ML18017A634
| ML18017A634 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 08/06/1979 |
| From: | Thompson O Office of Nuclear Reactor Regulation |
| To: | Rolonda Jackson Office of Nuclear Reactor Regulation |
| References | |
| 4953, NUDOCS 7908200008 | |
| Download: ML18017A634 (8) | |
Text
gp,S REg( 'Ip0 (IqO'NITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 AUG 06 t979 MEMORANDUM FOR:
Robert E. Jackson, Chief Geosciences
- Branch, DSS THRU:
FROM:
Lyman W. Heller, Leader Geotechnical Engineering Sect Geosciences
- Branch, DSS Owen 0. Thompson, Geotechnical Engineer Geotechnical Engineering Section Geosciences
- Branch, DSS
SUBJECT:
TRIP REPORT PLANT NAME:
Shearon Harris, Units 1-4 LICENSING STAGE:
Post CP DOCKET NUMBERS:
50-400/403 MILESTONE NUMBER'-18 TAC NUMBER:
4953 RESPONSIBLE BRANCH:
LWR-3; S. Miner, LPM REVIEW STATUS:
Awaiting additional information from Applicant Attached is a report of my site visit to Shearon Harris on April 17 and 18, 1979.
The trip was made because of questions regarding earthwork construction which were raised during a conference call between the applicant, Ebasco engineers, DPM and DSE personnel on Apri 1 13,
- 1979, I met IE Region II Inspectors Jack Harris and Joe Lenahan at the site.
The significant aspects of the site visit are as follows:
'C 1.
The field control of soil moisture content was reviewed.
IE Region II is taking appropriate steps to bring control into conformance.
2.
We learned that Category I pipelines and conduits are to be supported on selected backfill against structures as well as on general site fill.(designated as random fi11) which was placed about 4 years ago.
The condition of the soils supporting the pipelines were not addressed in the PSAR and thus they need to be reviewed.
In order to complete our review, additional information may be needed from the applicant.
Attachment:
As stated cc:
See next page wen 0. Thompson, Geotechnical Engineer Geotechnical Engineering Section Geosciences
- Branch, DSS
+~~0 V'088 00 Oop
W P
AUg 06 8g cc:
w/o attachment D. Muller D. Ross F. Schroeder cc:
w/enclosure J. Knight
- 0. Parr R. Jackson L. Heller L. Hulman S. Miner R.
Shewmaker 0.
Thompson F. Williams J. Harr'is, IE Region II PDR Local POR ACRS (16)
Trip Report Shearon Harris Docket Number:
50-400/403 Prepared by:
Owen 0. Thompson, GB, DSS On April 17 and 18, 1979 I visited the Shearon Harris site.
Those in attendance at the meeting were as follows:
On 4/17 and 4/18 Bob Black Eugene Kelly Jim Nevill W. 0. Pridgen George Forehand A. M. Lucas J. Harris
- 0. Thompson
~4/1 N. Pavone S.
Goyal S.
D. Floyd J. J.
Lenahan CP&L Licensing CP&L Civil QA Specialist CP&L Civil Field, PPCD
'CP&L Civil Engineering CP&L Principal QA Specialist CP&L Construction, Resident Engineer NRC Region II, Construction Inspector
- NRC, HQ Geosciences Branch Ebasco Ebasco CP&L Licensing NRC - Region II Civil Engineer The meeting was called by the applicant as a result of the observation by the NRC inspector that backfill was being placed and compacted around the main plant structure, specifically around the Waste Process
- Building, without attempting to control the moisture content.
The applicant had contacted NRR by phone on April 13, 1979 and stated that moisture control was not necessary for backfill around structures.
The discussion with the applicant revealed that some of this backfill will support Category I pipes and conduits.
We were also informed that some random fill which will support Category I pipes and conduits outside the plant area had been placed about 4
years ago.
At the meeting, we reviewed the construction drawings.
We inspected the site, including two borrow areas (the borrow area for "selected backfill" located northwest of theplant structure and the borrow area for the auxi liary dam and dike cores),
the core trenches of the main and auxiliary dams, the partly constructed core and random rockfill zone of. the auxiliary dike, and the backfilling operation at the Waste Process Building. My observations were as follows:
Borrow Areas The borrow pits were open and the surface had been recently disced.
The residual soil borrow materials were primarily silty clays to clayey silts with some zones of coarser grained soils.
Some of the different soils exposed in both borrow areas were easily distinguished by color differences.
I would expect that there could be similar variations with dep.h and the construction personnel indicated that this had been the case in past borrow excavations.
Suitable borrow materials meeting the specifications for dam core and "selected backfill" were being obtained down to depths of about 10 ft below original ground surface.
I noticed some areas where borrowing had terminated on weathered rock.
