IR 05000244/1979010
| ML17249A570 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 12/12/1979 |
| From: | Ebneter S, Markowski R, Varela A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17249A569 | List: |
| References | |
| 50-244-79-10, NUDOCS 8002150186 | |
| Download: ML17249A570 (30) | |
Text
U.
S.
NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION I
Report No.
50-244/79-10 Docket No.
50-244 License No.
DPR-18 Priority Licensee:
Rochester Gas 8 Electric Cor oration Category 89 East Avenue Rochester New York Facility Name:
R.
E. Ginna Station
/
Investigation At:
Rochester and Ontario New Yor k Investigation Conducted:
June 26-29.
Au ust 28-31 October Investigators:
S.
K.
Cha r
,
act r Inspector A.
. Varela, Reactor Inspector
. Markowsks, Reactor Inspector Approved by:
S.
D. Ebneter, Chief, Engineering Support Section 82, Reactor Construction and Engineering Support Branch Investi ation Summar
10-12 1979
/g T
>4'ate date rz-fr-TP date
/w 7,-
ate Areas Investi ated:
An investigation conducted by three regional based.investi-gators of containment concrete records.
The investigators reviewed concrete test data, structural integrity test reports, tendon surveillance records,
.and quality assurance records.
They also visually examined exterior surfaces of the contain-ment, and witnessed a tendon lift-offtest.
The investigation involved 131 inves-tigator hours at the licensee's corporate office and site.
Results:
No items of noncompliance were identified.
Region I Form 167 (August 1979)
I.
~BB d'.
On May 9, 1979 Region I received a letter from the Associate Editor of the "Rochester Patriot" newspaper.
The letter enclosed clippings of a story the Patriot had published in its May 4, 1979 issue.
The published story in the Patriot alleged that concrete used during'he c'onstruction of the R.
E. Ginna power plant failed to meet on-site test requirements.
The source of the information identified by the newspaper was a resident of Rochester who had worked for approximately a week as a concrete inspector at the power plant construction site in April 1967.
Region I'nitiated an investigation of the above allegations, and on June 8, 1979 interviewed the alleger in the regional office.
The alleger states as follows:
"I was employed by Pittsburgh Testing Laboratory (PTL) for a period of approximately fourteen (14) days in April or May of 1967.
I was hired on the basis of my representations to PTL even though I had no experience in concrete testing and received a couple of hours of on-the-job instruction.
I was assigned as an inspector to perform slump tests on truck-delivered concrete at the Ginna site.
I checked anywhere from 30 to 60 truckloads per day at the site for a period of about five days."
"Many of the truckloads did not meet the specified slump requirements.
In some cases, the drivers would adjust the concrete by adding water, sand or Portland until it passed.
In others, I just put the right numbers on the form even though it didn't meet slump requirements."
"In my opinion, the PTL testing that I was involved with during the period of my employment was not done properly, procedures were hap-hazard and supervision was inadequate.
I think the slump test is an inadequate test for concrete.
If the slump test is continued to be used, consideration should be given to have an independent party observe it and other measures taken to assure they can't buy off an inspector."
"In addition, I witnessed some concrete cylinder testing that did not pass the strength test.
I think this test is inadequate because the evidence is destroyed.
Perhaps additional cylinders should be made and kept for future tests or video tapes made of the test and gage."
B.
Identification of Involved Or anizations Rochester Gas 8 Electric Corporation (RG8E)
89 East Street Rochester,.
3.
4.
5.
RG8E is the licensed owner-operator of the R.
E. Ginna power station located in Wayne County',
Mestinghouse Electric Corporation (W)
Atomic Power Division Pittsburgh, Pa.
Westinghouse was the prime contractor engaged by RG8E to coordinate the design and construction of the Ginna station.
Bechtel Power Corporation (Bechtel)
50 Heal Street San Francisco, Ca.
Bechtel was engaged by Mestinghouse as sub-contractor to provide construction services for the plant.
'ilbert Associates, Inc.
(GAI)
Reading, Pa.
GAI was engaged as the Architect-Engineer for the plant, and provided the design services as a sub-contractor to Mestinghouse..
Pittsburgh Testing Laboratory (PTL)
Pittsburgh, Pa.
