IR 05000566/1981005
| ML20004B243 | |
| Person / Time | |
|---|---|
| Site: | Yellow Creek  |
| Issue date: | 05/07/1981 |
| From: | Conlon T, Harris J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20004B236 | List: |
| References | |
| 50-566-81-05, 50-566-81-5, 50-567-81-05, 50-567-81-5, NUDOCS 8105270438 | |
| Download: ML20004B243 (7) | |
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NUCLEAR REGULATORY COMMISSION j
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101 MARIETTA ST,, N.W., SUITE 3100 T
ATLANT4, GEORGIA 30303
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Report Nos. 50-566/81-05 and 50-567/81-05 Licensee: Tennessee Valley Authority 500A Chestnut Street
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Chattanooga, TN 37401 Facility Name: Yellow Creek Docket Nos. 50-566 and 50-567
License Nos. CPPR-172 and CPPR-173 Inspection at Yellow Creek Site near luka, Mississippi Inspector:
/1 k IrttA 8/ 7/N d. R. Harris Mte
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Approved 7 S' 7-f/
T. E. Conlon, Section Chief. EI Branch Date Division of Engineering and Technical Inspection
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SumARY Inspection on April 21-24, 1981 Areas Inspected This routine, unannounced inspection involved 31 inspector-hours onsite in the areas of structural concrete, foundations and previously identified items.
Resul ts
Of the three areas inspected, no items of noncompliance or deviations were identified.
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DETAILS 1.
Persons Contacted Licensee Employees
- L. S. Cox, Construction Manager
- C. G. Wages, Assistant Construction Engineer, QC
- R. G. Delay, Supervisor Materials and Civil QC Unit
- C. E. Hale, Assistant Construction Engineer, Engineering Support
- M. Harris, Civil QC Engineer
- J. N. Holladay, Supervisor, QA Unit
- C. A. Bursheats, Geologist
- J. Hunt, Civil QC Engineer
- N. Lizzo, Licensing Engineer
- G. Felpel, Civil Engineer, CEB, Knoxville
- D. Terril, Licensing Engineer Other.icensee employees contacted included three construction craftsmen, two technicians and three office personnel.
- Attended exit interview
- Telecon April 28, 1981 2.
Exit Interview
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The inspection scope and findings were summarized on April 24, 1981 with those persons indicated in Paragraph 1 above.
3.
Licensee Action on Previous Inspection Findings a.
(Closed) Infraction 50-566/80-14-01 and 50-567/80-14-01:
" Evaluation of Concrete Test Cylinders". No documentation was available to show that concrete test cylinders which broke below specified strengths were being tracked and evaluated.
The inspector examined the licensee's response dated October 21, 1980 and implementation of that response. QCIR 51057 was written and an evaluation of concrete test cylinders which broke below specified strengths was performed by the Yellow Creek materials engineer. The evaluation showed that the design strengtns would be realized at a later than design age but before the concrete is subjected to design stresses.
Procedure QCI 209 has been revised to clarify the requirement for tracking and evaluating test cylinder data and for writing of QCIRs on test cylinder breaks below required strengths.
This item is closed.
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(Closed) Unresolved Item 50-566/80-07-02 and 50-567/80-07-02:
" Concrete Controls".
The licensee did not appear to have a system for tracking the time interval between mixing and placing of concrete.
Examination of controls of concrete placement number RI-1-El showed that the licensee has instituted a more precise method of tracking the time interval between the mixing and placing of concrete. This item is closed.
4.
Unresolved Items Unresolved items were not identified during this inspection.
5.
Independent Inspection The inspector examined ongoing and completed work on foundations, structural concrete and structural steel in the unit one powerblock and intake pumping station and canal.
No violations or deviations were identified.
6.
Containment (Structural Concrete II) - Observation of Work and Work Activities, Unf t 1 The inspector observed partial placement of concrete pour number
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RI-1-El in the unit one reactor building. Acceptance criteria examined by the inspector appear in the following documents:
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Section 3.8 of the PSAR b.
