ML19339C496
| ML19339C496 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 11/12/1980 |
| From: | Davidson D CLEVELAND ELECTRIC ILLUMINATING CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8011180491 | |
| Download: ML19339C496 (3) | |
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.s P o Box 5000 e CLEVELANo. ohio 44101 e TELEPHcNE (216) 622-9800 e ILLUMINATING BLOG.
e 55 PUBLICSCUARE Serving The Best Location in the Nation DaNnn R. Davidson November 12, 1980 WCE PRESIDENT SYSTEM ENGINEERING AND CoNSTRUCuoN Mr. James G. Keppler j
Director of Region III Of fice of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Joad Glen Ellyn, Illinois 60137 a
RE:
Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Interim Report on Problem with Stainless Steel Cladding Inside Containment
Dear Mr. Keppler:
This letter is presented as an Interim Report as required by 10CFR50.55(e) concerning progress made in the i. estigation of a potential problem with the stainless steel cladding in ths suppression pools of both Units 1 and 2.
This item was initially reported by Mr. M. R. Edelman of the Cleveland Electric Illuminating Company to Mr. J. E. Konklin of your office on October 6, 1980.
Mr. P. L. Gibson and Mr. K. R. Pech from Project Organization participated with Mr. Edelman in the call.
An extension for the submittal of this interim report was requested of and granted by Mr. Konklin during a telephone conversation with Mr. Kacer on November 6,1980.
This report includes a description of the problem, planned corrective action, and the planned date for submittal of the final report.
Defir.t cion of Potential Problem:
It appears that the clad material composed of SA 516 Grade 70 plate with a 10-15% cladding of SA 240 Type 304 stainless steel may have become sensitized (i.e., carbide precipitation) during the normalizing process, thereby raising questions as to the effectiveness of the material as a corrosion protection barrier for the carbon steel plate behind it.
The stainless cladding may also have become embrittlet and, therefore, may no longer Se capable of performing as a strength element if used in such a capacity.
Background Information:
During the PT (dye penetrant) inspection of weld seams in the 304 clad material, micro-fissures were detected L1 the heat affected zone of the veld. Attempts to weld repair these fissures have resulted on some occasions in a propagation of the fissures into the area adjacent to the repair veld.
On other occasions, the repair was successful. The continued use of weld repair as a general solution to the repair of these fissures is now questionable until the extent of the overall problem has been more specifically identified.
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.L "r. James G. Keppler November 12,.1980 Establishing Extent of Problem:
1.
Determine if fissures develop or are present in all 304 clad material used.
2.
Determine if cracking is confined to heat affected zones.
3.
Tabulate mill certifications for carbon and physicals.
4.
Review carbon levels of material used to determine whether a correlation with fissuring exists.
5.
Map sensitized areas.
6.
Determine whether problem is limited to corrosion or also includes structural integrity.
Evaluation of Problem:
1.
Perform ev'aluation. of physical tests and metallegraphy to establish micro-fissure depth, frequency, and effect on physical properties.
2.
Establish water quality expected in plant operation for suppression pools.
3.
Determine effects of mirco-fissures on decontamination.
4.
Petermine effects of fissures on corrosive life of suppression pool liners.
5.
Compare fissuring of 304L versus 304 stainless steel.
Planned Corrective Action:
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Utilizing the information developed by the testing program described herein, j
determine whether the strength of material minus the stainless steel cladding meets design requirements.
In addition, establish the effects of micro-fissuring 1
on corrosion life expectancy and if it is found that corrosion is not a major problem, then develop criteria for fissures acceptable without repair. If corrosion is a major problem, determine What must be done wit 3 v.he clad matetial in question.
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Mr. Jemas C. K2pplar November 12, 1980 Planned Date For Final Report:
The final report will be submitted to the NRC by March 1,1981.
This time is required to complete testing program, perform engineering evaluation of test results,- and identify the action to be taken regarding the stainless steel clad in question.
f Ve,ry truly yours,?
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D. R. Davidson Vice President System Engineering and Construction ksz cc:
Mr. Jack Hughes Resident NRC Inspector Mr. Victor Stello, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 U. S. Nuclear Regulatory Commission c/o Document Management Branch Washington, D. C.
20555 i