PTL was a sub-contractor to Westinghouse to provide testing services for concrete and rebars.
Inland-Ryerson, Inc. (Inryco)
Melrose Park, Illinois Inryco (formerly Joseph T.
Ryerson 8 Son, Inc.) was a sub-contractor that provided design and erection services for the containment post-tensioning system.
II.
Summar of Findin s A.
Investi ation Findin s The inspection and review of available records related to concrete placement in the containment structure during the construction phase revealed the following:
1.
There was evidence of occasional malfunction of batch plant equipment which affected the consistency of concrete delivered to the sit.
The concrete affected by batch plant equipment mal function was placed mostly in structures other than containment although a
total of 103 cubic yards, in two different placements, got into the containment.
3.
4.
Records.indicate that there was some occasional-irregularity in field testing of concrete by PTL.
A small statistically acceptable percentage of the compression test cylinders did not meet the minimum design strength requirements.
B.
Conclusions Based on the evaluation and analysis of the above findings as discussed in detail in Section III.F of this report, the inspectors conclusions are as follows:
1.
The concrete placed in the containment structure substantially met the requirements of applicable specification, standards, and industry codes.
The occasional variation in the consistency of concrete placed was not such as to affect the structural integrity of containment as evidenced by the Structural Integrity Test, several Leak Rate Tests, and visual inspection.
2.
There was sufficient control exercised by several independent inspection groups to indicate that any substantial placement of
.
substandard concrete accepted by one individual was unlikely.
3.
The few instances of low strength of compressive test cylinders are so scattered and limited in number that their effect on strength analysis of containment structure is negligibl DETAILS III.A. Persons Contacted 1.
Rochester Gas 5 Electric Cor oration RG8E
"J. Arthur, Chief Engineer
'.
Covey, Manager, Civil Engineering C. Forbes, Civil Engineer G. Goetz, Project Engineer L. Lang, Superintendent, Nuclear Production B. Murray, Construction Coordinator J.
Noon, Assistant Station Superintendent T. Shuler, QC Engineer B.
Snow, Station Superintendent
"Denotes attendee at final exit meeting, others were present at interim meetings during this investigati,on.
2.
Pittsbur h Testin Laborator PTL)
E.
H. Clement, Payroll Supervisor (telephone)
J. Gentile, Manager, Buffalo Branch (telephone)
3.
Inland-R erson (INRYCO Inc P. Reinhardt, Manager, Business Development, Post Tensioning Division 4.'ilbert Associates Inc.
GAI J.
F. Fulton, Structural Engineer R.
E.
Pages, Senior Structural Engineer B.
Chronolo of Investi ation Region I received the letter from Rochester newspaper alleging the use of substandard concrete in the plant containment structure.
A brief chronology of'vents related to the conduct of investigation is as follows:
May 9, 1979 May 10, 1979 May ll - June 6, 1979 June 8, 1979 Region I initiated an investigation.
Region I reviewed Ginna docket file for background information and contacted the involved parties.
Region I interviewed the alleger in the regional offic June 21, 1979 Licensee was informed of the initiation of the investigation and requested to retrieve concrete production and placement records from its files for NRC review.
June 26-29, 1979 August 28"31, 1979 October 9-12, 1979 Region I conducted a review of the concrete records at the licensee,'s corporate offices; performed a
visual inspection of the containment structure at the plant s'ite; and witnessed the tendon lift-off test of the containment post-tensioning system.
C.
Res onsibilities and Interfaces of Identified Or anizations By review of records the inspector reconstructed the responsibilities of the involved organizations, interfaces, quality assurance program, and the manner of resolution of observed nonconformances identified during construction.
(1)
RG8cE The Rochester Gas and Electric Corporation had engaged contractors and consultants for the design and construction of the Ginna station.
However, as the sole applicant for the construction permit and owner, RG8E had the ultimate responsibility for the adequacy of design and construction, including quality assurance, of the power plant.
To fulfillthe above responsibilities RG8E had established an organi-zation directed by a Project Engineer.
In addition to other project functions, this organization maintained a quality control surveillance program.
This program was carried out by RG8E engineers and field inspectors.
The primary purpose of'his inspection program was to inde-pendently audit and monitor the quality control program established by the prime contractor and his subcontractors.
