ML19345G368
| ML19345G368 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/18/1973 |
| From: | Ashley Ferguson US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19345G365 | List: |
| References | |
| ZECH, NUDOCS 8104070056 | |
| Download: ML19345G368 (9) | |
Text
.o UNITED STATES
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ATOMIC ENERGY COMMISSION l
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WASHINGTotA D.C. 20545
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SEP 1 8 E
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k DOCKET NOS.:,50-338, 50-339, 50-404 AND 50-405 i
APPLICANT: VIRGINIA ELECTRIC POWER COMPANY (VEPCO)
FACILITY: NORTH ANNA POWER STATION, UNITS 1, 2, 3 AND 4 h
9 SU! DIARY OF MEETING HELD SEPTEMBER 7, 1973 o
Representatives of VEPCO met with the Regulatory staff at the North Anna Power Station site to discuss the chronology of events which led to the conclusion that.a fault existed at the site.
In addition, the staff, once again, exa=ined the excavations for the containments of Units 3 and 4.
A list of attendees is attached.
The significant points discussed are su::narized as follows:
1.
The Role of the Participants Re Geologic Studies S' tone and Webster (S&W), as agents of VEPCO, were responsible for following the site geology condition during the excavations associated with all Units.
Mr. Robert Henry was the S&W site geologist for Units 1 and 2; Mr. Robert Pastuzak was the S&W site geologist for Units 3 and 4.
Mr. John Breidis was their ic: mediate supervisor.
Dames and Moore (D&M) performed the initial foundation studies for all four Units and the supplemental geologic studies performed following the dis-covery of indications of a fault in the excavations for Units 3 and 4.
They were not involved in studies of the " chlorite seam" discovered in Unit 1.
2.
The Chrocology of Events
(
The chronology of. events in the containment excavations for Units 1, 2, 3 and 4,,and in the geologic investigation for Units 3 and 4, are presented in Appendix A.
Explanatory notes were added during the discussion of these chronologies.
3.
Virginia Division of Mineral Resources (VDMR) Analysis In February 1970, tension cracks were beginning to appear in the south wall of the Unit 1 containment excavation. The rock condition was investigated by Messrs. Breidis and Swiger (S&W). During this investigation, deforma-tion was noted in the rock bolt plates and it was concluded that there 8 o40700 56 2
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SbM!fARY OF MEETING HELD.
SEPTEMBER 7,1973 (VEPCO) was a good potential for a rock slide. In additica, a " chlorite seam" was noted and VDMR was requested to analyze certain rock samples. The copy of VDMR report on these samples is presented in Appendix B.
The suite of minerals in the " chlorite samples" was attributed to altered biotites. Because of the parallel strata; sets of parallel joints with slickensides; no indications of clay gouge or offsecs; the " chlorite seam" was not judged to be a fault.
4.
First Indication of a Fault On April 20, 1973, Mr. Robert Pastuzak (S&W) noted offset in a peg =atite dike following the last 10 foot lift from the contain=ent excavation for Unit 3.
On April 23, 1973, Mr. Breidis investigated and VEPCO was informed on April 24, 1973.
5.
Preliminary Investigations Initial investigations were directed toward establishing that the pegmatite dike was offset and not simply two such dikes that had bottomed out in the
" chlorite seam".
As the' investigation continued, examinations were made of injected materials, flow structures and quartz veins.
Some dating was performed by Teledyne. The stratographic sequence was noted and clay' gouge and slickensides were observed. As the excavation was completed, a second " chlorite seam" was noted in the southwest wall of the Unit 3 con-tainment excavation.
I 6.
Visit of Dr. Funkhouser, et al, to Excavations of Unit 1 i
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In February 1970, Dr. Funkhouser called Mr. H. Engleman (VEPCO) to request j
permission to visit the excavations to observe the rock formation therein.
They met at the site.
Dr. Funkhouser was accompanied by a few students and Mr. H. J. Webner.
Dr. Funkhouser observed the " chlorite seam" and other features within the excavation.
Mr. Engle=an does not recall Dr.
Funkhouser referring to the " chlorite seam" as a fault. He is aware of the significance of a fault in the excavation and is sure he would have notified other company representatives had he been informed a fault existed.
