ML18150A136
| ML18150A136 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/31/1984 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Varga S Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 106B, TAC-44622, TAC-44623, TAC-44633, NUDOCS 8411190303 | |
| Download: ML18150A136 (123) | |
Text
RESPONSES TO USNRC REQUEST FOR ADDL INFO RE RELIEF & SAFETY VALVE TESTING j':.M;'* **
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~ NOTICE -
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DEADLINE RETURN DATE RECORDS FACILITY BRANCH
RESPONSE TO US NRC REQUEST FOR ADDITIONAL INFORMATION TMI ACTION NUREG-0737 (II.D.1)
RELIEF AND SAFETY VALVE TESTING FOR SURRY POWER STATION UNITS 1 AND 2 DOCKET NOS. 50-280 AND 50-281
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r i \\ Question 1 The submittal does not include a discussion of consideration of single failures after the initiating events.
NUREG 0737 requires selection of single failures that produce maximum loads on the safety and relief valves.
Include a discussion describing how the single failure considerations are met.
Response
The limiting Condition II transient that incurs safety valve actuation is the loss of external load event (FSAR 14.2.10). The analyses assumed an initial core power of 102 percent of rated with no direct reactor trip (on turbine trip). In addition, the pressurizer spray and power-operated relief valves were assumed inoperable. The combined effect from these assumptions produced the greatest (fastest) reactor coolant pressurization rate.
As the peak pressure is observed ~ithin seconds of the transient initiation, single failures within the engineered safeguards systems would have little, or no effect, on the pressurization rate or peak pressure observed.
- Q!Jest1on 2 The Westinghouse valve inlet fluid conditions report stated that liquid discharge through both the safety and relief valves is predicted for an FSAR feedline break event. Where applicable, the Westinghouse report gave expected peak pressures and pressurization rates for those plants with this FSAR feedline break event. Surry 1 and 2 were not among them.
The Surry 1 and 2 plant specific submittal did not address the FSAR feedline break event.
NUREG 0737 II.D.1 requires that the transients of Regulatory Guide 1.70 Revision 2 be considered.
The feedline break is included in these transients. The submittal for the Surry 1 and 2 plan should discuss the FSAR feedline break ev~nts, and so state that it is either not applicable to the plant or provided pressures and pressurization rates and demonstrate safety and relief funct1onability for this event. Additionally, this liquid flow event should be considered in analyses of the safety and relief valve piping systems.
Response
The feedline break accident is not part of the Surry licensing basis.
Nuclear plants that were licensed prior to issuance of Regulatory Guide 1.70, Revision 1, were not required to consider the feedline break accident as part of their design basis; therefore, the FSAR-feedline break event is not applicable for Surry 1 and 2.
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- l Question 3 As pointed out in the plant specific submittal, results from the EPRI test on the Crosby safety valves indicate that the test blowdowns exceeded the 5%
value given in the valve specifications. If the expected plant blowdowns also exceed 5%, an increase in pressurizer water level could occur such that the water level may reach the safety valve inlet line and result in a steam-water flow situation. Also the pressure might be decreased sufficiently so that adequate core cooling might not be achieved.
Blowdown for the Surry 1 and 2 Crosby 6K26 safety valve, at its current ring settings was not discussed.
The submittal did state that the valve manufacturer (Crosby) and the NSSS supplier (Westinghouse} were reviewing the Crosby 6K26 ring settings.
Please provide the recommended ring settings along with the expected blowdown and a discussion addressing the increase in pressurizer water level and the adequacy of core cooling.
Response
Ring settings for the Surry l and 2 Crosby safety valves are as follows:
Valve N.R.
G.R.
l-RV-551A
-18
-250 l-RV-551 B
-18
-270 l-RV-551C
-18
-200 2-RV-551A
-16
-250 2-RV-5518
-16
-250 2-RV-551C
-16
-250 These ring settings were develo)ed during the Crosby production tests for each valve and reflect measured blowdowns of 4.5 - 5%.
Please note the ring settings indicated above were measured by Crosby from the highest "locked 11 position as noted in Crosby procedures and in the EPRI reports definition of key terms and parameters and not as measured from the a1evel position" as reported by EPRI.
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f i Blowdowns in excess of 5%, although not expected, have been analyzed in conjunction with the Westinghouse Owners Gtoup (WOG) program on safety valves.
The analysis utilized valve blowdowns in excess of 10%.
The results from these analyses showed no adverse effects on plant safety. The peak pressurizer water level calculated remained below the pressurizer inlet piping to the safety and relief valves.
Discussion *of the WOG program is contained 1n the Westinghouse report WCAP-10105, *Review of the Pressurizer Safety Valve Performance as Observed in the EPRI Safety and Relief Valve Test Program,"
dated June 1982.
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- t. Q_uestion 4
. The inlet piping pressure drops for the Crosby 6M6 EPRI test v~lves were compared to the calculated Surry 1 and 2 Crosby 6K26 inlet piping pressure drops.
The Crosby 3K6 and 6M6 pressure drops of the plant submittal Table 2-3 were taken from reference 8 of the submittal. Reference 8, *EPRI PWR Safety and Relief Valve Test Program Guide for Application of Valve Test Program Results to Plant Specific Evaluation~" Interim Report, March 1982, was not available to EG&G Idaho for review.
As result, the method of determining the pressure drops could not be verified. Provide a copy of Reference 8 and a discussion of how the pressure drops were determined.
Response
The March 1982 revis"ion of interim report "EPRI PWR Safety and Relief Valve Test Program Guide for Application of Valve Test Program Results to Plant-Specific Evaluation" was the document in existence at the time the Surry submittal was prepared. A copy of this report is attached. 1The pressure d~op was taken from this report.
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l l Question 5 The plant specific submittal stated that "No conditions have been established addressing extended High Pressure Injection Transients.N No description or discussion was provided for the safety injection system such as pump type and shut off head which would justify not addressing these transients.
Clarification should be provided regarding the extended high pressure injection event and justification why this event, which may lead to extended liquid discharge through the safety valves, need not be addressed.
If this event is plausible, expected conditions and verification that the expected conditions are bounded by the test data event should be provided.
Response
As indicated in the Surry FSAR Table 6.2-6, the charging pump discharge head is 5800 ft.
When taking into account the location of the charging pumps with respect to the elevation of the pressurizer safety valves, the head loss is such that the safety valves cannot be challenged in the event of a high pressure injection transient.
Since this event is not plausible, the extended high pressure injection transient. need not be addressed.
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Question 6 The plant spec1f1c submittal d1d not discuss relief valve 1nlet conditions for the cold overpressure transient. Since no low pressure steam tests were performed for these rel1ef vaives, provide a discuss1on explaining how the high pressure steam test data bounds the low pressure steam condition.
Response
The Surry l & 2 Relief Valve Cold Overpressure protection system operates to maintain pressure below the EPRI test cond1tions.
The system for both units 11mits the Reactor Coolant pressure to less than 435 psig for a temperature range of 100°F to 350°F.
The EPRI Cold Overpressure testing conditions therefore bound the Surry System with a maximum test pressure of 665 psig for a te~perature range of 100°F to 450°F.
Design Change Plan 77-08 installed the Overpressure Mitigating System.
The selection of set points for the PORV's was based on the procedure contained in Westinghouse "Pressure Mitigating System Transient Analysis Results," July 1977.
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i Question 7 The test results of the Crosby 3K6 and 6M6 safety valves with loop seals were used in the plant specific submittal to demonstrate that the Surry 1 and 2 Crosby 6K26 safety valve was bounded by the test valves.
The plant submittal stated that EPRI data indicated that steam flow rates in excess of rated flows are attainable.
In addition, the footnote to Table 4-3 of the submittal stated rated flow was achieved but not reported in the EPRI Test Report Tables.
Review of the EPRI test results indicate that flowrate data was presented as a percentage of rated flow for several of the Crosby 3K6 and 6M6 loop seal tests.
Provide a discussion explaining how the limited flow data for the Crosby 3K6 and 6M6 were extrapolated to demonstrate the Crosby 3K26 will achieve rated flow.
Clarification should also be given regarding the differing flow capacities in Table 2-1 and Table A-1 of the submittal.
Response
According to the EPRI Valve Selection/Justification Report NP-2292-LD, the 6M6 test valve was selected by Crosby to be representative of the K2 orifice safety valve design (6K26 valve) installed at Surry.
As noted in Table 4.4 of EPRI Report NP-2770-LD, Volume-6, the Crosby 6M6 test valve achieved rated flow for each of the tests reported at 3 percent accumulation regardless of the ring setting used in the test. A review of EPRI Tables 4-3 and 4-4 in Volume 5 of EPRI report*NP-2770 LO reveals that for steam tests of the 3K6 valve where blowdown was measured to be less than 10 percent, flow rates of 119-122 percent of rated flow at 3 percent accumulation were reported.
The
- EPRI tables indicate that lower than_ rated flows occurred at blowdowns greater than 15 percent. Crosby production testing has determined that the ring settings will provide blowdowns of 5% for the safety valves. This is within the range of both the 3K6 and 6M6 tests where rated flow was achieved; therefore, rated flow can be expected for the Surry valves. The flow rate on Table A-1 should read the same as Table 2-1, that is 293,300 lb/hr.
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i Question ~
The Surry l and 2 plant submittal did not make it clear in Figure 2-1 as to the mounting configuration of the EMOV block valves.
The EMOV block valves tested at the Marshall Steam Station were tested only in the horizontal piping with EMOV block valve stems in the vertical upright position.
Provide a discussion on the effects of installed block valve configuration on valve functionability if mounting configurations other than horizontal with vertical upright stem positions are used.
