ML20126A267
| ML20126A267 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 01/04/1980 |
| From: | Rolonda Jackson Office of Nuclear Reactor Regulation |
| To: | Parr O Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20126A095 | List: |
| References | |
| NUDOCS 8002140528 | |
| Download: ML20126A267 (7) | |
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App ~endix F
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UNITED STATES y7 i
NUCLEAR REGULATORY COMMISSION
. O m.. s WAss u.c Te n. c. c. x455 S
s January 4,1980 MEMORANDUM FOR:
Olan D. ?arr, Chief Ligh: Wa:er Reactors Branch tio. 3, OPM FROM:
Robert E. Jackson, Chief Geos:iences Branch, CSS
SUBJECT:
STAFF RESP 0t1SE TO WILLIAM H. WAR 0'S LETTER Ort SEISMIC ISSUES AT CLF CREEK Enclosed is the Staff risponse to William H. Ward's petition' to the Commissioners recuesting at least a partial.susper.sion of the construction pemit for the Wolf Creek Generating Station.
This Staff response is an expanded background for the seismic issue renti:ned in footnote 6 of the July 12, 1979 Director's De:isi:n under 10 CFR 2.205.
This Cirec:or's Cecision by Victor Stello, Jr.,
IE, denied Mr. Warc's petition.
It stated that the seismic issues contained in Mr. Ward's let:er were :reviously censidered by the Staff and do not alter the Safe Shu:d:wn Earthquake at the Wolf Creek site. Based upon the enclosed evaluaticn of Mr. Ward's concerns ar.d re:ent Staff licensing. decisions, we conclude that the 0.12; Safe Shu-down Earthquake is adecuately conservative and therefore j
re:c T snc -ha-Mr. Ward's repuest fer at least a partial suspension of the constructi:n permit for Wolf Creek be denied.
Dr. Phyllis Sobel, Geophysicist, preparad this evalt.atien.
She was assisted by Leon Reiter, Section Leader.
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c Robert E. Jackson, Chief Gecsciences Branch Civisicn of Systems Safety J
Enclosure:
As sta:ed
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J. Knight
,,4. Liebeman S. Varga S. Burns R. Ja:kson R. Rothoan L. Reiter-H. Lefevre R. McMullen R. Muller P. Sobel
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M. Licitra H. Thornbury, IE
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'J. Harbour W. Reirauth, IE M. Schutacher, IE 8002 W
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4 Appendix F STAFF RESPONSE TO WILLIAM H. WARD'S LETTER ON SEISMIC ISSUES AT WOLF CREEK On June'29, 1979, William H. Ward, Attorney for the Mid-America Coalition l~
forEnergyAlternatihes,wrotetheNRCCem.issionerstoadhisethemof j
several seismic issues affecting the Wolf Creek site and to request at least a partial suspension of the construction permit (Attachment
).
It c
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is the purpose of this Staff res;onse to address Mr. Ward's concerns.
Con:ern 1.
A report by the Xansas State Geological Surhey (KSGS),
i j
NUREG/CR-0294, concludes that the 1867 Manhattan earthquake was at least j
intensity VII-VIII (MM). Mr. Ward states that this earthquake was used j
as the basis for the Safe Shutdown Earthquake (SSE) and that the SSE was based j
on :he assumptien that the 1857 Manhattan earthquake could occur on the i
Hecaha Ridge at its closest appr:ach to the Wolf Creek site, 50 miles.
In l
j
. light of the new irfor,ation deheleped by the KSGS, the.12g horizontal i
accelerationSSEdoesnotnowap;eartobeconserhatihetoMr. Ward.
3 l
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Res:onse, The Staff hai reviewed the recort by KSGS and still finds the 1'
1867 Manhattan ear-hquake to be intensity VII (MM).
The assignment of intensity 4
VII-VIII is based upon an 1877 reper cf liquefaction.-on a f arm on the floodplain._
l oftheKansasRiher. ThatobserhaticnwasassignedintensityVIIIandplaced 9
closetotheepicenterbytheKansasGeologicalSurhey. Liquefactionishery a
dependent upon local site conditions and may occur in isoseismal areas that i
j may otherwise be associated with intensities less than VIII. The staff l
agrees with the standard references, such as Earthquake History of the United States (1973), which list this earthquake as an intensity VII (MM).