Later, Dr. Funkhouser requested and received permission to return to this site with Drs. Goodwin and Clement. The three geologists returned to the I
site about one month later accompanied by a few students.
l 7.
Units 1 and 2 Report A S&W report, " Report on Rock Conditions and Their Reinforcement in Con-tainment and Fuel Building Excavations North Anna Power Station for 1
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SUMMARY
OF MEETI!G HELD.
ON SEPTEMBER 7, 1973 (VEPCO)
Virginia Electric and Power Company", was given to the staff.
Seven f
additional copies are being prepared and will be forwarded when available.
i 8.
Clarification of Miscellaneous Points In response to questions by the staff, the following clarification statements were made:
Four shear zones are mentioned in the supplemental report, i.e.,
a.
Zones A, B, C and D.
Zones A, B and C appear in all four excava-tions. Zone D is interface between granite gneiss and hornblende gneiss and appears only in Units 3 and 4 excavations.
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b.
The micro-tremor instrumentation used during excavations was only used for short periods of observations to monitor blast effects. All monitoring was done by S&W; only two instruments were used. P waves were monitored parallel and perpendicular to folliage. Only peak velocity data was obtained. Data is insuffi-cient to interpret further,
- c. 'Slickensides in Units 1 and 2 judged to be due to rock slides.
Slickensides were not observed in undisturbed material.
d.
Slickensides is concentrated in Zone A.
The sum of movement in one direction due to all Zones is about e.
10-12 feet, f.
Indications of strain decrease as Zone A progresses toward Unit 1.
g.
Attempts of measuring residual stress were foiled due to the quantity of b7.
en rock.
Slickensides attributed to release of residual stresu, during weathering.
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N.
N. "A Robert L. Fe guso p, Project Manager
~" Pressurized Wa' ten Reactors Branch 4 l
Directorate of Licensing
Enclosures:
1.
List of Attendees 2.
Chronology Containment Excavation Events, Appendix A 3.
Virginia Division of Mineral
~ ~ ~
j Resources Report, Appendix B l
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i NORTH ANNA 3 AND 4 SITE MEETING SEPTEMBER 7, 1973 LIST OF ATTENDEES Atomic Energy Commission R. L. Ferguson W. P. Gammill S. M. Coplan A. T. Cardone H. E. LeFevre J. F. Devine - E0AA USGS F. N. Houser Dames & Moore (D&M) i R. C. McEldowney J. F. Gibbon Virginia Electric and Power Company (VEPCO)
S. V. Lowry G. Freeman P..R. Beament E. A. Baum F. M. A111 good, Jr.
C. M. Robinson, Jr.
i H. L. Engleman i
Stone & Webster (S&W) l l
J. Briedis I
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APPE; DIX A CHROM 0 LOGY CONTAINMENT EXCAVATION EVENTS NORTH ArWA UtilTS 1, 2, 3. 4 D;ccmber 7, 1969 Started Unit 1 Excavation.
Early February, 1970 Cracking of area along south wall noted.
Weathered rock above chlorite seam re-moved for personnel protection.
Fchrua ry 23, 19701/ 2/
Completed Unit 1 excavation.
Lota February, 1970 Additional rock above chlorite seam i
removed for personnel protection.
Fcbruary 27,19701/
Samples taken to Virginia Division of Mineral r.esources (VDMR) for analysis.
March 10,19701/
Results of analysis received verbally f rom (VDMR).
March 19, 1970 Date of (VDMR) letter with analysis.
il 6, 1970 Start Unit 2 excavation.
June 25, 1970 Complete Unit 2 excavation.
Septceber 15, 1971 Filed Units 3 & 4 PSAR.
Routine ref-erence to Units 1 & 2 chlorite seam made in " Report - Site Environmental Juna 17, 1972 !
Studies".
J:nuary 17, 1973 Start unit 3 excavation.
March 9, 1973 Start Unit 4 excavation.
April 28, 1973 Complete Unit 3 excavation.
June 15, 1973 Complete Unit 4 excavation.
1/
- Thise dates are estimate Records of exact dates are not available.
