ML19338F629

Final Deficiency Rept Re Use of Invalid Seismic Amplified Response Data.Corrective Actions:Containment Bldg Annular Steel Frame Redesigned to Increase Rigidity & long-term Audit of All Seismic Category I Sys Will Be Conducted

ML19338F629
Person / Time
Site:	Seabrook
Issue date:	08/28/1980
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19338F627	List: ML19338F629
References
10CFR-050.55E, 10CFR-50.55E, SBN-135, NUDOCS 8010200707
Download: ML19338F629 (5)

Text

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YJ Cd'*3 1: Companyof NewHampe.hi e SEABROOK STAT 10tJ Engincoring Offico:

20 Tumpiko Road.

August 28, 1980 SBN-135 T.F. Q 2.2.2 U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Office of Inspection and Enforcement

Reference:

1. Docket Nos. 50-443 and 50-444

2. 10 CFR 50.55 (e) Interim Report dated 12.6.79

3. 10 CFR 50.55 (e) Interim Report dated 5/30/80

Subject:

10 CFR 50.55 (e) Final Report on Use of Invalid Seismic Amplified Reponse Spectra

Dear Sir:

Interim reports on the subject 10 CFR 50.55 (e) were filed with your office on 12/6/70 and 5/30/80. The enclosed final report is submitted in accordance with the requirements of 10 CFR 50.55 (e). This deficiency was originally reported to the Region I Inspection and Enfcrcement Office by telephone on 11/6/79.

Should you require. additional information at this time on this matter, please contact us.

Very truly yours, M

John DeVincentis Project Manager JDV: tan cc: Director of Inspeccion and Enforcement US NRC, Washington, D.C. 20555 Encloture

8010200 70 7

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SEABROOK PROJECT FINAL REPORT l 9E USE OF INVALID SEISMIC AMPLIFIED RESPONSE SPECTRA

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Introduction \

On Tuesday, N$vember 6,1979, Mr.. J. DeVincentis, Seabrook Project Manager for Yankee Atomic Electric Company, reported by telephone to Mr. J. Mattia, NRC Region I Inspection and Enforcement inspector for the Seabmok Pmject, a significant design deficiency under 10 CFR 50.55(e). YAEC had that same day received written notice of the deficiency from the Seabrook architect-engineer-construction manager, United Engineers & Constructors, Inc., under UE&C letter number SBU-31426.

' This design deficiency involved the use of invalid seismic Amplified Response Spectra ( ARS) in the design of components supported by the l

i containment building annular steel framing.

1 An interim report on this subject was submitted on December 6,1979, with j

' Public Service Company of New Hampshire (PSNH) letter number SBN-106. This )

' interim report committed a final report to be submitted on June 1,1980. PSNH  :

letter number SBN-121 of May 30,1980 gave a status of committed actions and re-scheduled the final report to be submitted by September 1,1980.

i This report will give the final status of the actions committed to in the i

Interim Report and will also detail further corrective action UE&C is undertaking as a result of the design deficiency.

The following Corrective Action commitments are quoted from the Interim Report:

4 j Corrective Action

1. UE&C is conducting a short-term audit of selected seismic Category I 1

systems and componen,ts to assure use of correct Amplified Response Spectra in their seismic design.

4 2.

Containment building annular steel frame is being redesigned to increase

.its rigidity.

The intent is to reduce the values of the ARS imposed on the piping systems and other components supported by the annular steel frame.

{ 3 A " HOLD" has been placed on the design and analysis of piping systems located in the containment annulus.

4. UE&C will conduct a longer term audit of all seismic Category I systems i

and components to assure use of correct ARS in their seismic design.

5 When the redesign of the annular steel framing is complete, a seismic analysis of it will be performed, generating new ARS at significant individual points.

6. Existing analyses of Safety Class 2 and 3 piping running in the containment annulus will be reviewed against ARS generated in #5 above.

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'Where n cocsary, piping will b3 regn:1yzed to ccsura conform nce with applicalbe Code and regulatory requirements.

7. UE&C is currently reviewing the seismic design requirements of all other components supported by the containment annular steel frame. They are the following:

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a. 'C5ntainment Recirculating Air Units:

These would be used for post-LOCA hydrogen mixing and are Safety C1 ass ,3f

b. Containment Cooling Units:

These are non-safety-related, non-seismic Category I. However, they will be seismically designed since they are located in a seismic Category I buildinC.

c. Hydrogen Recombiners: '

There are two thermal-type recombiners mounted on the annular steel frame. They are safety Class 3, seismic Categor) I.

d. Cable Trays and their Support Systems:

Tray supports are seismic Category I.

e. Heating, Ventilating and Air Conditioning Ductwork Systems:

These are a mixture of Category I and non-Category I systems. i l

f. Air Compressors:

• Two small non-Category I units for instrumentation and control sup ply.

