ML20138R363

Insp Repts 50-424/85-53 & 50-425/85-38 on 851118-22.No Violations or Deviations Noted.Major Areas Inspected: Structural concrete,post-tensioning Activities & Employee Concerns in Civil Const

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: ML20138R360 ML20138R363
References
50-424-85-53, 50-425-85-38, NUDOCS 8512310223
Download: ML20138R363 (9)

See also: IR 05000424/1985053

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- UNITED STATES

[pa "Ecoq'o, NUCLEAR REGULATORY COMMIS$10N

[ ~ 7., REGION 10

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.. j 101 MARIETTA STREET.N.W.

2 ATLANTA, GEORGl A 30323

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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

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Inspector: bi

J. E Harris

/2/d 3/P S

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.

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. . REPORT DETAILS

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1. Persons Contacted

Licensee Employees

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4 *R. E. Conway, Senior Vice President

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• 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.

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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.

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4. Unresolved Items

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Unresolved items were not identified during the inspection.

! 5. Independent Inspection Effort

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Construction Progress

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The inspector conducted a general inspection of the soils and concrete

testing laboratory, concrete structures, ongoing concrete curing operations

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and backfill operations to observe construction progress and construction

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Within the areas examined, no violations or deviations were identified.

6. Containment, Structural Concrete (47054) - Unit 2

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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:

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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

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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

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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

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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

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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

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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.

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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

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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 l

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

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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). ,

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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-

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times round a decimal up (e.g., 96.5 to 97.0) to make t. tes,t ,

appear better, but that they had never witnessed or actually teen

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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.

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, 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.

During these inspections, controlling specifications and proce-

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dures were reviewed, work activities were observed and records

! were examined to verify that backfill activities were being '

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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

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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

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problems and eroded part of the backfill. Because~the applicant

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failed. to report the deficient condition to the backfill as ,

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required by 10 CFR 50.55(e), a Notice of Violation was issued.

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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 l

held with'the applicant at the site and at the Office of Nuclear l

Reactor Regulation (NRR) in Bethesda, Maryland regarding measures

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to be taken to correct the backfill. Corrective measures included

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testing to determine the extent of defective backfill, removal of

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.

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The NRC inspectors observed the corrective measures taken to '

i correct the backfill and examined records documenting the

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

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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

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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. l

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Review of NRC inspection reports also showed that a similar I

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

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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.

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