-2/ urther excavation was performed after this date to accommodate a change in
-F c21smic design.
3/
- In June 1972, J. Breidis prepared a report for S&W files of the rock conditions M their reinforcement in the excavations for Units 1 and 2.
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CHRONOLOGY GEOLOGIC IfP/ESTIGATION NORTH ANNA UNITS 3 & 4 i
Jrnuary 17, 1973 Started Unit 3 excavation.
' April 24, 1973 Vepco advised by Stone & Vebster of unusual features of chlorite seam.
April 25, 1973 Vepco retained Dames & Moore to con-duct investigation.
April 28,1973 Completed Unit 3 excavation.
April 30, 1973 Vepco met with Stone & Webster at site to discuss features of chlorite seam.
, 2, 1973 Vepco, Dames & Moore, and Stone &
Webster met at site to discuss feature.
No conclusion as to whether or not feature was a fault.
Concluded that a detailed investigation was necessary.
Dames & Moore began investigation.
May 8, 1973 Dr. Donald U. Wise, Professor of Structural Geology, University of Massachusetts, retained by Vepco to review and advise on investigation.
l May 14,.1973 Meeting at site between Vepco, Dames
& Moore, Stone & Webster, and Dr. Wise to review feature and investigation to date.
Based on that review, consensus was that feature was a fault but pro-hably very old and related to forma-tion of Piedmont millions of years ago.
15 s 16, 1973 Vepco attsr..ted to contzet AEC Project e
Manager and immediate superior to advise of fault and investigation.
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..:y 17, 1973 AEC representative returned call at which time AEC was informed of fault if and investigation.
Juna 18, 1973 Meeting with AEC at site to review status of investigation to date.
June 27, 1973
- w"-ACG Jelcon-to clarify status of the
' Investigation.
August 17, 19(3 Final report on investigation sub-mitted to AEC.
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-- On May 18,1973, Mr. Cardona (AEC) discussed the investigation of fault with Missrs. Spencer and Robinson (VEPCO) and set tentative date of site visit.
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?.fr. Jchn Srledis Add.esa Addreur Stone and Web ter 225 Franklin Street
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Boston, hiA 02110 L ika VEPCO tmcicar reactor site, North Anna River, Louisa County, Virginia.,
Dear Mr. Briedia:
The mc*viel you submitted for identification hos 1eri c.nclyzed ax:
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- 1 a) aphanitic. gray. green, undulose, schiatose, weathered rock with.
slichensidea: chlorite, chlorite.mant.morillonite i
b) undulose. fine-grained, biotite-chlorite schist: chlorite, biotite, hydrobiotita, montmorillanite-chlorite mixed layer clay f2 pale, greenish-gray, aphanitic soft, undul6se, sticketssides with white, friable, weathered cataclasts i
a) schistose matrix: chlorite, biotite, hydrobiotite, montmorillonite.
chlorite mixed layer i
b) feisic cataciast: microcline, pidgioclass. quartz, sericite, chlorite.
montmorillonite, epidote, clinozoisile
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' Yours very truly,
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l games L Calver d Src:a h:ogist
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Mahnial submitted will be held for o period of two weeks from the cbove date ofter which 4 - :.y ! - "'t.~.<d:d un' is re>ern :: 1.,;. ;;t7d.
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- Mi..fcha Briedic March 19.1970
- 3 buff, fine-grained, weathered, sheared biotite granite, epidotized:
microcline, plagiuclase qusrtx. bio:ite, chlorite, eericite, epidote f4 bluish-green, aphanitic, undulose schist with ' uff slickenmidos o
light colored:
a) chlorite =crscite, cuartz, montmorillonite bluish-green:
b) chtcrite (diabantite)
- 5 cream-colored, weathered, sheared, fine gr=ined, biotite granite with epidotized shear p! anes: K-f+1dspar, plagioclase, quartz, biotite, serici c. chlorite-montmorillonite, epidote f6 cream-colored. friadio, weathered, clayey, fel=i rock with 5% of very fine-grained (0. 25-0. 50 mm) blotite: urtho= tar.e, plagioclase, sericite, chierite-mon::norillonite, biotite, illitic clay t
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