ML20024C123
| ML20024C123 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/30/1983 |
| From: | DETROIT EDISON CO. |
| To: | |
| Shared Package | |
| ML20024C118 | List: |
| References | |
| RTR-NUREG-0798, RTR-NUREG-798 EF2-63927, EF2-63927-R, EF2-63927-R00, NUDOCS 8307120282 | |
| Download: ML20024C123 (27) | |
Text
e-ENRICO FERMI ATOMIC POWER PLANT, UNIT 2 EVALUATION OF SAFETY RELIEF VALVE PIPING AND TORUS ATTACHED PIPING FOR THE EFFECTS OF SITE SPECIFIC EARTHQUAKE REPORT NO. EF2-63927 REVISION O JUNE, 1983 THE DETROIT EDISON COMPANY 2000 SECOND AVENUE DETROIT, MICHIGAN 48226 8307120282 830708 PDR ADDCK 05000341 E
1 TABLE OF CONTENTS Page List of Tables 11 List of Figures lii 1.0 Introduction 1
2.0 System Description
3 3.0 Loads and Ioad Combinations 6
4.0 Analytical Techniques 15 5.0 Results of Analysis 19 6.0 Conclusions 22 7.0 References 23 A
i 1
4 9
e
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,--~,-,c e--,
-e-----, -, -, - - - --
--,--v~,--n-r,--v-,n-,
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LIST OF TABLES Page Table 1 - Affected Torus Attached Piping 5
Systems Table 2 - SRV Piping System Maximum Pipe 20 Stress Summary Table 3 - Torus Attached Piping Maximum 21 Pipe Stress Suminary l
{
e 4
4,
LIST OF FIGURES Page Figure 1 - Safety Relief Valve Discharge 4
Line and Main Steam Line Schematic
- ~
Figure 2 - Site Specific Earthquake 9
N -S (2% Damping) Response Spectra Applicable to the SRV Piping Figure 3 - Site Specific Earthquake 10 E-W (2% Damping) Response Spectra Applicable to the SRV Piping Figure 4 - Site Specific Earthquake 11 Vertical (2% Damping) Response Spectra Applicable to the SRV Piping Figure 5 - Response Spectrum Curves 12 (2% Damping) in North-South Direction Applicable to the TAP Lines Figure 6 - Response Spectrum Curves 13 (2% Damping) in East-West Direction Applicable to the TAP Lines Figure 7 - Response Spectrum Curves 14 (2% Damping) in Vertical Direction Applicable to the TAP Lines 4
-lii-
,-,----s.
,.m,---------,-----..-,-,-n-,-,.
,- - - -n--,
1.0 INTRODUCTION
The site-specific earthquake loads are seismic loads which evolved from a reassessment of the Fermi plant's capability to achieve safe shutdown under seismic conditions substantially more severe than the design basis earthquake.
The effects of the site-specific earthquake loads on the structures, systems and equipment necessary to achieve safe shutdown are addressed in the Fermi Seismic Re-evaluation Report (Reference 1).
Supplement No.1 of the Fermi-2 Safety Evaluation Report (SER) NUREG-0798 (Reference 2) required that the loads acting during the site-specific earthquake on the reactor building base mat due to suppression chamber uplift, torus attached piping and equipment, and the safety relief valve (SRV) piping system be addressed.
The evaluation of the uplift loads on the base mat was described in the Reference (3) report.
The evaluation demonstrated that these loads are less than the allowable capacity of the base mat.
Supplement No. 3 of the Fermi-2 SER (Reference 4) documented j
the NRC 's review and acceptance of the base mat evaluation.
~
This report documents the analyses performed for the SRV piping system in the drywell, and the affected torus attached piping (TAP) systems, to evaluate the combined
(
effects of the Site Specific Earthquake and normal operating l
loads, including SRV discharge.
The evaluation of these 1 -
B G
- piping systems for the LOCA and SRV discharge related loads defined by the NRC's Safety Evaluation Report NUREG-0661 (Reference 5) and the Mark I containment Load Dr inition Report (Reference 6) are addressed in the Fermi Plant unique Analysie Reports (References 7 and 8).