8. Existing UE&C procedures involving seismic design, especially those tret'cing Amplified Response Spectra, are uncer review to detennine the need for revisions or additions which will upgrade them in areas of selection, use and review of ARS.

9 Quality Assurance training sessions, in addition to those on the regular schedule, are planned on the subject of ARS treatment for all UE&C personnel who interface with ARS.

• Correction Action The following is the status of the corrective action commitments as listed above:

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1. The short term audit (UE&C internal audit number NH-314) of selected seismic Category I systems and components has been completed. Project engineering has responded to all findings and the responses have been accepted by the auditors. Several corrective actions remain to be l verified; however, no findings require corrective action in the form of structural codifications or major modifications to piping and pipe l sup ports.

2. Redesign of containment annular steel has been completed. All original design drawings in this area have been voided and design calculations re done. .

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3. ' Th3'CHOLD58 plcsed cn d:cign cnd ennlysis of affected piping cystcma hoo i t

been removed'cinco updatsd amplificd responts spectra for tha containmsnt

• building annular structural steel are now available.

The seismic analyses of these piping systems are being reviewed to determine the effect of the revised ARS. It is anticipated that no changes will be required in piping configuration; however, certain lines will require additiopal supports.

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4. The longer term audit (UE&C internal audits numbers NH-350 and NH-351)  ;

has been completed. Preliminary responses have been prepared for all i

findings 'or(" components. .It is anticipsted that corrective action will '

not require physical change to any component.

Findings on piping systems have been reviewed. Based on this review and on the results of the "short term" audit described above, it is anticipated that corrective action will not require modifications to piping configurations.

Detailed corrective action and its verification will be determined during the Seismic Verification Pmgram discussed below.

5. The pleted.

seismic analysis of the redesigned annular steel framing has been com Generation of the new amplified maponse spectra for the steel frame has been completed.

6. & 7. Review of analysis and seismic design requirements of Safety Class 2 and 3 piping and other components supported by the annular steel frame is under way. This review is in conjunction with the Seismic Verification Program discussed below.

8.

A new Seabrook Administrative Procedure No. 36 ( AP-36), " Control of Seismic Design",. has been prepared and issued to all UE&C personnel involved in this aspect of the Seabrook plant design.

9 An initial training session on the use of AP-36 for all UE&C personnel l who 1980.interface with ARS used on the Seabrook project was held on June 4, Seismic Verification Program

• The UE&C internal audits (NH-314, NH-350 and NH-351) cited above, showed that there are no other areas in the pir.nt where the seismic analysis of a group of local systems and componenets was based on seismic amplified rwsponse spectra of a different structure, as was the case of the piping and components supported by the containment annular steel. However, UE&C has undertaken a verification program (" Seismic Verification Program") to ensure that the seismic design and analyses for all seismic Category I systems those systemsand components is based on input derived from the final design of and components.

Category I systems are being reviewed for correctness.In addition, the sais Major design and analytical following: input being reviewed includes, but is not limited to, the

a. Location of pipe and component supports.

b.

c.

Type and fbuction of pipe and component supports.

Seismic points. amplified response spectra at all pipe and component support

Tha prograa will not cddesas tho cnnlyais of Satsty Cle.ca I c:mponInto and piping for which the NS'3 supplier is msponsible. However, it has been confirmed that the UE&C generated amplified response spectra for the containment stmeture used by Westinghouse in their analysis is correct and up-to-date.

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.3 Due tYthe nature of the verification program, the program cannot be l concluded without the final, as-built plant data. The verificatian program which is curmntifir progress would systematically identify the input ARS design parameter's taat have been used in the design for all safety related ,

systems and components such that, should a defect be uncovered as a result of I the pmgram, corrective actions can be simultaneously initiated. The corrective actions in general would consist of stiffening of a floor, a column, or of a beam, or reanalysis to examine design margins, or relocation of components as necessary. 'me completion of this verification program and corrective actions resulting will constitute final closecut of corrective action items 4, 6 and 7 noted above.

The verification program is scheduled to be complete before fuel loading.

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