ML20138R363
| ML20138R363 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/23/1985 |
| From: | Conlon T, Harris J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20138R362 | List: |
| References | |
| 50-424-85-53, 50-425-85-38, NUDOCS 8512310223 | |
| Download: ML20138R363 (9) | |
See also: IR 05000424/1985053
Text
.
.-
'
.
[pa "Ecoq'o,
UNITED STATES
-
.
NUCLEAR REGULATORY COMMIS$10N
[
~ 7.,
REGION 10
5
.. j
101 MARIETTA STREET.N.W.
2
ATLANTA, GEORGl A 30323
%.,
/
- ...+
Report Nos.: 50-424/85-53 and 50-425/85-38
Licensee: Georgia Power Company
P. O. Box 4545
Atlanta, GA 30302
Docket Nos.: 50-424 and 50-425
License Nos.: CPPR-108 and CPPR-109
Facility Name: Vogtle 1 and 2
Inspection Conducted: November 18-22, 1985
Inspector:
bi
/2/d 3/P S
_
J. E Harris
Da'te Signeo
Approved by N
/etspr
M
/r 7-g/fS'
T. E. Conlon, Section Chief
Date S'igned
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
This routine, unannounced inspection entailed 37 inspector-hours on site
in the areas of structural concrete, post tensioning activities. and emnloyee
concerns in civil construction.
Results: No violations or deviations were identified.
- _ .
g S/J. 3 /o 22 3
.
-
.
.
...
.
.
.
.
.
. REPORT DETAILS
.
4
1.
Persons Contacted
Licensee Employees
4
- R. E. Conway, Senior Vice President
4
1 ~
- D. O. Foster, General Manager Vogtle Project
- M. H. Googe, Project Construction Manager
- E. D. Groover, QA Site Manager
- R. C. Harbin, Manager, Quality Control
- P. Ciccanes, Regulatory Compliance Specialist
- G. A. McCarley, Project Compliance Conrdinator
Other licensee employees contacted included construction craftsmen,
engineers, and technicians.
,
NRC Resident Inspector
- R. J. Schepens
- Attended exit interview
2.
Exit Interview
The inspection scope and findings were summarized on November 22, 1985, with
those persons indicated in paragraph 1 above.
The inspector described the
areas inspected and discussed in detail the inspection findings.
No
dissenting comments were received from the liceitsee.
[
The licensee did not identify as proprietary any of tne materials provided
i
to or reviewed by the inspector during this inspection.
3.
Licensee Action on Previous Enforcement Matters
This subject was not addressed in the inspection.
'
4.
Unresolved Items
.
Unresolved items were not identified during the inspection.
!
5.
Independent Inspection Effort
l
Construction Progress
~
The inspector conducted a general inspection of the soils and concrete
,
testing laboratory, concrete structures, ongoing concrete curing operations
and backfill operations to observe construction progress and construction
I
activities.
I
_
. . .
.
.
.
2
'
Within the areas examined, no violations or deviations were identified.
6.
Containment, Structural Concrete (47054) - Unit 2
Theinspectorobservedpreparatibnforthefinalconcreteplacementofthe
~
Unit 2 containment dome. The placement was scheduled for November 22, 1985,
but had to be rescheduled for November 26, 1985, due to adverse weather
resulting from Hurricane Kate.
Acceptance criteria examined by the
inspector appeared in the following documents:
- -
Specification X2AP01, Placing, Finishing and Curing Concrete
Procedure CD-T-02, Concrete Quality Control
FSAR Sections 3, 12, and 17.
.
Observations showed that the area was being properly cleaned, that re-
inforcing steel was properly installed, and that equipment was being in-
stalled to allow proper placement of the concrete.
Examination of the
concrete testing laboratory and batch plant showed that the calib*ation of
the batch plant and testing equipment were current and that they were in
good working order.
Discussions with QC inspectors and craft personnel
concerning preparation for the dome placement indicated that they were aware
of the specification and procedure requirements for the preparation and
placement of the concrete pour for the dome.
Within the areas examined, no violations or deviations were identified.
7.
Containment (Post-Tensioning) Observation of Work (47063) Unit 1
The inspector observed the stressing of horizontal tendon numbers 127, 129,
and 139.
