IR 05000259/1990030
| ML18033B550 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/30/1990 |
| From: | Belisle J, Harris J, Lenahan J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18033B549 | List: |
| References | |
| 50-259-90-30, 50-260-90-30, 50-296-90-30, IEB-80-11, NUDOCS 9011160084 | |
| Download: ML18033B550 (10) | |
Text
foPR RECIr (4
'-:.,a UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323 Report Nos.:
50-259/90-30, 50-260/90-30, and 50-296/90-30 Licensee:
Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.:
50-259, 50-260 and 50-296 License Nos.:
DPR-33, DPR-52, and DPR-68 Facility Name:
Browns Ferry 1, 2, and
Inspection Conducted:
0 tober 2-5, 1990 Inspectors:
ena a
arris I
Approved by: Q~& 7 Q. CJ wCoor G. A. Gelisle, Chief Test Program Section Engineering Branch
, Division of Reactor Safety W/>o yo ate sgne i%%s ate igne
/~ 4'>
c3 Date igned SUYiYARY Scope:
This routine, unannounced inspection was conducted in the areas of followup on IE Bulletin 80-11, Masonry Wall Design, and licensee action on previous inspection findings.
Results:
In the areas inspected, violations or deviations were not identified.
Resolution of technical issues from a
safety standpoint was delayed.
Responsiveness to NRC initiatives, while generally acceptable, lacked thoroughness.
This was demonstrated by the failure of licensee engineers to evaluate the effect of materials which did not meet design requirements on, the structural integrity of masonry block walls.
9011 fb0084 90ll05 PDR ADOCK 0500025Ipi G
PN REPORT DETAILS
. 1.
Persons Contacted Licensee Employees R. Cutsinger, Supervisor, Civil Engineering, Nuclear Engineering J. Davenport, Licensing Engineer
- L. Myers, Plant Manager S.
Samaras, Civil Design Engineer NRC Resident Inspectors
- C. Patterson, Startup Coordinator
- W. Bearden, Resident Inspector
"Attended exit interview 2.
(Closed)
IE Bulletin 80-11, Masonry Wall Design, Units 1, 2 and 3 (37700)
a ~
Background The licensee responded to IE Bulletin 80-11 in letters to NRC dated July 8 and November 7, 1980.
The July 8 letter was the licensee's 60-day response to the bulletin.
This response summarized the'cceptance criteria to be used in the design evaluation, listed the walls affected by the bulletin, and listed the schedule for completion of the design evaluation.
The November 7 letter was the licensee's 180-day response to Bulletin 80-11.
This response included a detailed discussion of the re-evaluation criteria, and contained additional information on the function and types of masonry wall affected by the bulletin.
This response also identified walls which required modification to comply with the licensee's design criteria.
On March 4, 1981, the licensee informed NRC Region II that the re-evaluation criteria did not take into consideration all applicable loadings.
TVA submitted interim reports to NRC on April 7 and July 27, 1981, followed by a final report on October. 1, 1981 which clarified previously submitted information and included new data resulting from evaluation'of all applicable loadings acting on the walls.
In a letter dated January 28, 1983, the NRC Office of Nuclear Reactor Regulation (NRR)
requested additional information concerning the licensee's IEB 80-11 re-evaluation criteria.
TVA responded to this request in a letter dated April 22, 1983.
Following review of the additional information, NRR issued a Safety Evaluation Report (SER)
on January 16, 1984, which accepted, with the exception of wall numbers 3,
40,
and 75, the licensee's
.IEB 80-l1 masonry wall design re-evaluation.
On October I, 1984, the licenses informed NRC Region II that a
nonconforming condition had been identified regarding the effects of tornado depressurization on block walls in the reactor and control bay buildings.
This item was reported as LER 259-84-0030.
,In a
letter dated December 17, 1984, the licensee reported that they determined =that due to the effect of tornado depressurization loads, seven additional walls required modification to comply with design criteria.
During an inspection conducted January 3-6, 1989, documented in NRC Inspection Report Nos.'0-259, 260, and 296/89-02, the inspector identified two inspector-followup items ( IFIs)
which required
.
resolution prior to the closeout of IEB 80-11.
Resolution of these items is discussed in paragraph 3 below.
Inspection. of Completed Structural Modification The inspector examined structural modifications to masonry walls which were installed to reinforce the walls so that the walls would not be overstressed by various design loading conditions.
The modifications were installed under various work plans (WP) associated with Engineering Change Notice (ECN) P0370.
The inspector examined the installed modifications on wall numbers 103, 106, and 107 in the diesel generator buildings; wall numbers 300, 301, and 303 in the intake structure; wall numbers 5B, 5D, 7, 9, 22, and 109 in the Unit I reactor building; and wall number 90 in the Unit 3 reactor building.
The inspector also examined wall number 40 in the Unit 2 reactor building and wall number 74 in the Unit 3 reactor building.
These walls are removable shield walls.
There is no safety-related equipment on the exterior sides of 'hese walls.
The interior portions were not accessible.
However, the inspector examined drawing number 48N1139, Miscellaneous Steel, FW and MS Piping Pressure Panel, which shows steel reinforced panels which restrain the interior sides of the wall, and prevent the walls from failing inward toward the safety-related equipment located on the interior sides of the walls.
Discussions with licensee engineers disclosed that wall numbers 3 and 75 had been removed.
The inspector examined locations where these walls had been installed and verified that the walls had been removed.
