ML19273C008
| ML19273C008 | |
| Person / Time | |
|---|---|
| Site: | Phipps Bend  |
| Issue date: | 05/14/1979 |
| From: | Rolonda Jackson Office of Nuclear Reactor Regulation |
| To: | Baer R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7906180733 | |
| Download: ML19273C008 (2) | |
Text
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'4 UNITED STATES
$t t;ucLEAR REGULATORY COMM!sslON WASHINGTON,0, C. 20555 MM 14 gg MEMORANDUM FOR:
Robert L. Baer, Chief Light Water Reactors Branch No. 2, DPM FROM:
Robert E. Jackson, Acting Chief Geosciences Branch, DSE
SUBJECT:
ADDITIONAL FAULTS IN THE FOUNDATION OF REACTOR UNIT 2 PLANT NAME: Phipps Bend Nuclear Power Plant, Units 1 & 2 LICENSING STAGE:
Post CP DOCKET NO.: 50-553 i
MILESTONE N0.:
N/A RESPONSIBLE BRANCH:
R. Benedict, LPM, LWR-3 On March 16, 1979, Jerry Wills of the Tennessee Valley Authority (TVA) informed S. L. W&stler that a fault was discovered while mapping the ccw trench of Reactor Unit 2.
On March 29, 1979, S. L. Wastler visited the Phipps Bend site to investigate the ccw trench fault. The April 17, 1979 memorandum from L. Heller describes the ccw trench fault and i
discusses the results of the March 29, 1979 field trip.
In accordance with the guidelines provided in our August 14, 1976 memo, TVA submitted the enclosed report providing a detailed description of the fault and discussion of the fault's relationship to the regional geology. My staff has completed their review of this report and concurs with the conclusions reached in the report. The ccw trench fault is a minor cross fault associated with the formation of the Saltsville Fault family (approximately 250 mybp).
Therefore, based on the evidence to date, the ccw trench fault is considered to be non-capable within the meaning of Appendix A to 10 CFR Part 100.
5f
-ch Robert E. Jaf on, Acting Chief Geosciences B anch Divisioi of'$ite Safety and Environmental Analysis I
i
Enclosure:
1 As stated I
2352 357 cc:
See attached page 7 906180 '7 N e m
Robert L. Baer VM 14 1979 cc w/ encl R. Boyd R. DeYoung D. Muller R. Denise J. Greeves R. Benedict S. Goldberg S. Wastler PDR Local PDR I
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TENNESSEE VALLEY AUTHORITY CH AT*ANCCOA, rrNNtssrZ 374C1 500C Chestnut Street Tower II
_AFF.11 :379 Mr. Harold R. Denton, Director Division of Nuclear Reactor Regulation U.S. hiuclear Regulatory Coc=ission Washington, DC 20555
Dear Mr. Danton:
In the Matter of the Applications of
)
Docket Nos. CTN 50-553 Tennessee Valley Authority
)
STN 50-554 in a March 22, 1979, telephone conversation, Jerry Wills of my staff notified Olan Parr of your staff that an additional fault had been discovered at. our Phipps Bend Nuclear Plant in the unit 2 CCW trench area. A conference call was subsequently made to the NRC geologist, Sandra Wastler, on March 23, 1979, to discuss the fault. A site visit was scheduled and conducted on March 29, 1979, to allow the NRC geologist an opportunity to arnmine the fault. The enclosure provides a detailed description of this feature.
We do not consider this minor fault to be capable within the meaning of Appendix A to 10 CFR Part 100.
Very truly,yours,
'J. E. Gilleland Assistant Manager of Power Enclosure 2352 359
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'T900 6 0 P7 G An Ecual Occertur.ity Emoloyer M
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PHIPPS SE'Q NUCLEAR PLANT Transverse Fault Seneath South CCW Trench in Unit.2 Turbine Building Excavation of rock in the south CCW trench has exposed a fault which trends northerly across the trench between the T-3 and T-4 lines of the unit 2 turbine building.
The fault can be. described as a transverse fault, one which is normal to the regional trend of the geologic structure.
The fault is located 306 feet east of the unit I north-south base-line wnere it intersects the centerline of the south CCW trench.
It strikes N25 W, dips 60 W, and extends 24 feet to the northwest where it splits into two limbs. Both limbs continue an additional 56 feet to the northwest where they transitionally terminate into near vertical joints. waleh extend an undetermined distance.
The fault is defined by a distorted fracture zone approxi-mately 3 inches wide. Bedding is offset (right lateral movement) an average of 3 inches as it intersects the fault zone. As the zone approaches its transition to a near vertical joint, bedding can be traced through the distor,ted zone without breakage of beds.
The fault trace can be projected south to the overburden and saprolite of the plant excavation where no deformities of the overburden or overlying Quaternaraf terrace deposits were found.
This type fault has been described in the Phipps Bend Nuclear Plant PSAR, section 2.5.1.1.2-14, as a minor cross fault and is considered by Rogers (ref. 93 PB PSAR) to be commonplace 1.
M. P. Billings, Structural Geoloav (1972): Englewood Cliffs, New Jersey, Prentice-Hall, Inc.,
3d., p. 194.'
2352 360
in the Saltville Fault family area (four miles northwest of the Phipps St. '. site).
The fault was formed by stress relief due to pressure from the northwest and southeast direction: during the formation of the Saltville Fault family (250 mybp).
This fault, having been stable for 250my, is not considered to be capable of producing ground offsets or generating eart5 quakes.
Therefore, we do not classify it as a capable fault, within the meaning of Appendix A to 10 CFR part 100.
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