ML20044A621
| ML20044A621 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 05/25/1990 |
| From: | Roberts T NRC COMMISSION (OCM) |
| To: | Evans L HOUSE OF REP., APPROPRIATIONS |
| Shared Package | |
| ML20044A622 | List: |
| References | |
| NUDOCS 9006290295 | |
| Download: ML20044A621 (1) | |
Text
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.[p Mo I'o UNITED STATES m
gg NUCLEAR REGULATORY COMMISSION 7
W ASHING TON,0. C. 20$66
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May 25, 1990 CHAIRMAN -
The Honorable Lane Evans United States House of Representatives Washington, D.C.
20515
Dear Congressman Evans:
i I am responding to your letter of May 3, 1990, in which you requested to' be kept.up-to-date concerning the cracks discovered in the reactor vessel head of Quad. Cities, Unit 2.
As you noted, the NRCnstaff held a meeting
,s with Connonwealth Edison (the licensee) on April 19, 1990,'to discuss the cracks. Enclosure 1 is a copy of. the meeting summary. After reviewing the infomation presented at the meeting, the staff concurred that.
1,
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operation with the cracks; poses no safety concern.
Further,~the staff has-determined that the actions taken by Commonwealth Edison were timely and appropriate.
The licensee's examination and analysis revealed that most of the cracking was contained in the cladding, which is a stainless steel coating on the ins lde of the reactor vessel head and is not required;to maintain-strut tural integrity of the vessel. -For those cracks that occurred in the low-alloy steel reactor vessel-head, the deepest crack in.the base ~ metal i
penetra1.ed to a depth that was only about five percent of the total-L
.four-inch thickness of the vessel dome.
According to the-licensee's evaluation, the maximum predicted growth of the cracks over the remainder of this operating cycle should not be significant and therefore would not compromise the; structural integrity of the vessel.
In its letter of May 4,1990 (Enclosure 2), Commonwealth Edison committed l
to inspect the reactor vessel head at-the-next refueling outage, which is scheduled for Septenher 1991. The NRC staff will. review the results of that inspection and will detemine whether any expected growth of:the-cracks might compromise structural integrity of the vessel.
The NRC will continue to monitor the. situation through its nomal; inspection program.
As you requested, we will keep you updated on this' matter by sending you additional documents as they become available and'by notifying you of any planned meetings.
i Sincerely, Thomas M. Roberts Acting Chairman
Enclosures:
E TO(T ASCH SCAN As stated 9006290295 900525 Tl-PDR CONNS NRCC CORRESPONDENCE PDR
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