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In the Safety Ehaluatica Report (SER) fer the Wolf Creek site, the Staff chose a Safe Shutdown Earthcua%e (SSE) of intensity VII (MM).
This intensity was based on:
1.
The maximur, earthquake that could oc:ur in the Nemaha Uplift at its closest approach to the Wolf Creek site.
2.
The maximur random earthquake in t = region (for example, the 1956 Catoosa, Oklancena earthquake).
TheStaff'sanalysisdidnotinho1Yethedirectuseoft'he1867 Manhattan earthquake since a larger earthquake (intensity greater than VIII and less than X) was assumed to :ccur en the 1ec.tha Uplif t.
This larger earthquake was already astred to ccur at the closest approach of the Humboldt Fault tc the Wolf Creek site. Therefore, the risults of the Staff's analysis (an SSI cf intensity VII) are not mcdified by the KSCS results.
Ccncer, 2.
The si:e of the ap;rcoriate Wolf Creek SSE can be determined by reference tc the SER for another of tne S.NUPPS units, Tyrcne. Soth Tyrone ar.d Weif Creek are loca:ed in the Central Stable Region Tectonic Prohince.
The Tyrone SSE is C.2g horizontal a::eleratien.
Reso:n:e.
The Staff's assessmen: cf the SSE at both Wolf Creek and Tyrone considered both the maximum random earthquake and the maximum earthquake that cculd occur on a nearby structure.
The staff has evaluated the SSE at Wolf Creek and Tyrone in light of more recent licensing decisions.
As a result of this evaluation we see no eviden:e that the SSE at Wolf Creek is uncon-servative or that it is inconsisten: with recent licensing decisions.
l l
'WD 4'S 6+y4mm
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3 1.
Randoa earthq;ake at Tyrone.
Tne Tyrone site is r. ear the toen of Curand in western Wisconsin.
The site is in the Central Stabi'e Region Tectonic Prohince.
In the Tyrone i
SER (1975), the Staff considered the intensity VII-VIII Anna, Ohio earthquake cf 1937 as the largest earthquake in the Central Stable Region which could l
not be reasonably asse:iated with kncwn geologi: structure. Using the Trifunac-l Brady (1975) empirical relation beween intensity and ground acceleration, the Man vibratory ground acceleration correspending to MM int 5nsity VII-VIII is 0.2g.
T11s evaluation of the largest randoc earthquake near the Tyrone site is conservative 1
and similar t: re:ent licensing decisiens cade for other sites in the Central Stable Recica.
The Staff, hcsever, recogni:es significant variations in the historie 1
seisticity a;n:ng subre;iens of this large s;ructural tectonic province.
Based ca the les level cf seismici.ty in the vicini;y of the Tyrone site,and had the licer.see ;ihen sufficient supportive bases, the Staff may have considered an inter.sity lower than VII-JIII (MM) more appropriate for the random earthquake.
2.
Paxim;m earth:u$ke on the Midc:ntinent Ge: physical Anomaly and its effects
- - r at the Ty~cne site.
For tie parpose of es ablishing the 555 at the Tyrcne site, the Staff evaluated the effects of the maximum earthquake associated with the Midcontinent Geophysical Anomaly (G) on :he 7yrone site (55R.,1975). Tne Staff assumed that an intensity VIII earthquake could occur n structures associated with the MGA.
.n the SER the Staff assced that at its closest approach to the site, i.e. 45 ciles, the intensity at the site due to attenuation would be reduced to intensity VII'-VIII. 'Jsing urrent intensity-attenuatien relationships for the Central j
Stable Region (Supta and Nuttli,1976) attenuatien of the effects of the intensity VIII event at the closest point en the MGA to the Tyrone site, i.e. '5
.iles, results in a site intensity less than VII.
Using the Trifunac -
Erady (1975) e=irical relation be ween intensity and ground acceleration, the mean "7
T m
-... Yi:ratory;rcurdac:elerationccrrespcndingtoMMintensityVIIis0.12.
9 3.
