IR 05000373/1982043
| ML20028E343 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 12/27/1982 |
| From: | Jackiw I, Lanksbury R, Lankstury R, Lipinski R, Norton J, Reimann F NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20028E340 | List: |
| References | |
| 50-373-82-43, 50-374-82-11, NUDOCS 8301210242 | |
| Download: ML20028E343 (19) | |
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U.S. NUCLEAR R"GULATORY COMMISSION
REGION III
Reports No. 50-373/82-43(DETP); 50-374/82-11(DETP)
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Docket Nos. 50-373; 50-374 Licenses No. NPF-11, CPPR-100 Licensee: Commonwealth Edison Company
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P. O. Box 767 l
Chicago, IL 6C690 I
Facility Name: La Salle County Station, Unit 1 Inspection At:
La Salle Site, Marseilles, IL Inspection Conducted: August 23 - October 4, 1982
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F. W. Reimann Q./QM9R ury i
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Approved By:
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T st Pro ms Section Inspection Summary Inspection on August 23, - October 4, 1982 (Reports No. 50-373/82-43(DETP);
50-374/82-11(DETP))
i Areas Inspected:
Special inspection to follow up on allegations / concerns regarding construction deficiencies at the La Salle County site. The in-spection involved a total of 295 inspector-hours on site by several NRC inspectors.
Results: Twenty allegations pertaining to Unit 1 operation were addressed in special inspection 50-373/82-35; 50-374/82-06. This report describes allegations, findings and resolutions of items relating to Unit 2 and items that do not have an immediate safety impact. This report also provides followup findings on two items previously addressed in special inspection 50-373/82-35; 50-374/82-06.
8301210242 830107 PDR ADOCK 05000373 G
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SUMMARY AND CONCLUSIONS During May through July 1982, a special inspection was conducted in response to allegations concerning improper construction activities at the LaSalle County Station. These allegations were provided to Region III by telephone
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and in petitions flied by the Attorney General on behalf of the State of Illinois and by Ms. Bridget Little Rorem on behalf of the Illinois Friends of the Earth.
The allegations were grouped into three catagories:
(1) Category 1-Those allegations requiring satisfactory resolution in order to proceed with the
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licensing process of La Salle Unit 1; (2) Category 2-Those allegations that were judged to require a followup on a longer time frame which relate to LaSalle Unit 2, personnel concerns, and activities not having immediate safety impact; and (3) Category 3-Those allegations which range from too general and unsubstanciated to pursue to those which are subject to regula-tory jurisdiction of other agencies, or for which no further action is required by the NRC.
Special inspection report 50-373/82-35; 50-374/82-06 l
addressed the technical resolutions of the Category 1 allegations.
This report addresses the category 2 allegations and also provides followup findings on two category 1 allegations. No significant safety issues were identified during this special inspection. The staff concludes that there are no remaining issues to be reviewed as a result of the allegr.lons received.
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DETAILS Persons Contacted L. O. De1 George, Director of Nuclear Licensing D. L. Shamblin, Construction Project Manager T. E. Quaka, Site QA Superintendent C. Schroder, Nuclear Licensing R. T. Rose, Lead Structural Engineer D. J. Skoza, QA Engineer B. B. Stephenson, Project Manager Sargent and Lundy (S&L)
T. Longlais, Structural Engineering Department Head V. Reklaitis, Structural Project Engineer Walsh Construction Company M. R. Dougherty, QA Manager Background Information In early 1982 the Regional office received allegations regarding construction activities at the La Salle County Station. These allegations were grouped into three categories based on their significance: Category 1-Those matters needing prompt resolution prior to power operation ef Unit 1; Category 2-Those matters judged to require followup, but on a long time frama; and l
Category 3-Those matters which require no further investigative actions by the NRC staff.
On July 19, 1982, Region III issued special inspection report 50-373/82-35; 50-374/82-06 which presented the NRC findings with regard to the Category 1 allegations. This special inspection concluded that there were no remaining issues to preclude increased power level testing of La Salle Unit 1.
The report also stated that the Category 2 items would be considered later.
The items included in Category 2 were matters relating to NRC inspections; architect engineer activities; Unit 2 pipe hanger installations; improper management attitude; equipment damaged during installation; Unit 2 scaffold fire; and Unit 2 basemat pitted.
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In addition to the Category 2 items, subsequent to the issuance on July 19, 1982 of the special inspection report, two issues addressed in that report were raised again. First, four affidavits were submitted to Region III by bricklayers who had previously been employed at the La Salle County Station.
They disagreed with some of the details in the special inspection report and continued to assert that in many cases no mortar was placed in between l
the masonry wall blocks and that reinforcing wire was not used.
Secondly, on August 3, 1982 another affidavit was provided to Region III by GAP re-
garding an alleged 55 gallon.irum in the basemat of the pedestal. The
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alleger raised concerns whether the NRC made s good faith effort to look
'into his allegation.
