creek and Chanapecosh formation vhich dip away from the gorge. The combination of exposure by crosion of the clays and the weight of the basalt caused squeezing updip of the clays, eventually undermining the I
basalt and causing large rock falls.(Palmer 1977).
4 Ccology and_ Topography of the Site Bedrock bcncath the Trojan site consists of volcanic rocks of the i
Upper Eocene Coble series.
Boring, seismic, and laboratory test data show that the rock is relatively sound and composed of tuff, flow breccia, tuff breccia, agglomerate, and basalt.
Bedding planes within the rock. ara poorly developed, but those that have been mapped generally dip toward the west-southwest or southwest, away from the Columbia River. Geophysical data indicate that the volcanic rock also underlies the Columbia River cast of the site thus precluding the exposure to crosion of continuous clay strata like those described in the Columbia River Gorge (Palmcr, 1977).
The topography along the river valleys in the site region is characterized by many steep arcuate features.
The Trojan site is located on a bedrock ridge just east of one of these steep arcuate features within 1
the Columbia River Valley.
This valley was subjected to intense flooding i
during post glacial time (Bretz 1969).
It is likely, based on geologic
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evidence at the site, that the arcuate feature is the result of river.
bank scouring and erosion from rapid flood stage flow through a since-
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abandoned channel of the Columbia River, rather than landsliding.
Similar abandoned channels were reported by Piteau (l?77) following his study of landslides in the Fraser River Valley in southern British Colum5fa.
Piteau also presented evidence to show that the major single l
cause of landslides in that area was the presence of alluvial fans or l
carlier landslide debris on the opposite s'ide of the river, which l
deflected the river laterally and caus.ed undercutting and oversteepening l
l of slopes.
Such processes are not active at the site.
I 5.
Bases for Staff Position Although landslides are evident in the site region, landsliding is not likely to pose a hazard to the Trojan site.
The staff concludes that the Trojan site is not susceptible to landsliding for the following reasons:
1.
Available data indicate that the velcanic bedrock in the site area is continuous from the hills rest of the site, beneath the alluvial valley, through the site ridge, beneath the Colu=bia River, and on to the L'ashington side, and is not an active slide block.
2.
Interpretive seisnt: profiles shew that the surface of the bedrock bencath the alluviated channel is s=cothly rounded, as would be expected in a rapidly eroded bedrock channel, and not sharp and angular as would characterize a relatiecly recent and unstable slide block.
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Rock strata beneath the site and the area around the site on the Oregon shore dip, with relative consistency, southwest or west-southwest away from the River; and data presented by the applicant indicate that joints and shear zones are either not continuous or dip at secep angles, thus precluding the existence of a potential
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slido plane sloping toward the river.
r Geologic maps of the site vicinity o'n both sides of the Columbia a.
River show that bedding dips either 'in a southerly or westerly
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direction.
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Figure 2.5-16 in the FSAR, which is the Geologic Map of Final Foundations, shows that joints and shear zones are either dis-continuous, dip away from the river, or dip at a high angle such that a projection of that dip would not intersect the river valley.
c.
Correlation of bedding from boring to boring and interpretation of geophysical data show that, locally, bedding planes below founda:_
level are generally horizontal or dip away from the river.
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On a broader scale, based on geophysical data and surface mapping, the site lies on the eastern flank of a northwest trending syncline within which the bedding dips to the west, away from the river.
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Dip. af strata beneath the site show no evidence of rotation of beds-as would be expected within a landslide mass.
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The USGS reviewer exa:Ined the excavation for the plant on 1 October,1970, and reported that alth'ough no real bedding plancs were visible, some nearly horizontal, crude separations were ob.erved that were consistent with observations cade in natural exposures'of these rocks nearby.
4.
Based on a projection from mapped outcrops, the volcanic rocks underneath the site rest on the Cowlitz formation, which is described by the Applicant as well compacted but sometimes loosely cemented sandstones and siltstones.
Sandstones or siltstones are generally less suceptible to landslide development than clays, such as those described (Palmer 1977) as being part of the Eagle Creek and Chanapecosh formations.