Response
The Surry l and 2 mounting configuration of the EMOV block valve is the same as the block valve tested; horizontal.with vertical upright stem positions.
Question:
Response
- 9.
Thermal expansion of the pressurizer tank and inlet p1p1ng would be expected to induce loading on the inlet flange of a safety or relief valve at the time the valve is required to lift. Provide a discussion explaining how the effect that this would loading would have on valve operability was considered.
No specific evaluation of the inlet flange or the effects of piping loads on the operability of the safety or relief valves has been performed.
However, bending movements were induced on the EPRI safety/relief test valves demonstrating the functionability of the valves under the pipe loading conditions which may be expected.
The valves demonstrated their functionability and that the loadings were within acceptable limits.
Engineering analysis and design is presently being performed for the discharge piping support upgrades.
As a result of these upgrades the piping will be supported to minimize the loadings on the valves and to withstand the anticipated transients.
In addition to the present upgrade work the piping is laid out to minimize loadings on the valves as well.
During initial pre-op testing at Surry the relief valves were lifted at full pressurizer temperature and pressure.
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t 1 Ouestion 10 The Copes-Vulcan PORV with 17-4 PH plug and cage was subjected ~o additional cycles past the evaluation cycles at the Marshall test facility. Results 1ndicated that 100% closure was not achieved on some cycles. Plug to cage galling was found which kept the valve from completely closing. Surry 1 and 2 has PORV's of similar design.
Provide a discussion of this potential problem along with any action being taken for resolution.
Response
The Copes-Vulcan PORV successfully completed eleven (11) evaluation test cycles at the Marshall test facility and eight (8) additional test cycles at the Wyle test facility. The valve is considered adequate for the intended service and no design changes are currently being contemplated.
After the Marshall tests were completed, a new set of the same design cage and plug parts were installed and the valve was cycled to investigate the cage to body gasket performance and to support other Marshall Steam Station test functions.
The valve fully opened on demand and fully closed on demand for the next 43 cycles. Six (6) of* these cycles were performed under full pressure/flow conditions.
The remaining cycles were either dry, unpressurized actuations or openings/closings performed in conjunction with other valve testing. During the next 5 full pressure/flow tests performed, the valve did not fully close on demand.
However, the valve always closed to within 13% of
.* the full closed position. Disassembly showed galling of the cage and plug guiding surfaces.
As no design change is contemplated, routine maintenance of these valves will uncover progressive valve wear.
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I I i I f i Question 1 l Slowdown and expected valve stability for the Surry 1 and 2 Crosby 6K26 safety valve at its current ring settings were not discussed.
The plant specific submittal did state that the valve manufacturer (Crosby) and the NSSS supplier (Westinghouse) were reviewing the Crosby 6K26 ring settings. At the completion of their review, provi~e the reconmended ring settings along with the *expected blowdown and a discussion of the effects on valve stability, rated lift and rated flow.
Response
Please refer to the response to Question 3 for the ring settings and expected blowdown for*the Surry 1 and 2 safety valves.
Valve stability, rated lift and rated flow are not expected to be compromised due to these ring settings.
va*lve performance equal to or better than that detailed in the EPRI test is expected.
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! f I Question 12 The Westinghouse inlet fluid conditions report stated that liquid flow could exist through the PORV for the FSAR feedline break event and the extended high pressure injection event. Liquid PORV flow is also predicted for the cold over pressurization event. The EPRI/Marshall Block Valve Test Program did not test the block valves with fluid media other than steam.
The Westinghouse test program did include test with water; however the information presented in the report did not provide specific test results. Since 1t is conceivable that the EMOV could be expected to operate with liquid flows, discuss EMOV block valve operability with expected liquid flow conditions and provide specific test data.
Response
In June l, 1982 letter from R. C. Youngdahl to Mr. H. Denton, several block valve test submittals were made which included an explanation as to why block
- valve tests beyond the Marshall tests were not considered necessary, as well as an EPRI sunrnary report covering Westinghouse gate valve closure testing.
The Westinghouse report, transmitted to the NRC by the Youngdahl submittal, also includes a section on friction testing of stellited seating parts.
Friction-testing done by Westinghouse on Stellite test specimens (Note the Velan valve also has stellite seats) indicates that over the initial 200 cycles of testing, water test specimen friction factors increased from as low as 0.12 until a level of 0.4 to 0.15 is reached.
With 550°F steam, the
- friction factor starts in the 0.5 to 0.6 range (higher than the water tests) and drops to approximately 0.35 over ~he 200 cycle range.
Considering the 21 test cycles completed at Marshall Steam Station, and in view of the above frictional data, the thrust required to cycle the valve during the steam tests would be similar to that if the test medium were water.
- The block valve submittal stated that it covered Surry 1 and 2 i~ addition to North Anna 1 and 2.
The actual report-only seemed to address the North Anna 1 and 2 units. Review indicates that the Velan block valves used for Surry 1 and 2 are the same as the Velan block valves used for North Anna 1 and 2.
The plant submittal stated that the installed Velan block valves were similar to the Velan block valve tested. The Surry 1 and 2 Velan block valve model number and actuator RPM differ from these test block valves. Discuss the design differences and any effects on block valve operability and indicate if the North Anna report is intended to cover the Surry plants or if a separate report has been prepared.
Response
Vepco's plant-specific submittal for block valves qualifications for North Anna 1 and 2 and Surry 1 and 2 was transmitted via Vepco's letter Serial No. 514, dated September 1, 1982 to the NRC.
This submittal addresses both North Anna and Surry Power Stations PORV block valve adequacy.
Information provided by EPRI with regard to the description of the Velan block valve used for testing was reprinted from the EPRI-Marshall block valve report to the plant-specific submittal. A review of the test valve drawing (Velan drawing 88 425, Rev. B) shows the Surry valves to be similar in design.
As for the actuator motor RPM, internal gearing of the actuator is sized to provide proper valve stroke times and stem thrusts, thus making the Surry block valves similar in design to the Velan test valve
- QUESTION:
- 14.
RESPONSE: The submittal indicates that analyses of the safety and relief valve piping system are in progress or completed.
The information received thus far contains no presenta-tion of these analyses.
A detailed description of the
- methods and computer programs used to perform the thermal hydraulic-analysis should be provided when available.
This should identify parameters used in the thermal hydraulic analysis such as timestep, valve flow area, peak pressures and pressurization rates, node spacing, and valve opening times and should Aiscuss rational for their selection.
For loop seal cases, the assumed water and temperature distribution in the upstream and down-stream piping at the time of valve popping should be given and the development of this distribution explained.
Further, the method used for treating valve resistance in the thermal hydraulic analysis should be presented and the flow rates corresponding to the resistances used should be given.
Whether the flow rates through the safety valves were based on an ASME code derating of the safety valves should be explained.
A computer printout containing input and output from the thermal hydraulic analysis on a problem such as the locked rotor accident case should be provided.
The thermal hydraulic analysis was performed by using the Stone & Webster Engineering Corporation (SWEC) proprie-tary computer code WATSLUG.
The method and adequacy of this WATSLTJG program are detailed in Attachment A which contains general description and verification against REI.AP 5/MODl and EPRI test results.
The safety valve 2
flow area of 2.545 in was obtained from the maufacturer, while valve opening time of 0.01 second was based on EPRI test data.
Node spacing and time step are parameters applicable to RELAP and are not relevant to WATSLUG Program used.
Pressurizer peak pressure of 2575 psia and pressurization rate of 54 psi/sec were selected for loss of load transient from the Westinghouse speci.fication No.
G-67883B, Rev.
2 (see Attachment B for loss of load transient taken from~ specification).
Initially, a water slug average temperature of 400°F was used cons is tent with EPRI test No. 917 for a hot water seal and the downstream piping was conservatively assumed to be under ambient conditions.
Valve resistance in the thermal hydraulic analysis is considered by treating the valve as an orifice for water flow and as a nozzle for steam flow.
The steam flow rate corresponding to the resistance used was 293,330 lbm/hr at set pressure of 2485 psig with 3 percent accumulation.
The locked rotor accident case was considered in the analysis by compar-ison with other transients that coul.d actuate the relief and safety valves.
The loss of load case was selected for the analysis on the basis that it is postulated in~
specification to occur much more frequently than the cases of feedwater line break, reactor coolant pump locked rotor, and control rod ejection.
The most rapid pressurizer rise rate occurs with control rod ejection (470 psi/sec rise rate) which our analysis shows will create lower piping forces than the loss of load transient does due to backpressure caused by the incom-plete relief valve slug discharge event for the locked rotor case the pressurizer rise rate of 107 psi/sec indicated in the W Specificatin G678838 Rev. 2 (Attach-ment B) or 216 psi/sec indicated in the EPRI S/RV Test Program EPRI ~P-204Ti.. D Volume 3, *Table 5.5 will create forces within 3 percent of those. predicted for the loss of load case.
QUESTION:
- 15.
RESPONSE
- As with the thermal hydraulic analysis, a
detailed description of the methods and computer programs used to perform the structural analysis of the discharge piping should be provided.
The methodology for calculating forcing functions and applying the forces to the struc-tural model should be explained.
The methods used to model supports, the pressurizer and relief tanks and connections, and the portions of the safety/relief valves lying off the main pipe axis should also be described.
Other parameters such as lumped mass spacing, solution time step, damping, and cutoff frequency should be identi-fied and rationale for their selection given. Further, the load combination and corresponding allowable stress limits used should be explained.
The governing codes and standards used to determine piping and support adequacy should be identified.