Acceptance criteria examined by the inspector appear in the
following documents:
Specification X2AF04 - Rev. 3, Containment Post Tensioning System
i
VSL Field Instruction Manual for Installation af Post-Tensioning
System, Rev. 10
Drawing PT-11.2-1, Horizontal Tendons, Unit 1
Drawing P1372.23 Horizontal Tendon Stressing Data
'
Observations included checking calibration of the stressing rams, witnessing
measurement of elongation of the tendon strands, seating measurements,
>
lift off pressure, and cutting of wire strands following completion of
stressing activities. Ooservations and review of stressing data showed that
the stressing operations were being conducted in accordance with require-
ments and that the operations were being monitored by quality control
l
l
t
-
-
-
-
. - - -
-
,
.
.
'
.
.
-
3
,
inspectors.
Discussions with craft and quality control personnel and
responsible engineers indicated they understood the requirements for the
stressing operations.
Withintheareasexamined,novioiationsordeviationswereidentified.
8.
Containment (Post-Tensions) Review of Quality Records (47065) - Unit 1
The inspector examined quality records relating to post-tensioning activi-
ties for horizontal tendons in the Unit I containment. Acceptance criteria
examined by the inspector appear in the documents listed in paragraph 7.
Records examined were for horizontal tendon numbers 2, 3, 4, 9, 13, 14, 15,
19 and 20.
Records examined included; tendon installation reports, quality
control checklists, stressing reports, and tendon greasing reports.
Review of these records showed that the tendons were installed in accordance
with specification requirements and that problemt encountered during
stressing operations were being identified and properly addressed.
Within the areas examined, no violations or deviations were identified.
9.
Employee Concerns, Discussions, and Findings
The following employee concerns were reviewed:
a.
Backfilling Against North Wall of Control Building
(1) Concern
,
The north wall of the control building (an exterior wall at
level D) was backfilled before it cured. As a result, there was a
j
lot of honeycombing on the wall.
(2) Discussion
The inspector examined drawings of the control building, walked
down the exterior and interior of the control building, discussed
placement of concrete and backfill activities in the control
building with quality control inspectors and engineers and
examined records relating to backfill and concrete placement for
the control building.
Review of drawings showed that the exterior wall on the north side
of the control building begins at level B at elevation 180 and not
at the D level as stated in the concern.
Discussions with QC
'
inspectors and engineers and examination of records disclosed the
backfill was placed against the north wall of the control building
before the specified time.
This was identified by a quality
!
control inspector in Deviation Report CD-1762 dated February 17,
l
1982.
This deviation report stated that backfill was placed
!
.-
.-
.
l
4
against the north wall of the control building to elevation 196
which was contrary to requirements that no backfill be placed
above elevation 186 before placement of the level A concrete slab
which ties into the nor.th wall at elevation 200. This problem was
submitted for engineering review and as a result the backfill was
removed.
Analysis by design engineers showed that no structural
damage was done to the north control building wall. A walkdown of
the control building by the inspector showed no evidence of any
adverse cracking or structural damage.
Placement of the backfill against the wall would not cause
honeycomb in the concrete because by the time the forms were
removed, the concrete would have hardened to the point where the
backfill could not have had any affect.on the concrete surface.
.
Research of the literature and experience has shown that honeycomb
is caused by inadequate vibration near the out'r face of the walls
where the reinforcing steel interferes with :he flow of the
plastic concrete.
(3) Findings
Investigations showed that backfill was placed against the north
wall of the control building before the specified time. This was
identified and investigated by the licensee.
The backfill was
removed and the structure was evaluated to determine if the
backfill had caused any structural damage. The analysis showed no
structural damage due to the placement of the backfill.
A
walkdown of the structure by the inspector disclosed no evidence
of structural damage.
Backfill against the walls would not cause
honeycomb or defects in the concrete because the concrete would
have been in a hardened state by the time the forms were removed.
No problems with the quality of the concrete were substantiated.
b.
Falsification of Soil Density Tests-
(1) Concern
Soil density test results had been falsified.
Proctor tests were
run on the soil compaction which was done at the site.
Proctor
tests are tests to determine soil density and moisture and these
test were done on the compacted soil for the power block.
Individuals involved in this matter manipulated the test results
to indicate that they were acceptable. Results are too good to be
true in that results are too perfect.
(2) Discussion
The ' inspector examined Bechtel Specification X2AP01, " Earthwork
and Related Site Activities", and Georgia Power Company procedure
CD-T-01, " Earthwork Quality Control", and reviewed proctor and
-
~
. ~.
,
.
.
5
'
field density test data on compaction of soil material in the
power block from 1978 through 1980.