It is possible that there are clay zones in the Cowlitz formatJ.on beneath the site, either f rom deposition or weathering. However, the Cowlitz formation was subjected to the same deformation as the overlying volcanics, and bedding plancs would likely dip in a westerly direction, away from the Columbia River Valley in contrast to the bedding in other parts of the gorge where large landslides have occurred.
5.
Aeromagnetic and gravity profies show no anomalous break that might be associated with bedrock sliding.
6.
A major landslide upstream could tenporarily block the Columbia River; however, the site intake facility is located at a sufficiently low
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elevation relative to sea level, that the source of emergency cooling water v.ould not be cut off.
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In its report entitled " Geologic Hazards Review Trojan f?uclear Power Plant Site Columbia County, Oregen," the Oregon State l
Department of Geology and Mineral Industries concluded that j
"available geophysical data and geologic information collectively I
indicate that the site area is underlain by continuous bedrock and that deep mass movement is not a factor".
It is therefore our conclusion that landslides do not pose a potential threat to the site including the Spent Fuel Fool Facility.
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References fur Pa_rt,A, Landslides, i
1.
Breti, J. H.,1959, The Lake Nissoula ficods and the Channeled i
Scabland:
Jour. Geology, V. 77, fo. 5, p. 505-543.
l 2.
Palmer, L.,19/7, Large Landslides of the Columbia River Gorge, Oregon and Washington, Geological Society of America, Reviews in Engineering Geology, Volume III, pp. 69-83.
3.
Peterson, R. A., J. E. White & R. K. Dcdds,1972, Geophysical Survey Report Trojan tiuclear Power Plant Site; Prepared by the Trojan Geophysical Advisory Board for the U. S. Atomic Energy Commission, August,1972.
4 Piteau, D. R.,
1977 Regional Slope
,.s ility Controls and Engineering Geology of the Frazer arycn, British Columbia; Geological Society of America Rnians in Engineering Geology, Volume III 1977.
5.
Portland General Electric Company,1973, Final Safety Analysis Report, Volume 1.
I 6.
Portland General Electric Conpany,1969, Preliminary Saf ety Analysis Report, Trojan fluclear Plant, Volume 1.
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State of Oregon Department of Geology and Mineral Indust. ries, 1978, Geologic Hazards Review Trojan I uclear Power Plant Site Columbia County, Oregon, Open File Report 78-1, March 14, 1978.
i 8.
U. S. Atomic Energy Commission,1974, Safety Evaluation Report Trojan I;uclear Plant, Docket tio. 50-344, October 7,1974.
I 9.
U. S. Atomic Energy Commission,1970, Safety Evaluation Report by the Division of Reactor Licensing, US AEC, In the Matter of Portland General Electric Company, City of Eugene, Oregon, i
Pacific Power and Light Co., Trojan ::uelaar Plant, Occket tio. 50-344, October 19, 1970.
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B.
Volcanism 1.
Staf f Position Af ter CP and OL Reviews and Current NRC Position In its Safety Evaluation Report dated October 14, 1970, following the Construction Permit review, the staff concluded that:
"The applicant has evaluated potential lava flows, mud flows, and volcanic ash falls
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- and determined that they would not adversely affect the safe operation 1
of the Trojan reactor. We and our consultant.s, USGS, have reviewed the applicant's evaluations.
We conclude that the assumptions and evaluation techniques used by the applicant were reasonable and we agree l
5 with the applicant's conclusion."
In the Safety Evaluation Report (October 7,19 74), af ter reviewing the Final Safety Analysis Report, in support of the application for an operating license, the staff concluded that:
" based on this review, we conclude that investigations conducted since the issuance of our
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Safety Evaluation Report dated October 19, 1970, have disclosed nothing that would alter our original conclusion regarding the suitability of the Trojan Plant Site."
Since publication of the SER, new information has become available. We have reviewed these data and we see no reason to change our original conclusion.
2.
Basis for the Staf f's Conclusions Following the CP and OL Review During the review for the Trojan site the following potential volcanic hazards were evaluated as to their significance to the Trojan site:
ashfall, mudflows, pyroclastic flow, flooding, and lava. Crandell and O
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. Caldron (1969) indicate that if one of :he Cascade volcanoes erupts, "we believe that ash eruptions and mudflews are the two greatest hazards."
