IR 05000259/1985051
| ML18030A923 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/19/1985 |
| From: | Blake J, Liu W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18030A922 | List: |
| References | |
| 50-259-85-51, 50-260-85-51, 50-296-85-51, NUDOCS 8512060339 | |
| Download: ML18030A923 (12) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
ATLANTA,GEORGIA 30323 Report Nos.:
50-259/85-51, 50-260/85-51, and 50-296/85-51 Licensee:
Tennessee Valley Authority 6Nll B Missionary Ridge Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.:
50-259, 50-260 and 50-296 License Nos.:
DPR-33, DPR-52, and OPR-68 Facility Name:
Browns Ferry 1, 2, and
Inspection o
uc October 23 and
November 1,
1985 Inspecto Approv d b iu
. Blake, Section Chief ineering Branch 0 vision of Reactor Safety
)/'
ss ate Signed
)i ate Signed SUMMARY Scope:
This special announced inspection involved 35 inspector-hours on site in the areas of safety-related cable tray support.
systems, safety-related pipe support and restraint systems, inspector followup item, and licensee actions on previous enforcement matters.
Results:
No violations or deviations were identified.
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REPORT DETAILS 1.
Persons Contacted Licensee Employees w**R
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- K AWJ Lewis, Plant Manager Hall, Design Services Manager Guthrie, Assistant Manager, Design Services Rinne, Unit 2 Project Manager Beasley, Engineering Project Manager Marshall, Civil Project Engineer-Nye, Design Services Gaines, Office of Engineering (OE)
Carlson, gA Supervisor Nebrig, Modifications James, Design Services Morris, Compliance Supervisor Ziegler, Site Director Rutherford, Electric Design Project Engineer Domer, Director, Engineering Projects Barnett, Chief Civil Engineer Spates, Civil Engineer, OE Raulston, Unit 2 Restart Project Other licensee employees contacted included engineers, technicians, security force members, and office personnel.
Other Organizations
- R. Bryans, Project Manager, United Engineers and Constructors (UE8C)
- B. Scott, Engineering Manager, UE5C
- ~C. Miller, Nuclear Project Manager, UBC
- G. Rigamonti, Chief Power Engineer, VEDIC NRC Resident Inspectors and Management Personnel
"*A. Herdt, Engineering Branch Chief, Region II
- J. Blake, Materials and Process Section Chief, Region II
- "A. Johnson, Project Inspector, Region II
"*M. Liu, Reactor Inspector, Region II
- G. Paulk, Senior Resident Inspector, Region II
- C. Patterson, Resident Inspector, Region II
- "C. Brooks, Resident Inspector, Region II
"*R. Clark, Project Manager, NRR
""N. Chokshi, Structural Engineer, NRR
- Attended exit interview
"*Attended special meeting between NRC and licensee held on site on October 23, 1985.
"""Attended both exit interview and attended special meeting between NRC and licensee held on site on October 23, 1985.
2.
Exit Interview The inspection scope and findings were summarized on November 1,
1985, with those persons indicated in paragraph 1 above.
The inspector described the areas inspected and discussed in detail the inspection findings.
No dissenting comments were received from the licensee.
(Open) Inspector Followup Item 259, 260, 296/85-51-01, Inspection of Exiting Cable Tray Support Systems, paragraph 7.
(Open)
Inspector Followup Item 260/85-51-02, Corrective Actions Resulting From Interim Evaluation of Cable Tray Support Systems, paragraph 8.
The licensee did not identify as proprietary any of the ma'terials provided to or reviewed by the inspector during this inspection.
t 3.
Special Meeting on Cable Tray Support Systems and Conduit (}ualification Program A special meeting was held on site between NRC and licensee representatives on October 23, 1985.
During the meeting the licensee representatives presented the following programs:
a.
Cable Tray gualification Program ( 1)
Interim qualification for restart (2)
Long term qualifications (3)
Verification of installed concrete anchor bolts (4)
Cable capacity b.
