ML19351D052
| ML19351D052 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 09/18/1980 |
| From: | Gilberts D NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-79-14, NUDOCS 8010080651 | |
| Download: ML19351D052 (8) | |
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NSID NORTHERN STATES POWER COMPANY u e N N E A poC U S. M IN N E SOTA 55401 September 18, 1980 Mr. James G. Keppler Director, Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Cler r:11yn, IL 60137
Dear Mr. Keppler:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT Dockets No. 50-282 and No. 50-306 As described in earlier responses to IE Bulletin No. 79-14, the inspection is being conducted in two parts. These parts are first, physical and second, analytical.
A.
Physical Inspection l
The physical inspection included the actual verification of as-built drawings, by direct measurement and comparison.
Inspection elements involved in the physical inspection were piping geometry, support / restraint design, location, function, clearances, valve and valve operator locations and pipe attachment details. Teledyne Engineering Services (TES) pro-j cedure P-3697-1 and TES personnel were utilized for the actual inspection.
l B.
Analytical Inspection The analytical inspection portion involves the verification of input in-formation into seismic analysis. The bcsic approach being used is to re-view every walked down isometric drawing and hanger drawing and compare them with the data used for the seismic analysis.
Fluor Power Services, Incorporated, (FPS), the site architect / engineer, is performing the analy-tical portion of the inspection. For their review they have generated a procedure entitled " Procedure for the Verification of the Seismic Pipe Stress Analysis in Accordance with Field Walk Downs Performed by Teledyne Engineering Services". The following list contains the areas FPS is in-vestigating on each piping system.
1.
Verification Phase:
a.
Piping Geometry b.
Support and Restraint Type c.
Support and Restraint Location d.
Valve Locations 8 W0080 SEP 2 2 880 mod hp.
Mr. James G. Keppler September 18, 1980 Page 2 2.
Stress Analysis Review Phase:
a.
Valve Weights b.
Orientation c.
Location of Center of Gravity d.
Piping Sizes e.
Branch Connections f.
Piping Materials g.
Weight of Piping (are the correct weights input for the pipe and water and insulation) h.
Weights of Other Concentrated Masses (flanges, orifices, flow nozzles, etc.)
1.
Acceleration Spectras J.
Relative Displacement of Buildings k.
Stress Intensification Factor of 1.3 Input all Socket Welds (Field Routed Piping) 1.
Ensure all Upward (+Y) Pipe Hanger Loads are Adequately Restrained m.
Design Pressure n.
Radius Arm from Building Center of Mass o.
Torsional Constants C.
Extent of Inspection to Date All piping in the plant, both Units 1 and 2, which falls under the scope of this bulletin has been inspected physically.
The analytical inspections for these piping systems have not been completed but are in progress at the present time. Those portions of the piping sys-tems contained in Unit 1 containment have been completed and work is pro-gressing on the Auxiliary and Turbine Building, as well as on Unit 2 Con-tainment Building.
Status of Work Completed as of August 15, 1980 Weighted Percent Percent Percent Activity of Project Complete Complete Verification 20 100 20 Pipe Stress Engr. Review 5
95 5
Stress Analysis Review 40 91 36 Discrepancy Analysis 15 75 11 Discrepancy Reports 14 0
0 Summary Reports 4
0 0
Filing / Microfilming 2
0 0
Total 100 72
v Mr. James G. Keppler September 18, 1980 Page 3 D.
Results of the Inspection:
Results of the physical inspection for Unit #1 Containment, the Auxiliary Building and the Turbine Building were reported in a previous response to Bulletin No. 79-14 (60 day). Only the results of the physical inspection of Unit 2 Containment and the analytical inspection completed to date for all-buildings will be reported in this supplementary response.
Table 1, attached, lists the discrepancies found to date that have not been reported previously. Of these discrepancies, nonconformances were identified on two systems which were determined could affect operability of the system. The systems affected were:
- 1) the main steam lines, and
- 2) a portion of the cooling water system (service water). These two cases will be discussed in detail.
1.