A special inspection was initiated on August 23, 1982 to review the Category 2 items and to further evaluate the matter of the masonry walls construction y
and the 55 gallon drum embedded in the concrete.
Allegations / Concerns
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This report shows the allegations and the NRC findings for each allegation:
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Inadequate NRC Inspections Allegation: nanagement always knew two days in advance of NRC inspec-tions. The plant was cleaned up superficially. Further, the NRC never took initiatives to talk to workers.
Finding: The NRC inspection program has been carried out at LaSalle by various specialists from the Regional office who periodically visit the site, and additionally, since 1979 by resident inspectors who conduct on going inspections at the site. The two resident inspectors performed inspections a minimum of five days in most weeks, including weekends.
The resident inspectors are on site continuously to monitor site activi-ties, but they do not normally provide advance warning of specific areas to be inspected. The NRC inspection programs for construction, pre-operational testing, and startup activities (the portions implemented at La Salle County Station) provide for both announced and unannounced inspections. As a general NRC policy, inspections are unannounced.
However, in the interest of efficiency and manpower utilization some inspections are announced in advance. Following are cases where in-spections are announced:
(1) the activity addressed by the inspection is so large in scope that it is impossible for the licensee to prepare for or alter the inspection findings; (2) it is necessary for one or more key individuals to be present and available for the inspection activity to proceed; (3) the inspection is conducted in reaction to a specific event or concern which may or may not have been surfaced by the licensee; or (4) the licensee notifies the NRC of the time of a certain activity i
(such as a test) which is required to be witnessed in accordance with the NRC's program.
In cases such as these it is not practical to conduct unannounced inspections.
Of the approximately 331 inspections conducted at La Salle Station since 1976, approximately 228 were unannounced. Many of the announced in-spections were management meetings and program appraisals.
With regard to the contention that the NRC does not talk to workers, the NRC has always maintained a policy of open communications with any-one that comes forth expressing concerns about safety matters. This policy is implemented in many NRC inspection procedures. For example, quality assurance inspection procedures require that as part of the inspection, the inspectors conduct interviews with craft personnel.
In addition, at all NRC licensed facilities, notices are posted informing workers where and how to contact the NRC.
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In regard to the implied concern of station cleanliness, several initiatives resulted from NRC observations and concerns related to poor housekeeping: Five items of noncompliance were issued; top level regional and licensee management met on five occasions when NRC con-cerns were presen'id; and plant cicanliness was identified as an item which could affect the issuance of an operating license in 1981. As a result of the above, the licensee undertook several corrective actions to improve on cleanliness and housekeeping practices.
Conclusion: The prior announcement of NRC inspections at La Salle has been consistent with NRC policy in this area. Also, as part of the inspection program, the NRC inspectors conduct interviews with manage-ment and craft personnel and thus provide opportunity for these individ-uals to talk to the NRC. With regard to housekeeping, the enforcement history indicates that NRC actions were taken to assure that housekeeping levels were sufficient to meet regulatory requirements, and to provide reasonable assurance that poor housekeeping would not interfere with safe station operation.
2.
Communication Problems with the Architect Engineer Allegation? Many of the S&L engineers could not communicate about problems because they could not speak English. There were many legal Mexican aliens at the plant who did not speak English and also did not pay taxes.
Findings:
In discussions with the alleger, no additional specific details were provided regarding this allegation. The NRC inspector reviewed records and interviewed other personnel regarding this matter.
A licensee representative interviewed stated that the La Salle County Station has a program whereby many individuals from foreign national origins are employed at the plant. For example many foreign welders have been employed at the plant through this program and use w.1 ding procedures that had been written in Spanish. The NRC reviewed welding records of these individuals and found that their qualifications met the requirements.
With regard to S&L engineers, the inspector reviewed procedures and
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interviewed licensee personnel to determine if any safety significant issues were not properly resolved due to communication problems. The inspector also interviewed a number of NRC regional inspectors who had conducted inspections at the La Salle site. No problems in this area were identified.
It is noted that the licensee is implementing quality assurance procedures and instructions that require that conditions adverse to quality are promptly identified and corrected.
Conclusion:
It was found that while individuals from foreign national origins are employed at La Salle, no safety problems have resulted from communication problems. No further action is planned.
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3.
Pipe Hanger Installation in Unit 2 Allegation: There were pipe hangers installed in Unit I and the NRC ordered revisions. But Unit 2 is installing the same hangers the old, wrong way.
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Finding: During an NRC Inspection (50-373/81-44) at La Salle County Station conducted in December 1981 and January 1982, it was noted that some Unit 1 snubbers were installed too close to rigid single direc-tional pipe guides and others were analyzed to have small thermal movement. Based on these observations by the NRC, the licensee was requested to further evaluate the snubber design considerations. As a result of this evaluation, actions were implemented to make modi-fications to Unit 1 snubbers in the piping restraint system.