Dam and Oike Construction Cleaning and mapping of core trenches was continuing in the main and auxiliary dams.
Some parts of the core trench on the left side of the auxiliary dam were being filled and compacted with a self-propelled sheepsfoot roller.
Fill moisture content determinations were being made by the Speedy method.
3
'I A possible geologic fault in the left side of the main dam core trench was inspected.
This feature was being cleaned in preparation for mapping.
Near this possible fault, a hole, apparently man-made many years
- ago, was obser ved.
The hole was about 4 ft diameter and at least 15 feet deep in rock and was being cleaned out for inspection.
The separating dike had been constructed up to about 15 ft above the valley floor.
The core section of the dike had been sealed and no work had apparently been done there for some days.
The random rockfill zones of the dike also had been sealed.
The surface of the rockfill zone appeared to be very "tight" and appeared to be more soil-like than rock-like.. Some large rocks, up to about 30 inch diameter, were observed on the edges of the random rockfill sections.
Structure Backfillin I observed backfilling around the Waste Process Building.
A smooth drum vibratory roller was being used to compact the clay soil.
About a 20 ft depth of fill had already been placed and it appeared that an additional 40 ft or more would be needed to backfill to plant grade.
Near the Waste Process Building a 200-ft length of the service water intake pipeline was under construction.
Welding of pipes was in progress.
Backfilling around pipes had not been star ted.
The pipeline excavation near the Waste Process Building appeared to extend through the random fill and into natural residual soils.
At greater distances from the plant the pipeline reportedly will be supported on as much as 15 ft of random fill placed about 4 years ago.
4 Heetin Discussion To ics The applicant produced a site plan showing the locations of the following Category I pipelines, conduits and tanks located outside the main plant area:
emergency service water intake pipes emergency service water electrical duct banks emergency service water discharge pipes diesel fuel lines diesel tanks The diesel tanks reportedly are founded on rock while the other Category I pipes, lines and ducts are founded on or in one or more of the following materials:
wall of a structure selected impervious backfill around the structure residual 'soil sound rock random fill (placed a few years ago to "level" the site to E1. 260)
The PSAR in section 5E states that backfill around Category I structures will be compacted to 95K maximum dry density (ASTM D-698) at optimum moisture I
content.
Reference in the PSAR is made to pipelines and conduits in sections 1B.6.1.4 and 8.5.5 but there is no discussion of the support of pipelines or conduits. on fill.
The construction offill and backfill (for other than dams) is covered by Ebasco specification CH-8 and CP&L procedure TP-02.
These specifications identify two materials relevant to Category I-pipelines and conduits selected backfill to fill excavations around structures and random fillfor areas away from the main plant structures.
The selected backfill around Category I structures is required to be a low permeability material because the design groundwater level for lateral loads on structures is lower than the temporary flood elevation 4
of El 160 which would develop from a flood pool level behind the auxiliary dam.
The design assumed that a temporary rise in water level away from the plant will not affect the piezometric level adjacent to the plant because of the resistance to seepage through the impervious selected backfill.
~Sum ar 1.
The practicality of the PSAR commitment to,compact backfill to 95K I
density at optimum moisture content was discussed.
The Ebasco specification CH-8 does not require moisture control and thus is not consistent with the PSAR commitment.
The need for modifying CH-8 was discussed.
2.
The Ebasco
- Engineer, M. Pavone, stated that the below grade wall design was controlled by dynamic earth pressures, and full passive pressure was assumed in the design.
Thus, in general, he considered that the only concern with the backfill adjacent to safety related structures was that it should meet permeability requirements.
3.
A special condition not covered by CH-8 specification occurs when Category I lines are directly supported on selected backfill adjacent to structures.
I was informed that this condition was still being studied by the applicant.
4.
There are places where Category I lines are supported on general site fill (random filloutside the main plant area).
The Ebasco engineer, N. Pavone, stated that studies had been performed which showed that the Category I lines could with-stand the greatest possible settlement of the deepest random fill. I said that this statement did not appear to be substantiated on the basis of the information provided.
5.
The field control of moisture content and density were discussed at length.
The IE inspectors were not satisfied with the field control, particularly the accuracy of the measuring methods and the fact that some of the fill that has been placed does not meet specifications.
This issue was not resolved and was to be pursued by the IE inspectors.
6.
The applicant informed us that a field change was being made with regard to specifications for the random rockfill zones of the Auxiliary Dam and Dike.
We were informed that the change was simply to update the specifications and reflect the random rockfill requirements developed from the test fill program.
I stated that I would review the change and inform IE of the results.
I Subsequent to my site visit, the NRC inspector informed me on April 19, 1979 that the applicant had stopped placement of safety related fill (i.e. fill over, around, under or beside Category I structures, lines, tanks, etc.) until certain revisions to specifications are made and the acceptability of in-place materials is verified by NRR.