(2) H~h The R.
E. Ginna Nuclear Power Station was designed and built by the Westinghouse Electric Corporation as a prime contractor for RG8E.
The Project was directed by Westinghouse from the offices of its Atomic Power Division in Pittsburgh, Pennsylvania, and its representa-tives at the plant site during construction and plant start-up.
As the prime contractor Westinghouse had the responsibility of project quality assurance which included a quality c'ontrol program for con-truction.
Westinghouse's Nuclear Service Group was responsible for assuring on-site quality control.
The quality assurance functions of this group was also augmented and surveilled by another independent quality assurance group from Westinghouse headquarter The headquarters quality assurance group carried out its 'surveillance by site visits, audits and maintaining a field reliability program.
(3)
Bechtel Cor oration Bechtel Corporation was retained by the prime contractor-Westinghouse-to provide construction services for the plant.
As a constructor, Bechtel was responsible for the quality of work performed in the field, and the quality of materials and equipment procured by Bechtel for field use.
The scope of this responsibility included quality of work performed by both Bechtel and subcontractor field forces.
In order to carry out this responsibility, Bechtel maintained a
fi'eld engineering organization answering directly to the Project Superintendent.
This field engineering organization reviewed con-struction work and maintained a quality control surveillance program by gC engineers and inspectors.
The gC activities specifically related to concrete construction were carried out under the supervision of a Bechtel engineer who was responsible for variations in the water/cement ratio within the design limits.
He was also responsible for acceptance or rejection of concrete prior to placement.
Gilbert Associates Inc.
Gilbert Associates as the Architect-Engineer of the plant provided technical guidance with respect to specifications, codes and design requirements.
This responsibility also included providing guidance in the interpretation of specifications, drawings, and the quality and capability requirements of end products in work, equipment, and materials.
The inspector was informed by the licensee that to accomplish the above responsibility in concrete Gilbert maintained a senior struc-tural/concrete engineer at the site.
Pittsbur h Testin Laborator PTL was retained by Westinghouse to provide testing services for concrete and rebars.
To accomplish this responsibility PTL maintained a field force of technicians and testing equipment on site.
The concrete technicians of PTL were supervised by experienced and senior technicians on site.
The technical direction of PTL was provided by.its Buffalo, N.Y. office.
PTL technicians sampled fresh concrete delivered to the site for placement, and conducted all specified tests.
The test reports were submitted to Westinghouse and GAI for revie (6)
Inland-R erson Inc. (formerly Joseph T. Ryerson 8 Son, Inc.)
J.
T. Ryerson installed the containment. tendons in accordance with approved designs.
The installation of tendons was monitored by Bechtel gC engineer, GAI engineer, and Mestinghouse assistant/resident engineer.
It is. noted that these interfacing responsibilities provided for mul-tiple layering of responsibilities in quality assurance func'tions.
D.
Review of Records 1.
Concrete Records The following concrete records and related documents were reviewed:
a.
Concrete Mix Designs prepared by PTL b.
Concrete Field Test Reposts submitted by PTL c.
Cylinder Compression Test Reports submitted by PTL d.
Daily. Field Reports of Concrete Placements,submitted by Bechtel gC Engineer e.
Concrete Specification issued by GAI Based on the review of the above records and other information provided by RG8E, the inspector determined the following:
a e Some batch plant records (Batch Tickets) were not available.
However, unavailability of batch tickets was not significant to the investigation, because other field test reports were avail-able to directly determine the quality of concrete.
b.
There had been a malfunction of batch plant equipment as evidenced by Bechtel gC engineer's daily reports of March 13, and May 23, 1967.
The quantity of concrete affected by these malfunctions of equipment was relatively small.
On March 13 approximately seventy five (75) cubic yards was placed in containment basement floor, and on May 23 twenty eight cubic yards of concrete was placed in the containment exterior wall.
The compressive strength of the concrete placed in the basement floor, required to be 3,000 psi, was determined from concrete test report no.
868 to be 4,267 psi in twenty eight days.
On May 23, 1967, two hundred and sixty two cubic yards of concrete were placed in other structures, i.e., Turbine and Auxiliary buildings, and retaining wall, and twenty eight cubic yards in containment structure c-These equipment malfunctions were documented and reported to upper management of the project.