Section 2.0 of this report provides a brief description of the piping systems analyzed.
Section 3.0 defines the loads and loads combinations used.
The analytical methods are described in Section 4. 0.
The results are given in Section
- 5. 0, and conclusions in Section 6.0.
l l
G.
y
2.0 SYSTEMS DESCRIPTION The SRV piping system in the drywell consists of 15 individual, Schedule 80, SA-106, ASME Section III Class 2 piping lines.
These 15 lines are connected to the four main steam lines in the drywell at the SRV outlet flanges.
The
^~
arrangement of the 15. valves on the four main steam lines and the respective SRV discharge line numbers are i
schematically shown in Figure 1.
The lines are routed from the drywell area through the vent lines and into the suppression chamber to T-quencher devices.
The support arrangements for the SRV lines in the drywell consists of' snubbers, hangers, struts and a highly stiffened restraint at the vent line penetration.
1 Five torus attached piping (TAP) lines have been included in the path to cold shutdown during the Reference (1) e evaluation of the site-specific earthquake event.
The affected systems and piping, including selected design details, are listed in Table 1.
The supporting system for these lines consists of snubbers, hangers, struts, and guides external to the torus, stiffened restraints at the torus piping penetration, and strut supports inside the torus for some lines.
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SRV LINE (TYP) i q
MAIN STEAM LINE 8 LINE C MAIN STEAM MAIN STEAM LINE A LINE D e
Figure'1 SAFETY RELIEF VALVE DISCHARGE LINE.
ANd MAIN STEAM LINE SCHEMATIC
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t TABLE 1 AFFECTED TORUS ATTACHED PIPING SYSTEMS Torus Penet.
Operating System /Line Penet.
Size Pipe Pressure Operating Description Number (In. )
Schedule (PSIG)
Load RHR System X-223C&D 24
.375" wall 150 N/A Pump Suction I
RHR System X-210A &
18
.375" wall 150 Yes 1
Test Line &
X-211A 6
Sch. 40 Suppression Pool Spray Header RHR Test Line X-210B &
18
.375" wall 150 Yes
& Suppression X-211B 6
Sch. 40 Pool Spray Header RCIC System X-212 10 Sch. 40 25 Yes i
Turbine Exhaust RCIC System X-226 6
Sch. 40 12 5 N/A Pump Suction l
l l
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.._,...,,-_.-__,_..____.__m_,-
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3.0 LOADS AND LOAD COMBINATION The loads considered in the evaluation of the SRV piping system and the five TAP lines listed in Table 1 are the
~
internal piping operating pressure (Po), dead weight (DW),
SRV discharge transient loads (RVlA) during normal operating conditions, T-quencher water jet / air bubble loads (QAB), inertia loads (QABI) due to torus motion resulting from SRV T-quencher discharge, operating loads (OL), and site-specific earthquake inertia load (SSEI).
i The internal pressure (Po) in the main steam and SRV piping during normal operating conditions are 1130 psig and 445 psig, respectively.
For the five TAP lines, the internal pressures are listed in Table 1.
Dead weight (DW) loads include the uniformly distributed weight of the piping and the concentrated weight of all the pipe mounted equipment.
The site-specific earthquake inertia (SSEI) loads applied to the SRV piping and TAP lines are defined by the appropriate horizontal and vertical response spectra acting at the different piping support attachment elevations.
For the SRV piping, the building response spectra provided in Reference (9) at the different support elevations have been enveloped to develop the North-South, East-West and vertical spectra input at shown in Figures 2, 3 and 4.
The horizontal and.
vertical response spectra provided in Reference (9 ) acting on the reactor / auxiliary building floor at El. 583'-6" have been applied to the five TAP lines.
The applicable Reference (9) responso spectra in the North-South, East-West, and vertical directions are shown in Figures 5, 6
-~
and 7.