Conduit gualification Program (1)
Sample inspection (2)
Safety evaluation (3)
Design calculations (4)
Final report c.
HVAC Supports (1)
Design basis
(2)
Implementation of cr iteria (3)
Field inspections (4)
gualification tests Inadequate corrective action for safety-related cable tray systems e.
Management actions to prevent recurrence on future work 4.
Licensee Action on Previous Enforcement Matters b.
(Closed) Violation 296/85-21-01, Inadequate Design Calculations on Pipe Support HPCI R-86.
TVA's letter of response dated May 23, 1985, has been reviewed and determined to be acceptable by Region II.
The inspector held discussions with licensee's representatives and examined the corrective actions as stated in the letter of response.
The inspector concluded that TVA had determined the full extent of the subject violation, performed the necessary survey and followup actions to correct the present conditions and developed the necessary corrective actions to preclude recurrence of similar circumstances.
The corrective actions identified in the letter of response have been implemented.
(Closed)
Unresolved Item 259, 260, 296/85-21-02, Shear Force Distribution for IEB 79-02 Design Calculations.
This item involved shear force consideration in the calculation of concrete anchor bolts specified in TVA's civil Design Standard DS-C1.7. 1, Rev.
2, in which the shear force acting on anchor bolts during seismic event could be reduced to zero when the anchor bolt tensile load approached the allowable value.
The inspector held discussions with licensee representatives regarding the above concern and reviewed related documents.
It was found that TVA has revised the standard DS-C1.7. 1 to require that direct shear be distributed equally to all anchor bolts.
In addition, a
sampling program for completed support designs was reviewed for design adequacy.
The results of the sampling program appeared to be acceptable.
This item is considered closed.
5.
Unresolved Items Unresolved items were not identified during the inspection.
6.
Inspector Followup Item (92701)
(Closed)
Inspector Followup Item 259/85-21-04, Design Calculations for Support No.
CS R-1 This item involved hand calculations for baseplate analysis for which some of the calculation sheets were not signed by a checker.
Because of the complexity of the baseplate, the licensee determined -to use computer analysis to ensure the adequacy of the design.
Results of the analysis indicate that the existing baseplate design appears to be acceptable.
This item is considered closed.
7.
Inspection of Existing Cable Tray Support Systems The inspector held discussions with licensee representatives regarding the inspection of existing safety-related cable tray support systems.
It was found that cable tray support systems had never been inspected to any available procedures.
This can be substantiated from the fact that no documents were available for revieH to determine whether the installed support systems were consistent with the design documents.
In addition, SSO concrete anchor bolts were used in the installation of cable tray seismic restraints while the corresponding design drawings called for the use of cinch anchors.
As a result, there is no assurance that the installed cable tray support systems are consistent with the applicable design documents.
The inspector indicated that a written inspection procedure with acceptance criteria should be established prior to initiating field inspections.
Pending field inspection of the installed cable tray support systems to ensure the adequacy of the design,. this matter is identified as Inspector Followup Item 259, 260, 296/85-51-01, Inspection of Existing Cable Tray
'upport Systems.
Mithin the areas inspected, no violations or deviations were identified.
8.
Interim Evaluation of Cable Tray Support Systems Unit 2 Interim Evaluation Report United Engineers and Contractors (UE8C) performed the design evaluation of cable tray support systems for the licensee.
The evaluation was based on the interim acceptance criteria for which the cable tray/
support systems can sustain the Oesign Basis Earthquake; and the plant can be brought to a safe shutdown condition.
Six fixes were identified as a result of the UE&C's evaluation.
These six fixes are listed below:
(I)
Intake Pumping Station Included a vertical knee brace canti-levered from the ceiling to restrain motion in the longitudinal direction for essential tray routed directly above the cabinets.
