ML19207C025

Discusses Seismic Analysis of safety-related Piping. Configuration Input for All 195 Isometrics for safety- Related Piping Have Been Reviewed.Twelve Elbows & Three Large Radius Bend Isometrics Were Improperly Configured

ML19207C025
Person / Time
Site:	Brunswick
Issue date:	08/30/1979
From:	Utley E CAROLINA POWER & LIGHT CO.
To:	Ippolito T Office of Nuclear Reactor Regulation
References
GD-79-2161, NUDOCS 7909060325
Download: ML19207C025 (4)

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_ i August 30, 1979 FILE: NG-3514(B) SERIAL: GD-79-2162 Office of Nuclear Reactor Regul . ion Attention: Mr. T. A. Ippolito, Chief Operating Reactors Branch No. 3 United States Nuclear Regulatory Commission Washington, D.C. 20555 BRUNSWICK STEAM ELECTRIC PLANT LICENSE NOS. DPR-71 and DPR-62 DOCKET NOS. 50-325 AND 50-324 SEISMIC ANALYSIS OF SAFETY RELATED PIPING

Dear Mr. Ippolito:

During the week of August 13, CP&L and United Engineers & Constructors, our architect-engineer for our Brunswick Steam Electric Plant (BSEP), discussed with your staff a problem with the computer program, UESC-ADLPIPE-2, used to perform seismic pipe stress calculations on safety-related piping. Two types of problems were discussed: if the piping configuration was input incorrectly for pipe elbows (Problem 1) or for large radius bend (Problem 2) , the computer program would make internal adjustments to the configuration and would continue to calculate pipe stress, rather than aborting the run with an errer message that configuration input was incorrect. If input data was correct, the correct stress was calculated.

As committed to you in our telephone conversations and documented in our letter to you on August 17, 1979, we have reviewed the configuration input for all 195 isometrics for safety-related piping. When an error was detected in an isometric's input, the seismic stress analysis was rerun and the supports were reevaluated. The remainder of this lette;- describes the review, reanalysis and results for those isometrics where an inpt.t error was found.

Problem 1 - Pine Elbows The 195 isometrics contain 1515 elbows. Of these, only 12 elbows had the incorrect configuration input into the computer model. This involved the eight isometrics identified in Table 1. The correct configuration has been input into the computer program for reanalysis and the results are tabulated on Table 1. All stresses are within FSAR allow-able. There were 81 pipe supports evaluated on these eight isometrics and during reanalyses the loads went up on only three supports. The loads on these three supports were significantly less than support capacities.

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Mr. T. A. Ippolito Problem 2 - Large Radius Bends In our letter of August 17, we listed 12 isometrics where the pr ' iem with large radius bends was identified. Upon closer review it was fo 2nd that three isometrics (No. 5 - RHR, No. 201 - Instrument Air, No. 202 -

Instrument Air) were input correctly. The remaining nine isometrics have been reanalyzed, and the results are shown on Table 2. All pipe stresses are within FSAR allowable. Of the total 157 pipe supports evaluated, the load increased on 52. Two supports on the feedwater line and one on an SRV discharge line were identified as requiring a long term fix (load greater than allowable but less than structural integrity). On this feedwater line, two supports which were previously identified for a long term fix had the loads decreased below allowable such that no fix is now required. Of the remaining 49 supports, all newly calculated loads were less than allowable.

A copy of the revised input configuration and the output from the latest run from the UE&C-ADLPIPE-2 program for the run provided to you previously at a meeting on May 16,1979, (main steam with four SRV lined) will be submitted to you within two weeks for your further evaluation and comparison. If you have any further questions concerning this issue, please contact our staf f.

Yours very trt?.y ,

[.' [.) //

E. E. Utley Executive Vice President Power Supply & Customer Services EEU/j cb

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8 BRUNSWICK STEAM ELECTRF. PLANT SEISf1IC PIPE STRESS REANALYSIS TABLE 2 PROBLEM 2 - LARGE RADIUS BENDS Total ( } Total Isometric Stress Stress Number System Line Size 7/23/79 8/27/79 Remarks

• 14 flain Steam 24" 12321 9861 39 Supports (including 1 SRVDL) 1-LTF 14A 11ain Steam 24" 9810 7286 10 Supports (including 1 SRVDL) All Okay 15B ttain Steam 24" 9096 7287 32 Supports (including 3 SRVD'.)

15C Malu Steam 24" 8897 7028 30 Supports (including 3 SRVDL) All Okay 124 S.R.V.D. 10" 19433 19563 9 Supports All Okay 125 S.R.V.D. 10" 24413 15386 7 Supports All Okay 16 Feedwate r 18", 12" 14710 12386 15 Supports, 2-LTF 32 llead Vent 2" 9376 15958 26 Supports All Okay 119 S.R.V.D. 10" 12583 21133 9 Supports All Okay CO b.

( Total Stress from reanalysis completed with 7/23/79 letter.

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SEISMIC PIPE STRESS REANALYSIS TABLE 1 PROBLEtt 1 - P1PE ELBOWS Number of Total ( } Total Isome t ric Elbows With Stress Stress 7/23/79 8/27/79 Remarks Number System Problems Line Size 8 Reactor liead Vent 3 2", 1", 1/2" 35181 35181 24 Supports All Okay (2) 27 CRD 2 3" 8307 6123 11 Supports All Okay 44 RllR Torus Spray 1 6" 5068 6630 No Supports 121 SRV Discharge 2 10" 21910 17073 7 Supports All Okay 187 SRV Discharge 1 10" 20771 18938 8 Supports All Okay 178 Inst. Air 1 1" 3141 3141 14 Supports All Okay 606 Service Water 1 6" 13178 6969 12 Supports All Okay 662 Service Water 1 6" 2353 2428 5 Supports All Okay (I) Total Stress f rom reanalysis concluded with 7/23/79 letter.

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, Long-term fix for valve eccentricity previously reported

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