The removal of wall number 3 and 75, and the fact that no safety-related equipment is located on the exterior of wall numbers 40 and 74, resolves the concerns (exceptions)
noted in the January 16, 1984 SER.
The inspector also examined the quality records documenting guality Control (gC)
inspections of modifications (structural. supports)
installed on various masonry walls.
These records included the
C
i design drawings, and design change authorizations (DCA) to the drawings.
Records examined were as follows:
'ecords documenting inspections of expansion anchor installa-tions and visual inspections of welding associated with structural restraints installed on wall numbers 80 and 82, under WP 3061-88.
Records documenting inspections of wedge bolt installations, structural bolting, and thru-bolt installations associated with structural restraints installed on wall numbers 300, 301, and 303 under WP 1040-88.
Records documenting inspections of anchor bolt installations, structural bolting, thru bolt installation, and visual inspections of welding associated with structural restraints installed on wall, number 5B under work plan 1044-88.
Records documenting installation of concrete expansion anchors and structural bolting for structural restraints installed on wall number 5D under WP 2217-89.
c.
Conclusions Based on review of the licensee's actions to complete IEB 80-11 during inspections documented in NRC Inspection Report Numbers 50-"259,260, and 296/83-17 and 89-02, and review and acceptance of the licensee's design evaluation methodology by NRR, as documented in the above referenced SER, the inspector concluded that the licensee had complied with the requirements of IE Bulletin 80-11.
3.
Action on Previous Inspection Findings (92701)
a.
(Closed)
IFI (259,260,296/89-02-01),
Review guality Records Documenting Original Construction of Masonry Walls The licensee was unable to locate the original construction'C records documenting the construction and inspection of the masonry walls.
The masonry walls were constructed by two subcontractors to
, the licensee.
The work was considered non-safety related.
However,
- discussions with licensee engineers, including one of the engineers responsible for the oversight and quality control inspection of the subcontractors'ork, disclosed that the licensee performed numerous inspections of the masonry work.
These included sampling and testing of mortar and grout, testing of materials such as masonry units, sand, cement, and reinforcing, and inspection of work in progress.
Licensee engineers stated that the results of these tests and inspections were documented in written inspection reports.
However, these records were either misplaced, or possibly disposed of since
the masonry wall construction was considered non-safety related.
The licensee was able to locate gA audits and some records of contract correspondence which documented the approval and acceptance of masonry construction materials.
The licensee also located some correspondence concerning problems encountered with concrete used to fill masonry cells and stoppage of masonry work.
This included a
memo from J.
C. Killian, Construction Engineer, to file dated November 19, 1969, Subject:
Contract 68C58-61913 - Concrete Filled Masonry Walls in Control Bay - Bush Building Company.
This memo documented that cells in some masonry walls on the elevation 593 level were filled with 2000 psi concrete, not 3000 psi concrete as required by the construction drawings.
Attached to the memo were results of testing performed as samples of the concrete which showed that the.fill concrete did not meet design requirements for approximately one
'month during the start of masonry wall construction.
The licensee stopped work until the contractor revised their concrete fill mix design to one that complied with specification requirements.
The inspector questioned licensee design engineers regarding the effects of the reduction of the concrete fill strength from 3000 psi to 2000 psi on the structural integrity of the masonry walls.
The design engineers had been unaware of this problem until the inspector informed them.
At the request of the inspector, licensee engineers prepared an evaluation of the 2000 psi fill concrete.
This evaluation was performed in calculation number CD-(0303-900753, Evaluation of Masonry Walls With Cells Filled With Concrete of 2000 psi Strength.
The licensee submitted the calculation to the inspector subsequent to this inspection.
Review of the calculation showed that the maximum compression in the fill concrete is 200 psi.
The licensee also reviewed the reinforcing steel splice length (development length)
and verified that the design was adequate for a 2000 psi concrete strength.
Based on review of this calculation, the inspector concluded that the use of 2000 psi fill concrete did not significantly affect the structural integrity of the masonry walls.
The inspector also questioned licensee engineers concerning any surveys they had completed to ascertain the presence of reinforc-ing steel in the masonry walls.
Licensee engineers stated that presence of reinforcing steel was verified during the original IEB 80-11 walkdown program, and that reinforcing steel has been encountered during recent plant modifications.
Licensee design engineers informed-the inspector that they were also currently performing an evaluation "of unauthorized cutting of a
piece of masonry wall reinforcing steel during a recently completed plant modification.
Based on discussions with licensee engineers, the inspector concluded that-although the licensee was unable to locate the original masonry wall construction records, the licensee had a
program f'r inspection of masonry wall construction activities which provides assurance that the walls were completed in accordance with design requirement b.
, (Closed)
IFI (259,260,296/89-02-02)
Review Status of IEB '80-11, Analysis and Modifications During. the inspection documented in NRC Inspection Report Nos. 50-259,260,296/89-02, the inspector was unable to determine the status of Unit 2 masonry wall modifications," which required completion prior to restart of Unit 2.
Since that time, IEB 80-11 structural modifications have been completed on all Unit 1, 2 and
masonry walls, including those in areas common to all three units.
Exit Interview The inspection scope and results were summarized on October 5, 1990, with those persons indicated in paragraph 1.
The inspectors described the areas inspected and discussed in detail the inspection results.
Proprietary, information is not contained in this report.
Dissenting
, comments were not received from the'icensee.