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Volcanic Ash. Ash is esde up of fine volcanic particles that have been blown high into the air by explosions in a volcano. The extent and thick' ness of ash fallout is in'fluenced by the altitude to which it has been erupted, sizes of the particles, the directions and velocities of' the winds, and other meteorologic conditions.
Mount St. Helens is the closest (33 miles east northeast) and most likely source of ash that could affect the site. The applicant stated in the PSAR that even if the ash fall from the Crater Lake eruption were superimposed over Mount St. Helens, the resuiting ash fall would not have damaged the plant, nor caused interruption of the cooling water supply. Crater Lake is located in the Cascade Mountains in southern Oregon and was formed by violent eruptions of a volcano Ott. Mazama) about 7000 years B.C.
The staff agreed with that conclusion on the bases that :
(1) the site lies near the maxistra extent of ashfall when the contours showing the distribution of ash from the Mt. Mazara eruptions according to Williams (1942) are superin. posed on Y_ount St. Helens and other nearby volcanoes (PSAR Figure 2.8-15); (2) the prevailing winds blow away from the plant toward the volcano cost of the time and apparently have done so for thousacds of years; and (3) the source of cmergency cooling water is the Cal =hia River.
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!!udfl ows.
"Mudflevs are masses of water saturated rock debris which cove downslope in a =anner resembling the flowage of wet concr e t e."
(Crandell, 1976). Hudflows have been known to mcve many tens of kilometera down valley floors at speeds of 35 km/hr or more (Crandell, 1976). The possibility of a mudflow from Mount St. Felens endangering the site was considered during the CP stage.
The applicant concluded that, "A large mudflow on Mount St. Helens l
would likely move either down the Kalama River Valley or the Lewis River Valley.
The mouth of the Kalama River is close to the Trojan site, but on the opposite side of the Columbia River.
It does not seem credible that a debris flow down the Kalama would even reach the Columbia River, let alone that it could block it.
If it reached the Columbia River, its probable worst effect would be to muddy the river downstream as the Columbia removed and diluted the flow of debris emptying into it.
The slopes are so flat at the point where the Kalama discharges into the Columbia that a mudflow extending that far would be moving very slowly." The staff also concluded that nudflows did not constitute a hazard to the plant, c.
Floods. Floods can be caused by melting of snow on the flanks of a volcano.
These floodwaters can carry large amounts of rock debris which can be deposited many kilometers from the volcano.
An analysis of the flooding potential due to volcano eruption was
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. :.ade t,y 1*CI during the CP stage of the licensing process.
The worst case situation was failure of da:.s and reservoirs along the Lewis River.
It was concluded that ficoding from the Lewis River l'
reservoirs would not raise the Colurbia River enough to int?ndate l
the plant.
l A similar analysis was not done by the staff; however, the staff's hydrological engineering analysis snowed that the plant was safe from flooding even assuming the failure of upstream dams including Grand Coulee Dam. Any flooding caused by volcanic activity would be less serere than the failure of upstream dams on the Columbia
- River, d.
Pyroclas tic flow. As defined by Crandell (1976), pyroclast'ic flow is a mass cf hot, dry rock debris that roves rapidly down the flanks of volcanoes. Because of the distance that Trojan lies from the nearest voler.no, and the topography, pyroclastic flow was not regarded as a hazar!. to the site.
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Lava Flows. According to Crandell (1976) lava flows generally erupt quitaly, but can be proceeded by explosive activity. Lava flows are usually confined to the is.ediate slopes and toe of the volcano.
In order for lava to reach the site it cust be highly fluid and of steat velu e.
This is not characteristic of F.ount St. Helens and there is no evidence that lava from this volcaro reached the i
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3.
Variation of Volcanic Activity in the Pacific Northwest The staff finds 'no evidence indicating that there has been a recent increase in activity of Cascade volcanoes. Evidence is that future activity will continue much as it has in the past 10,000 years. The volcanoes nearest to the Trojan site:
Mt. St. Helens, Mt. Rainier, I
and Ht. Hood are considered active volcanoes. The available evidence i
J indicates that activity has been essentially constant though episodic l
for at leas t the ?,ast 10,000 years. Historic data show that Mount l
St. Helens was substantially more active during the 19th Century than during the 20th Century.