Finally, results from the analysis should.be presented and a safety evaluation of the safety/
relief valve piping system should be made.
The structural analysis of the upstream and downstream piping due to safety valve discharge was performed using SWEC's NUPIPE-SW computer program which performs an elastic static and dynamic analysis of three-dimensional piping systems.
The basic method of analysis used in NUPIPE-SW is the finite element stiffness method.
In accordance with this method, the continuous piping is mathematically idealized as an assembly of elastic structural members connecting discrete nodal points.
Nodal points are placed in such a manner as to isolate particular types of piping elements such as straight runs of pipe, elbows, valves, etc, for which force-deformation characteristics can be cate-gorized.
Nodal points are also placed at all discon-tinuities such as piping supports, concentrated weights, branch lines, changes in cross section, and eccentric weights such as valve operators.
- Loadings such as weights, equivalent thermal forces, and earthquake inertia force are applied at the n*odal points.
Stiffness characteristics of the interconnecting members are related to the effective shear area and moment of inertia of the pipe.
The stiffnesses of piping elbows and certain branch connections are modified to account for local deformation effects by the flexibility factors suggested in the ASME Section III.
The methodology used to calculate the forcing functions is described in the response to Question 14.
The forcing functions are then applied to the appropriate piping segments and a time history modal superposition analysis is performed using ~UPI PE-SW.
The dynamic model is a lumped mass three-dimensional representation of the actual installation.
Supports as well as piping are modeled in their true orientation which can either be coincident with global axis or skewed.
Supports as well as connections to the pressurizer and relief tank are modeled as elastic springs in the NUPIPE piping model.
The parameters for the time history analysis are selected to ensure sufficient accuracy and dynamic stability of the solution to the dynamic analysis of piping for fluid transient loadings.
Typically, the model will contain at least three mass points between restraints active in the same direction.
Due to the piping geometry and large number of supports on the pressurizer safety and relief valve piping, this typically results in closely spaced mass points.
The cut-off frequency and mode are selected by a review of the piping geometry and piping system response charac-teristics recognizing the fact that the typical modes of excitation in this analysis are the higher frequency axial modes.
The total analysis time and integration time steps are selected based on a review of the input forcing function and to ensure a stable solution.
- The damping value to be utilized for the analysis of the safety valve loop seal clearing event will be 1 percent of critical damping. This damping value is consistent with the value of the respective earthquakes (i.e., OBE and DBE) to which the safety valve discharge cases are combined.
The piping stress analysis for the Surry pressurizer safety and relief valve piping is performed in accordance with the ASA B31.l Code for Pressure Piping 1955 Edition.
The load combinations and allowable stress limit for the safety valve discharge condition are based on the UFSAR and EPRI recommendations and are:
Where:
s LP* Longitudinal pressure stress SDL
- Deadload stress 5nBEI
- Seismic stress due to DBE-inertia 5ocCl
- Occasional stress due to relief valve discharge case.
-Occasional stress due to larger of relief 50CC2 valve or safety valve discharge cases.
- Allowable stress at maximum operating condition
- The pipe supports are designed in accordance with the AISC Manual of Steel Construction 7th Edition..
The loading conditions and allowables are as follows:
DW + THER + SRSS (OBET, OCCl)
~ 1. 33 (Basic Allowable)
DW + SRSS (DBEI, OCC2) :. 1. 33 (Basic Allowable)
Where:
DW = Loads due to deadweight THER = Loads due to thermal expansion OBET = Operational basis earthquake (includes the effects of inertia and anchor movements)
DBEI
- Design basis earthquake inertia OCCl = Loads due to relief valve discharge OCC2 = Large of loads due to relief valve or safety valve discharge The baseplate analysis will meet or exceed the require-ments of I&E Bulletin 79-02.
The welded attachments to Class l' pipe will be evaluated in accordance with the ASME code cases ~122 and N391.
Welded attachments to all other (non-Class 1) pipes will be evaluated per ASME code cases N319 and N392
- QUESTION:
RESPONSE
- 16. The submittal should discuss whether multiple valve actua~ion conditions were considered in the analyses. The maximum loading on the piping
- typically occurs under a multiple valve actuation condition during which the valves open in sequence.
The experience of EG&G *Idaho indicates that the maximum loading occurs when the sequence of opening is such that the intial pressure waves from opening of the valves reach the common header downstream simultaneously.
- Thus, the method used to
~aximize loading on the piping should be discussed.
All safety valve discharge events are bounded by the loop seal clearing case.
The thermal hydraulic forcing func-tions for this case are developed using SWEC 's WATSLUG computer code which is described in the response to question 14.
The valve sequencing is selected such that the water slugs from pne, two, or three safety valve loop seals, whichever creates the maximum force in particular segment of pipe are considered.
They all join at the common discharge header and continue through the system as a combined mass.
The phasing of pressure waves are not significant for the water slug loop seal clearing event *
- Question 17 Testing indicated that for loop seal discharge, liquid, or transition flow, valve instabilities occurred causing the valve to chatter or flutter at frequencies from 170-260 hz.
The instability caused large pressure transients on the safety valve inlet piping.
The plant specific submittal presents the permissible pressures based on ASME Code allowable taken from Reference 9.
Review of Reference 9 concluded that the peak internal pressure pulses were within acceptable limits. However, the submittal does not discuss the bending moments resulting from the piping dynamic effects due to the fluid pressure oscillations combined with other appropriate mechanical loads.
Provide a comparison of the allowable piping moments with the computed moments resulting from the appropriate loading combinations with the piping dynamic effects included *
Response
The piping system response, including the safety valve loop seal region, is primarily governed by loads with frequencies less than 100 hz.
The frequency of the pressure oscillations is in the 170-260 hz. range which is significantly greater than the piping system frequency.
The upper limit of significant frequency content for piping systems is much less than this 170-260 hz range.
Consequently, no significant bending moment during the pressure oscillation phase of the transient will occur.
Due to the time phasing of the pressure oscillation (during water slug discharge through the safety valve) and the discharge piping loads (subsequent to water slug discharge through the valve), the pressure term and moment term
- were not added for Surry Units 1 and 2 pipe stress analysis, because,they do not occur simultaneously.
Even if they are considered coincident, the piping stresses are within allowables.
The piping at Surry for pressurizer safety piping is 6 in. Schedule 160, A376, TP316 material.
For this piping, the maximum allowable moment at an elbow, coincident with 5000 psi pressure, using a stress factor of 1.8 Sh, is 405 in.-kips. The maximum pressure of 5000 psi was observed during EPRI testing and it is the recommendation of EPRI in their March 17, 1982, letter to Utility Technical Contacts that this value be used.
Preliminary SWEC analysis indicates that the maximum bending moment which could occur simultaneously with the pressure transient is on the order of 80 in.-kips resulting from deadweight and design basis earthquake inertia and the maximum beinding moment at the safety valve inlet due to safety valve discharge load is on the order of 75 in.-kips. These values are significantly lower than the allowable moment of 405 in.-kips *
- J. ~'LREG 07:7 SURRY UNITS l & 2
!he pu=?cse of ';.A.TS~:G (Re:. 1) :.s :c ~e:e==ii:i.e :o-:-ci:i.g func:ic:1.s :n
?i?ing syste:s cur::.:i.g ~a:er slug disc~arge ~,en:s :er subsequen: =-~?u:
to ?ipi:ig d:mamic analysis
- The analysis is based upon ri~id body =c::.c~ of ::1e gene-:-ally subccoied Nater slug and ideal gas representaticns of t!le steam or air using =ig:.c col..imn :::1eory to :ac:::.li:ate :=ack:.ng :he seve=.al water-ste.::m er ~ater-a:::.r
- .:i.:er:aces.
The dr:::.ving force :.s t:1e steam ?!'es sure '.::et*..;een :he -;a:*,e and :he slug, less fri::::::.on and ot::1er :osses, and back pressure.
r::ens::.:v changes due :o ?OSSible local ::ashi:i.g cf :he ~ater s:ug are cons::.cered.
~av:.:ig recourse :o :~e cont=ol 7ol:.::ne :~ecry, :he subsequent segme~:
- crce calc~lation is carried out.
- ':le ::.nput consists of complete ?i?ing system geome:-:-y, ?i?e d:!.:!lens::.=:i.s,
- 1alve flow characteristics, *,alve open:.:i.g :::ne, ciet.ail ~!=st=ea:n steam condi:ions, and :.nitial do~stre~ s:aam or air condi:icns, ~hi:e :~e out?Ut contai:1.s forcing f~nctions for each ?i?ing seg?:1ent based ~pen
- ow -;e:oci:ies, pressures, and ~ensi:ies dur::.ng ::1e water slug disc~arge event.
For::es are ;JTi::en on tape for direc: :.nput :o ~I?E-Sw (~-:::)).
(Re:f. 2)
- Z.
?rogram Veri:ication
- '::e WATSll:G :nodel of :~e test ?rob:e!!l ::.s diag=a=ied in :ig,.zre 3A.3 **.;.-: and
- he :~'PIPE-Sw' model is c!iagral!lmed in F:::.g,.;re 3A. 3. A-2. ';A':'SlUG is *,e=:.::.ec:
- ,y co~paring :::1e soluti=n of ::iis test ?roble: to :he resu::s :or :~e sa=e
?!'Oblem obtai:1ed by a.n ::.:1de?encien: ana:~:~ica2. a.?prcac:l (F.!L-u>5 /!fOD :, ~e:. 3) as sho~-n in Figures 3A.3.A-3 and 3A.3,A-.:.. and
=eac:icns due :o :he WATSLUG forcir.g func:~c~s were com?areci *i:i ex?e~:..:e~:~:
~easure~ents from ates: run of this ?roblem (~?~~ :est 908, ?.ef. 3) as shewn i:i Figures 3A. 3.A-3 and 3.A.3...;,-,S.
