IR 05000327/1985029

Forwards Notice of Violation Omitted from Insp Repts 50-327/85-29 & 50-328/85-29 Transmitted on 851025

ML20209H788
Person / Time
Site:	Sequoyah
Issue date:	11/05/1985
From:	Walker R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Parris H TENNESSEE VALLEY AUTHORITY
References
NUDOCS 8511110227
Download: ML20209H788 (1)

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November.05, 1985

---jennesseeValleyAuthority

' ATTN: Mr. H. G. Parris Manager of Power and

- Engineering (Nuclear)'

6N11 B Missionary Ridge Place-1101 Market Street-Chattanooga, TN 37402-2801 Gentlemen:

SUBJECT:. REPORT NOS. 50-327/85-29 AND 50-328/85-29 (CORRECTION)

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'On October 25, 1985, NRC-transmitted:the subject report of inspection activities

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Due to an administrative error, Enclosure 1, Notice

'of - Violation, was not included with the inspection report transmitted on October 25,1985. -We are reissuing the report in its entirety. Please replace

- the earlier copy with the enclosed report.

cShould you have any questions concerning this letter, please contact us.

Sincerely, Original signed by D. Verrelli Roger D. Walker, Director Division of Reactor Projects

Enclosure:

= Inspection Report Nos. 50-327/85-29-and 50-328/85-29

REGION il p

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,, j 101 MARIETTA STREET,N.W.

• ATLANTA, GEORGI A 30323

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Report Nos.: 50-327/85-29 and 50-328/85-29 Licensee: Tennessee Valley Authority 500A Chestnut Street Chattanooga, TN 30372

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Docket Nos.: 50-327 and 50-328 License Nos.:

DPR-77 and DPR-79 Facility Name:

Sequoyah 1 and 2 Inspection Condu ted: August 20-23, 1985

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Inspector:

b N 88 W.

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Date Sign

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M Approved by;7 -

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g'/J./ K Flake, 5 tTon" h'cf ~

Date Signed Engineeri Divi of Reactor Safety SUMMARY Scope:

This special, unannounced inspection entailed 24 inspector-hours on site in the areas of safety-related cable tray support systems, and licensee event reports -associated with the failure of the chemical and volume control system sampling lines.

Results:

Two violations were identified - Inadequate design controls for seismically designed cable tray support systems, paragraph 5.b; Inadequate design controls for safety-related cable tray support baseplate installations, paragraph 5.c.

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REPORT DETAILS 1.

Persons Contacted Licensee Employees

• P. Wallace,-Plant Manager

• L. Nobles, Superintendent, Operations and Engineering

• J. Vineyard, Project Manager

• H. Rankin, Manager, Desigli Services

• C. Johnson, Civil Project Engineer

• K. Mogg, Section Supervisor, Design Services

• K. Spates, Civil Engineer, Civil Engineering Branch (CEB)

• T. Bucy, Civil Section Supervisor, CEB

• J. Holland, Project Engineer, Site Services

• G. Kirk, Compliance Supervisor

• D. Carven, Quality Assurance Supervisor L. Katcham, Civil Engineer, CEB Other licensee employees contacted included engineers, technicians, security force members, and office personnel.

• Attended exit interview 2.

Exit Interview The inspection scope and findings were summarized on August 23, 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.

(0 pen) Violation 327, 328/85-29-01, Inadequate Design Controls for Seismically Designed Cable Tray Support, paragraph 5.b.

(0 pen) Violation 327, 328/85-29-02, Inadequate Design Control for

. Safety-Related Cable Tray Support Baseplate Installations, paragraph 5.c.

(0 pen) Unresolved Item 327, 328/85-29-03, Evaluation of the CVCS Sampling Line Failure, paragraph 6.b.

The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspector during this inspection.

3.

Licensee Action on Previous Enforcement Matters This subject was not addressed in the inspection.

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4.

Unresolved Items Unresolved items are matters about which more information is required to determine whether they are acceptable or may involve violations or devia-tions.

One new unresolved item identified during this inspection is discussed in paragraph 6.b.

5.

Safety-Related Cable Tray Support Systems a.