The enclosed figure is a compilation of known activity of several Cascade volcanoes including.those most significant 4
to the Trojan site. The illustration is based on data published by j
several investigators.,which was presented in Portland General Electric's report entitled " Volcanic Hazard Study, Potential for Volcanic Ash I
Fall, Pebble Springs Nuclear Site, Gilliam County, Oregon." It can be J
seen from this illustration that Mt. Rainier and Mt. Hood have undergene sporadic activity for at Isast the last 10,000 years and Mount St. Helens i
for 4,000 years.
This type of activity is expected to continue in the future.
i L'orldwide data on plate tectonic activity support this interpretation.
The volcanic activity is related to processes at the plate boundary in e
. this region. Data indicate that plate tectenic activity in the United States Pacific Northwest is either continuing at a relatively slow cate as co: pared to erst tectonically active regions around the world, or has s topped co:pletely. This would explain the relative inactivity of the Cascade volcances, when compared to world vide data. For example, in the vicinity of the Aleutian Trench, where the Pacific Plate is actively subducting beneath the Alaskan Plate, volcanoes have erupted far tote frequently historically and with greater violence than in the U.' S. Pacific Northwest.
It is not possible to absolutely rule out that Mt. Hood, Mt. Rainier, or Mt. St. Helens could experience similar eruptions like those that forced Crater Lake. Crater Lake was created after violent eruptions of Mt. Mazzma tbout 7000 years B.C.
Hotrever, such an occurrence is considered to be very unlikely within the next few centuries (Crendell and "allineaux, 1975).
It would represent a coeplete change in activity froa that deconstrated' during the last 10,000 years for Mt. Hood and Mt. Rainier and 4000 years for bunt St. Helens.
Such an eruption at one of these volcanoes occurring simultaneously with the wind blowing
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tcward the site is extremely remote. Therefore it is reasonable to assuna that the /orst everes that have occurred in the geologic past at a specific volcano eculd occur there again.
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It is, the staff's position that any increase in volcanic activity i
that is postulated, based on a study of the activity of the Cascade volcanoes for the past 10,000 years is not likely to present a hazard l
i to the Trojan site. We believe that there will be no increase in i
activity based on the experience of the past 10,000 years.
Evidence from the plate tectonic theory supports this position.
4.
Data Subsequent to the SER's Considerable additional studies have been made of the volcanic hazards of the Pacific Northwest since publication of the Safety Evaluation l
Re po r ts.
Many of these studies have been conducted in' regard to the j
siting of nuclear power plants, such as the Washington Public Power Supply System (WPPSS) Nuclear Project 3.and 5, the Fuget Power Skagit site; and the Portland General Electric Pebble Springs site. The data i
included in the reports supporting license applications for these sites i
I are corspilations of data from many investigators. The USGS has i
published studies of volcanoes in the Pacific Northwest, among which are volcanic hazard essessment caps (Crandell,1976 and Mullineaux, 3
i 19 76).
The analysis of volcanic hazard for the WPPSS 3 and 5 site, which i
is 80 miles from the nearest volcano (Mt. Painier and Mount St. Helens) indicated that only ash could affect the site.
It further showed that s
less than 2 inches of ash would fall at the site even if the assunption is made that a Mt. }!azans type eruption occurred ac Mt. Rainier or "ount St. Helcas.
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I Based on a recommendation from the USGS, Puget Pcuer postulated that a mudflow similar to the Osceola nudflow from Mt. Rainier could occur at Mt. Baker, which is about 22 miles east of the Skagit site.
The analysis showed that such a mudflow would not adversely affect the site. Ashfall is believed to be the only form of cruption that poses 1
i a direct hazard to the Skagit site (USGS, 1977). The Skagit sit'e is I
located about 56 miles from Glacier Peak, the nearest volcano with an explosive history. Based on the superposition,of the 1912 Katmai l
Alaska eruption on. Glacier Peak, about 2 inches of ash would fall at I
the site. The Applicant assumed a maxi =ua ash accumulation of 6".
The staff and the USGS concluded that this was a conservative approach.
1 Unlike the WPPSS 3 and 5, Skagit and Trojan sites, the Pebble l
Springs site is located east and downwind of the Cascade volcanoes.