The SRV actuation case considered in the evaluation of the SRV piping and the TAP lines included the simultaneous actuation of the 5 lowest setpoint valves (1110 psi).
The discharge transient loads (RVlA) which occur during the discharge line clearing event are applied to the SRV piping.
The maximum forces associated with T-quencher water j et or air bubble drag are applied to the portions of TAP lines and associated supports inside the torus.
The maximum torus response resulting from the SRV actuation force time-history is utilized in generating the inertia / interaction loads (QABI).
The inertia loads for the SRV piping are applied at the vent pipe penetration.
For the 5 TAP lines the inertia loads are applied at the respective penetrations listed in Table. 1.
l l
The maximum line operating loads (OL) are applicable for the RCIC turbine exhaust lines (X-212 ) and the RHR test lines
( X-210 A & B, X-211A & B).
_7_
i l
The piping systems are evaluated for the following load combinations for piping stress and support loads, respectively:
SRV Piping PO + DW + RVlA + SSEI + QABI (piping stress) l DW + RVlA + SSEI + QABI (support loads)
TAP Piping Po + DW + SSEI + QABI + QAB + OL (piping stress)
DW + SSEI + QABI + QAB + OL (support loads)
In general, the methods used in the SRV and TAP analyses for combining dynamic loads are conservatively based on NUREG-0484, " Methodology for Combining Dynamic Responses" (Reference 11).
As described in NUREG-0484, when the time-phase relationship between the responses caused by two or more courses of dynamic loading is undefined or random, the peak responses from the individual loads are combined by absolute sum.
4 The methodology permitted by the NRC in Reference 10 has been selectively used in the analyses to reduce the predicted response of the piping.
As allowed by Reference 10, the method used in combining dynamic loads is the square root of the sum of the squares (SRSS) method.
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PERIOD, SEC
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l TIGURE 2 SITE SPECIFIC EARTHQUAKE N-S (2% DAMPING) RESPONSE. SPECTRA APPLICABLE TO THE SRV PIPING
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FIGURE 4 SITE SPECIFIC EARTHQUAKE
. VERTICAL (2% DAtiPING) RESPONSE SPECTRA APPLICABLE TO TIIE SRV PIPING
(,.,,
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10 20 30 Frequency (Hz) i Reactor /Auxilliary 1.iuilding, Floor Elevation l
583'-6"
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l FIGURE 5 RESPONSE SPECTRUM CURVES (21 DAMPING)
IN NORTH-SOUTII DIRECTION APPLICABLE TO Tile TAP LINES.
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m N
g 0
30 20 30 8
i Frequency (Hz)
Reactor /Auxilliary Building, Floor Elevation 583'-6" t
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FIGURE 6 RESPONSE SPECTRUM CURVES (2% DAMPING)
IN EAST-WEST DIRECTION APPLICABLE TO THE TAP LINES -
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FIGURE 7 RESPONSE SPECTRUM CURVES- (24 DMIPING)
IN VERTICAL DIRECTION APPLICABLE TO TIIE TAP LINES -
4.0 ANALYTICAL TECHNIQUES A standard, commercially available piping analysis computer code, PISTAR, is utilized in performing the SRV piping and TAP analyses.
An individual analysis is performed for each i*
of the five TAP lines.
Since the configurations of the drywell SRV piping vary considerably, all 15 SRV lines including their attached main steam lines are modeled and analyzed.
Four (4) individual SRV models are utilized, each i
with one main steam line and from two to five attached SRV lines.
The piping models developed in the Fermi Plant Unique Analyses (References 7 and 8) are utilized in this evaluation.
That is, the SRV piping systems and TAP lines are modeled as multi-degree of freedom, finite element systems consisting of straight and curved beam elements using a lumped mass formulation.
A suf ficient amount of detail is used to accurately represent the dynamic behavior of the piping systems for the applied loads.
Flexibility and stress intensification factors based on the ASME Code,Section III, Class 2 piping requirements are also included in the model formulations.
Stiffness values at a piping support location are established considering the combined effects of the snubber or strut and its backup supporting structure.
