ML20077J462
| ML20077J462 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/31/1983 |
| From: | MPR ASSOCIATES, INC. |
| To: | |
| Shared Package | |
| ML20077J456 | List: |
| References | |
| MPR-772, NUDOCS 8308160428 | |
| Download: ML20077J462 (23) | |
Text
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MPR ASSOCIATES. INC.
0YSTER CREEK NUCLEAR GENERATING STATION MARX 1 CONTAlhMENT LONG-TERM PROGRN4 PLANT-UNIQUE ANALYSIS SUPPLEMENTAL REPORT MPR-772 Prepared for:
General Public Utilities Nuclear Parsippany, New Jersey July 1983 8308160420 830809 PDR ADOCK 05000219 p PDR 1050 CONNECTICUT AVENUE. N.W. WASHINGTON. D.C. 20036 202 659 2320
M P R ASSOCIATES. INC.
TABLE OF CONTENTS
1.0 INTRODUCTION
1.1 Background
1.2 Scope of This Report 1.3 Sumary of Results 2.0 DESIGN STRESS ANALYSIS 2.1 Ring Girder Areas Near Piping Attachments 2.1.1 Local Torus Shell 2.1.2 Ring Girders 2.2 Piping Support Modifications on Ring Girder 2.3 SRY Piping Penetration on Vent Pipe 2.4 Torus Monorail
3.0 REFERENCES
1~0
. INTRODUCTION
1.1 Background
The Oyster Creek Nuclear Generating Station uses a containment structure for the BWR (Boiling Water Reactor) nuclear steam supply system desig-nated as the Mark I Containment system. The Mark I Containment Long-Term Program was initiated by the utilities whose plants have this containment design to re-evaluate the structure and its attachments considering the newly defined suppression pool hydrodynamic loads associated with an SRY (safety relief valve) discharge and a postulated LOCA (loss-of-coolant accident).
Two reports were prepared in August 1982 sumarizing the plant-unique analysis of t!.e Oyster Creek Nuclear Generating Station containment and attached piping for the Mark I Containment Long-Term Program loads. One report is titled " Plant-Unique Analysis Report - Suppression Chamber and Vent System" (Reference 3.2); and the other is titled " Plant-Unique Analysis Report - Torus Attached Piping" (Reference 3.3). These two reports present most of the structural evaluations required by the Mark 1 Containment Long-Term Program. The remaining structural evalua-tions are addressed in this supplemental report.
Since the analyses discussed in this repcet were performed using the same Mark I Program design criteria, load definitions and analytical procedures described in the previous reports, much of this material will not be repeated here. The three reports together represent the complete evaluation of the containment system required by the Mark I Containment Long-Term Program.
1.2 Scope of This Report This supplemental report covers the Mark I Containment Long-Term Program Plant-Unique Analysis (PVA) of several items for which results were not available for the plant-unique analysis reports (References 3.2 and 3.3). Specifically, the following structures are within the scope of this report:
(1) Local torus shell adjacent to ring girders supporting main steam relief valve (SRV) and demineralizer relief valve (Demin) discharge piping (2) Ring girders supporting the same piping as in (1)
(3) Modified piping supports on the ring girders (4) The penetration in the vent pipe for the SRV piping (5) The monorail installed inside the torus to facilitate maintenance.
This supplemental report does not modify the analyses or results of the previous plant-unique analysis reports (References 3.2 and 3.3); it provides results for the additional structures listed above which were not included in the previous reports.
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l 1 2.0 DESIGN STRESS ANALYSIS The design criteria used in these stress analyses are the same as described in the Oyster Creek PUA reports (References 3.2 and 3.3). The structural geometries analyzed, the methods of analysis, and the load definitions used in the analyses are also the same as described in the Oyster Creek PUA reports, as supplemented by the additional analyses which are described herein.
Specific information about the loads, load combinations, methods of analysis, and evaluation results for the structural components covered by this supplemental report are given in the following sections.
Section 2.1 covers the ring girder and local torus shell areas near piping attachments. Section 2.2 covers the ring girder piping support modi fications. Section 2.3 covers the SRV piping penetration in the vent pipe, :nd Section 2.4 covers the torus monorail.
