ML20041E173
| ML20041E173 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/17/1982 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| TAC-6605, NUDOCS 8203100216 | |
| Download: ML20041E173 (5) | |
Text
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. Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Attn:
Mr. Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Analysis of Dynamic Settlement on Category I Piping Gentlemen:
We are submitting the attached information in response to your request related to - the " Soil Analysis of Turbine Building and Northern Yard Area" report tha t was issued to you May 2, 1979.
In your letter dated June 20, 1980, we were requested to analyze the impact that the dynamic settlement in the Turbine Building Area would have on equipment and pipe connections within the Turbine Building.
The analysis has been completed and the results are presented in this report.
Seismic accelerations used in this analysis are based on the Soil Structure Interaction Amplified Response Spectra as rodified by the condition stated in the NRC letter dated May 25, 1979, from D. G. Eisenhut.
Duquesne Light considers the Soil System Interaction Amplified Response Spectra as the present and future design basis for the plant with respect to seismic accelerations. This basis and the analysis will be reflected in the FSAR which is currently being updated.
Very tru
- yours, 3
J. J.
arey Vice President, Nuclear Attachment poi s
f 8203100216 820217 PDRADOCKOSOOOg P
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Analysis of Dynamic Settlement on Category I Piping Page 2 cc:
Mr..D. A. Beckman, Resident Inspector U. S. Nuclear Regulatory Commission 4
I Beaver Valley Power Station e
Shippingport, PA-15077 U. S. Nuclear Regulatory Commission c/o Document Management Branch l
Washington, DC 20555 i
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ATTACFMENT IMPACT OF TURBINE BUILDING DYNAMIC SETTLEMENT s.
Equipment and piping systems which may be affected by the possible dynamic settlement of the Turbine Building have been reviewed. The review verified that there is no equipment or ciping system within the Turbine Building whose failure or malfunction could either cause a release of radioactivity that would endanger public safety or prevent safe shutdcwn of the station (Category I).
However, three piping systems located in the pipe tunnel connecting the Turbine Building with the Service Building were reviewed to assess the impact of dynamic settlement which could occur as a result of a seismic event. Two of the systems were selected on the basis that they are required to maintain the operability of the plant. The two piping systems are the Feed Waeer and the Main Steam Systems. The third system, the River Water System, was selected because the Category I portion of the system ending within'the Service Building Tunnel could be adversely influenced by the non-Categ'ory I branch lines of the system located within the Turbine Building. Pipe stresses in each system were evaluated for an imposed vertical displacement of 0.6 inches on all supports attached to the Turbine Building. The static vertical displacement of 0.6 inches is the average settlement calculated for all the borings taken as reported in " Soil Analysis of Turbine Building and Northern Yard Area".
Conservatively, no settlement was assumed for the Service Building.
The ANSI Code B31.1 (1967) does not address piping stresses due to building settlement conditions, but the ASME code section NC-3652.3 (b) does specify that pipe stresses resulting from any single nonseparated anchor movement shall not exceed (3.0S ) where Se = allowed pipe stresses c
at roem temperature. The value of Se is 15,000 psi for the piping systems studied. The calculated stresses in the piping caused by imposing the
s ATTACHMENT NDISLC:173 Page 2 average anticipated settlement on the oipe supports of the systems identified above are as follows:
1.
Feedwater system piping in this area consists of three (3) parallel 16 inch diameter lines (16"-WFPD-7-901, 16"WFPD-8-901 and 16"WFPD-12-901).
Feedwater line 16"-WFPD-7-901 was evaluated as being typical of the lines. The vertical movement was imposed at the point where it connects to the 26 inch manifold (26"-WFPD 901). The maximum stress level generated in the pipe due to the building settlement was 4600 psi, which is less than the allowable stress of 45,000 psi.
2.
Likewise, the Main Steam system piping in this area consists of three (3) parallel 32 inch diameter lines (32"-SHP-1-601, 32"-
SHP-2-601 and 32"-SHP-3-601).
Main Steam line 32"-SHP-1-601 was evaluated as being typical of these lines. Supports H-28, H-48 and H-49 were assumed to displace downward by the amount of the Turbine Building settlement. The resulting maximum stress level in the pipe was 4900 pai, which is less than the allowable stress of 45,000 psi.
3.
For River Water line 30"-WR-17-151-Q3, vertical movements were imposed at the floor anchor at El. 694 f t 3 in and at restraints on branch lines 18"-WR-185-151, 10"-WR-211-121, and 18"-WR-202-l 151-Q3. The maximum pipe stress level generated was 26,000 psi, which is less than the allowable stress of 45,000 psi.
l The oipe support stresses on the Feed Water and Main Steam lines were not evaluated due to the presence of pipe rupture restraints which f
prevent f ailure or non-Category I portions from influencing the Category I portions. For River Water Line 30"-WR-17-151-Q3, due to its Category I designation in the Service Building Tunnel, pipe support stresses in this l
area were also evaluated. Load combinations for the supports were developed l
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,' ATTACHMENT NDISLC:173 Page 3
,8 by the inclusion of thermal, deadload, selainec tnd dynamic building
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settlement effects. The maximum loading condition from River Water Line
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30"-WR-17-151-Q3 was determined to occur on support H 4'h Ubich was recently inspected as part of the effort to meet the requirements c;r IL Bulletin 79-02 and was modified as a result of the Pipe Stress Reanalysis effort.
The maximum stresses calculated for the members of support H-40 were a maximum bending stress of 5219 psi in the upper brace and a combined shear stress (torsion / direct shear) of 11004 psi in the upper horizontal member of the support frame. The above stresses are less than allowables per AISC code (ie.6 Fy bending &.4 Fy shear where Fy equals 36000 psi).
The maximum bending stress in the baseplate attached to the concrete d
was 7347 psi, as compared to an allowable stress of 27000 psi (AISC).
For the concrete anchors, the governing case was for a 3/4" 6 " Red Head" self-drilling anchor with a calculated load of 3046 lbs. tension versus an allowable of 3700 lbs. tension. This allowable value applies a factor of safety of 5 to the anchor manufacturer's published ultimate values and in-place concrete strength as reported in the DLC response for NRC IE Bulletin 79-02.
In consideration of the above results, it is concluded that in the event of a dynamic settlement, as identified in the report " Soil Analysis of the Turbine Building and Northern Yard Area", there would be no failure or malfunction of equipment or piping systems which could either cause a release of radioactivity that would endanger public safety or prevent safe shutdown of the station.
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