.-w,,--,,
n.
._-,..,-~,,,--,,,-.-v.-
,-n.--,,,..,,
+
t For TAP lines which include torus internal piping;, the entire piping system including the internal supports connected to the torus, is included in the model.
The hydrodynamic mass acting on submerged portions of the piping is also included in the model 4.1 Maximum Internal Operating Pressure (Po)
The effects of maximum internal operating pressure are evaluated utilizing the techniques described in subsection NC-3650 of the ASME Code,Section III.
l 4.2 Dead Weight Loads (DW)
A static analysis is performed for the uniformly distributed and concentrated weight loads applied to the piping.
4.3 Site-Specific Earthquake Inertia Loads (SSEI)
A dynamic response spectrum analysis is performed independently for each of the three orthogonal input l
directions utilizing the uniform response spectra method.
The resulting peak responses obtained for each of the three input directions are combined by the square root sum of squares methods.
A value of 2%
critical damping for the piping system is conserva-tively used.
All piping vibration modes b.elow 33 Hz are utilized in calculating the peak response.
To 16-e e
- yw
_.,_.,,,_,7
,7..,.,.-.
. -..,...,,,c_
,,_,,,,__,__m
-,,.,~m,.7m.,,.
I account for closely spaced modes, the individual modal responses are also conservatively grouped. by frequen-cies (within 10 %) and the modal responses within each group are combined by absolute sum.
The individual responses of the groups are combined by SRSS.
i l
4.4 Safety Relief Valve Line Discharge Loads (RVlA)
A dynamic analysis is performed for the SRV actuation loads (RVIA) utilizing the direct integretion time-history analysis technique.
Time-dependent forcing functions which represent the fluid momentum change during SRV actuation are applied along the axis i
of all pipe segments to determine the SRV piping response.
The forcing functions associated with a single SRV actuation are first applied to each SRV line In the model separately.
The peak response at a particular location in one SRV line is then obtained by computing the responses at that location due to l
actuation of all adjacent safety relief valves (with
{
j the same setpoint) on each main steam line.
l l
A direct integration time-step of sufficiently small l
size is selected to adequately account for the critical responses of the SRV piping systems up to 60 hertz.
A value of 1% critical damping for the piping system is utilized in determining the appropriate values of Rayleigh damping coefficients and for use in the direct integration process.
4.5 SRV Discharge Torus Motion Loads (QABI)
In applying QABI torus motions loads to TAP lines, a time-history dynamic analysis is performed using the coupled-transfer function analysis method described in Reference (8) to obtain the critical' response of the i
piping system.
The coupled-transfer function analysis method incorporates the coupled effects of the torus and attached piping into the results of the uncoupled torus and piping analyses.
A static analysis is performed on the SRV piping in the drywell, for the effects of the vent pipe penetration displacements due to the torus motion loads resulting from SRV T-quencher discharge.
The effects of this load are minimal.
4.6 SRV Discharge Water Jet / Air Bubble Loads (QAB)
(
The hydrodynamic loadings (QAB) applied to the TAP lines are analyzed using an equivalent static approach j
applying appropriate DLF's (dynamic load factors) and scale factors.
4.7 Maximum Operating Loads (OL)
An equivalent static analysis is performed for the j
effect of piping discharge end thrust loads for the applicable TAP lines..
v,
-,,---n r--
-n.--,-
n-.
.--------nn--
- - - ~ -, - -, - - - -
--e-
- 5. 0 RESULTS OF ANALYSIS The analytical results for the SRV piping and the five TAP lines are summarized in this section.
The maximum piping stresses for the applicable load combination sp~ cified in e
Section 3. 0 are presented in Table 2 for the SRV piping and Table 3 for TAP lines, along with the associated Code equations from NC-3650 (Class 2), and Code allowables.
The support reaction loads for the applicable load combination specified in Section 3. 0 are bounded by the original design capacity of the supports or the maximum support loads calculated from the Long Term Plant Unique Analyses (Re ferences 7 and 8 ).