1 During the review of the volcanic hazard for the Pebble Springs site, j
it was our position, and that of the U. S. Geological Survey, that a l
conservative and reasonable estimate of a maximum potential ash fall at the site should be modeled after the Yn ash layer which was erupted j
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froc Mt. St. Helens between 3,000 and 4,000 B.C.
This analysis resulted
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in the assumption of a thickness of 81/2 inches of uncompacted ash at the site, which is located 80 miles and 105 miles east of Mt. Hood and-Mount St. Helens respectively.
Since publication of the SER's the L'SGS has published 2 Volcanic Hazards Mcps (Crandell,1976 and Mullineaux, t
1977). The former designates zones in the state of Wash 1ngton within j
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9-which specific volcanic hazards are possible.
The latter shows volcanie hazard zones in the western United States.
The USGS also open filed a report entitled Potential Hazards from Future Eruptions of Mount St.
Helens Volcano, Washington (Crandell and Mullineaux,1976).
5.
Icpact of Subsequent Data on Original Conclusions 1
Based on the data that the staff is aware of, which has come to j
light since the CP & OL proceedings, the only form of volcanic eruption
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that could directly affect the Trojan site is Ash fall. ' However, new l
information has become available regarding several of the other potential hazards. These will be addressed first, followed by a discussion of i
ash fall.
Crandell (1976) and Figure 2.5.1S of the WPPSS Nuclear Project No. 3 Preliminary Safety Analysis Report, which is based on data presented by Crandell (1973), shows mud flow deposits just north of Longview, 1.'ashington in the Cowlitz River Valley. During its evaluation of i
this phenomenon PGE concluded that because of the distance from the volcano, and consideration that the intersection of the Cowlitz and Columbia Rivers was located downstream from the plant there was no potential hazard to the Trojan plant. Crandell (1976) also shows a potential mudflow hazard within the Kalama River Valley extending to about 8 niles from its intersection with the Columbia River.
This does not present a threat to the Trojan site. Much larger mudflows have occurred in the region such as the Osceola mudflow f rom Mt. Rainier, e
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which t_s used as a codel for the taxieum possible nudflow during the Skagit site retiew. However, since Mount St. Helens is a relatively i
young and unal:ered volcano, one would not expect such large quantities l
of potential cudflew material to be available on it, flanks as on j
those of the o*_ der' altered volcanoes like Mt. Rainier and Mt. Baker.
According to C andell and Mullineaux (1976), "The absence of an appreciable accunt of clay in mudflows from Mount St. Helens suggests that.large areas of hydrothermally altered rock did not exist on the volcano in the past; nor are they present today. For this reason, cudflows as large as the largest from Mount Rainier volcano (Crandell, 1971) are not ~ikely to occur in the foreseeable future at Mount St.
l Helens." Beca:se cf the distance from the Trojan site to the volcano, the nature of the intervening topography, the site being outside of the mudflow ha:ard zone specified by Crandell (1976), and the youthfulness of Mount St. Helens, we consider our earlier conclusion that mudflows do not constit te a threat to the Trojan site, as being still valid.
Crandell (1975) shows the potential for volcano induced floeding at the Kalaca :nd Lewis Rivers. As stated earlier, flooding from these 4
sources would le less than the assu=ption of failure of upstream dams on the Cole =bia F.iver. The site is considered to be safe from such events.
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. I' The distribution and thickness of ash deposits east of the cascade t
1 volcanoes are relatively well documented, at least those that originated i
within the last 10,000 years. The distribution of ash to the west of the volcanoes is not well documented, partly because the prevailing winds blow mostly toward the east, therefore, most ash has been trans-ported in that direction; and partly because investigations have not i
been conducted west of the volcanoes to the extent that they have to
^
the east. According to Crandell (1976) "No si t.ificant amount of tephra has fallen in the western sector beyond the b6se of the source volcano during the last 4,000 years at Mt. St. Helens, or during the l
last 10,000 years at the other large volcanoes in Washington." Crandell i
(1976) and Mullineaux (.1976) selected the respective tephra hazard
- ones west of each volcano to be 25% as great as those in the eastern i
sector, although the few ash beds known to exist west of their source i
vents are less than 10% of the distance that similar beds extend east of the source vents (Mullineaux 1976). This number is not completely l
arbitrary as it is based on the knowledge that not only do the prevailing winds blow to the east most of the time, but on the rare occasions when 4
they are blowing to the west, velocities are significantly less. This
,i is demonstrated by attached tables 3 and 4 from Crandell and Mullineaux 1
i (1976).
