ML20082F910
| ML20082F910 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 11/18/1983 |
| From: | Lear G Office of Nuclear Reactor Regulation |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20079F427 | List:
|
| References | |
| FOIA-84-35 NUDOCS 8311290352 | |
| Download: ML20082F910 (5) | |
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UNITED STATES j
I NUCLEAR REGULATORY COMMISSION
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WASHINGTON. D. C. 20555
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NOV 181983 Docket Nos.:
50-400/401
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f4 Eft 0RANDUM FOR: George Knighton, Chief Licensing Branch No. 3 Division of Licensing THRU:
James P. Knight, Assistant Director.
for Components 'and Structures Engineering
-Division of Engineering FROM:
George E. Lear, Chief Structural and Geotechnical Engineering Branch Division of Engineering
SUBJECT:
UPDATE TO FINAL SAFETY EVALUATION REPORT.
GE0 TECHNICAL ENGINEERING e..
Plant Name: Shearon Harris Nuclear Power Plant, Units 1 and 2 q,
. Applicant:
Carolina Power and Light (CP&L)
Licensing Stage:
OL Docket Numbers:
50-400/401 Responsible Branch:
LB-3,B.Buckley,LPbj Review Status:
Continuing
References:
(1) Letter from McDuffie of'CP&L to'H. Denton of NRC dated September 19, 1983.
Subject:
Response to Requests for Additional Information.
-(2) FHB Retaining Wall Design Calculations by EBASCO Services, Inc. for CP&L, dated September 19, 1983.
9 The subject final.SER was provided to you by my memo dated September 2, 1983.
You asaked that we update our SER for the presently planned retaining wall and backfill _that will replace cancelled units 3 and 4.
Failure of the high wall would -impact the fuel handling building; the wall is safety related but not classed as a seismic' Category I component.
We have reviewed the infonnation submitted by the applicant in References 1 and 2 related to the design of the retaining wall west of the fuel handling building. We have also had conference calls and a meeting with the applicant.
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. e find that stability of the retaining wall can not be established at this time because of the lack of the following information:
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George Knighton
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1.
Field and labo;atory tests to establish the soil properties of the e
random fill to be used in actual. construction.
2.
Analyses to confirm the' appropriateness of the assumed lateral soil pressures _ soil amplification under seismic conditions,. and the i
deadmen design.
3.
Settlement analy es to de,termine the effect of differential settlement on the retaining wall.
4.
Performance monitoring program during and after construction..
Our final SER update is enclosed'for inclusion in the published Shearon Harris Nuclear Plant Units 1 and 2 Safety Evaluation Report. This SER 4
update was prepared by Dr. J. T. Chen, Geotechnical Engineering Section, SGEB, DE.
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q George-u Lear, Chief Structural and Geotechnical Engineering Branch r-Division of Engineering C.
Enclosure:
As stated cc:
R. Jackson L. Heller-P. T. Kuo S. Kim J. - Kimball B. Buckley J. Chen-R. Kirkwood B. Youngblood 6
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Subject:
Final Safety Evaluation Report - Geotechnical Engineering Plant Name: Shearon Harris Nuclear Power Plant, Units 1 and 2 Docket No.:
50-400/401 Responsible Branch: LB-3 C # '# -
Prepared by:.J. Phi'ripf Geotechnical Engineer, Structural and Geotechnical Engineering Branch, DE The following sections summarize the staff's geotechnical' engineering review of the Shearon Harris Nuclear Power Plant, Units 1 and 2 (SHNPP),
as described in the Final Safety Analysis Report (FSAR) through Amendment Number 9 dated August 18, 1983.
The stability of subsurface materials and foundations (FSAR Section 2.5.4), the stability of slopes (FSAR Section 2.5.5), and embankments and dams (FSAR Section 2.5.6) have i
been evaluated in accordance with the criteria outlined in 10 CFR Parts 50 and 100, Regulatory Guide 1.70 Revision 3, Regulatory Guides 1.132, 1.138, 1.127, and the current Standard Review Plan (SRP), NUREG-0800 dated July 1981, Sections 2.5.4 and 2.5.5.
2.5.4 Stability of Subsurface Materials and Foundations The seismic Category I structures, systems, and components (SSC) for Units 1 and 2 that were reviewed for foundations stability are listed in FSAR Table 3.2.1-1.
Units 3 and 4 which were originally proposed, have been cancelled. The excavation for these units is to be backfilled against a retaining wall, approximately 400 ft. long,, along the west h
side of the Units 1 and 2 structures.
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The seismic Category I SSC that were reviewed are,as follows:
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- containment buildings l
- auxiliary buildings
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- fuel handling buildings
- waste processing buildings
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- tank'bu11 dings (housing the refueling water storage tank, the
-reactor make-up tank and the condensate storage tank)
.- diesel _ generator building l
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- diesel fuel oil storage building l
- Emergency Service Water (ESW) structures, pipelines and channels
- auxiliary dam, separating dike and channel
- main dam p.p..q, i s. /c c s.
