ML20084C285
| ML20084C285 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/19/1984 |
| From: | Curtis N PENNSYLVANIA POWER & LIGHT CO. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8404270191 | |
| Download: ML20084C285 (3) | |
Text
PPat Pennsylvania Power & Light Company Two North Ninth Street e Allentown, PA 18101 e 215 / 770 5151 Norman W. Curtis -
Vice President-Engineering & Construction-Nuclear 215/770-7501 L
APR 191984 i
Dr. Thomas E. Hurley
( --
Regional Administrator, Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 I'
SUSQUEHANNA STEAM ELECTRIC STATION FINAL REPORT ON A DEFICIENCY INVOLVING SDV VENT & DRAIN VALVE WATERHAMMER ER 100508 FILE 821-10 i
PLA-2116 Docket No. 50-388 i
References:
(1) PLA-1762 dated July 29, 1983 (2) PLA-1987 dated December 14, 1983 l
l
Dear. Dr. Murley:
This letter serves'to provide the Commission with a final report on a deficiency' involving waterhammer loading on the scram discharge volume (SDV) vent & drain lines after opening the SDV vent & drain valves on scram reset.
This deficiency was reported under 10CFR50.55(e) as potentially reportable by ~
telephone to Mr. G. Rhoads of NRC Region I by=Mr. J. Saranga of PP&L on June 28, 1983.
i..
A description ~of this-problem, the cause, and the safety implications were provided to the Commission in Reference (1).
Reference (2) submitted updated
~information to the NRC regarding the status'of PP&L's corrective actions.
This letter provides the.results and conclusions from our program.to examine this deficiency. The results 'of the testing and : analyses to resolve. this concern were' received in mid-March from Teledyne Engineering Services,-the
-testing contractor.. The reports for Unita 1 & 2 are available for NRC
. inspection.
The resultsof the Unit I test and supporting: computer analysis indicate that the'ma:.imum Unit.I SDV. reset stress in the vent line is:less than 1,000 psi
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and is approximately 6;500 psi for the drain 1ine.- The maximum Unit I-SDV reset waterhammer support loads are 154 lbs.'and'465 lbs. for the vent and L
drain. lines, respectively. The: evaluation of the pipe stresses and support i
loads'.against'the CRD Design Stress Report indicates that the' pipe stresses
~
are satisfactory and'estisfy the design criteria. The support loads are.
satisfactory with the exception of!the loads on support IN65'on the drain line-
'and-1858 on the vent-line. The. drain line support required the. addition of a brace and was upgraded accordingly during the recent (3/3-3/23/84) ReactorJ Recire. Valve' stem repair. outage. The. vent line support requires'an additional clamp to provide added restraint in the axial direction. Under the.
current design the waterhammer loads'slightly exceed the capacity of the
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clamp. However. a substantial number of scram cycles would-be needed before a.
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Page 2 SSES PLA-2116 APR 19 7984 ER 100508 Pile 821-10 Dr. Thomas E. Murley serious overstress condition would develop. We expect to modify this support prior to the end of 1984.
The results of the Unit II test and supporting computer analysis indicate that the maximum Unit II SDV reset stress in the vent and drain line piping is 4,400 psi and 4,200 psi, respectively. The maximum support loads caused by reset waterhammer are 683 lbs. and 1,060 lbs respectively. The evaluation of the pipe stresses and support loads against the CRD Design Stress Report indicates that the pipe stresses are satisfactory and satisfy the design criteria. This evaluation also indicates that all of the support loads are satisfactory except that the pipe clamp capacity in the axial direction is exceeded for one support on the drain line and six supports on the vent line.
These supports will be modified prior to initial criticality on Unit II under DCP 84-3064. A justification for interim operation until initial criticality was provided to your Mr. R. H. Jacobs, Susquehanna Sr. Resident Inspector, prior to Unit 2 fuel load.
In Reference (2), it was indicated that a cold test (TP-155-03) was expected to be performed on Unit 1 after the hot test (TP-155-02). The. cold test was not implemented because sufficient information was received from the hot test.
l Since the pipe clamp capacity is exceeded for one support on the drain line and six supports on the vent line, a possibility existed for a pipe leak sometime over the 40 year life of the plant if corrective action had not been taken. Consequently PP&L feels that this deficiency is reportable under 10CFR50.55 (e). We trust the Commission will find this report to be satisfactory.
~
Ker truly yours, V
n: = =%
N. W. Curtis Vice President-Engineering & Construction-Nuclear
.a W
l*o Page 3 SSES PLA-2116 APR 19 2384 ER 100508 File 821-10 Dr. Thomas E. Murley Copy to:
Mr. Richard C. DeYoung (15)
. Director-Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. G. Mcdonald, Director Office'of Management Information & Program Control
-U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. R. H. Jacobs U.S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655 Records Center Institute of Nuclear. Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, GA' 30339 T
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