The inspector verified that in early 1982, a Snubber Reduction Program
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was initiated by the licensee to also reduce the snubbers in Unit 2
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by either elimination or replacement with rigid struts. These modifi-cations involved removal of snubbers with small thermal movement, snubbers in subsystems with low operating temperatures and snubbers installed for hydraulic transients which can be deleted due to a more refined analysis.
Three pipe supports on Unit 2 (M09RH53 - 2837, 2832 and M09HP08 - 2830)
were visually inspected to verify that appropriate actions were being taken. No problems were identified. The inspector noted that these pipe supports were replaced with rigid struts because of their low I
thermal movement and a more refined analysis.
A total of about 196 have been eliminated on Unit 2 and about 156 more
are being evaluated for elimination.
Conclusion: The inspector verified that the snubbers installed in Unit 2 have been evaluated and are undergoing replacement or removal in accordance with a Snubber Reduction Program. These activities l
will continue to be inspected in accordance with the routine NRC l
inspection program.
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Heavy Handed Attitude Toward Workers i
Allegation: Management attitude at La Salle was heavy-handed toward workers who raised safety concerns. Management officials harassed workers who spoke out.
Employee morale was very low.
l Finding: The inspectors interviewed the individual who raised these concerns.in his affidavit. He stated that he was not personnally aware of any specific management personnel that were heavy-handed toward workers. His original statement was based on casual conversation with other workers. He also stated that he did not know of any individual who had lost his job for making a complaint about safety.
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The inspectors interviewed several construction workers at the site who stated they were not aware of management harassment toward workers.
Other workers contacted by the NRC refused to provide any information because of fear of reprisal from their management and/or co-workers.
In one case an individual stated that he had been threatened for talking to the NRC about alteration of billing records and other concerns that.
he had. His concerns have been provided to the appropriate authorities for resolution.
In discussion with licensee management personnel, the inspectors were informed that all personnel at La'Salle were notified to inform management about any deficient construction activities that they identify.
Conclusion: Several workers contacted during this inspection discussed their concerns freely with the NRC. On the other hand, several workers declined to discuss their concerns based on their fear of reprisals from management, co-workers and union representatives. No specific cases were identified where management officials had harrassed workers who had spoken out on safety issues.
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Equipment Damaged During Installation Allegation: Equipment was damaged during installation. The equipment damaged was electrical controls and gauges.
Finding: This specific allegation has been thoroughly reviewed and pursued in special inspection report 50-373/82-35; 50-374/82-06. No additional specific instances of damaged equipment were found during this special inspection.
Conclusion: This matter is considered closed. No further action is necessary.
6.
Unit 2 Scaffold Fire Allegation: A scaffold fire occurred in the suppression pool area in 1975 or early 1976.
Finding: On March 6, 1976, a scaffolding fire occurred in the LaSalle Unit 2 suppression pool area. Region III was notified of the fire on the same day. At the time of the fire, other than the downcomers, no safety-related equipment was installed in or above the suppression pool.
The concrete for the reactor support pedestal and the drywell floor above the suppression pool had not been poured at the time of the fire. The inspector discussed this matter with licensee personnel and reviewed the CECO fire report and the Marseilles and Seneca fire department reports.
Interviews with personnel who were actually involved with fighting the fire revealed that it was of a relatively small nature and that it never
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progressed to the point of producing flames.
The wood only smoldered, thus producing great quantities of smoke but not a great amount of heat.
The Fire Chiefs of the Marseilles and Seneca fire departments separately estimated the air temperature at the highest level that they worked at (approximately 12' below the upper steel liner) to be approximately
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i 100' F-110* F.
Per Chapter 6 of the FSAR, the design temperature of the suppression pool is 275' F.
Based upon the statements of the fire depatt-ment personnel and considering the nature of the fire, it is unlikely that the liner temperature from the fire would have exceeded design
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temperatures.
TWo inspectors from Region III had viewed the area in question just after the fire and did not set any significant structural or equipment damage. The inspector also verified by review of Walsh Construction Company records that the concrete above the suppression pool was not i
poured until after the fire (Pour #II 12 on 4/28/76).
Conclusion: A smoldering fire occurred in 1976 as alleged. However, no structural or equipment damage occurred during this fire. No additional followup action is planned.
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Unit 2 Basemat Pitted Allegation: During a coolant system test on Unit 1, water spilled on the floor of Unit 2 and pitted the basemat liner.
Finding:
Pitting of the La Salle Unit 2 suppression pool basemat liner was discovered in late February 1978 as a part of a fillet weld inspection following a stiffner channel modification to the liner. This pitting
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was reported to the NRC by Commonwealth Edison pursuant to 10 CFR 50.55(e)
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in Report 78-01, dated March 6, 1978. Commonwealth Edison determined
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that the pitting in the liner was caused by an electro-chemical reaction resulting from the presence of chlorine rich fire water on the liner.
