IR 05000423/1979006
| ML19256E113 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/11/1979 |
| From: | Ebneter S, Varela A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML19256E109 | List: |
| References | |
| 50-423-79-06, 50-423-79-6, NUDOCS 7910290058 | |
| Download: ML19256E113 (7) | |
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.U.S. NUC'. EAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT Region I Report No.
50-423/79-06 Docket No.
50-423 License No.
CPPR-113 Priority Category A
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Licensee:
Northeast Nuclear Energy Company P.O. Box 270 Hartford, Connecticut 06101 Facility Name:
Millstone Nuclear Power Station, Unit No. 3 Inspection at:
Millstone Unit 3, Waterford, Connecticut Inspection conduct d:
u 10- 3, 1979 S b 4 M71 Inspectors:
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P W '%.~Varela, Reactor Inspector date signed date signed
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date signed Approved by:
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U. tbnetgrf, Chief, Engineering Support
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date signed Section No'. 2, RC&ES Branch Inspection Summary:
Inspection on July 10-13. 1979 (Report No. 50-423/79-06)
Areas Inspected:
Routine, unannounced inspection by a regional based inspec-tor of quality verification records in qualifying new concrete mixes, unifor-mity of the concrete central mixer and truck mixers, and qualifications of reinforcing steel-cadweld splicers.
The inspector also observed work perfor-mance in cadweld splicing and testing and concrete mixing, placing and testing.
The inspector performed a site tour inspection and reviewed licensee action on previous inspection findings.
The inspection involved 26 inspector-hours onsite by one NRC regional based inspector.
Results:
No items of noncompliance were identified.
M/
326 Region I Form 12 (Rev. April 77)
7 9102 900 SF
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DETAILS 1.
Persons Contacted Northeast Utilities Service Company
- T. W. Deshefy, Resident Civil Engineer
- K. W. Gray, Supervisor-Construction Quality Assurance
- R. A. Hastings, Construction Quality Assurance J. O'Brien, Construction Quality Assurance Specialist
- S. R. Toth, System Superintendent / Generation Construction Stone and Webster Engineering Corporation
- W. B. Anderson, Assistant Superintendent Field Quality Control
- L. J. Barberie, Senior Field Quality Control Engineer
- P. A. Gagel, Project Quality Assurance - Boston Office D. Huntley, Construction Area Engineer
- R. H. Lane, Superintendent of Construction J. Lazorchak, Quality Control Batch Plant
- C. A. Marrs, Superintendent of Construction
- W. Mackay, Resident Manager J. Shirley, Concrete Construction Supervisor
- F. K. Sullivan, Hesident Engineer
- J. L. Whedbee, Assistant Superintendent Field Quality Control
- Denotes those present at the exit interview.
In addition the inspector interviewed.other licensee and contractor personnel during the course of inspection, including construction crafts.
2.
Site Tour The inspector conducted a walk-through inspection of the construction site on the afternoon,of April 10 to observe work in progress.
A concrete placement for the containment building was starting.
The inspector was informed this was the first exterior wall pour made this year and used recently approved new concrete mixes.
Therefore, the inspector delayed completion of the site tour to observe implementation of quality controls in mixing, transporting and placing of this concrete.
On the following day resumption of the walk-through inspection disclosed concrete preplace-ment activities of rebar installation and cadwelding for the containment exterior and interior walls, preparations for other concrete placements of the engineering safety features slab and of the basemat for the reserve water storage tank, and off-stand assembly of the containment dome liner.
Work activities involving about 500 craft personnel were noted for any
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obvious defects or noncompliance with regulatory requirements.
The inspec-tor also visited and reviewed activities in the site concrete and steel testing laboratory and the concrete central mixing plant and aggregate storage areas.
Observations were made of Quality Control activities and evidence of quality control in safety-related work areas.
No items of noncompliance were identified.
3.