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l 2.1 Ring Girder Areas Near Piping Attachments The SRV and demineralizer relief valve discharge piping are supported within the torus on six of the twenty total ring girders. Figures 6.1.2-4 through 6.1.2-7 in the torus PUA report (Reference 3.2) show these ring girder arrangements. This piping imposes loads on these ring girders which must be included in the evaluation of these ring girders and the adjacent local torus shell. These loads are considered in this analysis in addition to all the other loads imposed on the torus shell and ring girder in every bay as required by the Mark I Containment Long-Term Program.
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Specifically, in addition to the loads listed in Table 6.1-1 of the torus PUA report (Reference 3.2), the piping reaction loads on the ring girder are considered for each event evaluated in the Mark I Program.
These additional loads are listed in Table 2.1-1. The individual loads were grouped into the six potentially limiting load combinations listed in Table 6.0-1 of the torus PUA report (Reference 3.2) and the struc-tures were evaluated for each of these load combinations.
1 Load definitions used in these analyses basically were unchanged from l the previous torus PUA report (Reference 3.2). In the case of under- l l
water drag loads on the ring girder and vent header support columns, a random phasing methodology for post-chug was used which was developed '
generically for the Mark I owners (Reference 3.7).
The methods of analysis used to obtain the piping reaction loads on the ring girders were as described in the attached piping PUA report (Refer-ence 3.3), except that the reactions resulting from the motion of the torus due to pool swell, condensation oscillation, chugging, and SRV discharge were based on harmonic analyses of the piping response instead of response spectra analyses. These analyses were performed with the accepted ANSYS harmonic analysis program (Reference 3.6) using the torus 2 . ..
TABLE 2.1-1 ADDITIONAL LOADS CONSIDERED FOR THE EVALUATION OF RING GliiDER AREAS NEAR PIPING ATTACHMENTS GENERAL CATEGORY LOADS CONSIDERED RING GIRDER TYPE III Deadweight Deadweight of SRV Piping R.C.S Deadweight of Demin Piping S Deadweight of Catwalk R.C.S (2)
Earthquake (Operating Acceleration of SRV Piping R.C,5 Basis or Safe Shutdown) Acceleration of Demin Piping S Acceleration of CSSH Piping C (2)
Acceleration of Catwalk R C,5 (2)
Drag Pressure on Ring Girder R.C.S (2)
SRV Discharge
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Shell Motion on SRV Piping R.C.S Shell Motion on Demin Piping S Shell Motion on CSSH Piping C (2)
Shell Motion on Catwalk R.C.S (2)
Drag Pressure on Ring Girder R.C,5 (2)
Drag Pressure on vent Columns R.C.S (2)
Drag Pressure on SRV Center Supports C Drag Pressure on SRV Piping R,C,5 Drag Pressure on Demin Piping S Intermediate or Snall Shell Motion on SRV Piping R.C.S Break Accident Shell Motion on Demin Piping S (IBACO,PRCH,POCH) Shell Motion on CSSH Piping C (2)
Shell Motion on Catwalk R,C,5 (2)
Drag Pressure on Ring Girder R C,5 (2)
Drag Pressure on Vent Columns R.C.S (2)
Drag Pressure on SRV Center Supports C Drag Pressure on SRV Pipirg R,C,5 Drag Pressure on Demin Piping S Design Basis Accident Shell Motion on SRV Piping R C,5 (Pool Swell, DBACO, Shell Motion c't Demin Piping S PRCH, POCH) Shell Motion on CSSH Piping C (2)
Shell Motion on Catwalk R.C.S (2)
Drag Pressure on Ring Girder R.C.S (2)
Drag Pressure on Vent Columns R.C.S '2)
Drag Pressure on SRV Center Supports C Drag Pressure on SRV Piping R C.S Drag Pressure on Demin Fiping S Notes:
- 1. There are 3 types of ring girders grouped by the types of SRV piping supports attached to them: ring girders with rigid SRV supports (R), ring girders with sliding SRV supports and Dcmin piping supports (S), and ring girders with SRV center supports and Core Spray Suction Header piping supports (C).
