ML20010F636
| ML20010F636 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 08/25/1981 |
| From: | Youngblood B Office of Nuclear Reactor Regulation |
| To: | Delgeorge L COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8109110022 | |
| Download: ML20010F636 (7) | |
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TERA DEisenhut PD'l AUG 2 51981 JYoungblood LPDR JSnell NSIC Docket Nos.: STN 50-454 KKiper TIC s
and STN 50-455 MRushbrook ACRS (16)
SHanauer RVollmer Mr. Louis 0. DelGeorge
. TMu rl ey Director of Nuclear Licensing RMattson Comonwealth Edisor. Company.
...RHartfield, MPA Post Office Box 767 0 ELD Chicago, Illinois 60690
..01E (3)
Dear Mr. De1 George:
GStaley s,...,_,...,
Subject:
Request for Addition _al Informati.on,.for the Review of the Byron Plant, Unit 1 & 2', Geotechnical[En'gineering As a result of our continuing review cf.the Byron Plant, Unit 1 & 2 FSAR, we find that we need additio.nal information to. complete. our evaluation.
The specific information required js,in the area. of Geotechnical Engineering
'is presented in the Enclosure.,
To maintain our licensing review sche.dule.for.the Byron Plant FSAR, we will need responses to the enclosed request by 0ctober.12,1981. If.you cannot meet this date, please inform us wi. thin,seven days after. receipt of this letter of the date you plan. to submit your responses so that we may review our schedule for any necessary changes,.
Please contact J. C. Snell, Byron Licens.ing Project Manager,_.if you desire any discussion or clarification.of the. enclosed request.
Sincerely, e
g 4/f NN rigned by:
N B J. Youngblood b
er 1 B. J. Youngblood, Chief i
9,g Licensing Branch No. I t../. 7 J
t Division of Licensing l'g
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Enclosure:
',i m.y s '
As stated cc: See next page 1)
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NRC FORM 318 slo,80i NRCM O240 OFFICIAL RECORD COPY 4 um isso-329 824
Mr. Louis 0. Del George Director of Nuclear Licensing Commonweal th Edison Company Post Office Box 767 Chicago, Illinois 60690 ccs:
Mr. William Kortier Mr. Edward R. Crass Atomic Power Distribution Nuclear Safeguards and Licensing Division Westinghouse Electric Corporation Sargent & Lundy Engineers P. O. Box 355 55 East l'.onroe Street Pittsburgh, Pennsylvania 15230 Chicago, Illinois 60603 Paul M. Murphy, Esq.
Nuclear Regulatory Conmission, Region III Isham, Lincoln & Beale Office of Inspection and Enforcement One First Nation ~al Plaza 799 Roosevelt Road 42nd Floor Glen Ellyn, Illinois 60137 Chicago, Illinois 60603 Myron Cherry, Esc.
Mrs. Phillip B. Johnson Cherry, Flynn and Kanter 1907 Stratford Lane 1 IBM Plaza, Suite 4501 Rockford, Illinois 61107 Chicago, Illinois 60511 Professor Axel Meyer Decartment of hysics Northern Illinois University DeKalb, Illinois 60115 C. Allen Bock, Esq.
P. O. Box 342 Urbanan, Illinois 61801 Thomas J. Gordor, Esq.
Waaler, Evans & Gordon 2503 S. Neil i
Champaign, Illinois 61820 Ms. Bridget Little Rorem Appleseed Coordinator 117 North Linden Street Essex, Illinois 60935 l
l Kenneth F. Levin, Esc.
I Beatty, Levin, Holland, Basofin & Sarsany 11 South LaSalle Street l
Suite 2200 Chicago, Illinois 60603 l
l l
L
Geotechnical Engineering Questions Byron Nuclear Station Docket Numbers 50-454/455 241.1 Sinkhole Design Basis (2.5.4.10.4) 1.
Sinkholes have been identified on Fig. 2.5-101. Describe the investigation program that was carried out to determine the locations and dimensions of the sinkholes and their current state of activity.
2.
Provide the bases for your conclusion that (a) the maximum diameter of the post-pleistocene aged sinkholes is approximately 50 feet with the average being approximately 25 feet, and (b) no sinkhole greater than 50 foot diameter will occur along the makeup line.
3.
Identify, and provide a brief description of other projects i
where the design-basis sinkhole was chosen according to the age of the sinkholes.
l (App. 2.5.G) 4.
Provide details about the solution enlarged joint identified as Area of Concern No. 3.
These details should include the orientation, width, and depth of the joint.
5.
Provide documentation which forms the basis for your conclusion that the Area of Concern No. 11 is not related to a sinkhole.