Review of Prequalifying Records of New Concrete Mixes and of Concrete Mixing Facilities at Site The inspector reviewed laboratory records (Pittsburgh Testing Laboratory Reports #78035-78039) prequalifying coarse aggregate from the Wallingford quarry for new concrete mixes required by ASTM C-33 including the follow-ing related standards identified in specification #282 for design of concrete mixes:
ASTM C-136 Gradation C-117 Wash Loss C-142 Clay Lumps C-123 Coal and Lignite C-29 Unit Weight C-88 Soundness C-127 Specific Gravity and Absorption C-131 Los Angeles Abrasion C-227 Alkali Reactivity (Chemical)
C-289 Alkali Reactivity (Mortar Bar)
C-295 Petrographic Analysis Qualification records were also reviewed of three production tested con-crete mixes designed for safety related work.
Ten cubic yard batches were pr1duced at the site central mixer using the above coarse aggre-gate, (other concrete ingredients were those previously used).
Compres-sive strength test cylinders broken at 7, 14, 28 and 60 days were found acceptable.
Engineering approval dated March 28, 1979 was observed to identify 13 concrete mixes, their ingredient weights per cubic yard, strength designation, usage for each mix, and slump, air and temperature requirements.
Records of the batch plant central mixer and mixing trucks for conformance to ACI 301 Section 7.1/NRMCA-ASTM C94 requirements on uniformity of con-crete mixes were reviewed.
S&W inspection reports, IR #S-9000547, -579,
-611 and -744 dated April 9-19, 1979 show satisfactory uniformity in the l97/
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prescribed six properties for concrete tested at 15 and 85% of the batches.
No items of noncompliance were identified.
4.
Review of Cadwell Splicer Qualification Records The inspector reviewed qualification records of iron workers engaged in cadwell splicing of reinforcing steel for safety related structures.
Records of eleven current cadwelders were evaluated to verify u nformance to criteria identified in job specification C-999, Placing Conccete and Reinforcing Steel, Quality Standard 9.11 and Quality Assurance lirective 9.1.
The following records evidenced satisfactory implementation of quality controls for qualification of operators number 28, 63, 64, 67, 70, 82, 85, 86, 87, 88 and 90:
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Qualification keport Cadwell Production Summary
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Cadwell Production Test Cycles
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No items of noncompliance were identified.
5.
Observation of Work Performance and Quality Controls in Cadwelding The inspector observed reinforcing steel installation and cadwelding of vertical and diagonal rebue number 18 for the containment exterior wall and the interior of containment crane wall.
Diagonal cadwelds number 15895 and 16377 were observed prepared, assembled and shot by operator #67 on the exterior wall at about elevation 14 between azimuth 95 and 105 and
- 15816 vertical at elevation 52, azimuth 150.
These essential items required by job specification C-999 and Erico publication RB 10M 974 were observed accomplished.
ends of rebars reference marked, cleaned, gapped and preheated
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cadwell sleeve centered on rebar gap, lifted from rebar and preheated ceramic fiber packing material installed and fittings placed over
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rebar at sleeve ends
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tap hole guide tube, cer6.Jic insert and pouring basin placed in position
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preparation of crucible and clamps on basin after cleaning and
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heating of graphite to remove moisture cadwell filter metal cartridge remixed and poured in crucible over
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ceramic insert and steel disc followed by starting powder safety preparation prior to and ignition of powder - (The inspector
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observed appurent spillage of molten metal at junction of crucible and pouring bat.n on splice #15895.
This was attributed to excess wear of the equipment.
Inspection by QC found slag in tap hole extending into id of sleeve and rejected this splice.
The splice was cut-out and replaced by two other cadweld splices.
Investiga-tion undertaken by licensee of the cut-out splice disclosed in longitudinal slice of the sectioned splice #15895 that slag at tap hole did not extend into the annulus.)
The inspector also observed laboratory testing of cadwell splices for tensile strength.
Cadwelder qualification tests and production cut-out samples were observed tested by qualified personnel using calibrated equipment.
Number 18 vertical cadweld splices T-15965 and 15966 were observed to qualify cadwelder #86.