The Trojan site is near the outer boundary designated as zone B by Mullineaux (1976), and described as an area subject to 5 cms or more 6
l
, + -. -
w 2,...
l of' ash f rom a "large" eruption similar to the ': aunt St. Irelens eruption about 3,400 years ago. The site is located in en area designated by Crandell (1976) as one of very low to lew potential hazard to known
]
human life and health, and one of probable taxicum tephra thickness of less than 5 cms. With regard to the spent fuel building, the weight of 5 cm of uncompacted ash on the fuel building roof would impose l
loads well within the design limits of the roof.
(ESAR Ta' ale 3.8-2 gives live load design limits for facility roofs.)
The staff concludes that information that has become available since publication of the SER's does not cause us to alter our original conclusions that the site is suitable froc a volcanic hazards stand-i i
point including the spent fuel pool.
6.
Conclusions a.
It is the staf f's position that there is no present increase in volcanic activity in the Cascade volcanoes. Available evidence a
indicates that activity has been relatively consistent over the I
past 10,000 years. The historic record shows that Mount St. Helens was far more active during the 19th Century than during the 20th Century.
Future activity is expected to be sLoilar to that which 4
4 has occurred during the past 10,000 years.
.\\ very large eruption, i
j like the Crater Lake eruptions, of one of the larger Cascade volcanoes cannot be completely ruled out.
However, such an occurrence sinultaneous with "high altitude winds blowing toward
\\
1
the site is considered to be extremely cemote. Any increase in volcanic activity that is postulated, based on the activity of the Cascade volcanoes for the past 10,000 years is not likely to present a hazard to the site.
b.
Because the Trojan site was shown to be safe from a more severe hydrologic event (failure of upstream dams on the Colu=bia River, including Grand Coulce Dam), floods caused by volcanic activity will not present a hazard to the site.
I c.
Due to the distance of the Trojan site from the Cascade volcanoes and the topography, pyroclastic and lava flows do not pose a threat to the site.
d.
Mount'St. Helens is a young, unaltered volcano; therefore, large
. quantities of potential mudflow material are not likely to be avail-able on its flanks. We conclude that mudflows are not likely to threate e site.
e.
Ashfall is conside're represent the greatest potential azard in this part of the Northwest.
It is ely that any ash will fall on the Trojan Plant because the prevailing winds w away from the when plant and toward the volcano; and even during those rare t a
's they blow toward the plant, velocities are significantly lower.
s Superposition of the ash distribution from the Mt. Mazama eruptions a t Mount S t. Helens would not adversely af fect the safe shutdown capabili'ty of the site.
o O
o e aimy m
-e mem = = = m m aumm.g w mses
=+=e e n e
. summe s e enn e.e
f.
In its !!srch 18, 1978 report to the State Depart.ent of Inergt entitled " Geologic Hazards Review Trojan !!uclear Fo, er P*. ant Site, Colu=bia County, Oregon," the State of Oregon Department of Geology and itineral Industries concluded that "no new evidence hus come to light to require modification of conclusions regarding volcanic hazards as they are presented in the FSAR."
g.
The Applicant cocunitted in the SAR's to take the necessary steps to mitigate the effects,of a volcanic eruption including shutting down the plant.
References in items (a) through (e) to the " site" include the spent fuel pool.
Based on the above, the staf f reaffirms its conclusion following the licensing reviews, that the Trojan site, including the spect fuel pool, is suitable from the volcanic hazards point of view.
e i
j
~
s REFERENCES FOR PART B - VOLCANISM 1.
Crandell, D.R.,1971, Postglacial lahars from Mount Rainier volcano, Washington U. S. Geological Survey Professional Paper 677, 75 pages.
2.
Crandell, D. R.,1976, Preliminary Assessment of Potential Hazards froa Future Volcanic Eruptions in Wushington, U. S. Geological Surrey Misc. Field Studies Map MF-774.
