ML19331E239
| ML19331E239 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/28/1980 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SBN-135, NUDOCS 8009090419 | |
| Download: ML19331E239 (5) | |
Text
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Mh W33D f4 Company of New Hampchts e i
SEABROOK STATION Engineering Office:
i 20 Turnpike Road August 28, 1980 s
SBN-135 T.F. Q 2.2.2 U.S. Nuclear Regulatory Commission Pagion 1 631 Park Avenue King of Prussia, Pennsylvania 19406 Attention: Office of Inspection and Enforcement Re fstrence :
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 daced 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 en 12/6/79 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 ! Inspection and Enforcement Cffice by telephone on 11/6/79.
Should you require additional information at this time en this matter, please contact us.
Very truly yours, i
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~'n John CeVincentis Project Manager JDV:can cc: Director of Inspection and Enforcement US NRC, Washington, D.C.
20555
-Enclosure i
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SEABROOK PROJECT FINAL REPORT ON I'
USE OF INVALID-SEISMIC AMPLIFIED RESPONSE SPECTRA
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- Int roduc tio'n 2'
On Tuesday, November 6, l'979, 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 Seabrook Pmject, a significant design deficiency under 10 CFR 50.55(e). YAEC
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had.that same day receiveo written notice of the deficiency from the Seabrook f
. 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 centainment building annular steel.raming.
An interim report on this subject was submitted on December 6,1979, with Public Service Company of New Hampshire (PSNH) letter number SBN-106. This interim report committed a final report to be submitted on.AJne 1,1980.
PSNH letter number SBN-121 of May 30,1980 gave a status of committed actions and l
re-scheduled the final report to be submitted by September 1,1980.
This report will give the final status of the actions commir' ed to in the Interim Report and will also detail further corrective action UEF is undertaking as a result of the design deficiency.
The following Corrective Action commitments are quoted from the Interim Report:
Corrective Action 1.
UE&C is conducting a short-term audit ci Jelected seismic Category I systems and components to assure use of correct Amplified Response f
Spectra in their seismic design.
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 1,ocated in the containment annulus.
4.
UE&C will conduct a longer term audit of all seismic Category I systems 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 perfonned, 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,15 above.
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- b Where ' n c~csary, piping will be reznalyzed to cature conforma
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applicalbe Code and regulatory requirements.
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7.
UE&C _is currently reviewing the seismic design requirements of all other
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components supported by the containment annular steel frame. They are
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tihe following:
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. g Yntainments Recirculating Air Units:
a.
g; These would be used for post-LOCA hydrogen mixing and are Safety Class y 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 building.
c.
Hydrogen Recombiners:
There are two thermal-type recombiners mounted on the annular steel frame. They are safety Class 3, seismic Category I.
d.
Cable Trays and their Support Systems:
Tray supports are seismic Category I.
e.
Heating, Ventilating an'd Air Conditioning Ductwork Systems:
These are a mixture of Category I and non-Category I systems.
f.
Air Compressors:
Two small non-Category I units for instrumentation and control s up ply.
8.
Existing UE&C procedures involving seismic design, especially those treating Amplified Response Spectra, are under review to detemine 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:
1.
The short term audit (UEAC internal audit number NH-314) of selected seismic Category I systems and components has been completed. Project engineerird has responded to all findings and the respon;es have been
-accepted by the auditors. Several corrective actions remain to be verified; however, no findings require cormctive action in the form of structural modifications or major modifications to piping and pipe supports.
2.
Redesign of containment annular steel has been. completed. All original design drawings in this area have been voided and design calculations redone.
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The CHOLD2 placed cn design and analysis of affected piping systems has i
been removed since updated amplified response spectra for the containment 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 additi{nal supports.
1 4.
The longer ters audit (UE&C internal audits numbers NH-350 and NH-351) 27 has been,comyleted. Preliminary responses have been prepared for all findings on components.
It is anticippted that corrective action will not require physical change to any o'aponent.
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 Program discussed below.
'l-5.
The seismic analysis of the redesigned annular steel fenming has been completed. Generation of the new amplified response 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 reviev *
- in conjunction with the Seismic Verification Program discusseo
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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 who interface with ARS used on the Seabrook project was held on June 4, 1980.
Seismic Veri fication Program The UE&C internal audits (NH 314, NH-350 and NH-351) cited above, showed that there are no other areas in the plant where the seismic analysis of a group 13T local systems and componenets was based on seismic amplified response scectra of a different structure, as was the case of the piping and components supported by the containment annular steel. However,.UESC has undertaken a verification program (" Seismic Verification Program") to ensure that the seismic design and analyses for all seismic Category I
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systems and components is based on input derived from the final design of those systems and components.. In addition, the seismic analyses for all Category I systems are being reviewed for correctness. Major design and analytical input being reviewed includes, but is not limited to, the following:
Location of pipe and component supports.
l a.
b.
Type and function of pipe and component supports.
Seismic amplified response spectra at all pipe and ecmponent support c.-
points.
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The prograo will not cddress th3 cnalysio of Saf;ty Class I components 5
and piping for which the NSSS supplier is msponsible. However, it has been L.
confirmed that-the UE&C generated amplified response spectra for the j
containment structure used by Westinghouse in their analysis is correct and j
up-t o-d at e.
Due to )he nature of the verification program, the program cannot be concluded without the final, as-built plant data. The verification program 3 !
which is currently,in progress would systematically identify the input ARS
'l, design parameters that have been used in the design for all safety related
'i systems and colisponents such that, should a defect be uncovered as a result of the program, cornetive actions can be simultaneously initiated. The corrective actions in general would consist of stiffening of a floor, a i_
column, or of a beam, or manalysis to examine design margins, or relocation of components as necessary. The completion of this verification program and corrective actions resulting will constitute final closeout 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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