ML19211D185
| ML19211D185 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 01/04/1980 |
| From: | Peoples D COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-26, NUDOCS 8001170004 | |
| Download: ML19211D185 (4) | |
Text
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Commonwealth Edison
(
One First National Plaza. Chicago, lilinois V
Address Reply to: Post Office Box 767 Chicago, Illinois 60690 January 4, 1980 Mr. James G.
Keppler, Director Directorate of Inspection and Enforcement - Region III U.S.
Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Dresden Station Units 1, 2, and 3 Quad Cities Station Units 1 and 2 Response to IE Bulletin 79-26, Boron Loss from Control Blades NRC Docket Nos. 50-10/237/249/254/265 Reference (a) :
J. G.
Keppler letter to C.
Reed dated November 20, 1979
Dear Mr. Keppler:
Reference (a) transmitted IE Bulletin 79-26 which required a response for Dresden Units 1, 2, and 3 and Quad Cities Units 1 and 2 concerning the loss of boron from control blades.
Our responses to Items 1 End 2 of IE Bulletin 79-26 are provided in Enclosure 1 for Dresden 1, Enclosure 2 for Dresden 2 and 3, and Enclosure 3 for Quad Cities 1 and 2.
As indicated, responses to Items 3 and 4 will be made in accordance with the requirements of the Bulletin.
Please address any questions you may have concerning this matter to this of fice.
Very truly yours, 8 1 Tuyu D.
L.
Peoples Director of Nuclear Licensing Enclosure cc:
Director', Division of Reactor Operations Inspection \\ 8001170 d)CIb
~ 'l ENCLOSURE 1 DRESDEN 1 RESPONSE TO IE BULLETIN 79-26 l BORON LOSS FROM BWR CONTROL BLADES Item 1 Edison's Nuclear Fuel Services Department routinely calculates the boron depletion history for each of the 80 control blades in the Dresden 1 reactor. In the past, this information has been calculated on a nodal and blade average basis. To comply with the Bulletin, the EOC 11 B10 depletion data for the three nodes composing the upper one-fourth of each blade were averaged. This method will be continued for future Dresden 1 operations. Item 2 No blades reached 34% B depletion averaged over the upper one fourth of the blade during Cycle 11 operation. Routine blade shuffling combined with the replacement of up to 8 lead exposure blades with new blades at'BOC 12 will prevent any blades from reaching this value of B10 depletion during the upcoming cycle. The current blade management program should minimize the possibility of this occurrence in future cycles. Items 3 and 4 Items 3 and 4 will be responded to in accordance with the requirements of the bulletin. T76'1 236 4
ENCLOSURE 2 DRESDEN 2/3 RESPONSE TO I.E. BULLETIN 79-26 6 BORON LOSS FRO:1 BWR CONTROL BLADES Item 1 10 depletion averaged over the top one-fourth A record of current B of each control blade in Dresden Units 2 and 3 has been established, and station procedures are now being revised to include a monthly check of current control blade B10 depletion. This information then is used to make predictions of future control blade exposures. Item 2 The table below categorizes present upper one-fourth segment average blade exposures and identifies the number of blades which are predicted to exceed 34% B10 depletion by the next refueling outage. Total Number of Number of Blades Blades Predicted to Currently >34% Execed 34% by Next Outage D2 3 26 D3 0 0 Item 2a 10 All control blades predicted to reach 34% B depletion during this cycle or the next will be replaced in the next refueling outage, at which time the possibility of shuffling less depleted blades also will be investigated. The same strategy will be used during future outages. Item 2b Our records and predictions indicate that no condition will be reached in current operating cycles where any blades attain greater than 42% B10 depletion (averaged over the top one-fourth of the blade) or where greater than 26% of the control blades exceed 34% depletion on Units 2 or 3. Items 3 and 4 Items 3 and 4 will be responded to within the time frame identified in the bulletin. 17151 237 . ~,..,-
ENCLOSURE 3 QUAD CITIES 1/2 RESPONSE TO IE BULLETIN 79-26 BORON LOSS FROM BWR CONTROL BLADES Item 1 The review of the operating history of the Quad-Cities Station control blades has found maximum control rod segment exposures of 1.37 snvt and 1.08 snvt for gnit one and Unit Two, respectively. This translates into maximum B delpletions, averaged over the upper quarter of the blade, of 22.8% for Unit One and 18.1% for 10 Unit Two. be25%ofB{gncethethresholdforB leaching is believed to depletion, no boron leaching ris expected to have occurred. Review of control rod exposures will be made on a continu-ing basis. = Item 2 No control blades are expected to have greater than 34 percc 10 B depletions, averaged over the upper one-fourth of the blade, by the next refueling outages. Continued review of control blade exposures shggld minimize the possibility of control rods exceeding 34 percent B depletion. Items 3 and 4 Items 3 and 4 will be responded to in accordance with the requirements of the bulletin. 1761 238}}