Main Steam Lines See attached Fluor Power Services Report In addition to the FPS report, the following information is provided:
a.
The pipe clamp at point 270 has been modified for Unit #2.
The similar Unit #1 pipe clamp will be modified prior to Unit #1 startup after the ongoing refueling outage.
(See Page 7 of the attached report.)
b.
Modifications to Unit #1 where snubbers are attached to the en-capsulation sleeves will be made prior to startup.
(See Page 7 of the attached report.)
c.
Material for Phase II (temporary modification) is being procured and installation will follow receipt of material. Delivery dates are not yet available.
t 2.
Cooling Water Lines NOTE: The problem found on the cooling water lines was reported under LER-79-30.
3 During FPS review of the seismic analysis on a portion of the cooling water system, two snubbers (CWH-394 and 2 CWH-44) were discovered to have been installed in the wrong direction.
CWH-394 and CWH-44 are
)
hydraulic shock and sway supports that are intended to keep piping stress in the cooling water lines to the containment fan coil units j
within acceptable limits during a seismic event. During a seismic event these two snubbers would not have performed their intended
' function.
The apparent cause for the incorrect installation was that during initial plant construction a decision to standardize pipe support loading directions was made. CWH-394 and 2 CWH-44 appear to have been overlooked during the standardization process. The cooling water system was one of the systems that had its load direction designations changed.
a.
Mr. James G. Keppler September 18, 1980 Page 4 2.
Cooling Vater Lines (Continued)
To correct the problem both hangers CWH-394 and 2 CWH-44 were re-positioned where they could perform their design function.
Another problem on the cooling water system was uncovered during the review of piping modifications to the cooling water system inside Unit 1
- 1 containment. The modification included additional piping which was tied into existing cooling water lines. This design work was done by Stone & Webster.
Fluor Power Services' review of the effect of the modification on the existing piping system showed additional snubbers were needed on two of the lines. These snubbers are to be added during the September 1980 refueling outage.
E.
Schedule for Completion of the Analytical Inspection Phase Verification: Complete Pipe Stress Engineer Review: October 15, 1980 Stress Analysis Review: October 15, 1980 Discrepancy Analysis: October 15, 1980 Discrepancy Reports: November 30, 1980 Summary Report: November 30, 1980 Filing / Microfilming:
December 15, 1980 An additional report will be made at the completion of the project to report any additional discrepancies found.
Yours truly, We&-
D. E. Gilberts Vice President Power Production cc:
Mr. G. Charnoff Director - Office of Inspection and Enforcement Washington, D. C.
Director - Division of Operating Reactors Office of Nuclear Reactor Regulation Washington, D. C.
Mr. C. D. Feierabend, NRC Resident Inspector Attachment DEG:nk
TABLE 1 IE BULLETIN 79-14 PKG DISCREPANCY RESOLUTION STATUS 104 Portion'of chlorine line at C.W.
Analyze to ensure that pipe is Pending tie in never analzyed.
not overstressed 100 Valve weights and C.G.S improperly Reanalyzed - revise loads on hgr Pending imput detail sheets 217 119 Va'lve weights and C.G.s improperly Reanalyzed - revise loads on hgr Pending 99 input detail sheets 55 Valve weights and C.G.s improperly Reanalyzed - revise loads on hgr Pending input detail sheets.
37 Flange weights and control valve Reanalyzed - revise loads on hgr Pendinn 45 C.G.s improperly input detail sheets 17 Pipe orifice improperly input Reanalyzed - revise hgr loads Pending 6
Seismic restraint orientation of Reanalyzed - revise hgr loads Pending CChil-61 improperly input 233
-Eccentric Forces on axial restraints Reanalyzed - revise hgr loads Pending 103 Valve weight and hanger location Reanalyzed - revise hgr loads Pending improperly input 188 Portion of line never analyzed Perform analysis Pending (Fuel Oil) 172 Portion of line never analyzed Peerform analysis Pending (Puel Oil) 51 Incorrect piping geometry and hgr Reanalyzed - revise hgr loads Pending locations 135 Fig weights, valve weights, valve Reanalyzed - revise hgr loads Pend ing 138 C.G.s improperly input
Page 2 of 4 TABLE 1 IE BULLETIN 79-14 PKG.