- 2. These loads were also considered in the evaluation of the 16 ring girders and adjacent local shell that do not support the SRV or Demin piping, although they are not listed in Table 5.1 1 of the PUA report (Reference 3.2). The stress results in that Reference include these loads.
- 3. Abbreviations are defined below:
SRV - Safety-relief valve discharge piping Demin - Demineralizer relief valve discharge piping CSSH - Core spray suction header piping PRCH - Pre-chug load POCH - Post-chug load IBACO - Condensation oscillation during an Intermediate Break Accident DBACO - Condensation oscillation during a Design Basis Accident
structural motions obtained in the analysis of the torus (Reference 3.2). The local ring girder support modifications to the SRV and demineralizer relief piping discussed in Section 2.2 of this report were also included. As expected, the piping stresses from the response spectra analyses presented in the piping PUA report (Reference 3.3) bounded the harmonic results. Thus, the piping responses still meet the Mark I Program requirements as discussed in that report.
Peak total responses from each load source (such as DBA condensation oscillation) were calculated separately in the analysis. When two or more dynamic load sources were included in a Mark I Program load combi-nation, such as PUAAG Case No. 20 with DBACO + EQ(0), the peak total responses for independent dynanic load sources were combined on a
" square-root-of-the-sum-of-the-squares" basis, as proposed generically by the Mark I owners.
A separate stress analysis was made for each of three ring girder types:
(1) a ring girder which supports the end of the SRY Y-quencher with a rigid support, (2) a ring girder which supports the center of the Y-quencher and the Core Spray Suction Header, and (3) a ring girder which supports the end of the Y-quencher with a sliding support and which also supports the demineralizer relief valve discharge piping. The ring girder geometry for each ring girder included the modified piping supports at each location.
Acceptance criteria are unchanged from the torus PUA report (Reference 3.2). Calculated stresses are compared to appropriate service limits from the ASME Boiler and Pressure Vessel Code (Reference 3.8), as specified in the Mark I Program structural acceptance criteria (Reference 3.5). Whenever possible, service limit C load combinations which bound service limit A/B combinations (e.g., (DBAC0 + EQ(S))
instead of (DBAC0 + EQ(0))) are compared to service limit A/B allowables to reduce the total number of load combinations requiring evaluation.
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l j 2.1.1 Local Torus Shell Areas Stresses in the shell were compiled from several analyses performed with finite element models used to evaluate loads applied both in-plane and out-of-plane with respect to the plane of the ring girder. Details of these analyses are discussed in the torus PUA report (Reference 3.2).
Results from these analyses were processed as explained in the reference report to obtain stress intensities in the shell at the ring girder structural discontinuity. Membrane stress intensities are classified as local primary membrane (P L ) and bending stress intensities are secondary bending (Q) in accordance with ASME rules (Reference 3.8).
Table 2.1.1-1 shows a summary of the limiting calculated stresses in the local torus shell in the vicinity of each of the three ring girders.
All the calculated stresses meet the applicable Mark I Containment Long-Term Program allowat,les. In addition, it should be noted that these allowables are based on material properties which are the minimum values permitted by the Code. The material of the torus shell at Oyster Creek is significantly stronger than these Code minimums (e.g., the yield strength is at least 32". higher than Code minimum).
A bounding fatigue analysis also was performed for this local shell region using the fatigue methodology described in the torus PUA report (Reference 3.2). A maximum usage of less than 0.60 was calculated, which meets the Mark I Program acceptance criteria.