Documentation indicates that this water was introduced into the suppress-ion pool as a consequence of a scaffolding fire within the suppression pool on March 6, 1976 and not during a coolant system test as alleged.
Although the fire water was pumped out, the residual chlorine and re-maining water interacted to cause the pitting. A complete description of the pitting mechanism and results of the Commonwealth Edison evalua-tion can be found as an enclosure to the letter from L. O. De1 George to J. G. Keppler, dated November 6, 1978.
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On February 28, 1978, an inspection was made of the Unit 1 suppression l
pool stainless steel liners (bottom and sides) for pitting. No evidence of pitting was found anywhere in Unit 1 on the bottom or on the side of the liners or anywhere around the stainless steel concrete encased columns.
After the completion of repairs to the Unit 2 suppression pool liner, the repaired areas were examined visually and by liquid penetrant examination.
The completed repairs to the liner were then examined by a Region III inspector and found satisfactory as reported for Open Item 374/78-XX-03 in Inspection Report 50-374/80-15. Final verification of the integrity of the liner will be made during the Containment Integrated Leak Rate Testing performed per PT-PC-201.
To prevent the recurrence of the mechanism resulting in the pitting in the Unit 2 pool liner, La Salle has established a policy that all construction fire extinguishing material, including water containing I
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chlorides, will be promptly removed should they come in contact with type 304 stainless steel plates or tanks. This preventive action was implemented on both La Salle Units 1 and 2, as committed to in a letter from L. O. De1 George to J. G. Keppler, dated November 11, 1978.
Conclusion: No further action regarding this matter is planned.
8.
SS-Gallon Drum in Containment Concrete Allegation: A 55 gallon drum was left embedded in the concrete at La Salle Nuclear Station.
Finding: This allegation was addressed in NRC special inspection report No. 50-373/82-35; 50-374/82-06.
Initially, the alleger believed a barrel was embedded in Unit 1 concrete. As described in the report, no evidence could be developed to substantiate the allegation. During subsequent interviews with the alleger, he stated he was not sure of the specific
location of the barrel but that it is possible that the barrel may be outside the Unit 1 area.
On August 24 through 27, 1982, the Region III inspector reviewed labor and payroll records and concrete pour records in cross referencing specific information obtained from the alleger. The individual speci-fied the Walsh Construction Compaay General Foreman who supervised pre pour cleanup and indicated that he remembered for sure it was a concrete slab with at least a 20 foot span. The General Foreman named worked from November 11, 1975 to June 16, 1976 at La Salle. The in-dividual who brougnt forth the allegations was terminated in the winter of 1975-1976. Walsh records were cross checked to identify all concrete pours made during the time that the individual and the General Foreman were both employed. A total of 76 pours were accomplished during this period.
Screening these records revealed that one pour was placed in a shored slab with dimensions which could possibly accomodate a 24 inch diameter by 36 inch 55 gallon drum. The slab is located in the Unit 2 Reactor Building, above floor elevation 710'6", between column lines 16-17.2 and G-6.6' west of H.
The cubicle beneath the slab con-tains drywell drain equipment including a vertical heat exchanger with drain water entering and leaving at the top.
The slab is 36" thick with grids of No. 6 horizontal reinforcing bars at 12" centers in both directions near the top and bottom faces.
The licensee responded to an NRC request to perform an engineering assessment of the slab postulating an embedded drum. Assessment of the slab was accomplished for load stresses and radiation safety margins considering an empty 55 gallon drum (24 inches diameter and 36 inches long) situated at any location in the roof slab.
Load stress computa-tions were accomplished using the ultimate strength design method.
Minimum safety margins of 2.0 in flexure and 2.2 in shear were deter-mined (actual moment = 33.76 ft. kips, moment capacity = 67.9 ft. kips and actual shear stress = 57 psi, allowable shear stress = 126 psi respectively).
In the radiation assessment, the heat exchange piping was assumed to be 2" schedule 40 and the source is 100% reactor water
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decayed for 90 seconds. The analysis indicates that considering 12" of concrete being effective, the actual dose rate above the roof will be less than 4mr/hr. This is within the permissible initial design dose rate of 5.0 mr/hr.
Conclusion: One area was found which met all the varying conditions such as the size of the slab, the individuals involved and the time the slab was poured. The 36" roof slab of the cubicle at elevation 723' 0" is capable of carrying design loads and effecting radiation shielding with adequate safety margins even if a 24" diameter by 36" long drum is located
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In the most critical position in the slab.
In view of the above, no
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a/ditional followup action is planned to determine whether or not such a drum actually exists in that location.