DISCREPANCY RESOLUTION STATUS 119 Hgr. CWH-39 4 analyzed 90 of.f Reanalyzed - installed new Hgr.
Complete orientati6n.
103 Improper analytical input.
AFWH-44 Reanalyzed.
Found satisfactory Complete 124 217 Hgr. CWH-44 analyzed 90 off Reanalyzed.
Installed new Hgr.
Complete orientation 202 Interference @ AFSH-29 Interference removed to comply Complete l\\" movement req'd per analysis.
161 Motor valve C.G.s not include'd in Reanalyze Pending original analysis.
59 Hgr. RHRRH-19 analyzed for upward Modify hgr to suit Pendino force of 504#
51
.Hgr CWRH-46 analyzed for upward Modify hgr to suit Pending force of 307#
51 Hgr.CWRH-53 or 54 analyzed for Modify hgr to suit Pending upward force of 26#
121 Unbalanced pressure force at Reanalyze piping on dwg A-6684 Pending bellows, weights of flg's and air filters 2-10 Excessive gap between pipe and Roanalyzed - will shim to specs.
Pending hgr #CWRH-2 8 (W.R. written)
~
TABLE 1 IE BULLETIN 79-14 PKG.
DISCREPANCV RESOLUTION STATUS 88 Marginal overst'ress in upset and Reanalyzed, Modify AFWH-8 Pending 132 faulted condition Revise hgr loads 68 Analyzed usir.g incorrect response Reanalyzed.
New snubber required.
Complete spcctra Revise hgr loads.
24 Analysis converted from'ADL pipe Revise hgr loads per analysis (CVCS)
Pending 31 (NSC) to pipe stress (FPS) 47 Analysis converted from ADL pipe Revise hgr loads per analysis (SI)
Pending (NSC) to Pipe Stress (FPS)
Line 24N converted from ADL pipe Revise hgr load per analysis (RC)
Pending (NSC) to pipe stress (FPS) 33 Analysis converted from ADL pipe Revise hgr loads per analysis (RC)
Penu...;
42 (NSC) to pipe stress (FPS) 163 Valve weights improperly input Reanalyze Pending Hgr AFWH-17 not analyzed for uplift Reanalyze - modify hanger to suit Pending load
~
~
Hgr AFWH-2 not analyzed for uplift Reanalyze - modify hanger to suit Pendino load Hgr AFSH-18 not analyzed for uplift Reanalyze - modify hanger to suit Pending Load Hgr AFSH-30 not analyzed for uplift Reanalyze - modify hanger to suit Pending load
Page 4 of 4 TABLE 1 IE BULLETIN '79-14 PKG.
2[SCREPANCY RESOLUTION STATUS E7t AFSH-41 not analyzed for Reanalyze - modify hgr to suit Pending uplift load Hgr AFWH-42 not analyzed for Reanalyze - modify hgr to suit Pending uplift load Hgr APWH-38 not analyzed for Reanalyze - modify hgr to suit Pend ing uplift load Hgr AFWH-47 not analyzed for Reanalyze - modify hgr to suit Pending uplift load Hgr AFWH-16 not analyzed for Reanalyze - modify hgr to suit Pend ing uplift load Hgr APWH-9 not analyzed for Reanalyze - modify hgr to suit Pend ing uplift load Hgr RAFWil-26 not analyzed for Reanalyze -modify hgr to suit Pend ing uplift load 151
.Hgr. CWH-236 found removed Reanalyzed - hgr will be re-Pending from pipe installed 151 Hgr'CWH-295 found removed Reanzlyzed - hgr will be re-Pending from pipe installed 255 Hgr. CVCil-19 found unattached Reanalyze - relocate hgr where Pendino from pipe it can be installed 179 Hgr RCVCH-221 found removed Reaaalyzed - hgr will be re-Pend ing from pipe inscalled