(2)
Intake Pumping Station
-
Included trussing nonessential tray adjacent to the essential tray to prevent longitudinal deformation or failure which could compromise the integrity of the essential tra (3)
Unit 2 Reactor Building - Involves decoupling a Unit 2 control rod drive (CRD) hydraulic unit support from a cable tray support since the deflection of the flexibly supported cable tray could adversely affect the essential CRD support.
(4)
Unit 2 Cable Spreading Room:
Requires replacement of a missing rod hanger which was deleted when the fire protection piping was routed at the location of the support.
(5)
Intake Pumping Station
- Involves removing one U-bolt from all double U-bolt conduit restraints above the electrical cabinets.
(6)
Common Electrical Tunnel (Rectangular Section)
Involves restraining cable trays which are overhanging their support brackets.
Control Bay Mark 31 Cable Tray Support:
UE&C's final report for Unit 2 interim evaluation of cable tray/
supports was partially reviewed to determine the adequacy of the design evaluation in accordance with the established interim design criteria.
The inspector noted that the baseplate and anchor bolts for Mark 31 cable tray support had not been adequately analyzed with respect to load combinations resulting from-the Design Basis Earthquake.
Results" of the design analysis performed by the licensee representatives, Office of Engineering, revealed that both baseplate stresses and anchor bolt loads are greater than the interim allowable values.
Control Bay Mark 10 and Mark 65 Cable Tray Supports:
During the inspection, the inspector also reviewed the applicable design drawings to determine whether the critical cable tray supports were included in the design evaluation performed by the UE&C.
The review of design drawings 48N1040 through 48N1046 indicated that Mark 10 and Mark 65 cable tray supports appeared to be more critical than Mark 31 identified in the aforementioned paragraph in terms of design loads imposed during a seismic event.
The licensee's repre-sentatives confirmed that these two cable tray supports are essential to Unit 2 operation, thereby they should be evaluated based on the same interim design criteria.,
Reactor Building Cable Tray Seismic Restraints:
The inspector reviewed calculation set 7841-008-C-1-002 o, the UE&C's evaluation report.
It was noted that the seismic loads used in the support calculation was based on the seismic acceleration obtained from the response spectrum at elevation 593 level.
The cable tray seismic restraint evaluated is located at elevation 621 level.
Therefore, the seismic accelerations should have been obtained from elevation 621 response spectrum.
At the time of this review the response spectrum with 7% damping at elevation 621 had not been developed.
As a result,
the cable tray seismic restraint at elevation 621 level can not be assured that the evaluation indeed meets the interim design require-ments.
On the basis of the above (a, b, c, and d), documents reviewed and the discussions held with licensee's representatives, it is determined that the licensee will take corrective actions with respect to the afore-mentioned concerns which are essential to Unit 2 operation.
Pending licensee's completion of the above identified six fixes, and the resolution of the above concerns prior to Unit 2 operation, these matters are identified as Inspector Followup Item 260/85-51-02, Corrective Actions Resulting from Interim Evaluation of Cable Tray Support Systems'ithin the areas inspected, no violations or deviations were identified.
9.
Potential Modifications
Ouring the review of the UEKC's report, the inspector noted that a number of cable tray supports in the reactor building, control bay area, intake pump house area, common electrical tunnel area, and the diesel generator buildings can only meet the interim design criteria.
There is a
good indication that unless design justifications are provided
+o minimize the impact to the existing cable tray 'systems, it is anticipated that some."
additional cable tray support systems may have to be modified in order to meet the long term design requirements.
Within the areas inspected, no violations or deviations were identified.
10.
Safety-Related Pipe Support and Restraint Systems (50090)
As of October 30, 1985, 257 of the 468 supports for Unit 2 have been reinspected per SMMI-14.4. 1.3-L with four inspection teams.
Each team consists of one design engineer, one gC inspector and one steam fitter foreman.
Of the 257 supports inspected minor problems were identified on 189 supports.
These minor problems which were identified as loose nuts, missing locking devices, undersize welds, etc.
are currently being corrected by the licensee.
Within the areas inspected, no violations or deviations were identified.