These reports also indicate that there
'as sufficient control to evaluate the quality of concrete because on May 23, three loads of concrete were rejected.
There apparently were some i,rregularities in field tests of con-crete by PTL technicians, however, it was observed, documented, and reported to management by Bechtel gC engineers as evidenced by reports of January 30, April 4, April 12, and May 25, 1967.
d.
Some of the cylinder compression test reports indicated that in few cases some individual and some sets of test cylinders did not achieve the design strength for the concrete mix.
However, these instances were so scattered and small that they were considered to be isolated occurrences rather than a quality trend.
e. 'here was adequate supervision and control on placement of con-crete.
This was evidenced by the field report of Bechtel gC engineer documenting the presence of RGE gA engineer an'd GAI engineer on concrete placements.
The report also indicates that these personnel took active part in evaluation and disposition of any irregularity in delivered concrete.
This observation was further substantiated by the concrete rejections based on out of specification characteristics in delivered concrete.
(Field Reports 1/6/67; 1/23/67 2/1/67. 2/9/67. 2/10/67; 3/21/67; 4/13/67; 5/1/67; 5/23/67; 6/9/67; 6/20/67)
To further substantiate this conclusion, the inspector initiated a review of in-service performance of the containment structure.
2.
In-Service Surveillance Records The inspector initiated a review of'ocuments test data, and other direct and indirect evidence of in-service structural behavior of the containment.
The following documents, test data, and reports were
'eviewed:
a.
The Structural Integrity Test Report prepared by GAI.
b.
Initial Tendon stressing plan and Report prepared by INRYCO.
c.
Tendon Surveillance Test Reports and data for tests conducted in 1969, 1970, 1972, and 1977.
d.
Integrated Leak rate Tests of containment conducted in 1976 and 1978.
Based on the review of above documents the inspector determined as follow The structural integrity test (SIT) of the containment structure was conducted on April 11-12, 1969.
The test data were evaluated and analyzed by GAI.
In the final report of SIT, GAI stated that:
"The crack pattern spacing and widths were within the expected and predicted limits.
As the design of the concrete contain-ment vessel was based upon cracked concrete sections, and the crack widths were much less than predicted, the containment vessel more than meets the design criteria."
Therefore, the containment structure was sound and acceptable for service as intended for this plant.
A comparison of the initial stressing, and the June, 1977 in-service surveillance test data of the post-tensioning tendons reveals that the rate of stress relaxation in tendons was not as expected.
However, the licensee has not finished evaluation and/or determined the cause of this tendon relaxation, and has no initial explanation for this behavior.
However, the licensee's followup action consists in eval-uating the surveillance procedure for adequacy, checking of the cali-bration of instruments used in the test, and review of -previous test data.
The last integrated leak rate test of the contai.nment was conducted in March 28-29, 1978.
The leak rate test was performed with the internal building pressure of slightly greater than 35 psig.
This test was wit-nessed by NRC inspectors, and is documented in NRC report 50-244/78-08.
The licensee's report on the test states that no significant leaks were detected and no evidence of structural deterioration of the external concrete was observed.
This report was also reviewed and found accept-able by NRC as documented in NRC report 50-244/78-16.
Visual Ins ection of Containment Structure A visual examination of the accessible exterior vertical concrete wall and dome of the containment structure was performed on August 30, 1979.
The NRC inspector visually examined the containment exterior wall ver-tical surface that could be viewed from accessible platforms, walkways, interior rooms of adjacent buildings, exposed bridges and ground level.
Particular attention was given to the surfaces exposed to atmospheric weathering at the dome, the spring line, elevation 330', approximately 30'elow the top post tensioned anchorages, and the exposed easterly quadrant from the dome to ground level.
The following'bservations resulted:
Apparent closed tensile stress cracks were noted on the horizontal ledge at top of the vertical wall radiating outward from the post tensioned anchorage The dome adjacent to most anchorages also evidences minor vertical stress cracking within the first concrete ring pour of the dome.
The vertical wall ten feet below the ledge and approximately at each anchorage appears to have experienced minor stress cracking during the initial post tensioning.