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TABLE 2.1.1-1 5tpe%RY OF LIMITING STRESSES Im LOCAL 700u5 5 HELL NEAR RIhG GTAT,ER5 .ITri FIFI45 ATIL",@E%I5 ASME CALCULATED ALLCWA8tE LOCATION TYPE OF SERVICE STRESS STRESS LOAD STRES5 LEVEL (kst) (kst) COMBINATIC4 Shell at Local Primary Membrane A/8 20.7 29.0 08A(CO) + EQ(5)
Rigid Support stress Intensity Ring Girder (Pg )
C 28.5 53.4 DBA(PS) + SRV + EQ(5)
Primary + Secondary A/B 60.7 69.5 DBA(CO) + EQ(0) 5 tress Intensity (Pg + Q)
Shell at Local Primary Membrane A/8 21.2 l 29.0 CBA(C0) + EQ($1 C+nter Support Stress Intensity Ring Girder (Pg )
C 29.3 53.4 DSA(PS) + SRV + EQ(5)
Primary + Secondary A/8 68.9 69.5 08A(CO) + EC(0)
Stress Intenstty (Pg + Q)
Shell at Local Primary Membrane A/S 21.3 I 29.0 DBA(CO) + EQ($1 51tding Support Stress :ntensity !
Ring Girder (Pg )
C 28.9 53.4 DBA(PS) + SRV + EQ(5)
Primary + 5econdary A/8 63.1 69.5 CBA(CO) + EQ(0)
Stress Intensity (Pg + Q)
}
]
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2.1.2 Ring Girders As described in the torus PUA report (Reference 3.2), stresses at several cross-sections of the ring girder were determined from the results of two primary finite element models. One model was used for loads in the plane of the ring girder; and the other model was used for out-of-plane ring girder loads.
Stress intensities at these cross-sections, including any secondary effects in the ring girder and welds, are classified as gtneral primary membrane (P m ) or primary membrane plus bending (P m +P b ) as defined in the ASME rules for integral attachments to metal containments (Reference 3.8). Shear stresses in the throat of the attachment fillet welds are also evaluated.
Table 2.1.2-1 shows a summary of the limiting calculated stresses in each of the three types of ring girders with piping attachments. All the calculated stresses meet the applicable Mark I Containment Long-Term Program allowables. In addition, it should be noted that these allowables are based on material properties which are the minimum values permitted by the Code. The material of the ring girders at Oyster Creek is significantly stronger than these Code minimums (e.g., the yield strength is 28" higher than the Code minimum).
A bounding fatigue analysis also was performed for these ring girders using the fatigue methodology described in the torus PUA report (Reference 3.2). A maximum usage of less than 0.6 was calculated, which meets the Mat k I Program acceptance criteria.
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TABLE 2.1.2 1 SLwnY cr LIMITING STRE55E514 T0pt:5 RING G!RDERS LTT'rf7TPIVOTT131MTs A5ME CALCLt4TED LOCATION TYPE OF ALLOh4BLE l SERvtCE STRESS STRESS LOAD STRESS LEVEL (kst) (kst) COMBihAT104 pigid Support General Primary Mererane A/8 13.8 19.3 DBA(CO) + EQ(5)
Ring Girder Stress Intensity (P )
Primary Menbrane Plus A/8 28.7 29.0 DBA(CO) + EQ(5)
Bending Stress Intensity _
(P, + PD I
Weld Primary Shear Stress A/S 12.3 15.0 08A(CO) + EQ(5)
Center Support General Primary Membrane A/B 14.4 l 19.3 08A(PS) + $df + EQ(5)
Ring Gtrder Stress Intensity I (P,)
C 14.4 35.6 DBA(PS) + SPV + EQ(5)
Primary Membrane Plus A/S 28.2 lI 29.0 08A(PS) + SRV + EQ(5)
Bending Stress Intensity (P, + Pb I C 28.2 53.4 OBA(PS) + SRV + EQ(5)
Weld Primary Shear Stress A/B 10.2 15.0 DBA(PS) + SRV + EQ(5)
C 10.2 15.0 DBA(PS) + SRV + EQ(5) 51tding Support General Primary Mec6rane A/8 13.8 19.3 CBA(PS) + SRV + EQ(5)
Sing Girder Stress intensity .
