ML19263D040
| ML19263D040 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/13/1979 |
| From: | Rueter D ARKANSAS POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| 1-039-6, 1-39-6, NUDOCS 7903200471 | |
| Download: ML19263D040 (2) | |
Text
H E L P t !J G BUILO ARKANSAS ARK ANS AS POWER G LIGHT COMPANY P O BOX 551
- UTTLE AOCK. AAKANSAS 722o3 * [501) 371-4191 March 13, 1979 DONALD A. RUETER OtAECTOR TE(.;HNICAL ANC ENVIAONMCNTAL SERVICES 1-039-6 Mr. Robert W. Reid, Chief Division of Operating Reactors Branch #4 U. S. Nuclear Regulatory Commission Washington, D. C. 20555
Subject:
Arkansas Nucleat One-Unit 2 Docket No. 50-313 License No. DPR-51 Technical Specification Change Requesc (File:
1511.1)
Gentlemen:
Our January 19, 1979 submittal proposed a change to the Arkansas Nuclear One-Unit 1 (ANO-1) Technical Specification concerning Steam Generator Tube Surveillance. This letter supplements and provides additional basis for that submittal.
Our present specifications require:
"Where experience in similar plants with similar water chemistry indicates critical areas to be inspected, then at least 50%
of the tubes inspected shall be from these critical areas."
The experience of similar plants is indeed valuable, and, com-bined with the evidence collected during our inspections, we can now define these " critical areas".
We have found that many of our degraded or defective tubes are in areas having irregular flow conditions and/or fluid properties, such as those with a drilled opening in the fifteenth support plate, or that area composed of tubes within three rows of the open in-spection lane. Due to the high percentage (- 57%) of the total number of tubes having reportable imperfections being located in these specific areas, we feel these areas should be closely monitored.
By inspecting 100% of the tubes in these areas, g
we can more effectively monitor and control leakage that may yI develop in our steam generators.
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Mr. Robert W. Reid, Chief March 13, 1979 We propose that tubes in the critical areas not be included in the sample for which the results determine the required ections per Tabic 4.18-2.
The required actions for results of inspections of the critical areas are defined in Note (2) below Table 4.18-2.
Also we propose that the inspection intervals should be independent for each group. This will assure that a group with a problem is inspected at timely intervals, but will not penali::e a group with good inspection results to frequent, redundant inspections. As the specification states now, one of the problem groups may have inspection results which fall into Category C-3, but the inspection results for the entire sample may not if the other groups show good results.
You will note that wc have also removed the Prompt Notification requirement from the C-2 Result classification in Table 4.18-2.
We feel that prompt notification is unwarranted for results in this classification and redundant to the report required by Technical Specification 4.18.6 within 45 days of inspection completion.
Finally, w; feel that the proposed technical specification will increase the margin of safety through closely monitoring known problem areas. This change will ultimately reduce exposure to personnel because prolonged tube inspections due to action required from results of samples taken from knowm problem areas will be reduced.
Very truly yours,
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Donald A. Rueter DAR: ERG:1g