- .e hA!SL~G generated :orcing func:icns and the =esultan: ~?I?~-5~
supper: =eactions compare favorabl:,,..ri:h the :U::.A.?5/~0D :. ?red::'..;::ed
.:orcing :unctions and :he EPRI ?:J.easured support reactions, res?ec:i*:e:::.
- 3.
1eferences
"*...rA:'SLUG" (ME-212).:ompu:er code :,y.... ::.. 3sieh and D. A. 7an Ju:--:1e, Ver. 0, Rev. 3, December 198: and :~e re:ated doc~:nentaticn calculation 376.4i0.1-NP(B)-038-FD, Re*,. :, "*.Jater Slug :::>ischa:-ge *-
?!?i~g System (~ATSLUG) - P=e?roduc:icn Ue~sion 3", da~ed :tar=~ 3, l9S2.
- 2.
~1JPI?E-Sw', "!iE-110, V03,!.l4 (created SZ.095), "Comput:er cocie :or Sc-:-ess Analysis of ~uclear Piping" *
- 3.
"Application of ~LAPS/~OD 1 :-::r ca.!.::'..!lation of Safetv anci Relie.: 'Ja:..ve Discharge ?iping Hydrodynamic !.cads:', !:i.terim Re?ort, ~rc:i 1982, ":>y
!ntermountain Technologies, !~c., :aaho :a::s, Iciaho, Project ~anage=
3.. K. House.
~TO:::S:
-~,....,-
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- .36.3
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OUTSDE
- >I.-\\.'1£._.:3 c:~n
- a. 625 6.625 6.52.5
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0.906
- 0. 55..,
o.:s 0.688 u *.;::
- ~~
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- YOUNG's '.'!ODULUS OF ?T_::: * ::!3.3**:c :.06 ?S:
~OT
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Lo: !.A,!TI /lll!L.!!1 VALVE L.G : OOW Nsi"lt[AM AREA CHANG£ L.1 a P*,! !XIT IX1 : 'TR.AILJNC3 El)CIE Off SLUG 1
.,_ FORC:NG FUN~lON OIR!CTION,
- D E~q I ~S'T' ( R!F. 3)
SE'lMENT.~
'.VATSLUG ~OCEI. i=tPE ~UMBER 1 - FIRE!SURIZER 'T'O !..4 2* Lo'l"O !..~
- ! - L.G ro 1..F GAS i
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SAMP!..E P~CSL.EM
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a:u 160 SUPPORT 5
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- LEGEND, 0
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- lPRI TUT CRff. S) SEGMENT NO.
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FIGURE 3A. 3.A - 3 COMPARISON OF SEGMENT 2 fOHCING FUNCTION I
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FIGURE 3A. 3.A - 4 COMPARISON Of SEGMENT 3 fORCING FUNCTION I w 0
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-llOO SURE IS R£TURIIEO
=
IIITIJ.:. u:..:.:! n £ I!~~
er, COIISl!iEMT Wl':'H *CRIUL PRES*
- 1173 a::
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SURIZEII KE!:UP.
-600 iIME {SECO~CS)
Figure a - Loss of Load - Fr~ssuri:er ?l'"essure Vari at fen (80 cycles)
E:ttrac:ed f:-om 1:ies:::..nghcuse Equipmer. t Speci~icat::..on G-673838, Rev. ~, 10/ 19 /77, "Pressurizer Safety Valves, AS:1E Beiler* and ?ressure Vessel Code,Section III, Class 1."
'Page 11 of 2!3
- ATTACHMENT C MAXIMUM CALCULATED EPRI APPLIED
,r RATED BENDING BENDING FLOW MOMENT MOMENT VENDOR MODEL LBS/HR (IN.-LBS)
(IN.-LBS)
CROSBY 98,9381 SAFETY HB-BP-86 293,230 (2)
VALVE COPES-VULCAN 19,6021 RELIEF D-100-160 210,000 (2)
VALVE NOES:
- 1.
Loads from SWEC Calculation No. 12846-NP(B)-030-Xl2, Revision 1, dated December 17, 1981, VEPCO Surry Unit 1 Pipe Stress Analysis of Pressurizer Safety and Relief System.
- 2.
We are not aware of any EPRI tests which applied bending moments to either of these particular or similar valves in conjunction with discharge tests.
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ELECTRIC POWER RESEARCH INSTITUTE EPRI April 5, 1982.
TO: -
UTILITY TECHNICAL AND LICENSING CONiACTS. PWR NSSS VENDOR PRIMARY COMTACTS
SUBJECT:
"GUIDE FOR APPLICATION OF VALVE TEST PROGRAM RESULTS TO PLANT SPECIFIC EVALUATIONS"- REVISION 1 At the request of the participating Utilities, EPRI and the Utility Technical Advisory Group (TAG) have compiled a guideline report des-cribing a suggested procedure for Utilities to follow in preparing plant-specific submittals in response to NUREG 0737 ("Clarification of TMI-1 Action Plan Requirements")Section II.0.1.A Requirements.
Attached to this letter is a copy of the subject report. A draf~
copy of this report was transmitted for your review on February 23, 1982.
All comments have been incorporated into the attached.
If you have any questions regarding the attached, please contact~~-
WJB/11 Attach.
Sincerely, *
~
~ 1' 8~~-*---
Warren J. Bilanin Pro gram Manager Safety and Analysis Department Headc:iuarters 34i2 Hillview Avenue. Po~t Offic~ Box 10412. Palo Alto. CA 94303 (415) 855-2000
,,, __... ______,-..,,... *0,," **-----***--**- * *-- -....,,,,. *- ~"""'.*, ** ~ --*--
Revision 1
~EPRI PWR SAFETY AND RELIEF VALVE TEST PROGRAM
' GUIDE FOR APPLICATION OF VALVE TEST PROGRAM RESULTS TO PLANT-SPECIFIC EVALUATIONS INTERIM REPORT, MARCH 1982 (RESEARCH PROJECT Vl02)
Prepared by:
MPR Associates, Inc.
1140 Connecticut Avenue, N.W.
Washington, D.C. 20036 Prepared for:
Participating PWR Utilities and Electric Power Research Institute 3412 Hillview Avenue Palo Alto, California 94304 EPRI Project Managers:
T. E. Auble J. F. Hosler PWR Safety and Relief Valve Test Program Nuclear Power Division
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Revision l PREFACE
~his guide has been developed to assist participating PWR Utilities in determining the applicability of the various test results from the EPRI program for their plant-specific evalu-ations.
The overall key to using the guide is to most closely match the valve/piping configurations tested by EPRI with actual plant installations.
In following this approach care should be t~ken not to overlook the results of any test for possible applicability, i.e., each test conducted on a representative valve type may have some generic or indirect applicability.
However, the closer the tie between specific EPRI tests and the plant installation, the more direct the applicability of the results. It is expected that the approach developed in this guide will be useful for virtually all of the plant evaluations.
Revision 1 TABLE OF CONTENTS
- -~
I.
INTRODUCTION A.
Purpose of the Application Guide B.
Contents of the Guide II.
PROCEDURE TO BE FOLLOWED IN PLANT-SPECIFIC EVALUATIONS A.
Flow Charts for the Evaluations
- 1.
Evaluation of Valve Performance
- 2.
Evaluation of Piping/Support Adequacy B.
Workscopes for the Evaluations
- 1.
Utility
- 2.
Valve Manufacturer
- 3.
NSSS Vendor
- 4.
EPRI III.
EVALUATION OF TEST RESULTS FOR PLANT-SPECIFIC CONDITIONS IV.
A.
B.
Identification of Pertinent Plant Parameters Procedures for Evaluation of Test Results
- 1.
Safety Valve Performance and Associated Piping/S~pport Adequacy
- 2.
Relief Valve Performance and Associated Piping/Support Adequacy C.
Identification.of Potential Problem Areas and Possible Alternatives to Address Undesirable Valve Performance SUGGESTED FORMAT FOR JULY 1, 1982 PLANT-SPECIFIC SUBMITTAL V.
REFERENCES
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VI.
Revision l TABLE OF CONTENTS (Cont'd)
APPENDICES A.
B.
- c.
Procedure for Calculation of Valve Back Pressure Procedure for Calculation of Inlet Piping Pressure Effects Procedure for Verification of Alternative Methods to be used in Evaluation of Piping/Support Adequacy D.
Procedure for Assessment of Applicability of Specific EPRI Safety Valve Tests E.
Load Combinations and Acceptance Criteria for the Safety and Relief Valve Piping Evaluation ii
A.
Revision l I.
INTRODUCTION Purpose of the Application Guide The purpose of the application guide is to provide a pro-cedure for utilities to follow in preparing plant-specific submittals in response to NUREG-0737 ("Clarification of TMI Action Plan Requirements")Section II.0.1-A, Requirements.
Specifically, NUREG-0737 requires the following:
- 1.
An evaluation of safety and relief valve function-ability for plant-specific operating and accident conditions.
- 2.
An evaluation of piping and support adequacy for plant-specific conditions.
In preparing the application guide, it was assumed that the utilities would obtain.assistance from the valve manu-facturers and NSSS vendors in performing the required evaluations. Specifically, it was assumed that:
- l.
The utilities (with possible assistance from architect-. I engineers er other piping designers) will perforlJI the eval- ;
uations of piping and support adequacy.
- 2. -
The valve manufacturers will perform the evaluations of valve performance.
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- 3.