(P,)
C 13.8 33.6 DBA(PS) + SRV + EQ(5)
Primary Mesbrane Plus A/8 26.1 29.0 OBA(PS) + SRV + EQ(5)
Bending stress Intensity (P + Pb I C 26.1 53.4 OBA(PS) + SRV + EQ(5) i held Primary Shear Stress A/8 8.9 15.0 OBA(PS) + $RY + EQ(5)
C 8.9 1., DBA(PS) + SRV + EQ(5) ee
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2.2 Piping Support Modifications i
Local modifications have been designed for two of the piping attachments on the ring girders in order to reduce local ring girder stresses due to pipe reaction loads and other loads on the ring girders. The center support arms for the SRV Y-quencher are spread farther apart where they attach to the ring girder. Existing clamped supports are modified to become welded supports at the demineralizer relief valve discharge piping attachments on the ring girder. Also, gussets are added between the ring girder flange and web at the attachments for the SRY Y-quencher center support arms and the demineralizer piping supports.
These modifications have been analyzed using the same Mark I Program loads and acceptance criteria used for the piping supports discussed in the attached piping PUA report (Reference 3.3). The results of this analysis show that all the calculated stresses meet the applicable Mark I Containment Long-Term Program allowables. Specifically, the modified SRV Y-quencher center support is less than 82% of allowable for the limiting load case (DBA(CO) + EQ(S)), and the modified demineralizer relief valve piping supports are et less than 70% of allowable for the limiting load case (PRCH + SRV + EQ(S)).
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2.3 SRV Piping Penetration on Vent Pipe The SRV penetration stresses were evaluated using the piping loads obtained from the piping calculation described in Section 2.1 of this report. The two SRY piping systems and associated piping penetrations in the vent line heads are described in the PUA, Reference 3.3, Section 3.8. Limiting service stress limits and load combinations for the SRV penetration are also specified in the PUA in Section 2.2.2. The SRV penetration stiffness (resistance to applied forces and moments) was calculated using a finite element model of the vent line head.
Stresses in the vent line head and reinforcing pad adjacent to the SRV pipe were calculated using the Bijlaard analysis methods described in Reference 3.9. Bijlaard stress factors were taken directly from Reference 3.9 for the SRV penetration analyses. Stress analysis methods were as described in the PUA, Section 5.3, except that in many cases for the SRV penetration, the relative signs of reaction forces and moments were available from time-history piping analyses. When these relative signs were known, stress intensity ranges were calculated using the sign information rather than by considering all possible sign combinations, as was described in the PUA. In addition to the stresses in the vent line head caused by the presence of the penetration, stresses caused by the pressure difference between the drywell and the wetwell were considered. A summary of the stress intensity analysis results for the SRY penetration is shown in Table 2.3-1. All stresses are below ASME Code allowables, and, therefore, the penetration meets the requirements of the Mark 1 Containment Long-Term Program.
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l TABLE 2.3-1
SUMMARY
OF LIMITING STRESSES IN THE SRV PENETRATION STRESS ASME CALCULATED ALLOWABLE CLASSIFICATION SERVICE STRESS LOAD COMBINATION STRESg LEVEL (ksi) (ksi)
P L A/B 26.5 28.9 STAT 2 + DBA(PS) + EQ(OBE)
C 29.8 49.9 STAT + DBA(PS) + SRV + EQ(SSE)
Pt+Q A/B 57.4 66.5 STAT + DBA(CO) + EQ(0BE)
NOTES:
- 1. Allowables at 340*F.
- 2. STAT includes deadweight of pipe and torus plus thermal and pressure loads.
I l
l i The SRV penetration transition was evaluated for acceptability by using piping stress analysis results. Results are shown in Table 2.3-2. As can be seen from the table, the limiting stress intensity is less than the ASME Code allowable, and the SRV piping transition meets the requirements for acceptability for the Mark I Containment Long-Term Program.
The nozzle fatigue analysis methodology described in the PUA, Section 7.2, was used for the SRV penetration. Results of the analysis show a 29% usage for the SBA scenario, a 43.2% usage for the IBA scenario and a 19.4% usage for the DBA scenario. Since the percent fatigue usage for each LOCA type is less than 100 percent, the penetration is acceptable for fatigue.