The inspector also inter-
viewed seven quality control inspectors that were involved in
inspection of compaction of backfill in the power block.
Review of specification X2AP01 and procedure CD-T-01 showed that
the required field compaction of the backfill is specified in
tems of percent of maximum dry density as determined from the
laboratory modified proctor test (ASTM D-1557).
In-performance of
the laboratory proctor test (ASTM D-1557), soil samples are
compacted at varying moisture contents in a steel mold of known
volume using a specified compacting effort.
The purpose of the
test is to determine the maximum soil density and the corre-
sponding optimum moisture content at which this maximum density
can be obtained. .The test results are presented as a plot of the
dry density versus moisture content.
Connection of the plotted
points results in a curve shaped line.
A line to the curve peak
from the vertical axis containing density values in pounds per
cubic foot represerts the maximum dry density for that material
and a vertical line from the peak of the curve to the horizontal
j
axis containing water content values in percent of dry weight
represents the optimum moisture content at which the maximum dry
density is obtained.
Specification X2AP01 requires that soil in
the power block to be compacted to an average of 97 percent of the
maximum dry density determined by the laboratory proctor test.
The specification also requires that the moisture content of the
soil at the time of compaction be within minus three percent or
plus two percent of the optimum moisture content determired by the
laboratory proctor test.
Procedure CD-T-01 details the method for quality control testing
of Category I backfill to assure the backfill is compacted to the
density and moisture limits determined by the labo atory proctor
test.
The testing is performed by quality contrcl (QC) soil
inspectors using field density (sand cone) tests (ASTM D-1556).
The results of the field density tests and the scil samples
collected in performance of the field density tests are sent to
the soils laboratory by the QC field inspectors.
In the soils
lab, laboratory technicians test the soil samples and calculate
the results of the field density tests.
The field density test
results are determined by comparing the density of the in-place
soil (determined by sand cone method) with the laboratory proctor
results and computing the percent compaction (field density
divided by proctor density) of the in-place backfill material.
Review of the field density test data from 1978 through 1980
showed that, for the most part, the power block ' backfill was
compacted to a density of 97 to 107 percent of the maximum density
determined by the laboratory proctor.
Some of the field density
tests showed that backfill was compacted to 93 to 96 percent of
l
the maximum proctor density.
These low test results were
.
l
identified and addressed by the licensee.
Review of the data
1
l
__
_
_
_
_
.___ __._.
__.
-
_
_
_ _ _ _ _
_ , ,
.
'
!
-
,
,
- $
'
6
,
,
i
'
indicated that the results were reasonable and normal for the
compacted effort being used to compact the backfill (compacted
with a ten ton vibratory roller).
,
,
t
,
,
Interviews.with the seven quality control inspectors disclosed no
evidence of manipulation or falsification of soil test data. Two
inspectors indicated that they heard one individue(would some-
times round a decimal up (e.g., 96.5 to 97.0) to make t. tes,t
i
,
'
appear better, but that they had never witnessed or actually teen
the individual do this. . Review of test data by this inspector
showed no evidence where decimals had been rounded up. All seven
inspectors stated that they had no knowledge of any falsification
of test data and indicated that they were satisfied with the
. quality of the compaction of the backfill.
,
!
In addition to the investigation of compaction of soil material in
,
j
the power block during this inspection to satisfy the stated
concern, this NRC inspector and two other NRC inspectors from the
l
Region II office nave examined controls on backfill activities
during routine inspections conducted from 1978 through 1985.
j
During these inspections, controlling specifications and proce-
_
dures were reviewed, work activities were observed and records
!
were examined to verify that backfill activities were being
'
conducted in accordance with NRC requirements.
During these
'
visits, the inspectors also discussed quality control of backfill
activities with civil quality control inspectors to verify that
quality control inspectors understood the. specification require-
ments and that these requirements were being implemented. During
these inspections, several minor violations regarding control of
,
moisture content were identified.
The licensee was responsive in
i
addressing and correcting these items.
During one of these
i
inspections conducted on November 16-18, 1979, this NRC-inspector
was informed by the-Georgia Power Company QA supervisor that a
,
severe storm on November 2, 1979, had aggravated ongoing moisture
>
'
problems and eroded part of the backfill.
Because~the applicant
failed. to report the deficient condition to the backfill as
,
required by 10 CFR 50.55(e), a Notice of Violation was issued.