Design Document Review The inspector reviewed portions of the follcwing documents pertaining to safety-related cable tray support systems to determine whether appropriate design criteria have been - established and whether they comply with NRC requirements and the licensee commitments.

Design Criteria No. SQN-DC-V-1.3.4, Category I Cable Tray Support

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System, August 20, 1975 Design Input Memorandum for Design Criteria for Category I Cable

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Tray Supports, May 1, 1985 CEB 80-16, Dynamic Earthquake Analysis of the Diesel Generator

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Building and Response Spectra for Attached Equipment, April 9, 1973 CEB 80-67, Dynamic Earthquake Analysis of the Additional Diesel

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Generator Building and Response Spectra for Attached Equipment, June 24, 1983 Supplementary Seismic Analysis for the Additional Diesel Generator

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Building, August 27, 1981

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CEB Report No. 75338, Static Load Tests of Cable Trays and Support-

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ing Connections, December 4, 1975 b.

Design Calculations Review The inspector reviewed portions of the following design calculations associated with the safety-related cable trays support systems.

Location Reference Drawing

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I Control Building 48N1297, 1298, 1299 and 1300 Brackets A thru J

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Auxiliary Building 48N1363 thru 1369 Reactor Building 48W 952-1 and 952-2 i

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• Diesel Generator Building-18N251 thru 253

• Additional-Diesel Generator Building 18W298-1 and 298-2

• Discrepancies were identified during the review.

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The above cable tray support design calculations were reviewed for

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conformance to analysis criteria, applicable codes HRC requirements-and the licensee commitments.

Additionally, these calculations were

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evaluated during the review for thoroughness, clarity, consistency, and accuracy.

In general, the design. calculations appeared to be accep-

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table with the exception of those for the two diesel generator build-ings identified below:

(1) Design Calculations for cable tray support mark numbers 9,11, 11A, 31 and 32 in the diesel generator building were reviewed.

It was found that these calculations were performed by using a modal

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superposition dynamic computer analysis.

The computer programs consider only the dynamic modal response in the frequency range of

interest.

There was no consideration given to the effects of rigid body motion from the response sptetrum zero period accelera-tion (ZPA).

A review of the aforementioned design calculation-revealed that many of the cable tray supports were rigidly or

close to rigidly designed.

As a' result, the accelerations gene-rated from the dynamic analysis were generally small when compared

to the response spectrum peak accelerations.

The use of these

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small accelerations alone in the design of the rigid supports for the cable tray support systems is nonconservative and is inadequ-i ate in tenns of NRC requirements.

This can be seen from the design calculations for cable tray supports mark numbers 31 and

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32, where zero acceleration in the X direction and 0.08g accelera-

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tion in the Z direction were generated from the dynamic computer

analysis and were used in the design.

The effects of ZPA or the ground acceleration had not been considered in the design analysis f

when these cable tray supports were rigidly designed.

For operat-

ing basis earthquake (OBE), the response spectrum ZPA or the l

ground acceleration -(elevation 722'-0") is 0.379 which is the additional seismic. load that should have been considered in the

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design analysis.

I (2) Design calculations for cable tray support mark numbers 1 and 2 in the additional diesel generator building were reviewed.

The inspector noted that the same dynamic computer programs were

i-utilized in the design analysis.

The effects of ZPA had not been

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onsidered in the design analysis.

The inspector held discussion with licensee representatives regarding the above concerns.

It was concluded that the effects

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of the response spectrum ZPA or the ground accelerations should have been considered in the design analysis when the supports were rigidly designed. Since the cable tray supports in the two diesel

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generator buildings were rigidly designed and had not considered the effects of the response spectrum ZPA, these supports may not be able to serve their intended function during a seismic event.

The improper design of the cable tray support systems is a viola-tion of 10 CFR 50, Appendix B, Criterion III, and is identified as Violation 327, 328/85-29-01, Inadequate Design Controls for Seismically Designed Cable Tray Supports.

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Design Drawing Review The inspector reviewed portions of the following design drawings associated with the cable tray support systems.

Location Drawing Number

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• Auxiliary Building 48N1369, Rev. 2 Reactor Building 48N1505 Control Building 48N1297, 1298, 1300, 1302 Diesel Generator Building 18N251, 252 and 253

• Indicates discrepancy identified during the review.