The NSSS vendors will perform the evaluations of overpressure protection system performance.
~.
The utilites will coordinate the overall evaluation effort and prepare the plant-specific submittal to the NRC.
The delineation of responsibilities outlined above is based on impressions gained throughout the program regarding_ which crganization(s) was probably best suited to accomplish a particular task. It is recognized that some utilities may
- elect to perform more or fewer tasks than assigned in this guide.
The important point is that the guide highlights the tasks that need to be done and assigns them to an appropriate organization.
The participating utility has final control over both the scope of work details and the organization assigned.
The Application Guide is based on directly using test results from the EPRI program in the plant-specific evalu-ations.
Thus, in order to use the guide, one must estab-lish the one (or more) valve/piping configuration tested by EPRI which most closely matches the plant installation.
It is expected this approach will be useful for virtually all of the plant evaluations.
The guide assists in de-fining the limits cf applicability of the EPRI data.
I - 2
B.
Revision 1 Contents of the Guide
'l'he contents of the applicati.on guide are summarized in the-* following:
Section II -- Procedure to be Followed in Plant-Specific Evaluations A.
Flow Charts for the Evaluations
'l'his section describes the overall approach to be followed in performing the evaluations of valve performance and piping/support adequacy.
B.
Workscopes for the Evaluations
'l'his section discusses the workscopes for the evaluations to be performed by the utilities, the valve manufacturers,. the NSSS vendors and EPRI.
0 Section III -- Evaluation* of Test Results for Plant-Specific Conditions A.
Identification of Pertinent Plant Parameters This section identifies the pertinent plant-specific safety and relief valve, inlet piping, discharge piping and valve actuation transient parameters to be assembled by the utilities for use in the evaluations.
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B.
- c.
Revision l Procedures for Evaluation of Test Results This section provides the procedures to be used in performing the evaluations of valve performance and piping/support adequacy.
For.the valve per-formance evaluation, it provides guidelines for identifying applicable valve tests, a table to be used by the valve manufacturer to ~ocument valve performance characteristics, and a suggested set of acceptance criteria for valve performance.
For the piping/support adequacy evaluation, it provides suggested guidelines fpr the evaluation and a suggested set of structural acceptance criteria.
Identification of Potential Problem Areas and Possible Alternatives to Address Undesirable Valve Performance This section provides a listing of potential problem areas regarding valve performance and piping/support adequacy identified based on the results of the EPRI Safety and Relief Valve Test Program. It also discusses possible alterna-tives to be considered by the utilities to address undesirable valve performance features.
Section IV -- Suggested Format for July l, 1982 Plant-Specific Submittal This section of the guide provides a suggested format for the July l, 1982 plant-specific submittal to the NRC.
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Revision 1 Section V -- References This section provides a listing of the various EPRI Program reports to be used by the utilities in per-forming the plant-specific evaluations.
Section VI -- Appendices A.
Procedure for Calculation of Valve Back Pressure This appendix outlines a suggested procedure and guidelines for the calculation of valve back pressure.
B.
Procedure for Calculation of Inlet Piping Pressure Effects This appendix provides a suggested procedure and guidelines for the calculation of inlet piping pressure effects.
C.
Procedure for Verification of Alternative Methods tc be used in Evaluation of Piping/Support Adequacy D.
This appendix provides a suggested procedure to verify the adequacy of the alternative methods to be used to evaluate the structural adequacy of the piping and supports.
Procedure for Assessment of Applicability of Specific EPRI Safety Valve Tests
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- I This appendix outlines a procedure to assist in
~
. l determining the applicability of EPRI safety valve tests to specific plant evaluations
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E.
Revision 1 Load Combinations and Acceptance Criteria for the Safety and Relief Valve Piping Evaluation This section provides recommended load combinations and acceptance criteria to be used by the utilitie~
in evaluating the adequacy of the safety and re-lief valve piping and supports.
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Revision 1 II.
PROCEDURE TO BE FOLLOWED IN PLANT-SPECIFIC EVALUATIONS A.
Flow Charts for the Evaluations la Evaluation of Valve Performance Safety Valves The flow chart provided in Table II-1 illustrates the overall procedure to be followed in performing the evaluations of safety valve performance.
input for the evaluations consists of:
EPRI valve program reports as listed in Section V of this guide.
List of pertinent plant parameters as identified in Table III-1.
The evaluations to be performed consist of the following:
The An evaluation of test results by the valve manufacturer to identify any potential problem areas regarding valve performance.
0 An evaluation by the NSSS vendor to identify 1 I
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j any potential problem areas regarding overpressu* ~
, I protection system performance.
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Revision l An evaluation by the utility of possible alternatives to address undesira"ble valve performance features.
The~ output from the evaluations consists of:
0 A report for submittal to the NRC which documents the results of the plant-specific evaluations.
This report would address the selection and schedule for implementation by the utility of any required modifica-tions to the valves and/or the overpressure protection system parameters.
Although not shown specifically in the flow chart, a significant amount of interaction is expected to be required among the utility, valve manufacturer and NSSS vendor during the course of the evalu-ations. Also, it is expected that the utilities will assume the responsi~ility for coordinating the overall evaluation effort.
II - 2
Revision 1 Relief Valves The evaluation of relief valve performance should also be performed following the procedure shown in Table II-1. However, this evaluation should be more straightforward than the safety valve performance evaluation and it is expected that the utilities would perform the bulk of the evaluation.
- 2.
~valuation of Piping/Support Adequacy The flow chart provided in Table II-2 illustrates the overall procedure to be followed in performing the evaluations of piping/support adequacy.
The input for the evaluations consists of:
0 0
Verified computer codes for determination of hyd~aulic loads and EPRI valve program reports as listed in Section V of this guide.
List of pertinent plant parameters as identified in Table III-1.
The evaluations to be performed by the utility consist of the following:
0 0
J.n evaluation of the piping stresses and support loads using the EPRI-provided codes or other method which has been verified by comparison of predictions with EPRI test data provided in Reference 7.
A comparison of calculatod ci~ing stresses and support loads with allowables and identification of any potential problem areas.
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0 Revision l An evaluation of possible alternatives to address potential piping/support problem areas.
The output of the evaluations consists of a report for submittal to the NRC which provides the results of the plant-specific evaluations.
The report may include, if required, the selection and implementa-tion schedule of modifications to the piping and supports.
Workscopes for the Evaluations Tables II-3 through II-8 summarize the workscopes for the various evaluations to be performed by the utility, the valve manufacturer, the NSSS vendor and EPRI.
The tables are identified as follows:
Table II-3 II-4 II-5 II-6 II-7 II-8 Organization Utility Utility Valve Manufacturer Valve Manufacturer NSS Vendor EPRI II -
4 Evaluation Safety and Relief Valve Performance Piping/Support Adequacy Safety Valve Performance Relief Valve Performance Safety and Relief Valve Performance Valve Performance and Piping/Support Adequacy
TABLE 11-1 Revision l APPLICATION OF VALVE TEST RESULTS TO :PLANT -
SPECIFIC EVALUATIONS OF VALVE PERFORMANCE EPRI-UTILITY VALVE MANUFACTURER*
NSSS VENDOR I
I
~---------.._ _________ _._ _________ _.. _________ i-ASSEMBLES I
PROVIDES VALVE:
PERTINENT I
PROGRAM REPORTS
~ -
PLANT INFORMATION FOR EVAl.UATIONS (SEE TABLE III-1)
I I
.I EVALUATES TEST EVALUAT~S TEST
- 1 ll!:SULTS AND ll!:SULTS AND IDENTIFIES ANY
'IDENTIFIES A.~Y POTENTIAL PROBLEM POTE:~TIAL PROBLEM ARU.S REGARDING AREAS REGARDING VALVE PERFORMA~CE SYST£!'1 P£R:0R.'~~CE I I I
0 IDENTIFIES IDENTIFIES ALTERNATIVE:
AI.TER.~ATIV!: I VAI.VE:
SYSTEM/AN1'LYSIS MODIFICATIONS.
MODIFICATIONS AS REQUIRED AS REQt:!RZD i
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- PROVIDES, EVALUATES*
l ASSISTANCE AI.TEP.NATIVES TO UTILITY IN.
AND SELECTS I
EVALUATION MODIFICATIONS..
AS ~uouI RI:D
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- I SC:HED'OLES IMPLEMENTATION OF SELECTED MODIFICATIONS AS REOt'IRED I
0 PREPARES
. I PLANT-SPECIFIC:
SOBMITTAL I
FOR THE NRC:
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Revision 1 TABLE 11-2 APPLIQATION OF VALVE TEST RESULTS TO PLANT - SPECIFIC EVALUATIONS OF PIPING ADEQUACY EPRI UTILITY PROVIDES VERIFIED ASSEM!llS COMPUTER CODE AND PERTINENT VALVE PROGRAM Pl.ANT ltEPORTS FOR lN!'OiUO.TION
'CTILITY EVALUATIONS (SE£ '1'AB~£ III*l)
~ '
CSING EPRI*PROVIDED CODE OR OTHER VERIFIED Ml:THOD EVALUATES STP.!:SSES AND SUPPORT LOADS IN PIPING Ip COMPAR!:S LOADS AND STRESSES WITH AI.LOWUU:S AND IDENTIFIES ANY POTENTIAL PROBLt:?-! AR!:AS 0
EV.Al.L"TES, St:LECTS AND SCHEDULES lMPI.£1'!!:NTATION OF MODIFICATIONS TO PIPING AND SUPPORTS AS JU:Ot'IR~:,
~,
PR.EPARES PLANT-SPECIFIC SUBMITTAL FOR '1'BE NRC II - 6
Revision 1 TABLE II-3 WORKSCOPE FOR UTILITY EVALUATION OF SAFETY AND RELIEF VALVE PERFORMANCE The utility will perform the following:
- 1.