'
Subsequently a Confirmation of Action letter -dated November-15,
.
1979, from NRC Region II to Georgia Power was issued in which it
was understood that Georgia Power would not continue with backfill
placement'in or around the power block area or concrete placement
-
on affected structures without concurrence of NRC. Meetings were
held with'the applicant at the site and at the Office of Nuclear
l
Reactor Regulation (NRR) in Bethesda, Maryland regarding measures
i
to be taken to correct the backfill. Corrective measures included
testing to determine the extent of defective backfill, removal of
i
defective backfill and foundation slabs, installation of drainage
'
facilities and a dewatering system and application of gunite (sand
cement mixture) on slopes to prevent additional erosion problems.
i
I
L
L
-
._
_
_ _ _ _ . _
.
. - . .
.
. ..
.
. .
.
.. .
.
_
. - .
_
__
.
,
..
7
The NRC inspectors observed the corrective measures taken to
'
correct the backfill and examined records documenting the
i
corrective measures during several onsite inspections. Results of
these inspections showe.d that the backfill was properly repaired
and that measures were taken.to prevent future erosion problems.
Reviews of backfill activities were also performed by Geotechnical
!
Engineers from the NRC office of Nuclear Reactor Regulation (NRR).
These reviews resulted in some concerns being raised by an NRR
Geotechnical Engineer regarding the density of the compacted
backfill in the power ' block.
To satisfy these concerns, samples
representative of the Category I backfill were taken by the
licensee and tested by both an independent testing laboratory and
the licensee's testing laboratory.
The sampling and testing of
these samples were witnessed and reviewed by NRC inspectors.
Comparison of the test results from the two laboratories indicated
that the methodology being used by the licensee to control the
compaction of the backfill was reasonable and correct.
In
addition to the laboratory tests, the licensee hired a drilling
company to perform in-place standard . penetration tests on the
!
existing backfill to verify that the density of the backfill meets
!
design requirements.
These standard penetration tests were made
l
by driving a two-foot eight-inch long cylindrical tube (called a
sampling spoon) having a two-inch outside diameter and a one-and-
three-eight inch inside diameter into the existing backfill.
In
this method, the sampling spoon, which is attached to drill rods,
<
is driven into the soil by blows of a 140-pound hammer falling
from a height of 30 inches and impacting on a driving collar-
attached to the drill rods.
Each blow count is accomplished by
raising the cylindrical shaped hansner, which has a center hole
that allows it to be raised along the shaft attached to the drill
collar, with a rope to a height of 30 inches and then allowing the
'
hammer to free fall and strike the drive collar.
After the
,
sampling spoon has penetrated six inches into the soil, the
penetration test is started and the number of blows required to
-
produce .the next one foot of penetration is recorded.
Anything
- over 50 blows per foot is considered very dense.
Review of the
penetration data showed the following range of blow counts for the
backfill: 0-10 feet, 32- 131 blows with a conservative average of
50 blows; 10 to 30 feet,62-200 blows with a conservative average
,
of 100 blows; 30 to 80 feet, 100 to 200 blows with a conservative
average value of 150 blows.
Results of the confirmatory testing
by the independent laboratory and the standard penetration tests
,
indicated that the recorded density values accurately reflect the
in-place density and compaction of the backfill.
t
Review of NRC inspection reports also showed that a similar
concern was identified in 1981.
This concern indicated that
results from backfill proctor analyses were altered to indicated
that failing tests complied with specification requirements. This
1
t
m.
.--.
._
_ . , _ , _ . . .
. _ . . _ - . . . .
,,__m.
. - ~ . ~ . _ . _ , _ . _ . _ . , . . . . _ _ _ - - _ .
_ . _ , - - .
. -
.
.
O
'
8
concern was investigated by an NRC Region II inspector and an NRC
investigator during the period of May 18 to August 7,1981.
Results of this investigation, documented in NRC report number
50-424/81-09 and 50-425/81-09 dated October 22, 1981, indicated
there was no evidence that test data was being altered to indicate
failing tests meet requirements.
(3) Findings
Review of records and discussions with civil quality control
inspectors failed to show any evidence that backfill records were
falsified.
Additional independent confirratory testing of the
backfill by independent organizations confirmed that the
methodology being used and that the in-place density of the
backfill met specification requirements.
The concern was not
substantiated.
i
l
l'
!
!
l
l
l
l
-a
-
-
e .9
9-w
.w
,-.,4-
w
- . -