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Improper Masonry Wall Construction and Mortar Quality Allegation: High density walls were constructed with insufficient amount of mortar between the blocks. Also, in many cases the rein-forcing wire was not installed.
In addition, the mortar was not properly proportioned.
Finding:
Since the date of issuance of Special Inspection Report 50-373/82-35; 50/374/82-06, four additional affidavits have been re-
ceived from bricklayers previously employed at the La Salle Plant, who alleged that the workmanship of masonry walls was poor, mortar was
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sandy, the joints were not filled with mortar and the reinforcing wire
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was omitted in the joints. To discuss the additional affidavits, a meeting was held at the Ramada Inn in Ottawa, Illinois, on August 11, 1982.
In addition to the NRC, those in attendance were representatives of the Government Accountability Project (GAP), Illinois Friends of the Earth and two of the former bricklayers who filed the affidavits. As a result of the meeting, it was agreed, in view of the new affidavits, to follow up on the original allegations by taking the following actions:
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Additional review of samples taken during construction as well as those cored from the walls after they had been constructed.
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Taking additional sworn statements from personnel involved in masonry wall construction.
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More in-depth review of the overall QA/QC programs which were im-plemented during construction of the walls.
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Further review of the licensee's response to Bulletin 80-11 which
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related to the identification and evaluation of masonry walls whose failure could affect a safety-related system.
Inspection of the walls for visible indications of poor workmanship e.
such as bulges.
The above activities were conducted between August 23 and September 13, 1982.
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a.
Inspection of Testing of In Progress and As-built Samples The following documents pertaining to testing of sa:aples taken from masonry walls have been obtained from A&H Engineering Company and reviewed by the inspectors.
Reports D-121-1-7 and 35 pertaining to the test performed on
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receipt of the blocks on site.
Reports of all of the tests performed on the cored samples
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taken from as-built walls (Reports D-117-1-1 through D-117-1-26)
with the drawings indicating location of the cores.
A sample of the test performed on fresh mortar during con-
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struction, Report D-122-1-113.
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Findings:
Tests Performed During Construction of the Wall (1) Masonry Blocks
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Reports D-121-1-7 and D-121-1-35 and information obtained from the constructor's personnel at the site indicate that
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the masonry blocks were tested upon arrival at the site at a frequency of one in 25,000 blocks received. The reasons for this apparently low frequency of testing were as follows:
(a) At the time of the construction of the block walls, they were not classified as Category 1 structures.
(b) The blocks were tested by the manufacturer, Illinois Brick Company, Broadview, Illinois, and upon arrival of the material at the site the contractor received a certificate stating that the blocks met the Spet i#tcation ASTM C-145
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in accordance with job specification do. J 2598.
The tests were performed by the A&H Engineering Company and consisted of checking compressive strength, density and moisture content. Report D-121-1-7 covers tests on three specimens which
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were tested for density and moisture content. Report D-121-1-35 refers to four specimens, two of which were tested for density and moisture content and the other two for compressive strength.
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Report D-121-1-7 states that the density for the three specimens tested varied from 143.7 to 146.4 pounds per cubic foot, and the i
moisture content varied between 0.6 and 0.7 percent. The accept-i able limits are 140-150 pounds per cubic foot and up to 30 per-cent for the density and moisture, respectively. Report D-121-1-35 indicates that the compressive strength of the two specimc..s tested was 5060 and 5620 psi (with the minimum speci-fied of 2500 psi), the density of another specimen was 142.4
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I and 147.5 pounds per cubic foot and the moisture content was 1.0 and 1.8 percent. The acceptable values, again, are 140 to 150 pounds per cubic foot for density and up to 30 percent for the moisture content.
(2) Testing of the Mortar The reports pertaining to testing of mortar during construc-tion, such as Report D-122-1-113, have been reviewed. The mortar used was type M, the specified compressive strength as per ASTM specifications was 2,500 psi at 28 days and fre-quency of testing was one test per 5,000 blocks laid, according to specification No. J-2592.
The compressive strength of
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sample No. 113, as evidenced on Report D-122-1-113, was 2010, 2384 and 2970 psi at 7, 14 and 28 days respectively, which
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exceed the minimum specified value. All other sampics for which reports were reviewed indicated that the samples exceeded the minimum specified values.
(3) Tests Performed on Constructed Walls During initial construction, many masonry walls were not con-sidered safety related. NRC Bulletin 80-11 required that all masonry walls in the vicinity of safety-related equipment or i
having safety-related equipment attached to them be classified as safety related, and required that additional tests be per-formed on these walls. The tests were in compliance with
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Sargent & Lundy Specification J-2592, which calls for a test frequency of one test for each 5,000 square feet of wall area and refer to the appropriate ASTM specifications. The reports pertaining to testing of the cored samples taken from the walls indicate that there have been 75 tests performed. Of the 75 samples, 5 failed initially and have been repeated. The addi-
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tional samples were takan generally in the.same area as the i
original samples. The failure of samples was attributed to the fact that when cutting of 2" x 2" cubes frca the cores, the surface area was not exactly flat and the load was not uniformly applied over the entire area. All of the additional samples tested, met the requirements of the ASTM specification. A total of 96 tests were performed.