Identify pertinent plant information listed in Table III-l, including:
- 2.
Valve parameters*
Inlet piping parameters Discharge piping parameters Valve actuation transient parameters Evaluate alternative modifications identified by valve.
manufacturer and/or NSSS vendor and select modifications for implementation.
- 3.
Schedule implementation of selected modifications to valves.
- 4.
Prepare plant-specific submittal for the NRC.
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l Revision 1 TABLE II-4 WORKSCOPE FOR UTILITY EVALUATIONS OF PIPING/SUPPORT ADEQUACY The utility will perform the following:
- 1.
Identify pertinent plant information listed in Table III-l, including:
Valve parameters Inlet piping parameters Discharge piping parameters Valve actuation transient parar.ieters
- 2.
Using EPRI-provided code or other verified (by comparison with valve test results) method, evaluate stresses and support loads in inlet and discharge piping.
I
- 3.
Compare loads and stresses with allowable values and identify any potential problem areas.
1
- 4.
Evaluate, select and schedule implementation of modifica.-
tions to piping and supports as required.
S.
Prepare plant-specific submittal for the NRC.
II - 8
A.
B".
Revision 1 TABLE II-5 WORRSCOPE FOR VALVE MANUFACTURER EVALUATION OF SAFETY VALVE PERFORMANCE Bases for Evaluation The following will be provided to the valve manufacturer for his use in the evaluations:
- 1.
Applicable EPRI test progra~ outputs.
- 2.
Plant information listed in Table III-1 Scope of Evaluation The valve manufacturer will perform the following:
- l.
Define performance for as-installed valve ring settings.
based on:
EPRI test data*
Valve manufacturer's test data 0
Valve manufacturer's supporting analysis The evaluation should:
0 Determine which fluid conditions result in stable or unstable valve performance.
0 Establish valve performance characteristics (e.g., blowdown, lift, flow opening time, etc.).
- 2.
Define performance for optimal valve ring settings accordance with the steps identified in l above.
- 3.
Recommend valve modifications to provide improved performance, if needed (e.g., to provide reduced blowdown, stable water performance, etc.).
- 4.
Document performance recommendations and bases for recommendations to the utilities.
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Revision 1
'!'ABLE II-6 WORKSCOPE FOR VALVE MANUFACTURER EVALUATIONS OF RELIEF VALVE PERFORMANCE Bases for Evaluation
'l'he following will be provided to the valve manufacturer for his use in the evaluations:
- l.
2.
Applicable EPRI test program outputs.
Plant information listed in Table III-1 Scope of Evaluation The valve manufacturer will perform the following:
- l.
Establish valve performance characteristics (e.g., opening time, flow, closing time)
- 2.
Recommended valve modifications to provide improved performance, if needed *
- 3.
Document performance recommendations and bases for recommendations to the utilities.
II -
10
Revision l TABLE II-7 WORRSCOPE FOR NSSS VENDOR EVALUATION OF SAFETY AND RELIEF VALVE PERFORMANCE A.
_Bases for Evaluation B.
The follo~ing will be provided to the NSSS vendor for his use in the evaluations:
- l.
Applicable EPRI test program outputs.
- 2.
Plant information listed in Table III-1.
- 3.
Valve performance characteristics (e.g., blowdown, lift, flow, opening time, etc.), as established by the valve manufacturer.
Scope of Evaluation The NSSS vendor will perform the following:
- 1.
Evaluate test results and document system acceptability or identify any potential problem areas regarding NSSS overpressure protection sys-tem performance.
- 2.
If potential problems are identified:
0 0
0 Identify alternative modifications to NSSS overpressure protection system and/or overpressure transient analysis parameters to resolve un-acceptable performance.
Concur with system/analysis modifications selected by utility for implementation.
Prepare report which justifies acceptability of system/analysis modifications selected for implementation *.
II - 11
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Revision 1 TABLE II-8 WORKSCOPE FOR EPRI EVALUATIONS Valve Performance
- 1.
Provide valve program reports for utility evaluations.
- 2.
Provide on-going assistance to utilities in the understanding and use of program outputs as required.
Piping/Support Adequacy Provide verified computer code and valve program reports for utility evaluations of inlet and discharge piping and support adequacy.
The eode provided by EPRI is to be used for the calculation of the time-dependent hydraulic loads applied by the fluid on the piping.
II - 12
III.
Revision 1 EVALUATION OF TEST RESULTS FOR PLANT-SPECIFIC CONDITIONS A.
Identification of Pertinent Plant Parameters A list of pertinent plant parameters to be identified by the utility is provided in Table III-1.
Possible sources to be used by the utility in compiling the required in-formation are listed below:
- l. Plant Final Safety Analysis Report/Cold Overpressuri-zation Analysis Report
- 2.
Plant Technical Specifications
- 3.
Plant installation drawings and system isometrics
- 4.
Valve Documentation and Nameplate Information
- s.
Initial valve manufacturer's test data and periodic set pressure verification test data.
In addition, the EPRI valve program reports (see Section V) and the appendices to this guide should be useful as follows:
0 0
0 The test conditions justification report (Reference 3) and plant conditions justification report (References 4, 5 and 6) should be useful in assembling the valve actuation tran~ient information.
Appendix A provides a procedure to be used for the calculation of valve back pressure.
Appendix B provides a procedure to be used to calculate the inlet piping pressure drop associated with valve opening and pressure rise associated with valve closing.
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Revision 1 Procedures for Evaluation of Test Results
- 1. *.
Safet Valve Performance and Associated Piping Support Adeguacy The procedure to be used to evaluate safety valve performance for plant-specific conditions is as follows:
0 0
0 Step 1 The utility provides the assembled plant in-formation (Table III-1) and the applicable EPRI valve test program output to both the valve manufacturer and the 'NSSS vendor.
Step 2 The valve manufacturer identifies the specific EPRI tests which are applicable for the plant-specific safety valve evaluation being performed.
An outline for conducting this type of evaluation is provided in Appendix D to this report.
Step 3 Based on.the information provided by the utility (see Step 1 above) and the valve manufacturer's own test data and supporting analyses, the valve manufacturer determines the valve performance characteristics and completes the performance summary sheet provided in Table III-2 for both as-installed and optimal ring settings.
III -
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0 0
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Revision l Step 4 The utility performs an evaluation of safety valve inlet and discharge piping stresses and piping sup-port and valve loads*
Step 5 The NSSS vendor compares the valve performance characteristics listed in Table III-2 with the valve characteristics assumed in the FSAR (or other design)
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any conditions for which the actual and assumed valve performance characteristics are not consistent (see Table III-3 for performance characteristics to be considered).
Where not consistent, the NSSS vendor should judge the acceptability of the deviation and provide the basis for his judgment.
Step 6 The utility compar~s the safety valve piping/support loads and stresses with the allowable values and identifies any conditions for which the allowable values are exceeded (see Table III-3 for definition I,
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of piping and support allowable loads and stresses).*.{
I Step 7 The utility (with assistance from the valve manufacturer and NSSS vendor as required) identifies --J any conditions for which acceptable valve performance is not obtained.
The utility then evaluates III -
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Revision l possible alternatives which could provide acceptable valve performance and selects any needed modifications to be made to the valves or piping.
Step 8 The utility, valve manufacturer and NSSS vendor prepare reports which document their evaluations and justify the acceptability of any modifications selected for implementation.
Relief Valve Performance and -Associated Piping/Support Adequacy The procedure to be used to evaluate relief valve per-formance for plant-specific conditions is outlined in the following. It is noted that these evaluations should be straightforward and it is expected that the utility could perform the bulk of the evaluations.
0 0
Step l The utility assembles the plant information (Table III-l) and the applicable EPRI valve test program outputs.
Step 2 Based on the plant information and the EPRI valve tes data, the valve manufacturer (or utility) determines the valve performance characteristics and completes the performance summary sheet provided in Table III-4 This evaluation should consider any differences in tll air and/or electrical supply and.{o~ pilot-operated valves the pilot vent discharge tubing for that in-stalled in plants compared to that tested
- III -
4
0 0
.Revision 1 Step 3 The utility performs an evaluation of relief valve inlet and discharge piping stresses and piping support and valve loads.
Step 4 The NSSS vendor (or utility) compares the per-formance characteristics listed in Table III-4 with the valve characteristics assumed in the cold overpressurization analyses and identifies any conditions for which the actual and assumed valve performance characteristics are not consistent (see Table III-3 for performance characteristics to be considered).
Step 5 The utility compares the relief valve piping/
support loads and stresses with the allowable values and identifies any conditions for which the allowable values are exceeded (see Table III-3 for definition of piping and support allowable loads and stresses).
Step 6 The utility identifies any conditions for which acceptable valve performance is not obtained, and then evaluates possible alternatives III -
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which could provide acceptable valve performance and selects any needed modifications.
Step 7 The utility, valve manufacturer, and NSSS vendor prepare reports which document their evaluations and justify the acceptability of any modifications selected for implementation.
C.
Identification of Potential Problem Areas and Possible Alternatives to Address Undesirable Valve Performance Based on the results of the EPRI valve tests, it is apparent that there are some plant conditions which could result in valve performance characteristics which are not within acceptable limits (as currently defined).
As discussed in previous sections, the first step in addressing these poten-tial concerns is to perform analyses to attempt to demonstrate that the observed valve performance can be accommodated in the plant.