The above design drawings were partially reviewed for conformance to design analysis and the licensee commitments. The inspector found that baseplates with oversize holes were actually used in the installation.

Design Drawing 48N1369, Rev. 2, specified 1 3/16" diameter holes in the baseplates for 3/4" diameter wedge bolts.

In accordance with TVA procedure, the currect hole size in a baseplate should be 1/16" larger than the nominal bolt size.

In this case, the correct hole size in the baseplate should have been 13/16". The inspector held discussions with licensee representative with respect to the above concerns.

It was found that a total number of 16 baseplates inspected, (8 per unit),

all were actually installed with each baseplate containing 4 drilled holes that were 3/8" larger than the required size.

It was further noted that the oversize holes specified on the design drawing was a design error.

As a result, these 16 baseplates may not be able to

serve their intended function as required by the design.

This is a violation of 10 CFR 50, Appendix B, Criterion III, and is identified as Violation 327, 328/85-29-02, Inadequate Design Controls for Safety-related Cable Tray Support Baseplate Installations.

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Within the areas inspected, two violations were identified.

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6.

Licensee Event Followup (92700)

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. Licensee event status

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The licensee informed Region II on August 12, 1985, that a routine t

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walkthrough by En auxiliary. operator identified a crack through the weld arescof the chemical and volume control system (CVCS) 3/4 inch sampling 'line.

The weldscrack is almost identical in location te the

.one reported by the licensee on Unit 2, on July 30, 1985. The licensee

'has completed weld repairs on both units, and' pipe supports are being designed and installed on,both branch lines.

t Neither of the two branch lines contained supports prior to detection

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of the leaks.

The licensee hts completed walkdowns of the CVCS lines in both units, except high radiation areas in containment, and found no other unsupported branch lines.

Metallurgical analysis of the Unit 2 crack indicated that the failure

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mechanism was low stress, and high cycle fatigue._ Vibrational analysis of both lines has not identified the source of any vibration which may have occurred..

The licensee is continuing to make efforts and to-determine the cause of the failure to the two sampling lines,.,

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Piping Stress and Pipe Support Eysluation t,

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The inspector held! discussions with licensee representative regarding the above concerns.h It was determined tha't the piping group was to perform two design ) analyses.

One was to determine whether a pipe

- support was require'd in acco(ilether the allowable code stresses weredance wit

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the other was to determine w

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being met in accordance with the rigorous analysis criteria.

Results of the two design analyses indicated that no supports were required for the two sampling lines in terms of meeting the flexibility requirements

and the stress allowable requirements.

The inspector reviewed portions of the aforementioned design analyses and the-design guidelines contained in the CEB Report 75-18.

It was found that the design analysis-on sheet No. 4 contained an error in the flexibility check in that 0.00045 was shown to be less than 0.0002.

With the error corrected., the design analysis did indicate that a support was require / for the 3/4 inch samp1 ng lines. The above design

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analysis had been checked ard reviewed by the licensee responsible engineers prior to the inspector's finding. The inspector held discus-sions with -licenseevepresentatives.with regard to the above concern.

It was decided that the licensee's responsible group was to pursue a further des'1gn analysis in that a more detailed analysis was required to determine whether a support was needed.

Pending further evaluations to be performed by the licensee to determine the cause of the failure

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for the sampling line, this matte.r is identified' as Unresolved Item

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327, 328/85-29-03, Evaluation of,the CVCS Sainfling Line Failure.

Within the areas inspected, no violations or deviations were identifi-

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Licensee's Corrective Action

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Subsequent to the inspector's finding with respect to the seismic analysis, the licensee issued a memorandum on August 23, 1985, stating that TVA has committed to reanalyze the cable tray supports in the two diesel generator buildings to include the effects of the additional seismic loads that were associated with the response spectrum ZPA or the ground accelerations.

In addition, the following actions will be taken; a.

Civil Project Engineer will be responsible tor limiting the performance of the dynamic modal analysis'to selected qualified individuals.

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The CEB central staff will provide direction and training of the use of dynamic modal analysis where required.

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A design input memorandum will be issued for the cable tray support design criteria.

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