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l TABLE 2.3-2 L
SUMMARY
OF LIMITING STRESSES IN THE SRV PENETRATION TRANSITION ,,
d STRESS ASME CALCULATED ALLOWABLE CLASSIFICATION SERVICE STRESS LCAD COMBINATION STRESS (jg)
LEVEL (ksi) (340'F )
General Primary .
Membrane Stress 12.6 16.5
Intensity (P,)
Note:
- 1. Material allowables based on the use of A201 Grade B material.
t I
'u um 1 ' - . = = _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ . _ . _ _ _ . _ _ _ _ - - .
I '
l 2.4 Torus Monorail 2.4.1 Description A 3-ton capacity monorail has been installed to facilitate modificatfor.s to the inside of the torus and to its internals. The monorail consists of a chainfall hoist and carriage which runs along the bottom flange of a standard S10x35 I beam. The monorail runt 360* around the inside of the torus. It is attached to each ring girder by large bolted clamps similar to those used for the torus catwalk (Reference 3.2). Clamps are attached to the ring girder flange approximately 40* off the torus vertical centerline and radlally outboard from the reactor vessel.
During normal plant operation, the~ hoist and carriage assembly will be removed from the torus. The beam and clamps remain in place and are classified as miscellaneous internal' torus structures as defined in the Mark I Program structurai acceptance criteria (Reference 3.5).
2.4.2 Load Definition s
'The monorail is located above the pool surface and above the height of maximum DBA pool swell. The limiting loads on the monorail are froth impingement loads caused by DBA pool swell. These loads are defined in accordance with Reference 3.1 using the load definition procedures of Reference ~3.4.
2.4.3 Analysis An equivalent static analysis of the monorail and its supports was performed. For conservatism and simplicity, a single bounding load case was defined based on maximum possible upload (based on Region II froth acting vertically upward) simultaneously with maximum oossible hori-zontal load (based on Region I froth acting horizontally).
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Acceptance criteria for the analysis were service level E limits, as specified in Reference 3.5, for torus miscellaneous internal structures under DBA pool swell conditions. The results of the analysis show that all stresses in the monorail are within service level D limits. Stresses in the attachment bolts and clamps are less than 20% of allowables. The results alto show that the monorail beam does not meet the level D cri-terion for lateral buckling. The analysis evaluated the effect of lateral buckling of the manorail and concluded there is no significant change in the load carrying capacity or the calculated stresses for the monorail following lateral buckling. Hence, the monorail meets service level E limits of the Mark I Long Term Program in accordance with Reference 3.5.
l,
, ,s s
s I
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,r l 3 '. 0 REFERENCES 3.1 U.S. Nuclear Regulatory Commission. Safety Evaluation Report, Mark I Containment Long-Term Program Resolution of Generic Technical Activity A-7. NUREG-0661, July 1980.
3.2 MPR Associates, Inc., Oyster Creek Nuclear Generating Station Mark I Containment Long-Term Program Plant-Unique Analysis Report Suppression Chamber and Vent System. MPR-733, August 1982.
3.3 MPR Associates, Inc. Oyster Creek Nuclear Generation Station Mark I Containment Long-Term Program Plant-Unique Analysis Report Torus Attached Piping. MPR-734, August 1982.
l 3.4 General Electric Company. Mark I Containment Program Load Definition Report. NED0-21888, Revision 2, November 1981. ,
3.5 General Electric Company. Mark I Containment Program Structural Acceptance Criteria Plant-Unique Analysis Application Guide. NE00-24583-1, October 1979.
3.6 Control Data Corporation. ANSYS User Information Manual.
Publication No. 840006608, Revision B, September 1979.
3.7 Structural Mechanics Associates. Design Approach Based On FSTF Data For Combining Harmonic Amplitudes For Mark I Post-Chug Response Calculations. SMA 12101.05-R001, October 1982.
3.8 American Society of Mechanical Engineers. Boiler and Pressure Vessel Code Section III Nuclear Power Plant Components Division 1. 1977 Edition with Addenda through Summer 1977.
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3.9 Welding Research Council. Local Stresses in Spherical and Cylindrical Shells Due to External Loadings. WRC Bulletin 107, March 1979 Revision.
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