ML20207L542
| ML20207L542 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/05/1986 |
| From: | Eenigenburg E COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 86-145, CAL-85-04, CAL-85-4, NUDOCS 8701120223 | |
| Download: ML20207L542 (2) | |
Text
[
]
Commonwealth Edison
-t r Dresden Nuc'rt Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920 November 5, 1986 DJS LTR:
86-145 James G. Keppler Regional Administrator Director of Inspection and Enforcement Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Reference:
DJS Ltr.86-368 to J. G. Keppler from D. J. Scott, dated May 29, 1986.
Dear Sir:
This letter is in reference to the Confirmatory Action Letter 85-04 regarding the Main Steam Line Snubber Monitoring System for Dresden Unit 2.
Item 2 of this Confirmatory Action Letter requires a verbal notification to Region III within 2 working days followed by a written report and safety evaluation within 30 calendar days.
One occurrence has been identified during this reporting period:
Occurrence #36 Notification made to I. Yin by G. Smith on October 10, 1986 The written report and safety evaluation for this occurrence is attached.
Sincerely, E. D. Een e urg Station Mhna er Dresden Nuclear Power Station DJS:JW:hjb Enclosure cc:
J. Almer J. Welch J. Achterberg l
J. Williams File / Misc.
File / Numerical g
l jPj"$$SEb!!il7
- @ 10 m o
1L 3b
(
C.
fn Occurrence #36 On October 9, 1986, at 0840 hours0.00972 days <br />0.233 hours <br />0.00139 weeks <br />3.1962e-4 months <br />, Unit 2 was operating in coastdown at a steady power level of 89.1% (2252 MWt) and a load of 720 MWe when the Strain Gauge (SG) associated with snubber #53 exhibited two negative spikes in excess of 200 kips in less than 200ms and thereafter remaining constant at-120 kips. The corresponding Linear Variable Displacement Transformer (LVDT) for that snubber exhibited no linear movement during the strain gauge indi-cations or any time thereafter. Upon investigation of the equipment outside the drywell no abnormalities were discovered. As a corrective action this strain gauge was taken out of service to prevent the continuous tripping of the monitor. At the next opportunity an investigation of the drywell equip-ment will be performed to determine the source of the signal distortion.
Since no abnormalities or unusual steam line transients have been identified the safety significance of this event is minimal.