Field exploratory borings or other methods should be used to verify that no significant cavity is present beneath the pipeline in Area of Concern No. 11.
a,
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(2.5.4.12) 6.
Explain why the foundation bedrock for the major plant structure,
(2.5.1.2.6) was grouted.
If the grouting is to retard the downward percolation of groundwater, thereby reducing the solution activity, provide the investigation results that were made to determine the existence of any significant cavities in the foundation rock.
(App 2.5.A 4) 7.
Sig'nificant communication between grout holes was reported.
In Area A shown on Fig. 2.5A-4, the communication between grout holes extended over 200 feet. What is the largest grout take for holes located in this area? Provide the bases for the conclusion that gr:ut communication is related to solutioning along the joints and bedding planes. Provide a similar discussion for i
Area C.
(App 2.5.A.4) 8.
The major grout communication pattern is reported to have a north-west-southeast trend. An extension of this trend northwestward will encounter Area of Concern No.11 along the pipeline, and the 150-foot diameter sinkhole. Discuss the significance of this trend on the design of the pipeline. Actual field investigation data should be included in the discussion.
(App 2.S.G 9.
Groundwater is reported to vary from El. 740 feet to El. 840 feet Appendix) depending upon the location and the season of the year.
Discuss the groundwater fluctuation effects on the solutioning and sinkhole activities.
. 241.2" 9.
Low Seismic Velocity Zones i
(2.5.4.4)
Seismic Refraction surveys have detected several low velocity zones which are stated to be related to weathering and solutioning of jointed, fractured bedrock. Discuss the relationship of two low velocity zones (Sta. 37+00 and 31+00 on Fig. 2.5-65) to the U
presence of sinkholes and the potential impact on pipeline design.
241.3 Backffll (2.5.4.5.1.4)
Fig. 2.5-78 shows that the backfill has about 5 percent material passing the No. 200 sieve. Discuss the applicability of the Modified Proctor Test (ASTM 1557-70) for this type material. Also provide maximum and minimum density values for similar material using ASTM D2049-69.
241.4 Liquefaction Potential (2.5.4.8) 1.
The SSE for the Byron site is 0.29 Explain why the artificial I
j time-history confoming to R. G.1.60 scaled to 0.129 rather than 0.29 was used in the evaluation of the liquefaction potential.
(2.5.3.8.3) 2.
Describe the analytical model used in the one dimensional wave propagation analysis. Also, identify the soil layers and material properties used in the analysis.
i
e
. (2.5.4.8.3.3) 3.
Provide the basis for the failure criterion for the laboratory samples.
Based on this criterion, what is the maximum seismically induced lateral movement along the river bank?
(Fig. 2.5-86) 4.
Discuss the liquefaction potential of the soil at depths between 50 to i
65 feet shown on Fig. 2.5-86, where the etandard penetration resistances are within the zone where the liquefaction potential is described as depending on soil type and earthquake magnitude.
241.5 Static Lateral Pressure (2.5.4.10.5.1) i Provide the value and the test results of the lateral earth coefficient for the compacted granular soils.
241.6 Pipeline Settlements & Seismid Responses (App 2.5G &
i 2.5.4.13) 1.
Provide the final ground surface profile along the pipeline l
on Plate 3.
l 2.
Although the weight of the pipeline, as stated, is 12ss than the weight of the excavated so;l; settlement along the pipeline should be anticipated in areas where site grade has been raised by filling and the compressible soil underneath the pipeline has variable thickness and coinpression characteristics. Provide settlement l
estimates of the pipeline located in the arns identified as Areas of Concern No.11 and 12. Actual testing data should be used in the analyses.
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3.
The pipeline as shown on Plate 1 is approximately.3 miles long and extends frcm the River Screen House on the Rock River to the Essential Service Cooling Tower in the plant site area.
The soil supporting the pipeline has variable properties and has thicknesses varying from about three feet to about 100 feet over bedrock. The seismic amplification characteristics are affected by the thickness and properties of the soil deposit.
Provide analytical results showing the seismic amplifications along the pipeline and discuss their impact on the pipeline design.
4.
Poorly graded, loose, non-plastic soils were encountered at Areas of Concern No. 11 and 12. Provide an evaluation of the liquefaction potential and seismically induced settlements of these soils. Since surface water could percolate around the edoes of the cohesive cover, the degree of saturation for the soil beneath the pipeline should be considered in the analysis.
241.7 Concrete Cracks During our site visit of May 19, 1981, cracks were observed in the mat connecting the two essential cooling towers.
Investigate.
and determine the cause of the cracks.
.