TVA specification G-2, Plain and Reinforced Concrete c.
Procedures QCI C-201, C-202, C-205, C-208 and C-212 d.
Drawing numbers 4P.E0447 - Sheets 1 through 6 and 4RE0448 -
Sheets 1 through 7 Observations showed that forms were tight and clean and rebar was properly installed and clean.
Preplacement inspection was indicated by the signed pour card.
Pla ement activities pertaining to delivery time, freefall, flow distance, layer thickness and consolidation conformed to specifications. Activities were continuously monitored by QC personnel.
Samples for temperature, slump air content, unit weight and test cylinders met frequency and acceptance criteria.
Examination of the batch plant and storage facilities showed that inspection, materials and records controls were in accordance with acceptance criteria.
Postplacement observations showed that curing controls were being performed in accordance with specifications.
No violatirns or deviations were identified.
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Licensee Identified Item 10 CFR 50.55(e)
a.
(Closed) Item 50-566/80-07-03:
Defective Concrete Pour in Auxiliary Buil Jing.
Concrete placement Al-P3 failed to obtain ilitial set in normal time.
The inspector examined the licensee's final response dated June 13, 1980 and the pour placement area.
Portions of the affected area were removed and cores were taken on the remaining inplace concrete.
Strength test results frcm the cores varied from 3790 psi to 6,500 psi, with one test below the specified strength of 4000 psi.
A detailed analysis showed that 6 minimum compressive strength of 3000 psi will meet all loading requirements for slabs represented by pour Al-P3.
Drawings in the 4RE0417-5R series have been revised to show the new design strengths.
This item is closed.
b.
(0 pen) Item 50-566/80-07-04 and 50-567/80-07-04:
Improper Documentation and Utilization of TVA Computer Program " Inertia" The program is specifically designed for use with closed wall sections but it was also used for open wall sections.
Dynamic structural response calculations are unconservative when used for open wall sections and foundation anchor rod designs in
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the control buildir,g.
The licensees final response dated October 14, 1980 does not adequately address safety implications and corrective action for structures with open sections.
In a telephone discussion on April 28, 1981, with TVA licensing and design engineers listed in paragraph 5, the licensee agreed to seno a revised response by May 28, 1981. This item remains open pending NRC review of the licensees revised response.
c.
(Closed) Item 50-566/80-08-01 and 50-567/80-08-01: Deficiencies in Concrete Testing Aggregate samples were not taken correctly, the 3/8 inch aggregate gradation was out of specification numerous times between March 26, 1980 and the loading rate of 73 psi per second applied to concrete test cylinders exceeded the specified loading rate of 20-50 psi per second.
The inspector examined the licensee's interim reptrts dated May 21, July 19 and August 20, 1980 and the final report dated December 1, 1980.
Examination of these reports showed that no safety concerns exist. Analysis of the increased loading rate showed that the obtained strength would be slightly more than one percent higher than that obtained from the specified
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-4-loading rate. A review of records showed that a one percent error would not affect the acceptance of the concrete. Analysis of the aggregate gradations showed that the aggregates were slightly coarse and that the principal effect would be some harshness in the concrete mix. The licensee has, instituted a method to collect a more representative aggregate sample, revised procedure QCI C-204 to clarify additional testing requirement on aggregate gradations, and installed a sign on the test cylinder break machine specifying loading rates.
This item is closed.
d.
(Closed) Item 50-566/80-08-02 and 50-567/80-08-02:
Improper Placement and Compartion of Concrete.
A licensee audit of pour number A2-01 disclosed improper lift height and water being pushed with the concrete. A review of the QCIR log showed 32 QCIRs were written in 1979 and 22 QCIRs to date on honeycomb. Honeycomb is due to impreper compaction.
Improper compaction is considered to be a generic problem at Yellow Creek.