In view of the documents provided to the inspectors it appears
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that the testing of the material during construction and on I
as-built conditions of the wall was performed in compliance with appropriate job specification.
b.
Additional Statements from the Former Employees
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In view of the additional affidavits and as a result of the meeting j
in Ottawa, Illinois on August 11, 1982, the NRC staff decided that it would be appropriate to take statements from more individuals regarding the quality of work in the masonry walls.
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.i In nrder to fulfill this task sworn statements were taken from a number of individuals that were forme:ly employed on construction of the masonry walls and that have first hand knowledge of quality
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control and workmanship exercised during construction. These statements were taken by the NRC and are voluntary and confidential.
Findings:
(1) The statement from the QC Supervisor taken previously had been summarized in special report No. 50-373/83-35(DETP).
During a subsequent interview taken under oath, he repeated
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again that to the best of his knowledge the quality control of the mortar and of workmanship exercised in the construction of the masonry walls was in compliance with the quality assur-ance manual. He stated that he is not aware of quality of mortar not meeting the specifications and he does not have any knowledge of anyone being told to continue to work without the proper material.
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(2) Two former employees of V. S. Wallgren Company, who were responsible for mixing the mortar used in construction of the walls were interviewed. Both of them testified that they do not have any knowledge of anyone being told to rush on with the job at the expense of quality of workmanship.
They mixed mortar in accordance with the instructions, i.e.,
3 bags of cement per 45 to 48 shovels of sand.
(8-9 shovels of sand, depending on size, corresponds to one cubic foot.)
Their supervisors were constantly observing their work and they never put out any shoddy mortar mix.
(3) An employee of A&H Engineering Company, who was responible for testing samples taken either during construction (mortar and masonry block units) and after the walls have been erected provided a statement to the NRC. His testimony confirmed the information previously obtained either by review of the test reports or by discussion of test procedures with personnel on the site. He stated that during construction fresh mortar was tested at a frequency of one test per 5,000 blocks laid, which was according to specifications and the high density blocks were tested at a frequency of one block per 25,000.
Two blocks were selected at random for each test and one of them was tested for density and absorption and the other for its compressive strength. He confirmed what the inspectors found in the records, regarding samples of the existing walls in response to IE Bulletin 80-11.
He also stated that he was responsible for all laboratory records and to the best of his knowledge they are accurate and reflect the actual test data.
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(4) Three additional former bricklayers who worked on contruction
of masonry walls were interviewed.
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They all testified that the quality of workmanship and material was good and there was no pressure applied by management to rush on with the job at the expense of quality. The material used was of good quality and there was no evidence of sandy mortar. When material was not available the work was stopped and not resumed until the new. shipment was on site.
They stated they were not aware of sandy mortar, lack of reinforc-ing in the joints and masonry blocks laid one on the top of the other without mortar between them in order to expedite the work or because of unavailability of mortar.
The statements obtained from various individuals involved in con-struction of the walls provided the inspectors with a wide spectrum of information which ranged from definitely negative to those in which there was no knowledge of any deficiencies.
In view of such a broad variety of statements an evaluation of the actual conditions was made.
In this regard the staff performed additional tasks and inspections such as evaluation of the walls on the bacis of the actual conditions. This evaluation was performed as an extension of the staff's review of response to IE Bulletin 80-11 and is des-cribed in more detail in Section d. of this report. Results from this and other affidavits helped to formulate the final conclusion which is stated at the end of this report.
c.
Inspection of the Overall QA/QC Programs during Construction of Masonry Walls The following documents were reviewed within the scope of verifying the QA/QC programs pertinent to masonry wall construction:
(1)
Illinois Brick Company, Invoice No. J7482 (2)
V. S. Wallgren QA Manual (3) Walsh Construction Company, letter dated 2/5/79 approving V. S. Wallgren QA Manual (4)
V. S. Wallgren Masonry Check lists dated 5/7/79, 5/8/79 and 5/31/79.
(5) Walsh Construction Company Masonry Check lists dated 12/?4/79, 1/18/80, 5/15/80, 7/24/80, 9/4/89 and 1/21/81.
(6) Walsh Constructica Company Quality Control Procedure, No. QCP-18, dated July 25, 1979.
Findings:
The masonry blocks used in construction of the walls at the La Salle Station were manufactured by the Illinois Brick Company of Broadview, Illinois. The invoice (item (1)) contains a signed statement that the material meets the specification ASTM-C145 in conformance with the requirements of Specification No. J-2598.