Should these efforts be unsuccessful, several alternatives are available to resolve these potential problems.
A list of potential problem areas and some possible alternatives to be considered to address the undesirable valve performance is provided in Table III-5. It should be noted that this list is not intended to be complete, but only to serve as a checklist or starting-point for the more detailed performance evaluations to be perf~rmed by the utilities, valve manufacturers and NSSS vendors.
III -
6
Revision 1 Table III-6 provides a general summary of the safety valve test results obtained in the EPRI program.
Some considera-tions to be taken into account in evaluating off-normal valve performance for various conditions as n9ted in Table III-5 sre discussed below:
Safety Valves
- 1.
Performance with Steam Flow For virtually all safety valve/inlet piping combinations tested, ring settings were established
. i
- in the EPRI tests which provided stable valve per-formance with steam inlet conditions.
- However, these ring settings resulted in valve blowdo"F outside of normally accepted limits (i.e., greater than five percent).
Therefore, re-evaluatiort of selected NSS system overpressure transients should be performed by the NSSS vendors to show that in-creased valve blowdown is acceptable.
Other poten-tial alternatives would be to utilize an alternative valve or shorten the valve inlet piping so that stable performance can be obtained with reduced
- 1 blowdown (i.e., near five percent).
- 2.
Performance with Subcooled Water Flow
. )
For some cf the safety valves tested, the valves
_j chattered with subcooled water inlet conditions
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- 3.
Revision l For these cases, if the fluid conditions for a specific plant include subcooled water, the utility/NSSS vendor could show that the subcooled water can be handled by other than ~a;ety valve actuation.
This could be accomplished by use of the PORVs to vent the flow (at a pressure less than the safety valve set pressure) or by op-erator termination of the transient. Another possible solution is to utilize an alternative valve which performs in a stable manner with sub-cooled water or to modify the existing valve (e.g., using an assist device) to provide stable performance.
Performance with Cold Loop Seals For the tests (with the spring-loaded valves) which utilized cold loop seals at the valve, a number of undesirable performance characteristics resulted, including large pressure oscillations in the upstream piping, delayed valve opening until loop seal clearing, and high pressures and loads in the discharge piping.
(Elevated temperature loop seal tests resulted in reduced piping loads.)
Possible alternatives to eliminate these undesirable per-formance features include draining the loop seal, heating the loop seal to near saturation or utilizing an alternative valve which provides better III -
B
Revision 1 performance with the loop seal.
However, before a decision to ~rain or heat loop seals is made, careful consideration should be given to the potential consequences, e.g., increased potential for valve seat degradation and resulting steam/
hydrogen leakage.
Relief Valves Acceptable performance was obtained with most of the relief valves tested.
An off-normal result obtained was delayed valve closure for two of the relief valves (Dresser Electromatic and Target Rock) with fluid conditions that result from loop seal installations.
For plants which utilize these valves with loop seals, possible alternatives to consider include heating or draining of the loop seal, or utilizing an alternative valve which is less sensitive to the thermal transient.
However, before a decision to drain or heat loop seals is made, careful consideration should be given to the potential consequences of such operation as noted above.
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Revision l TABLE III-1 PLANT INFORMATION TO BE ASSEMBLIED BY UTILITY Following is a list of valve/piping information to be assembled by the utility for the evaluations:
- 1.
Safety Valve Information Number of valves Manufacturer
- 2.
Type Size (inlet, outlet, orifice)
Steam flow capacity (rated and maximum)
Design pressure and temperature Inlet flange rating Discharge flange rating Allowable applied load (should consider the applied load which resulted during testing)
Set pressure Accumulation (specified and existing, if available)
Blowdown (specified and existing, if available)
Ring settings (specified and existing, if available)
Original valve procurement specification Original valve quality assurance package Maintenance documentation package for valve Relief Valve Information Number of valves Manufacturer Type Size (inlet, outlet, orifice)
Steam flow capacity (actual)
Design pressure Design temperature Inlet flange rating Discharge flange rating Allowable applied load (should consider the applied loads which resulted during testing)
III - 10
- 3.
Revision 1 TABLE III-1 (C~nt'd)
Opening pressure (include all settings)
Closing pressure (include all settings)
Original valve procurement specification
-O~~ginal valve quality assurance package
~intenance documentation package for valve For air-operated valves:
Air supply system pressure &nd systern schematic (tubing diameter, length, configuration, etc.)
For pilot-operated valves:
Electrical supply system voltage and current and wiring schematic Pilot vent path schematic (pipe diameter, length, configuration, etc.)
Inlet Piping Information Design pressure Design temperature Configuration from pressurizer to valve (include an isometric drawing of the installation showing piping diameter, length and orientation)
Pressurizer nozzle configuration Loop seal (include volume and temperature of water in loop seal)
Piping supports (show location on isometric and list type and capacity of individual snp~rts in a table)
Steady-state flow pressure drop (including velocity head) (l)
Acoustic wave pressure amplitude(l)
- 4.
Discharge Piping Information Design pressure Design temperature Configuration (include an isometric drawing of the J
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- l. l Pressurizer relief tank design pressure Piping supports (show location on isometric and list ty~e and capacity of individual supports in a table)
Note:- (l)
See Appendix B, applies to safety valves only.
III - 11 l
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Revision l TABLE III - l (Cont'd)
Valve Actuation Transient Information FSAR Transients I
Pressure (opening, peak, closing)
Temperature Pressurization rate at valve opening Maximum back pressure <2 > (:.;team condition)
Fluid range (e.g., saturated steam, saturated water, steam to water transition, subcooled water)
Valves actuated (number and type)
Cold Overpressure Transients (l)
Pressure ranges (opening, peak, closing)
Corresponding temperature ranges Pressurization rate at valve opening Maximum back pressure< 2 > (steam condition)
Fluid range Valves actuated (number and type) d I
t (l)
Extende High-Pressure nJection Transien s Pressure range (opening, peak, closing)
Corresponding temperature range Initial pressurization rate Maximum back pressure( 2) (steam condition)
Fluid range Valves actuated (number and type)
Notes:
(l)
Applies to relief valves only (2)
See Appendix A III - 12
.r A.
Revision l
. TABLE III-2 SAFETY VALVE PERFORMANCE
SUMMARY
SHEET Parameters for Safety Valve Installation in Plant The following parameters are to be tabulated for the plant inst*allation.
They are to be used to identify the tests with the representative valve/piping configuration most nearly corresponding to the plant configuration.
- l.
- 2.
Safety Valve Manufacturer Type Size Inlet Piping Piping length Piping diameter Dry or loop-seal
- 3.
Discharge Piping
- 4.
- s.
- 6.
Back pressure range (for steam actuation)
Inlet Piping Pressure Drop (Steam Actuation)
Steady-state Acoustic (after loop seal discharge)
Applicable Test Numbers (Selected by comparing preceding information with EPRI test data)
Valve Ring Settin~s Rin Upper Middle Lower Ring Settings As-Installed O timal III - 13
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Revision 1 TABLE III-2,(Cont'd)
Valve Performance Summary The following,ralve performance characteristics are to be determined fro1n the data for the applicable tests for both as-installed and optimal ring settings.
- l.
Behavior Mode Fluid Condition Saturated steam Loop seal Transition Water 650°F 550°F 400°F Stable
- 2.
Performance Characteristics*
Chatter Flow Fluid Condition Opening Opening Capacity Saturated steam Loop seal.
Transition Water 650°F 550°F 400°F Pressure (psia) Time (sec) (lb/sec)
In addition, determine maximum back pressure for saturated steam condition.
III -
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. Other Closing l'ressure (psia)
TABLE III-3 DEFINITION OF ACCEPTABLE PERFORMANCE FOR SAFETY AND RELIEF VALVES AND INLET AND DISCHARGE PIPING Revision 1 Following. is a definition of acceptable performance for safety and relief valves and inlet and discharge piping:
A.
B
- Safety Valves
- l.
Va1ves open and close in a stable manner.
(A ~1n1mum amount of valve chatter or flutter is permitted pro-vided no change in critical valve dimensions or wear of seating surfaces results.) See Not~ (1).
- 2.
- Valve performance characteristics are consistent with FSAR (or other design) overpressure analysis assumptions, including:
opening pressure opening time flow capacity closing pressure (i.e., blowdown)
Relief Valves I
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Valve performance characteristics are consistent with cold overpressurization analysis assumptions, including:
- c.
(1)
(2) opening time flow capacity closing time Inlet Piping (see Note 2)
- l.
Piping stresses during valve discharge transient less than design stresses.
- 2.
Piping support loads less than design loads.
- 3.
Applied load on valve less than design load.
(The design 1 loads should con,ider the applied loads which resulted during testing.)
It jhould.be noted that when valve chatter occurrect durin~ non~f loop seal tests, the valve was assisted open to terminate tt.e event.
Therefore, the degree of vadlve ~n~e1rnals dd7tg7aqation
- J during an actual in-plant event un er s1m1 ar con 1 ions may pe __ more severe than was observed in the testing.
Load combinations and allowable piping stresses and
- 1 support loads listed in Appendix E.
III -
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Revision l TABLE III-3 (Cont'd)
Discharge Piping (see Note 1)
- 1.
Piping stresses during valve discharge transient less than design stresses.
- 2.
- 3.
- 4.
Piping support loads less than design loads.
Maximum pressure less than maximum acceptable valve back pressure.
Applied load on valve less than design load.
(The design loads should consider the applied loads which resulted during testing.)
(l)
Load combinations and allowable piping stresses and support loads listed in Appendix E.
Revision 1 TABLE III-4 RELIEF VALVE PERF01U1ANCE SUW1ARY SHEET A.