Random ear:n ut<e at Wolf Creek.
The Wolf Creek site lies in southeast Karsas in the Central Stable Region Te:tenicProhir.ce. In the Wolf Creek SER, the S}aff considered the maximum random earthcutke to be intensity VII' (IO!).. This position was reiterated in i
a more recint Staff decision in the same region-the Black Fox site in eastern Oklaho a (SER,1977). The Staff recogni:ed the low lehel of seismicity in :1e hicinity of the Black Fox site and considered the maximum random earthcut:<e to be intensity VII.
4 V.axinu earth;ulke en the Nemaha Uplift and its effects at the Wcif Creek site.
For ths purpcse Cf istablishing the SSE at the Wolf Creek site, the Staff evtlua:ed :ne effects of the maximum ear:hquake associated with the Nemaha Uplif t (NU' cn the Wolf Creek site (SER,1975).
The Staff assumed that intensitie! grtiter than VIII and less than X could occur on the Nemaha
~
U;;ift. In a :re recen: StaffdecisienfortheElackFoxsite(SER,1977),Jthe
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Stiff-foun0 thst an earthouake of intensity VIII was a more reasonable maxi.:un ehent en the
.'.'U, based cn similarity with other structures in the Central Stible Regi:n which hahe associated seismicity.
(This Staff de:isien was s ppor ed by the Black Fox Licensing Board Decision " Partial Initial Oe:isi:n Au:horizing Limited Work Authori:ation,' L5P-73-26, 8 NRC 102, lil (1973), Aff'd ALAB - 573, Slip Op. at 40 (Dec. 7, 1979)). Using curren; in ensity-attenuation relationships for the Central Stable Regien (G;p;a and Nut:li,1976), attenuatien of the effects of the intensity VIII event at the closes; point on the NU to the Wolf Creek site, i.e. 50 miles, results in a site intensity less than VII.
a Conclusien h
Therefore, based upon or.r s aluation of che SER's for the most recent
-licensing decisiens, we con:lude that it is not necessary to hahe the same SSI at the Tyrone and Welf Creek sites. Applying a current intensity-attenuation relatica at both sites, a site intensity of VII is in adequately conserhatihe halue fer the effects of the maximum earthquake i
on significant nearby scruccures. At the Tyrone site the maxitum rando:
earthquake was censerha:iheiy chesen to be intensity VII-VIII but the Staff could haUe cor.sidered a icwer incensity based en the low level of seismicity in the hicinity cf the site. At the Wolf Creek site credit was gihen 'for the lower lehel of seismicity in the hicinity of the sice and i
f the maximur randca earthquake was censidered to be intensity VII.
Ar.alysis of f;RC Socasored Research Prc:rans Affectino the Wolf Creek Site The KS35 repcrt cer.-ioned ir. Ward's le-ter is part of a cooperatiYe geologic, seismic, and ge0;hysical research program by seheral state geological surheys that is seekin; o define the structural setting and tectonic his'.ory cf the Nenaha Uplift and tie Midcontinant Gecphysical Anomaly in orcer :c prohide the bases for a more realis;ic appraisa.1 cf the earthquake risks in the siting of l
nuclear f acilities in the Ncrth American Mid-Continent.
This infermation is used as a basis for continuing restar:h and as input to the ehaluation i
or seismic risk in che regien within and around the Nemaha Uplift.
The i
research effert thus far has increased cur current data base and cur under-scandinc of earthquake phencment in the hicinity of the Nemaha Uplif t; however, this lMo~i TiGn-~5Es~rli~lnfiTatifa~nesc~ tim 6dify anyprevicus licensing.
decisions, i
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o As part cf this ccoperative research program, the N?,C is funding a five year detailed study cf the sources cf seis.icity in the Ne ahz Uplift area.
The results cf wcrk ccepleted in ?hase I is curren-ly being reviewed.
There-fore, it is too serly to assess the irsact on nuclear power plant licensing.
The to;ai it;act of the five year stucy cannot be assessed until the overall program is ccepleted and synthesi:ed with seismic monitoring data. The prelimintry resuits are being considered in the development of a tectonic province or seistic 2:ning map of the eastern U. S.