ML20087L657
| ML20087L657 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 02/08/1974 |
| From: | Burstein S WISCONSIN ELECTRIC POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20087L649 | List: |
| References | |
| NUDOCS 8403270332 | |
| Download: ML20087L657 (2) | |
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%s__,s WISCONSIN Electnc muncome 231 WEST MICHIGAN, MILWAUKEE, WISCONSIN 53201 i
February 8, 1974 Mr. Jamce G. Koppler, Regional Director Directorate of Regulatory Operations, Region III U.
S. Atomic Energy Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
DOCKET NOS. 50-266 AND 50-301 POINT BEACII NUCLEAR PIANT ABNORMAL OCCURRENCES IN PIPING SYSTEMS In reply to your letter of January 11, 1974, and its attached R.O. Information Request 74-1, " Abnormal Occurrences in Piping Systems", this is to advisc you that revicw of records at Point Beach Nuclear Plant has' revealed only one instance of a L
piping vibration event.
This instance of vibration occurred in Class B piping and would not normally be the subject of a report to the AEC Directorate of Regulatory Operations.
On December 30, 1971, during a heatup of Unit 2 reactor from the cold shutdown to the hot shutdown condition, vibration was noted in the residual heat removal piping in Unit 2 containment.
The reactor coolant system pressure and tempera-3 ture at that time were 900 psig and 375'F, respectively.
At least l
one reactor coolant pump was running.
I system was not in service.
The vibration was first noticed at valve 2MOV-701, this being the first-off valve from the "A" main coolant loop on the ten inch piping to the suction side of the residual heat re-
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moval pumps.
The report on the vibration noted-it as consider-able at the pressure and temperature noted, then decreasing to negligible as the heatup continued.
Startup personnel of the system designer, Westing-house Electric Corporation,' wore informed and a representative of that company sketched the piping layout and took some rudi-montary measurements indicating that the vibration was observ-l' able on much of the length of this pipe where it ran within~the containment.
The same piping did not vibrate beyond the contain-ment boundary.
No physical damage of the pipc's hangers or sup-r ports could be found.
8403270332 740212 PDR ADOCK 05000266 S
PDR FEB i 1 4nyt t
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o Mr. James,G. Keppler February 8, 1974 In the two years since this single occurrence, it shas not been possible to duplicate the exact conditions that created the vibration.
Extended plant operation at power and very few cold shutdown to hot shutdown heatups have kept this piping well outside the narrow range of pressure and tempera-ture at which it was observed to vibrate on this one occasion.
The question of this pipe's vibration was raised orally with Westinghouse Electric Corporation again in October of 1973; no report having been made by them on the initial sketches and data taken by their personnel.
Their written reply, dated November 9, 1973, indicates they will be prepared to make a representative available to take further measurements on this piping during the heatup of Unit 2 following the refuel-ing of this unit in November, 1974.
As indicated, we are attempting to evaluate this experience further, including the possibility of duplicating the specific conditions which appeared to have generated this vibration.
Should our investigation show that a vibration prob-lem can exist in this piping, even under very specific condi-tions, we will inform you further.
t Very truly yours, Sol Burstein Exec tive Vice President cc:
Assistant Director for Construction and Operation Directorate of Regulatory Operations i
U. S. Atomic Energy Commission
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Washington, D. C.
20545 i'
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