The inspector concluded that since the containment structure has no ring girder and.is post tensioned only vertically, the outer surfaces of the dome and the vertical wall regions adjacent to the top anchorages were subjected to radial displacement during the initial structural integrity test.
The above closed stress cracks appear as indications that the normal reinforcing steel adequately controlled crack enlarge-ment during the initial testing.
Since no structural deterioration exists in the concrete the integrity, strength and.durability of the concrete existing after ten years service is assured.
~
~
not cons>dered evidence of st E.
Containment Post-Tensionin S stem The accessible exterior wall areas below elevation 300 disclosed apparent random shrinkage cracks and possibly some stress cracking around the barrel of the containment structure.
None of these cracks appear to be new, some were observed to have required grouting, however, they are ructur al deterioration.
As stated previously in this report, the review of test data of the June 1977 tendon surveillance program indicated that the relaxation characteristics of the containment tendons were not as anticipated.
Although, the stress level in the tendon, as determined from the most recent lift-offtest, was within the limits of plant technical specification (60K of ultimate stress),
the rate of relaxation was not as expected of similar post-tensioning systems.
The inspector requested that the licensee management address this apparent anomaly.
Pursuant to this request the licensee stated that they would secure the services of GAI and INRYCO in this effort.
RG&E also committed to perform a new tendon lift-offtest to verify the validity of the previous test data.
The previous test data (1977 test) indicated an average prestress of 60.2X of ultimate stress.
However, the historical data of some of the tendons indicated that the relaxation of individual tendons had not stabilized.
l.
Observation of Tendon Lift-OffTest The tendon lift-offtest was conducted during the week of October 8-12, 1979.
The inspector witnessed the test.
Twenty-two tendons were.selected for lift-offincluding fourteen which had been tested previously.
Two tendons were detensioned and their
associated rock anchors were visually inspected and checked for move-ment during liftoff.
Surveillance wires were pulled for further relaxation testing.
Two methods of detecting lift-offwere utilized.
The first was the sounding of the shims supporting the anchor nut.
This had been the method utilized in previous testing.
The second method utilized a 0.032" shim.
Subsequent to liftoff utilizing the sounding,.method, the tendon was stressed to 6X overstress and the shim (.32") was inserted.
The tendon was then reseated and a second liftoff was performed until the shim could be removed.
This shim method was intended to verify the adequacy of previous data collected by the sounding method.
Preliminary results indicated good correlation.
All tendons were lifted off utilizing both methods.
The avera e of the twenty-two tendo'ns based on the shim method was below 60 appro-ximately 59.6X).
Also two tendons had been relaxed and retensioned and no movement of the associated rock anchor was measured.
Inspec-tions were conducted to determine if any tendon wires had broken.
No wire breakage was observed.
On October 12, the licensee and his agents (INRYCO, Inc.
and GAI)
presented the following evaluation:
a.
Data gathered previously by the sounding method was confirmed, although there were some previous data which was lower than experienced during this test; b.
12K relaxation of the tendon wire over forty years had been assumed in design.
Gilbert Associates (the AE) stated that this may not have been realistic.
Previous liftoff test data have been evaluated and the rate of relaxation has been determined to be similar to predicted, although the magnitude of relaxation is apparently higher; c.
Concrete creep, rock anchor movement and environmental effects would not have caused the changes in the liftoff forces measured; and, d.
The data is being reviewed by Gilbert Associates and further plans (i.e., for retensioning) will be developed subsequent to this review.
By letter dated October 18, 1979, Rochester Gas 8 Electric formally reported the results of the testing performed.
They further stated that a retensioning procedure is currently being developed by GAI and a schedule for retenstioning will be developed for completion of the work as soon as practica The method of testing and the test results and evaluation (as stated in the October 18, 1979 letter) are currently undergoing further review by the NRC to determine the need for further NRC and/or RGE action at this time.
The adequacy of the response remains unresolved (79-1,0-01).
F.
Findin s and Evaluation The findings and their evaluations by the inspector are as follows:
Partici ation of the Alle er in. Field Test of Concrete 2.
The alleger did in fact work as a technician on the construction site, however, the amount of time he spent on concrete placement activities was approximately eleven (ll) hours.