The staff will review the 400 foot long retaining wall as a sefsmte' Gategoryt structure because a postulated failure of the retaining wall could affect the safety of the adjacent seismic Category I' fuel handling building. The stability analysis of the retaining wall ha: et-been d., /* c i reviewed by the staff; the staff's evaluation of the analysis will be
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l addressed in a supplement to the SER.
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The staff's evaluation of the geotechnical engineering aspects of the l
foundations for the main powerblock structures, the ESW screen structure, intake structure and pipelines and the ESW discharge r
o iI-structure and pipe-lines'are discussed in the following parts of Section
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I' Shearon Harris Units 1 and 2 Docket Nos.: 50-400/401 Final SER Input Update - Geotechnical Engineering Prepared by:
- e. Chen, GES, SGEB, DE
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'2.5.5 Stability of Slopes 2.5.5.1 FHB Retaining Wall Due to the cancellation of Unit's 3 and 4, the containment buildings and
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tank building for Units 3 and 4 have been deleted, and a retaining wall west of the fuel handling building will be provided to separate the fuel
' handling building from the plant grade fill.
This retaining wall is to consist of two rows of reinforced concrete. pipes erected one over the other and a reinforced concrete wall on top of the pipes.
The pipes are filled with concrete and are held back by three rows of tie rods and deadmen.
The wall above the pipes is not tied to deadmen.
2.5.5.2 properties of Soil Backfill The soil backfill west of the retaining wall is to be random fill in accordance with EBASCO Specification CAR-SH-CH-8 (FSAR Appendix 2.5 I).
The soil properties of the backfill assumed in the design are:
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Unit Weight Coefficient of Cohesion C
Internal Friction pef p'
ksf Long Term 135 30 0
Short Term @-
Optimum floisture 26 1.2 Wet 9
2.0 These properties, as stated by the applicant in Reference 1, are based on tests performd on site for as built backfills.
However, the staff fir.ds that these properties are associated with selected impervious materials from Borrow Area Z, designated as
" selected backfill" in-accordance with EBASCO Specification CAR-SH-CH-8, and are not considered by the staff to be representative of the random fill to be used against the retaining wall.
Thus, field and laboratory tests on random fill used in actual construction are needed to demonstrate that the design parameters used in the design are appropriate.
2.5.5.3 Stability of Retaining Wall The retaining wall, as stated by the applicant in Reference 1, has been designed against full hydrostatic pressure and against seismic conditions in accordance with Positions C-2 and C-4 of Regulatory Guide 1.29.
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' The groundwater is assumed to be at El. 251 feet, the same.as the design
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ba~ sis groundwater level for the plant island, and this design assumption is acceptable to the staff.
The lateral soil pressures against the wall include static and dynamic soil loads.
The static and dynamic soil loads are obtained by assuming
-that 'the random fill is a cohesionless soil with an internal frictiol
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angle of 30'.
This assumption may not be valid because the random fill as defined in EBASCO Specification CAR-SH-CH-8 may be any excavated unclassified material.or rock.
Since the strength characteristics of the random fill has not been determined, as discussed in.the previous section, the staff is unabl.e to conclude that the assumed lateral soil pressures,against the wall are appropriate.
The dynamic soil load was calculated using a seismic coefficient of 0.17 g.
Since the randcm fill will have a' depth of about 60 feet, soil amplification may take' place under seismic conditions and the staff requires a soil amplification study to demonstrate that the seismic coefficient is
' conservative..
The design of the deadmen by the applicant utilized two approaches (Reference 2):
a convent;ional approach described in NAVFAC DM-7 was used to design deadmen at El. 250 while a bearing capacity approach was used to design the daadmen at Elevations 232 and 214.
Since the bearing capacity approach to design the deadmen is non-conventional, additional
. design analyses using NAVFAC procedures are required from the applicant to demonstrate that the deadmen design is acceptable.
2.5.5.4 Differential Settlements The retaining wall is supported mostly on modified random fill with
. thickness ranging from 10 to 20. feet.
The modified random fill is
. subjected to consolidation under the load of the retaining wall.
Differential settlements may_ take place which would affect the stability and p'erformance of the retaining wall.
Settlement analyses are, therefore, required from the applicant to demonstrate that the differential settlements would not adversely ~ affect the stability of the retaining wall.
2.5.5.5 Monitoring Program
.To assure that the. performance of safety components will remain within acceptable limits, a monitoring program is usually implemented. The applicant has not provided any information related to the inspection program during and after construction of the retaining wall.- The staff requires, as a minimum, the applicant to carry out the following monitoring program:-
.(1).During Construction:
'1. Compaction control for moisture and density of th6 random fill placed in accordance with NAVFAC procedure:.
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