The inspectors have been informed that since then the company has been sold out and that all records other than those pertaining to taxes have been destroyed.
The QA Manual of V. S. Wallgren (item (2)) was retiewed and approved by the Walsh Construction Company, by letter dated February 2, 1979 (item (3)).
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o The Manual describes the Quality Assurance Program which is designed to comply with the requirements of 10 CFR 50, Appendix B and ANSI N45.2.1577, " Quality Assurance Program Requirements for Nuclear Plants." In accordance with the QA provisions of the manual, all of the masonry walls built after the date of the approval of the manual, February 5, 1979, have been built in compliance with quality assurance requirements stated in 10 CFR 50, Appendix B.
The QC of the walls during construction was checked according to the check lists by V. S. Wallgren and Walsh Construction Companies (items (4) and (5)) respectively. After V. S. Wallgren completed the job, QC was implemented by the Walsh Construction Company according to the Quality Control Procedure No. QCP-18 (item (6)).
Review of the QA/QC procedures based on the documents listed above reveals that quality assurance and quality control provided at the La Salle Station on the masonry walls was adequate.
d.
Further Review of the Licensee's Response to Bulletin 80-11 In response to the IE Bulletin 80-11, the licensee informed the NRC that the necessary reassessment evaluation was performed on the La Salle masonry wall design. Furthermore, upon review of the submittals by the licensee, the staff concluded that the require-ments for addressing IE Bulletin 80-11 have been fulfilled.
(See SER Supplement #2, dated February 1982, Section 3.8.3)
In view of the allegations made by the workers employed in con-struction of the walls the staff embarked on an extensive investi-gation of the as-built condition of the walls. As a result of the meeting between the NRC staff and representatives of Public Interest groups in Ottawa, Illinois, on August 11, 1982, the li-censee was requested to inform the NRC when, due to modifications, any additional holes would be cored. This would provide the NRC an opportunity to inspect the wall for voids and mortar quality.
Shortly thereaf ter, the staff was notified that a large section of a masonry wall had been exposed in Reactor Building Unit 2.
On August 24, 1982, a visual inspection was made of this section of wall.
Present during this inspection were the NRC, a former brick-layer, 2nd a representative of GAP. The section of the wall was 32 l
inches wide, 19 inches deep and 18 feet, 6 inches high.
In the lower section a complete opening,'approximately 3 feet square, was made through the wall. The opening thus allowed the staff to examine a large section of the wall for voids, reinforcement and mortar quality.
The wall, located at floor elevation 710' 6" on line 16 and between column lines A and C, was used in the investigation as a representa-tive sample of all of the masonry walls in the plant. The records pertaining to the quality control during construction as well as those pertaining to the testing of samples taken from the wall after it had been constructed were examined. Records showed that the wall was built in May 1980. The Masonry Construction Checklist showed
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that materials used complied with the requirements. After comple-tion of construction, cores were taken from the wall and tested (A&H Report D-117-12 dated April 28, 1982). Two samples were taken in that particular wall (Samples #22W and #24W).
Both of them ex-ceeded the minimum specified compressive strength of 2500 psi by a substantial amount (4050 psi in case of Sample #22W and 3665 psi in case of sample #24W).
In one instance where the first sample failed to meet the required compressive strength (e.g., the wall in reactor building, Unit 2, elevation 710' 6" on coln=n line C between lines'15 and 16),
additional samples were taken: #15W which met the requirement at 3585 psi and #10W which failed to reach the specified compressive strength of 2500 psi (A&H Report D-117-12).
Two additional samples
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were cored from the wall and tested, namely #10W-A and #10W-B.
Of these two, one failed at 2160 psi and the compressive strength of the other was found to be 3200 psi. The basis for the acceptance
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of the failed sample was ACI-318-77 paragraphs 4.8.1.1 and 4.8.4.4.
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Paragraph 4.8.1.1 stipulates that for evaluation and acceptance l
of concrete, the frequency of testing should be not less than once for each 5000 square feet of surface area for slabs and walls.
Paragraph 4.8.4.4 states that the concrete in an area represented by core tests is considered structurally adequate if the average
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of three cores is equal to at least 85 percent of f'c (the speci-fled compressive strength, psi) and if no single core is less than 75 percent of f'c.
It should be noted that the ACI-318-77 standard
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is for reinforced concrete structures, but has been used as a basis for evaluation of the subject masonry walls.
Since the test results show that the average of the three samples exceed 85 percent of the minimum specified compressive strength (2125 psi vs 2500 psi) and the lowest of the three samples tested was 2160 psi which is higher than 75 percent of the specified strength (.75 x 2500 = 1875 psi) the inspectors concluded that the results of the tests are acceptable.
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Upon examination of the exposed joints it was found that the quality of the mortar appeared to be acceptable, and reinforcing wire was present, in accordance with the drawings. However, some voids were present in the wall.
