ML17194B491
| ML17194B491 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/17/1983 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| CAL, NUDOCS 8303220068 | |
| Download: ML17194B491 (2) | |
Text
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~ONFIRMATORY ACTION LETTER Docket No. 50-237 Commonwealth Edison Company ATTN:
Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
MAR 1 7 1983 This refers to the telE;!phone discussion between Messrs. R.Rybak and J. Wujciga and others of your staff and Mr. W. S. Little and members of the Region III staff on March 14, 1983, regarding mechanical snubber damage inside the drywell, on the Dresden Station, Unit 2 Main Steam (MS)
Lines B, C, and D.
With regard to the matters discussed, we understand that you will complete Items 1 through 5 prior to returning Unit 2 to power operation, notify Region III within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after completion of Items 7 and 8, and provide data and inspection results to Region III as discussed in Items 6 and 9.
- 1.
Functionally test all snubbers installed on the MS and the Safety Relief Valve (SRV) discharge lines inside the drywell.
- 2.
Non-destructively examine the portions of the MS and SRV discharge lines that are:
(1) in the vicinity of the snubber failures, and (2) in high stress areas determined by analysis.
- 3.
Visually inspect, inside the drywell and torus, the structural attach-ments, auxiliary steel members, main structure, and all fasteners, including concrete expansion-type anchor bolts, where all MS and SRV discharge line snubbers, rigid strut restraints, and pipe whip restraints are connected.
- 4.
. Visually inspect the entire MS and SRV discharge piping suspension system components within the containment boundary.
Those that are submerged in the suppression pool water are to be excluded.
- 5.
Repair, replace, readjust and modify as necessary, all defective structures and piping suspension system. components.
- 6.
Perform system tests based on testing outlined in Items 7 and 8 below.
Upon completion, have test procedures, measurement data, and youi evaluation of the results available for Region III review within 7 days after completion of testing.
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~NFIRMATORY ACTION LETTER
- Commonwealth Edison Company 2
MAR 1 7 1983
- 7.
Thermal expansion piping displacement test data is to be taken at all piping suspension system component locations on all four MS lines, and on the SRV discharge piping for MS lines C and D.
The measurements should be taken at (1) line temperature less than 120°F, and (2) MS operating temperature between 450°F to 550°F.
- 8.
Piping dynamic test data is to be taken and should include instru-mented measurements to provide a means to directly obtain or to calculate piping maximum dynamic forces and movements at the con-cerned locations.
The snubber reaction loads should be continuously monitored at all previously failed snubber locations.
The dynamic plping movements should be measured in terms of the piping axial, the horizontally lateral, and the vertically lateral directions for MS lines C and D where maximum displacements are expected based on engineering evaluations.
The testing should be conducted (1) at normal system operating temperature and pressure, and (2) for SRV lift and closure.
- 9.
Report to Region III within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after identification, all (1) damaged structures and components identified in Items 1 through 4, and (2) test results identified in Items 7 and 8 that deviate from existing conditions specified in ASME Code Stress Reports.
Please inform us immediately if your understanding of these actions is different from that stated above.
"Original Signed by James G. Keppler" cc:
D. L. Farrar, Director of Nuclear Licensing D. J. Scott, Station Superintendent James G. Keppler Regional Administrator DMB/Document Control Desk (RIDS)
Resident Inspector, RIII RIII Karen Bargstadt, Office of Assistant Attorney General R. Gilbert, NRR R. Bevan, NRR J. Axelrad, IE J. Taylor, IE E. Jordan, IE
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