The inspector examined the licensee's. response dated July 11, 1980, implementation of that response and discussed the response with responsible engineers. QCIR 23356, QCIR 51054 and NCR YC-066 and YC-101 were written on the subject pour.
Examination of NCR YC-066 showed that the placement was stopped with only 10 percent of the. pour completed, that the deficiencies were
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corrected and that the remaining 90 percent of the pour was placed without incident.
Examination of records showed that the responsible QC and craft personnel were reinstructed on required placement techniques and that a log has been established to monitor honeycomb. Observation of pour placement number RI 1-El showed that proposed corrective actions are being implemented.
This items is closed.
e.
(Closed) Item 50-566/80-11-02: Earthfill Placement and Inspection for Unit 1 ERCW Spray Pond A licensee audit disclosed that earthfill activities were not
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belns controlled in accordance with acceptance criteria.
Region II:IE issued a confirmation of action letter dated June 24, 1980, in which it was understood that the licensee will not resume earthfill activities in the Unit 1 ERCW pond until the deficiencies listed in Audit No. YC-C-80-07 had been resolved and corrective measures concurred in by the NRC.
NRC RII:IE examined the licensee's response dated July 11, 1980 and issued a confinnation of concurrence letter dated July 16, 1980, concurring with the licensee's plans for resumption of earthfill in the ERCW spray ponds.
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-5-The inspector examined the licensee's response dated July 11, 1980 and observed implementation of that response.
Laborers were observed picking unsuitable material from the fill.
Insufficiently compacted material has been removed, the allow-able amount of root material specified by the G-9 specification was clarified through a design information request, more frequent moisture tests are being made, penetrometer tests were being performed, and additional block samples were taken to verify that insitu compaction requirements were met.
Examination of test results showed that compaction requirements were being met. This item is closed.
f.
(Closed) Item 50-566/80-14-02: Omission of Reinforcement Steel in the Reactor Control Building.
The licensee reported a CDR on August 26, 1980, regarding 84 reinforcing bars (rebars) that were left out of wall pour C1-F1 in the reactor control building.
Region II:IE issued a confirmation of action letter on August 27, 1980, in which it was understood that class I concrete containing rebar would not be placed until tne matter was investigated and appropriate corrective measures were taken.
NRC RII:IE examined the licensees response dated September 11, 1980 and issued a confirmation of concurrence letter dated September 16, 1980, concurring with the licensees plans for
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resumption of placement of class I concrete.
Observations by the NRC inspector showed that the missing rebar were installed in the appropriate location by drilling and grouting into place with nonshrinking grout.
Examination of records showed that the licensee reinspected 5,500 exposed rebar and found four missing rebar. These were identified and disposition 1d on NCR YC-096.
Observation of QC controls on pour number RI 1-El showed taat detailed takeoffs from drawings on number of bars, bar size and bar locations are new being made by the QC inspectors and used for prepcur inspections.
The takeoff details are reviewed by a senior level QC inspector before being used for preplacement inspection. This item is closed.
(Closed) Item 50-566/81-05-01 and 50-567/81-05-01: Bent, Mis-located and Missing anchor bolts and rebar.
Nonconformance report number YC-154 was upgraded to significant and reported to NRC as a CDR on February 20, 1981 because of eight previous related NCRs concerning missing, mislocated and bent reinforceing bars and anchor bolts.
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The inspector examined the licensees response dated March 24, 1981 and implementation of that response.
The licensee has added an independent QC review of drawing takeoffs of rebar and embedments in concrete pours.
Craftsmen have been instructed to use their fabrica'. ion takeoffs to verify that all materials are included in the pour. Associated NCRs were examined by the inspector for correct oispositioning. This item is closed.
(0 pen) Item 50-566/81-05-02 and 50-567/81-05-02: Tornado Depressurization Design Deficiency.
Drawings for the instake and ERCW pumping station structures do not provide for sufficient vents for adequate depressurization during tornado conditions. A written report is due May 2, 1981.
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