The rebar is 50 ksi yield, 70 ksi ultimate supported 85 ksi minimum prior to bar pull out and break in the respective splices.
Production splice T-16058 made by cadwelder #88 supported 88.5 ksi prior to bar break within the sleeve.
These splices reflect qualification and quality verification of work accomplished according to criteria identified in regulatory guide 1.10.
No items of noncompliance were identified.
6.
Observation of Work Performance and Quality Controls in Structural Concrete The inspector observed work being performed and quality verification of work accomplished in structural concrete placement on three separate days during his presence on the site.
Containment exterior wall pour #C-3241 involved 180 c.y of 3,000 psi-60 day pump mix #302, 425.cy pour #C-3238 for the reserve water storage tank basemat/ pump mix 302, and the engineer-ing safety features slab at elevation 4.6, pour #C3242, which also used pump mix 302 designated for mass concrete.
The inspector determined work was accomplished according to applicable specifications, codes, standards, NRC requirements and SAR commitments.
The inspector verified that activi-ties were accomplished according to criteria identified in the following:
Millstone Nuclear Power Station Unit 3 PSAR Chapter 3 and its
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referenced codes, standards and PSAR Chapter 17 M/
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Job Specification #C-999, Placing Concrete and Reinforcing Steel,
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Revision 1, Addendum C, August 7, 1978 and E&DCRs #FS-2123, April 16, 1979 and #FS-2216, June 13, 1979 Job Specification #C-281, Mixing and Delivering Concrete
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S&W QADs 10.2, 11.2; QSs 10.12, 11.11
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The inspector observed construction supervision and engineering person-nel directing work activities, and quality control personnel inspecting, testing, and providing quality verification of these activities:
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Preplacement Preparation and Inspection Report:
checkout cara signed off by crait supervisors and responsible field engineer indicating forms properly secured, tight and clean; rebar properly placed, secured, free of nonbonded concrete, excessive rust scale and proper form distance; construction joint adequately prepared and cleaned; release of pour by area engineer and approval by Quality Cont ol completed prior to placement.
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Delivery and Placement:
proper mix specified, central mixed and truck delivered; properly controlled concrete remixing in truck vhen approved water was added at truck discharge; pumped thru steel pipe; controlled prior to pumping for slump, air and temperature; correlation testing at end of pump line and truck discharge, and casting of cylinders for compressive strength by qualified person-nel using calibrated equipment at prescribed frequency; controlled drop of concrete thru rebar; concrete liquefaction, horizontal movement and densification of concrete adequately controlled; ade-quate crew and equipment applied with coordination directed by field engineering supervision.
Batch Plant Operation:
accuracy of material and temperature con-
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trol; generation and control of batch records-truck tickets; QC inspection for frequency and scope, using qualified inspectors and Quality Control personnel.
Aggregate and Cement Storage:
cement bulk storage provided adequate
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protection relative to moisture and storage time does not exceed requirements; aggregate stored in bins wiihout segregation; inspec-tion of concrete materials prior to usage; aggregate in process sampled and tested.
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Construction Joint Preparation and Curing:
containment exterior
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wall was rugasol treated, air-water jetted after initial set to remove surface mortar and expose aggregate; moist curing prescribed for seven days.
No items of noncompliance were identified.
7.
License Action Regarding Previous Inspection Findings (Closed) Unresolved Item (423/78-06-01):
Engineering action taken to provide a 42 square foot window, in the ring girder surrounding the con-tainment building, for crack pattern mapping during the structural inte-grity test was reviewed.
A new engineering drawing EC-49X-6 was observed to provide a 6 x 7 window at the top of basemat through the ring girder in the engineering safety features area.
This satisfies the requirement of regulatory guide 1.18.
8.
Management Exit Interview At the conclusion of the inspection on July 13, 1979, a meeting was held at the Millstone 3 site with representatives of the licensee and engineer-constructor organization.
Attendees at this meeting included personnel whose names are indicated by notation (*) in Paragraph 1.
The inspector summarized the results of the inspection as described in this report.
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