ML19290D026
| ML19290D026 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 01/04/1980 |
| From: | Andognini G BOSTON EDISON CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-26, NUDOCS 8002150488 | |
| Download: ML19290D026 (3) | |
Text
e 7A B O STO N EDISON COMPANY GENERAL OFFICES SCO BovtsfoN STREET GOSTON, MaSBACNusETTs o219 9 G. CARL ANDOGNINI S U PE Rf MTENDE NT NuCLCAR CPEN ATIONS DEPARTMENT January 4, 1980 BECo. Ltr. #80-4 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA.
19406 License No. DPR-35 Docket No. 50-293 Response to IE Bulletin #79-26
Dear Sir:
In a letter dated November 20, 1979, you transmitted IE Bulletin #79-26 titled "Bo'ron Loss from BWR Control Blades".
Boston Edison Company was requested to review the following action items for applicability to Pilgrim Nuclear Power Station:
Item No. 1 The operating history of the reactor is to be reviewed to establish a record of the current B10 depletion averaged over the upper one-fourth of the blade for every c>ntrol blade; the racord is to be maintained on a continuing basis.
This action is required on all reactors whether shut-down for refueling or operating.
Response
The reactor operating history since plant startup was reviewed and a record of the B10 depletion' averaged over the upper one-fourth of the blade for every control blade has been established and will be maintained on a continuing basis.
Item No. 2 Identify any control blades predicted to have greater than 34 percent B10 deple-tion averaged over the upper one-fourth of the blade by the next refueling outage.
Describe your plans for replacement of identified control blades.
a.
b.
Describe measures which you plan to take justifying continued operations until the next refueling specifically addressing (1) any blade with greater than 42 percent depletion averaged over the upper one-fourth of the blade; 8002150 fgg
BOSTON EDISON COMPANY Mr. Boyce H. Grier, Director January 4, 1980 Page 2 and (2) the condition where you find greater than 26 percent of the control blades calculated to have greater than 34 percent depletion averaged over the upper one-fourth of the blade.
Response
No control blades were predicted to have greater than 34 percent B10 deple_
tion averaged over the upper one-fourth of the blade by the next refueling outage.
a.
N/A b.
N/A Item No. 3 At the next cold shutdown or refueling outage, conduct shutdown margin tests to verify that:
a.
full withdrawal of any control blade from the cold xenon-free core will not result in criticality; and b.
compliance with the shutdown margin requirement in a manner that accommo-dates the boron loss phenomenon (i.e., by including a plant specific increment in the shutdown margin that takes the potential loss of boron from control blades identified from evaluation of Item 1 into consideration).
Response a. & b.
Since there are no blades predicted to exceed 347. B10 depletien during a given cycle at Pilgrim Station, it will not be necessary to include additional nargin to account for potential loss of boron in the Shutdown Margin Demonstration Tes t.
Item No. 4 Perform a destructive examination of the most highly exposed control blade at the end of the next cycle and provide results of the examination within one calendar year after removal of the blade.
The results to be reported should include:
a.
Tube number or identification.
b.
The evaluation of each crack in the tubing.
c.
The calculated B10 depletion versus elevation for each tube.
d.
The measured B10 loss versus elevation for each tube.
e.
The maximum local depletion for tubes having no cracks.
f.
The maximum local depletion for tubes having no loss of boron.
Alternately, the results of a destructive examination of a blade of similar fabrication and operational history may be provided within one year of the date of issuance of this Bulletin.
If the highest local B10 depletion is less than 50 percent, this examination can be deferred until the next refueling.
BOSTON EDIGON COMPANY Mr. Boyce H. Grier, Director January 4, 1980 Page 3
Response
We are currently discussing this matter with General Electric and will respond to this item per the bulletin time frame.
Should you have any further questions or concerns in this area, please do not hesitate to contact us.
Very truly yours,
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United States Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operation Inspection Washington, D. C.
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