ML17037B870

Letter and Enclosed Report on the Deficiency Concerning Structural Steel Copes, an Analysis of the Safety Implications, and the Corrective Action Taken

ML17037B870
Person / Time
Site:	Nine Mile Point
Issue date:	02/09/1978
From:	Rhode G Niagara Mohawk Power Corp
To:	Robert Carlson NRC Region 1
References
Download: ML17037B870 (8)

Text

REC:

CARLSON R T NRC REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

DISTRIBUTION FOR INCOMING MATERIAL 50-410 ORG:

RHODE G K DOCDATE: 02/09/78 NIAGARA MOHAWK PWR DATE RCVD: 02/15/78 DOCTYPE:

LETTER NOTARIZED:

NO

SUBJECT:

FINAL DEFICIENCY REPT CONCERNING NOTCHING AND IMPROPER REPAIR WELDING OF STRUCTURAL STEEL COPES AT UNIT 2.

COPIES RECEIVED LTR 1

ENCL 1

PLANT NAME: NINE MILE POINT UNIT 2 REVIEWER INITIAL:

XJM DISTRIBUTOR INITIAL:

DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS CONSTRUCTION DEFICIENCY REPORT

< 10CFR50. 55 ( E ).

(DISTRIBUTION CODE 8004>

FOR ACTION:

ASST DIR VASSALLO++LTR ONLY PROJ E44LTR ONLY BRANCH CHIEF VARGA>>LTR ONLY LIC ASST SERVICE<<LTR ONLY INTERNAL:

EXTERNAL'EG FILE+4W/

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GOSSICK 8( STAFF4+LTR ONLY BOYD++LTR ONLY HELTEMES++W/ENCL KNIGHT4+LTR ONLY TEDESCO++LTR ONLY STANDARDS DEV. ++W/ENCL LPDR'S OSWEGOr NY4'4'W/ENCL TIC++W/ENCL NS IC4 +W/ENCL ACRS CAT 34+W/1,6 LTRS NRC PDR4+W/ENCL OELD++LTR ONLY MIPC< +W/ENCL DEYOUNG++W/ENCL R.

MATTSON++LTR ONLY ROSS++LTR ONLY EISENHUT+4LTR ONLY K SEYFRIT/IE4+W/ENCL DISTRIBUTION:

LTR 40 ENCL 28 SIZE:

1P+2P THE END CONTROL NBR:

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KmIVmc>Xmr rltrN)W NIAGARAMOHAWKPOWER CORPORATION/300 ERIE BOULEVARDWEST, SYRACUSE, N.Y. 13202/TELEPHONE (315) 474-1511 February 9,

1978 Office of Inspection and Enforcement Region I Attention:

Mr. R. T. Carlson, Chief Reactor Construction and Engineering Support Branch U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pennsylvania 19406 n

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C04II I ~'tee 4%q~sse4 I~

Re:

Nine. Mile Point Unit 2 Docket No. 50-410

Dear Mr. Garison:

Attached is the final report of the deficiency concerning structural steel copes at our Nine Mile Point Unit 2 construction site.

This condition was reported to your staff orally on December 9,

1977 and in our January 9,

1978 letter.

In accordance with Section 50.55(e)(3) of the Commission's regulations, the final report includes a

description of the deficiency, an analysis of the safety implications and the corrective action taken.

Very truly yours, NIAGARA MOHAWK POWER CORPORATION I

~c,.lC.

'Gerald'.

Rhode', Vice President System Pro)'ect Management PEF/szd 7>oq6004'5 Attachment Xc:

. Ernst Volgenau, Director Inspection and Enforcement Branch U.

S. Nuclear Regulatory Commission Washington, D.

C.

20555

DESCRIPTION OF DEFICIENCY On May 3, 1977 Mr. A. Toth, our Region I NRC Inspector, informed personnel at our Nine Mile Point Unit 2 construction site of a potential generic problem involving notching and improper repair welding of structural steel copes.

During fabrication, structural steel was inspected at the fab-rication shop on a random basis by Stone 8 Webster Procurement guality Control Inspectors in accordance with the Stone 8 Webster specification.

Although this specification required compliance with the AISC specification and Code of Standard

Practice, there was no specific attribute indicating that the 4" minimum cope radius or its condition should be checked.

Upon receipt at the construction site, structural steel was receipt inspected, but again no specific measurement of copes was required.

Subsequently, site guality Assurance personnel identified copes in guality Assurance Category I beams which did not conform to the j;" minimum radius and notch-free requirements of Section 1.23.2 of the AISC specification.

II.

ANALYSIS OF SAFETY IMPLICATIONS An inspection of the 145 pieces of guality Assurance Category I structural steel received at the site revealed the following:

l.

31 pieces in storage are unsatisfactory due to failure to meet the >" minimum cope radius.

2.

3 pieces in storage are unsatisfactory due to notches in the web cope.

3.

2 pieces in storage are unsatisfactory due to porosity and undercut of welding in the cope area.

4.

2 pieces installed are unsatisfactory due to improper flange blocks.

Reinspection of the two erected beams showed that they had flange blocks which did not meet the ~" minimum radius criterion, but that they did not have web copes or notches.

Investigation in-dicated that the flanges at the blockouts were reinforced, providing an acceptable load path, therefore, they are acceptable.

Copes of the thirty-six remaining guality Assurance Category I structural steel beams with less than >" radius, improper welds and/or notches could lead to beam failure under certain loading conditions and are therefore not acceptable.

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III. CORRECTIVE ACTION As a result of a consultation<wi,th AISC authorities concerning the interpretation of the cope criteria, an Engineering and Design Co-ordination Report has been issued which contains details for ensuring full compliance with AISC cope requirements.

This report states that copes must have a minimum radius'>of.~, andbe, notch-free.

Local gages and bumps with a maximum depth/hei'ght'iof 1/8" are allowed if smooth and not sharp.

The structural steel fabricator, Gives Corporation, has initiated shop practices to provide a nominal 3/4" cope radius to ensure future compliance with the 4" minimum required by the AISC specification.

All of the coped structural steel beams which have been fabricated, erected and delivered were inspected for compliance with Section 1.23.2 of the AISC specification.

Nonconforming pieces have been hold tagged.

Repairs will be performed to bring the web copes into compliance with the 4" minimum radius and notch-free criterion.

Stone 5 Webster's Procurement guality Control Inspectors have been instructed to check for proper copes when they perform their random inspection of shop fabrication work.

Stone 8 Webster's Field gual-ity Control Group will also perform a 100 percent inspection of structural steel for correct cope at receipt inspection.

These measures will ensure that no nonconforming structural steel will be satisfactorily accepted into storage or installed at the Nine Nile Point Unit 2 construction site.

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