The quantity of concrete placed specifically in containment structure during this time period was approximately 56 cubic yards.
Mixin of In redients in Concrete at Job Site Mixing of additional water in concrete at the job site as alleged is documented in the concrete records.
The mixing of water at the job site was performed in accordance with the project procedures.
This practice was also observed and documented by AEC inspectors in report no. 50-244/68-05.
The practice was con-sistent with codes and standards applicabl'e to the project and is still permitted by specifications and present standards, and codes.
If the full amount of water permitted by the mix design for a given water-cement ratio is not added at the batch plant, the remaining water may be added at the job site within the limits of the design water-cement ratio.
3.
There is no evidence that any ingredient (sand, rock, cement),
other than water, was added at the job site.
Placement of Concrete with Excessive Slum The primary function of in-process field test of concrete is to assure production and placement of uniform concrete of desired strength and quality.
Concrete is a hardened mass of heterogeneous material subject to the influence of numerous variables.
In concrete production and construction proper control is achieved by the use of satisfactory materials, proper mixing of these materials into concrete of desired quality, and good practices in transporting, placing, curing, and protecting the freshly placed concrete.
It is well established that strength and serviceability of concrete is governed to a large extent by water-cement ratio.
The temperature,
gradation, nominal size, and shape of'course and fine aggregate and variation in air entrainment of a concrete of given water-cement ratio affects the consistency, thereby, contributing to the variation in mea-sured slump at the time of placement.
The absolute quantitative data of slump measurements in themselves are not a true indication of the strength and durability of'oncrete, rather they are a qualitative indication of the workability of the concrete mix and must be. judged in conjunction with other indicators and in-process control of the production and placement.
The concrete placed in the containment structure substantially met the requirements of project specification and industry codes and standards.
There were occasional variations in the consistency of delivered con-crete during the early part of 1967 (January - May), however, the instances were not such as to degrade the overall structural integrity of the containment.
Any variation in the consistency of delivered concrete was reviewed and approved by a representative of GAI before the placement.
The technicians conducting the field tests were supervised by a more experienced senior technician of PTL.
These tests were generally witnessed by a Bechtel QC engineer, RG8E QA engineer and the final disposition of concrete was made by a Structural/Concrete engineer of the GAI present at the point of placement.
The inspector, therefore, determined that there was sufficient control exercised by several independent inspection efforts that any placement of substandard concrete accepted by one individual technician was unl ikely.
Failure of Concrete C linders to Meet the Desi n Stren th There were several. test reports indicating that some individual cylinders did not meet the required design strength of the concrete.
The function of compressive strength test of concrete cylinders is to assess the general quality and durability of structural concrete on a random sampling basis of representative batches of concrete.
The con-cept of this test is based on statistical methods'he statistical method provides an adequate basis for assessing from such results the potential quality and strength of concrete in the structure.
As with all statistical probabilistic methods, it is erroneous to con-clude that the strength and/or durability of structure is in jeopardy when a single or, to some extent, a limited number of specimens fail to meet the specified requirement.
Therefore, random variations and occasional failures to comply with strength requirements are inevitabl T This concept has been well recognized in the codes and standards.
The codes applicable to the construction and also currently applicable codes, accept a probability that lOX of all strength test may fall below the specified strength.
The observed instances of strength, failure of cylinders are so scat-tered and limited in number (less than 1X) that their effect on strength analysis is neglibible.
5.
Tendon Relaxation
, Based on the lift-offtest results the licensee has informed Region I that the average stress in tendon is 59.6X of ultimate strength of the tendon.
The technical specification for the plant requires at least a 60K stress level in the tendons.
Also, the licensee has provided Region I their preliminary evaluation of, and response to, the questions presented by the inspector regard-ing post-tensioning system, however, the final response is still under evaluation by GAI, and has not been received by Region I.
The question of the adequacy of licensee's response has been referred to IE Headquarters for further evaluation and resolution (79-10-01).
6. 'nresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance or deviations.
Unresolved items disclosed during this investigation are discussed in paragraph III.E.l.
G.
Exit Interview The inspector met with licensee representative Mr. J. Arthur at the conclu-sion of the investigation on October 12, 1979.
The inspector summarized the purpose, scope, and findings of this investigation.