It should be noted that the design of the masonry walls at La Salle did not specify reinforcing wire and thus the reinforcing wire was not considered in the analysis (Information No. 5, enclosure to Commonwealth Edison letter to NRR dated July 8, 1980). However, during the inspection it was noted that the construction drawings
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for the masonry walls required the use of truss type, 3/16 inch diameter side rods and No. 9 cross ties for reinforcement, thus providing additional strength to the walls. These design assump-tions give additional confidence that the analysis was performed on the basis of considerable conservatism. The inspectors verified that this type of reinforcing was installed in the masonry walls observed at La Salle.
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In view of the presence of voids, the inspectors decided that their impact on design considerations should be reassessed.
In this
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regard a meeting was held on August 30, 1982 with the licensee and his A&E, Sargent & Lundy, (S&L) at the S&L Office in Chicago. The licensee was requested to consider the impact of the observed voids on the design of the walls, as follows:
(1) Evaluate the percentage of observed voiding of mortar as com-pared to design requirements.
(2) Perform an analysis of the walls based on moment of inertia considering presence of the voids.
(3) Submit for review, where applicable, an analysis based on the modeling technique for a cracked section of the wall.
(4) Submit for review an analysis of walls spanning vertically, allowing for the voids.
(5) Evaluate the effects of voids, for walls spanning horizontally, l
on allowable stress parallel to the joints.
A follow-up meeting was held with the licensee and his A&E on
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September 13, 1982, in Chicago to discuss the items agreed on at
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the meeting of August 30, 1982. During this meeting the licensee was requested to:
(1) Determine, for the wall which had been exposed, the amount of voids, as a percentage of mortar completely filling the joints, which could be tolerated allowing 10% overstress over the allowable.
(2) Evaluate the impact of the condition stated in (1) above on:
(a) The criteria to which the licensee has committed himself to in the project.
(b) The NRC criteria for masonry walls contained in Appendix A of the Standard Review Plan, Section 3.8.4, Revision 1, dated July 1981.
On October 4, 1982, the licensee submitted the attached evaluation of the masonry walls design for La Salle based on the voids observed in these walls. The methodology of the analysis was reviewed and found acceptable. The licensee will formally submit a revised response to IE.Bulletin 80-11 which will include their consideration of voids in the masonary walls.
e.
Tour of the Plant to Identify Bulges in the Walls In view of the specific allegations that in many of the masonry walls mortar was omitted altogether and that in some of the joints
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the amount or mortar was excessive, thus resulting in visible deformations (bulges), on September 2, 1982, a comprehensive tour was made by the inspectors in search of such deformations. The tour encompassed pratica11y all safety relate? areas in botn units which wnre accessible. No bulges were observed.
The allegation that some of the walls are bulging due to nonuniform amount of mortar in the joints was not substantiated.
Overall Conclusions and Assessment of Structural Integrity of the Walls:
The staff reviewed all available records of testing, during construction
and of as-built conditions; took statements from former employees having first hand knowledge of workmanship and quality control during construc-tion; toured through the plant in search of visible deformations and bulging; reviewed records pertaining to the fabrication of the masonry units; surveyed voids found in a large exposed section of the wall; and reviewed the analytical reassessment of structural integrity of one wall which was used as a representative sample illustrating typical situation of any masonry wall in the plant. On the basis of the findings resulting from the above investigation, it can be concluded that:
The quality assurance procedures have been found acceptable and
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l records were kept in an orderly fashion.
The tests were performed on mortar and masonry units in accordance
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with appropriate ASTM specifications and the results were found acceptable.
Both negative and positive statements were made by workers inter-
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viewed regarding the quality of the masonry walls at La Salle.
However, records, observations and evaluations, when taken together indicate that the walls were constructed to meet the design require-ments.
The tour through the plant did not reveal any irregularities,
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deformations or bulges.
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The local voids observed in the large section of the wall have been
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surveyed and reanalyzed on the basis of actual conditions.
Based on this reanalysis of masonry walls at La Salle submitted by the li-censee, the observed voids will not impair the structural strength or integrity of the walls.
As stated above, the NRC staff reviewed records, interviewed personnel, evaluated the methodology of the analysis of the masonry walls and
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toured the plant. While local voiding was confirmed in masonry walls at La Salle, the analysis conducted shows that this will not prevent the masonry walls from performing their design function. One allega-tion of inadequate construction in a non safety-related masonry wall in Unit 2 turbine building was investigated. The sample taken from this wall verified that it had been constructed in accordance with specifica-tions. Other allegations of deficient walls relating to the turbine l
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and radwaste buildings were not investigated since they are non safety-related. The NRC staff concludes that based on the above, the masonry walls at La Salle Station meet the applicable design specifications.
No additional followup inspections are planned.
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