Crandell, D. R.,1973, ' ap Showing Potential Hazards from Future M
3.
Erupt,1cns of Mount Rainier, Washington, USGS tbp I-836.
4.
Crandell, D.
R., and H. H. Waldron,1969, " Volcanic Hazards and the Cascade Range," Of fice of Emergency Preparedness, Region Seven, Geologic Hazards and Public Problems Conference Proceeding, Santa Rose, Calif. (May 27-28, 1969).
5.
Crandell, D. R., and D. R. Mullineaux,1976, Potential Hazards from Future Eruptions of Mount St. Helens, Volcano, Washington, U. S.
Geological Survey Open File Report 76-491.
4 6.
Mullineaux, D. R.,1976, Preliminary Map of Volcanic Hazards in the 48 conterminous United States, MF-786.
4 7.
.artland General Electric Company,1973, Final Safety Analysis
^
'eport, Volume 1.
8.
Portland General Electric Company,1969, Preliminary Safety Analysis Report, Trojan Nuclear Plant, Volume 1.
9.
Puget Sound Power and Light Company,1973, Preliminary Safety Analysis Raport Skagit Nuclear Power Project, Volume No. 4.
10.
Shannon & Wilson, Inc.,19 76, Volcanic Hazard Study Potential for I
Volcanic Ash Fall Pebble Springs Nuclear Plant Site, Gilliam County, Oregon, Revision 1, Iby 17,19 76, Repoet to Portland General Electric Company.
11.
U. S. Atomic Energy Commission,1970, Safety Evaluation Report by the Division of Reactor Licensing, US AEC, In the Matter of Portland i
Cencral Electric Co., City of Eugene, Oregon. Pacific Power &
Light Co.
Trojan Nuclear Plant, Docket No. 50-344, October 19, l'370.
12.
U. S. Atomic Energy Commission, 19 74, Safety Evaluation Report Trojan Nuclear Plant, Docket No. 50-344 October 7, 1974.
D
=mme ee
.e e
.e*
,*i-w m-se e
e.
\\
13.
U. S. Geolegical Survey,1977, Stat.:s of Reviee ?uget Sound Power and Light Co:pany, Skagit Nuclear Power Project, Units 1 & 2 Project No. 514, Skagit County, *-ashington, ::7.C Docket Nos.
50-522 and 50-523.
14.
State of Oregon Department of Geology and iineral Industries,1978, "Geologie Hazards Review Trojan Nu: lear Power Plant Site Colu hia County, Oregon," Open File Report 78-1, :: arch 14,1978.
15.
U. S. Nuclear Regulatory Commissio',1973 Supple:ent No. 3 Safety n
Evaluation Report relat.ed to construction of Pebble Springs Nuclear Plants Units 1 and 2, Docket No~s. 50-514 and 50-516.
16.
Uashington Public Power Supply Systen, 1974, Preliminary Safety Analysis Report WPPSS Nuclear Project No, 3. Volume 3.
- 17. Williams, H. A.,1942, "The Geolory of Crater Lake National Park, Oregon," Carnegie Institution of Washington Publication 540, 1942.
O e
e
+
e
M Table 3.--ftean viind speeds, in knots (1 knot = 1.15 mi/h or.1.85 km/h). at various al tit :- :.
Based on 20-year record (1950-1970) at Quillayute, Wash. (Winds Aloft Summary of it;-
r Weather Service, U.S. Air Force, available from the National Climatic Center, AsheviTIE H.C.)
FROM-----
N NME flE ENE E
WNW f."4 NNW TOWARD---
WNW fiW NilW N
NNE NE ENE E
alt.
