ML20129B587

Responds to Request for Addl Info Re Draft SER Open Items 3,8 & 112.Cluster of Wells Will Be Installed Northwest & Southeast of Powerblock.Surface Protective Casing Will Be Placed Around Each Well

ML20129B587
Person / Time
Site:	Vogtle
Issue date:	05/31/1985
From:	Bailey J GEORGIA POWER CO.
To:	Adensam E Office of Nuclear Reactor Regulation
References
GN-635, NUDOCS 8506050272
Download: ML20129B587 (4)

Text

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Georgis Power Company Rout 3 2. Box 299A J

• Wayresboro, Georgit 30830

' Telephone 404 554-9961 404 724-8114 Southern Company Services, Inc.

Post Office Box 2625 Birmingham. Alabama 35202 Telephone 205 8704011 Vogtle Proj.ect May 31, 1985 Director of Nuclear Pee.ctor Regulation File: X6BK10 Attention: Ms. Elir.or G. Adensam, Chief Log: GN-635 Licensing Branch #4 Division of Liceming.

U. S. Nuclear Reg Aatory Commission Washington, D.C. 20555 NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMPERS CPPR-108 AND CPPR-109 V0GTLE ELECTRIC GENERATING PLANT - UNITS 1 AND 2 REQUE'iT FOR ADDITIONAL INFORMAT10N! DSER OPEN ITEMS 3, 8, & 112 REF: LETTEE. GN-622 TO MR. DENTON FROM MR. BAIIEY DATED MAY 21, 1985

Dear Mr. Denton:

Enclosed for your review is a plan for performing the task discussed in the above referenced letters If your staff requires any additional information, please do not hesitate to contact me.

Sincerely, J.~A. Bailey Project Licensing Manager JAB /caa xc: D. O. Foster R. A. Thomas J. E. Joiner, Esquire B. W. Churchill, Esquire

-M. A. Miller B. Jones, Esquire L. T. Gucwa G. Bockhold, Jr.

H. H. Gregory, III T. Johnson B 2MW PDR ADOCK 05000424 C. D. Teper E PDR L. Fowier /

Vogtle Project File (

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1 A cluster of wells will be installed to the northwest and to the j southeast of the powerblock. The tentative location of these well '

clusters is shown on Figure 1. sach of the two clusters will consist of three observation wells open to discrete intervals in the.mari, one each )

in the upper, middle, and lower portions of the earl bed. ,

The first hole drilled at each cluster will be cored in the earl to within 5 to 10 ft of its base. This primary hole will be continuously ,

coced and have in-situ pomeability tests conducted in the cored interval. The occurrence of permeable zones and limestone interbeds will allow the designation of the monitoring intervals in the adjacent wells open to intervals in the upper and middle portions of the mari. The core i will be used to evaluate the competency of the earl as a foundation l material. The following describes this work: )

1) A 10-inch diameter hole will be drilled using a tricone bit from the l ground surface to a depth of 10-ft below the upper contact of the mari. Revert drilling fluid will be used to remove cuttings from the hole during drilling. Permanent casing will be placed into the '

hole and sealed into the mael with cement grout. The grout will set for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to continuation of drilling.

2) The hole will be flushed with clear water and any remaining Revert removed with ' Fast Break'. The hole will be advanced by diamond

• core drilling methods in accordance with ASTM D 2113. Core drilling shall be done with double tube, ball-bearing, swivel-type, 4-inch core barrels or larger fitted with bottom (face) discharge bits.

The maximum amount of core recovery is required and the driller will perfom the work in a muuuur to accoa.plish this purpose. Ceinding of the core afher a core barrel has become blocked will not be pemitted. A blocked core barrel shall be pulled irrespective of the interval drilled. The driller will preserve all core semples in good condition in labeled boxes in conformance with AgTM D 2113.

Core boxes will be clearly and permanently marked on the outside lid with project name, hole number, box number and depth of core within the box. The hole number and box number shall also be marked on both ends of the box and on the inside of the lid. Depth of runs shall'be marked on spacer blocks between runs.

An engineering geolofist will supervise the core drilling operation. He will record change in advance rate, fluid losses or gain, and other portinent aspects of core drilling. The geologist will los the core samples in detail, verify its proper handling and photograph the core.

3) In situ permoability tests will be conducted in the mari as the core hole is advanced. The tests will be water pressure tested in accordance with procedures in the Us Bureau of geclamation " garth Manual", Test Designation 3-18. (These tests are in general agreement with US Corps of gngineers test procedures described in ax @

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i%Y. 31 *fi5 13:2< M HTEL SFO 9038~ pj RTH 381-80 of the " Rock Testing Handbook"). A test will be conducted following 10 ft of coring in the earl. The core drilling

. tools will be pulled from the hole following flushing with clear water. a single pneumatic packer will be set approximately 10 ft off the bottom of the hole. Testing will be. conducted according to the methods described in E-18. If significant permeable zones are found in the test interval, additional tests will be conducted using double packers to define the permeable sons. The drill core will be reviewed to aid in determining the permeable zone.

4) Based on the data collected during core drilling and peruoability testing, the location of the discrete monitoring intervals in all three holen will be determined. The deep monitoring well will be placed in the primary hole, with the wells monitoring the upper and middle intervals of the earl in adjacent holes. The monitoring intervals will consist of zones of significant permeability and/or lenses of predominantly calcareous materials (limestone interbeds and shell zones). The upper and middle earl monitoring wells will be drilled a minimum of 10 to 15 ft from adjacent holes.'

5) The wells will consist of Casagrande-type porous stone tubes 18 inches in length, 3/4-inch ID, and 1 1/2-inch OD. Riser shall be 3/8-inch standard schedule 80 PVC. The installation will be in accordunew with Us Bureau of Reelemation " Earth Manual" Designation E-28. Connection between lengths of PVC may be either threaded couplings or unthreaded, cement-sealed couplings. Appropriate measures shall be taken to insure that each coupling is water-tight and f truly attached to the ends of each connected length. The screen section shall be attached to the risee in accordance with the screen manufacturers recoaumendations, or in the manner described in Designation E-28, paragraph 3.

The open interval, monitoring hydrostatic conditions in the mael will not exceed 5 feet. Clean sand will be used as the filter pack material in the monitoring interval. An impermeable seal a minimum of 2 feet in thickness will be placed in the annular space immediately above the filter pack. The annular space above the seal will be filled with a neat cement grout alx of one part cement to one part water by volume. The grout will be placed using the tremie method.

Each Surf ace protective casing will be placdd 'around each well.

well will be clearly identified on the surface casing.

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