The results of the TAP equipment, components and valves meet the acceptance criteria as stated in Section 5. 0 of Re ference ( 8 ).
E e o
TABLE 2 SRV PIPING SYSTEM MAXIMUM PIPE STRESS
SUMMARY
Po + DW + RV1A
+ SSEI + QABI SRV Line Number (PSI) 2586 18900 4093 18600 l
4094 13600 2596 19600 2595 22500 2593 14200 2594 15700 2587 22700 2590 19300 2592 22300 2591 16900 2589 19900 2588 13400 4096 13900 I
4906 14700 ASME III Code 9
Equation (NC-3650).
Service Level D 36000 Allowable Stress (ksi) y m
TABLE 3 TORUS ATTACHED PIPING MAXIMUM PIPE STRESS
SUMMARY
Allowable Po+DW+QAB+QABl System Stress (4)
+SSEI+0L (1)
_jPSI)
( PSI )
- X-223C&D 36,000 28,428 X-210A & 211A 36,000 31,029 X-210B & 211B 36,000 30,855 X-212 36,000 24,283 X-226(2) 44,640 44,129 X-226(3) 36,000 25,218 (1) OL apalicable only to X-210A & 211A, X-210B & 211B, and A-212.
(2) Austenitic steel segment of piping system.
(3) Carbon steel segment of piping system.
(4) ASME III Code NC-3650 Equation 9.
i Maximum combined stress, regardless of individual stress locations.
F
6.0 CONCLUSION
S The evaluation results have determined that the SRV piping and the TAP lines stresses and support loads meet the requirements of service level D for ASME Section III, Class 2 piping, when subjected to the combined effects of a, l
~ ~
Site-Specific Earthquake with other normal operating loads.
The affected equipment, components and valves in the TAP system have also been confirmed to meet the applicable i
acceptance criteria.
As a result the requ rements of l-NUREG-0798 (Reference 2), as they relate to confirming the SRV piping system and the af fected TAP systems design for an earthquake substantially higher than the design basis earthquake, are co'nsidered to be met.
i 9
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7.0 REFERENCES
(1) "Enrico Fermi Atomic Power Plant, Unit 2, Seismic Re-evaluation Report", EF 2-53332, Rev.1, July 15, 1981 (2) " Safety Evaluation Report Related to the Operation of Enrico Fermi Atomic Bower Plant, Unit No.
2", NUREG-0661 Supplement No. 1, U. S. Nuclear Regulatory Commission, September 1981
- ~
(3) " Evaluation of Site-Specific Earthquake Base Mat Uplif t Lo ad s", NUTEC H Re por t DET-04-0 50, Revision 0, May 4, 1982 (4) " Safety Evaluation Report Related to the Operation of Enrico Fermi Atomic Bower Plant, Un it No.
2", NUREG-0798, Supplement No. 3, U. S.
Nuclear Regulatory Commission, January 1983 (5) " Mark I Containmant Long-Term Program", Safety Ev aluation Report, USNRC, NUREG-0661, July 1980 (6) " Mark I Containment Program Load Definition Report",
General Electric Company, NEDO-21888, Revision 2, December 1981 (7) "Enrico Fermi Atomic Bower Plant, Unit 2, Plant Q11gue Analysis Report", Volume 1 through 5, NUTECH Report DET-2 0-015-1, 2, and 5, Revision 0, April 1982 (8) "Enrico Fermi Atomic Power Plant, Unit 2, Pl ant Ikt ique Analysis Report for Torus Attached Piping and Suppres-l sion Chamber Penetrations", NUTECH Report DET-19-076-6, Revision 0, June 1983 (9) " Floor Response Spectra and Envelopes - Reactor Auxil-l iary Building and RHR Complex", Detroit Edison Document EF2-55599, November 23, 1981
( 10 ) Letter from D.
V. Vassallo (NRC) to H. C.
Pfefferlen (GE),
" Acceptability of SRSS Method for Combining Dynamic Responses in Mark I Piping Responses", dated March 10, j
1983 i
8.
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