(ad 3,000 18.6 16.3 14.8 11.5 11.6 12.4 13.8 18.l' 24.2 25.7 25.4 24.2 23.5 21.8 22.4 21.2 0
4,300 26.7 21.7 18.7 15.1 13.7 15.5 18.2 21.5 27.2 30.7,. 31.3 31.1 31.0 29.4 29.6 28.5 5,500 33.2 27.8 27.9 18.5 N.6 'l6.8 20.8 22.9 32.2 36.6 38.6 38.3 38.4 37.3 35.7 36.9 9,100 48.6 43.8 36.5 29.9 30.2 26.4 32.2 38.0 46.8 52.5 55.9 55.4 56.2 50.8 51.6 53.9 12,200 40.9 31.5 30.3 14.9 19.7 16.9 18.8 28.0 35.8 43.8 48.5 50.3 50.9 46.2 46.3 45.4 16,200 20.1 12.4 11.3 6.3 6.4 9.0 9.7 13.8 15.5 21.1 23.7 25.8 26.2 25.1 23.7 21.4 Average-- 31.4 25.6 23.2 16.0 16.5 16.1 18.9 23.7 30.3 35.1 37.2 37.5 37.7 35.1 34.9 34.6 f;.,. Gera.h//, D.C W /).J. trL'Aheou, / 4 74, A /-,, A*,/ //> cede h-5fera.
s*/. //o/re.r V /<wo, &usr 4a k., as cc./.f ed J'wy u fop 6*.., r a f ^1o v.,/
y i
rn pi. e.,..s n - n.
l 0
Table 4.--Percenta3e of wimi.. by month, a t.ix al titmins from about 3.000 to 16,000 m. averai'wl.
Itasel on 20-yearjir[n~El_(,1yi0-I'17,0)[ $1t[_Qiit'l1)(/p}t'i,]!fsh,(( Win _d,s,,,A1,0',t,Jppiiary_ oi the Air l@f t/i,
~
^
ymvic.3, U.S. Air forro. av.iilabl.' from the fla tiona l Clima tic Center,,. Asheville, ti.c. ).
E M-----
N title NE ENE E
WN11 tiW fm i TOWARD---
WNW NW NNW N
NNE NE ENE E
3.4 1.4 0.7 0.5 0.5 0.2 0.5 1.0 2.7 6.8 12.5 16.9 18.4 15.2 11.9 7.0 F r.Il - - - - - -
3.9 1.9 1.3
.6
.8 1.1 2.0 1.8 3.7 6.5 10.8 14.2 16.4 15.2 12.3 7.4 (MR------
4.5 2.1 1.1
.5
.9
.9
.9 1.5 4.3 8.4 12.2 14.2 15.5 '12.7 1 2. 11 7.6 APR------
4.2 2.7 2.1 1.4 1.2 1.3 1.6 2.6 4.8 7.0 11.9 13.4 14.8 12.2 11.3 7.6
~
MAY------
4.4 2.2 1.6 1.0 1.0 1.6 3.0 3.9 6.9 8.6 13.6 15.0 13.0 10.1 7.7 6.0
. JUNE-----
3.7 2.8 2.3 1.7 1.4 1.5 1.7 2.8 6.0 9.0 13.9 14.9 13.4 10.0 8.6 6.2 JULY-----
3.1 1.9 1.4 1.0
.9
.9 1.1 2.2 4.0 8.6 18.9 19.8 13.8 9.4 7.5 5.7 AUG------
3.1 2,3 1.5 1.0 1.0 1.2 1.6 2.6 5.1 9.0 15.8 17.6 14.7 10.0 8.1 5.4 SEPT-----
- 5. 3 2.4 1.6 1.1 1.2
.8 1.2 2.2 3.2 7.9 12 2 12.7 14.7 14.7 11.3 7.7 OCT------
2.2 1.4
.7
.4
.2
.2
.5 1.1 3.8 8.7 16.6 19.9 19.2 12.5 7.8 4.6 NOV------
3.3 1.4
.5
.2
.4
.4
.8 1.7 3.5 8.1
.13.9 17.0 20.2 14.0 11.3 5.1 j
DEC------
3.1 1.2
.4
.3
.3
.3
.5
.9 3.2 8.8 14.4 17.4 18.5 14.4 10.5 6.0 AVERAGE--
3.7 2.0 1.3 0.8 0.8 0.9 1.3.2.0 4.3 8.1 13.9 16.1 16.1 12.5 10.1 6.4 Fi -.,. Crancle//, 0. rz
--.cl /J. R. Mat /ine o us; sp y d,,,0 /e n M / A b u = rw!r Aom Shee Gr.y h'.
,e of /foun/ S/. He/ent 44/ con e, wo eNayA n, &fr. G e.rys,J So u ~7 Q a-,
pk fepees* 74 99/
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