Parameters for Relief Valve Installation in Plant The following parameters are to be tabulated for the plant installation.
They are to be used to identify the tests
_with the representative valve.
- 1.
Relief Valve Manufacturer Type Size
- 2.
Inlet Pipini Dry or loop-seal 3.*
Valve Operator Air supply system details or electrical voltage/current Other (size, force capacity)
- 4.
Applicable Test Numbers III - 17 j.
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TABLE III-4 (Cont'd)
B.
Valve Performance Summary The following valve performance characteristics are to be.determined from the data for the applicable tests.
Fluid Condition Saturated steam Water Seal Transition
- Steam to water
- Nitrogen to water Water (at high pressure set-point)
- Maximum temperature
- Minimum temperature Water (at low pressure set-point)
- M-aximum temperature
- Minimum temperature Opening Time (sec)
Ca Closin Time (sec)
III -
18
Revision 1 TABLE III-5 LIST OF POTENTIAL PROBLEM AREAS AND POSSIBLE ALTERNATIVES TO ADDRESS UNDESIRABLE VALVE PERFORMANCE Potential Problem Areas Safety Valves and Associated Piping
- 1. Valve blowdown required to provide stable valve performance for steam flow is not within FSAR/Tech Spec limits.
- 2. Valve chatters with subcooled water flow conditions and
~!~wdown cannot be adjusted to provide stable valve performance Possible Alternative Re-analyze selected NSSS system overpressure transients to show that increased valve blowdown is acceptable from the standpoint of plant operation considerations.
(Note, since all plants are de-signed to accommodate losses of reactor coolant resulting from a range of possible*size openings in the reactor coolant system, it is apparent that increased valve blowdown is not a safety concern.)
Utilize alternative valve which provides stable performance with smaller blowdown.
Relocate valve closer to pressur-izer to allow stable performance to be obtained with reduced blowdown.
Show that subcooled water condi-tions can be handled by other than safety valve actuation, e.g., operator action or use of PORVs.
Utilize alternative valve whicr-performs in a stable manner with subcooled water, (e.g.,
Framatome/Crosby 6M6, or Target Rock 69C) or utilize an auxiliary lift device with the existing valve.
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Potential Problem Area
- 3. With-cold loop seal arrangement, valve provides unacceptable per-formance, e.g.:
pressure oscillations (water hammer) in upstream piping delayed valve opening until loop seal clears high pressures and loads in discharge piping Relief Valves With cold loop seal arrangement, valve closure following discharge is delayed Possible Alternative Provide a drain at low point in loop seal piping back to the pressurizer-to prevent water accumulation(l).
Provide heaters to increase temperature of loop seal water to near saturatior (approximately 650°F).< >
Utilize alternative valve which provides better performance with loop seal.
Provide a* drain at low point in loop seal piping to prevent water accumulation\\l).
Provide heaters to increase temperature of loop seal water. (1)
Utilize~alternative valve which is less sensitive to the thermal transient.
NOTE:
(l) Before a decision to drain or heat the loop seals is made, careful consideration should be given to the potential for valve seat degradation and result-ing steam/hydrogen leakage.
III -
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TABLE III-6 EPRI P~R S~FETY AND RELIEF V~LVE TEST PP.OGRAM SAFETY VALVE TEST RESULTS sur.MARY (1)
- 1 I
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I (CRITERIA:
STABLE PERFORMANCE/NO CHATIER)..
1
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TESTED VALVES STEAM LOOP SEAL TRANSITION INLET FLUID CONDITIONS WATER sso°F DRESSER 31739A SHORT INLET YES YES YES N/A (2 >
YES (4 >
N/A YES YES YES 6S0°F YES YES YES(! :
I LONG INLET DRESSER 31709NA SHORT INLET YES YES MO YES NO LONG INLET C 3 >
- CROSBY 3K6 SHORT INLET LONG INLET CROSBY 6M6 LONG INLET NO YES YES YES NIA YES <4 >
YES <4 )
YES tlO YES
. YES YES NO J
NO I
TARGET ROCK 69C LONG INLET YES YES YES YES ( 6)
YES YES ( 6)
NO YES
- , I CROSBY 6N8 YES N/A YES J
LONG INLET
. l FRAMATOME/CROSBY 6?16 LONG INLET YES YES YES YES YES YES ; I NOTES:
(l)
The summary is for valve performance after reference ~est ring :
settings had been established and does not generally reflect ex-;
pect~d performance with current in-plant ring settings.
(2)
Indicates the condition is not applicable to the valve/piping l
combination tested.
(3)
Piants which utilized this valve/piping combination have been modified and now have a short inlet.
- J (4). Chatter observed on loop seal portion of test.
(5)
The valve had a limite*d lift and did not relieve the transient.
(6)
Observed inlet pressure fluctuations indicated possible valve flutter.
III - 21
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I ' I Jtevision 1 IV.
SUGGESTED FORMAT FOR JULY 1, 1982 PLANT-SPECIFIC SUBMITTAL A suggested format for the July l, 1982 plant-specific submittal to the NRC is provided in the following.
It should be noted that
- the.submittal outline is provided only as a general guideline for utility consideration and it is recognized that more or less information may need to be included in a particular plant-specific submittal.
I.
DESCRIPTION OF SAFETY AND RELIEF VALVE INSTALLATION This section should provide a summary description of the overall valve installation.
In addition, this section should provide a list of key plant parameters as listed in Table IV-1, including:
0 0
0 0
Safety valve parameters Relief valve parameters Inlet piping parameters Valve actuation transient parameters II.
RESULTS OF PLANT-SPECIFIC PERFORMANCE EVALUATIONS A.
Safety and Relief Valve Performance This section should discuss the following:
- 1.
Evaluation of pertinent test results and identification of conditions which could result in unacceptable valve performance.
- 2.
Identification of modifications selected for implementation to provide acceptable performance.
III.
IV.
B.
Revision 1 Inlet and Discharge Piping Adequacy This section should discuss:
- -.1.
Evaluation of stresses and support loads in inlet and discharge piping and identification of any overstressed piping or overloaded supports.
- 2.
Identification of modifications required to provide acceptable stresses and loads in piping ana supports.
CONCLUSIONS REFERENCES This section should include a listing of all references utilized in the evaluations, including:
A.
Safety and Relief Valve Test Reports B.
Valve Selection/Justification Report
- c.
Plant and Test Condition Justification Reports D.
Discharge Piping Load Model Report V.
APPENDICES
~he following appendices should be included:
A.
Summary of report by valve manufacturers which justi-fies the acceptability of *valves or the modification Cs) selected for implementation.
B.
Summary of report by NSSS vendor which justifies the acceptability of the existing system or modification(s}
selected for implementation.
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D.
Revision 1 Summary results of calculations of inlet and discharge piping loads and stresses.
Schedule for evaluation and implementation of modifications (if modifications are_ required).
IV -
3
- 1.
- 2.
Revision.1 TABLE IV-1 LIST OF KEY PLANT PARAMETERS Safety Valve Information Valve Parameters Number of valves Manufacturer Type Size (inlet, outlet orifice)
Rated capacity (steam)
Inlet Piping Parameters Diameter Length Type (dry, loop seal/te~perature}
Actuation Transient Parameters Fluid range (e.g., saturated steam, saturated water, subcooled water, etc.)
Maximum back pressure (steam condition)
Relief Valve Information Valve Parameters Number of valves Manufacturer Type Size (inlet, outlet, orifice)
Capacity (steam)
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Inlet Piping Parameters Type (dry, loop seal/temperature)
Actuation Transient Parameters Fluid range (e.g., saturated steam, saturated water, subcooled water, etc.)
Maximum back pressure (steam condition)
IV - 5
Revision~
V.
REFERENCES Following is a list of*reports issued by EPRI to document the results of the safety and relief valve test program.
Also noted are the draft and final publication dates of the report and the date when the report will be submitted to the NRC via the PWR utilities.
. 1 Report Date l
Final Submitted to NRC 1
- 1.
- 2.
- 3.
- 4.
- s.
- 6.
- 7.
B.
- 9.
- 10.
- 11.
EPRI Report Draft Safety and Relief Valve Test Report 3/1/82 4/1/82 Valve Selection/Justification Report 9/81 12/81 Test Condition Justification Report 3/5/82 4/1/82 B&W Plant Fluid Condition Justification Report 10/8/81 3/17/82 CE Plant Fluid Condition Justification Report 11/18/81 3/10/82 W Plant Fluid Condition Justification Report 10/8/81 1/29/82 Application of RELAPS/MOD1 for Calculation of Safety and Relief Valve Discharge Piping Hydrodynamic ~oads (includes Discharge Piping Data) 3/5/82 4/1/82 Marshall Relief Valve Test Report 8/Bl 10/81 Wyle Phase II Relief Valve Test Report 9/81 12/81 Wyle Phase III Relief Valve Test Report 3/9/82 4/1/82 CE Safety Valve Test Report 6/1/82 7/1/82 4/1/82 4/1/82 4/1/82 4/1/82 4/1/82 4/1/82 4/1/82 N/A N/A N/A N/A N/A Not Applicable.
These reports contain supplementary
-information
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APPENDICES Revision 1
Revision 1 APPENDIX A PROCEDURE FOR CALCULATION OF VALVE BACK PRESSURE
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Purpose
~he purpose of this appendix is to provide a suggested procedure and guidelines for the calculation-o~ safety and relief valve backpressure for the plant.
This backpressure
- is to be compared with the test backpressure as discussed in Appendix D.
B.
Discussion Because of the sensitivity to back pressure exhibited by the safety valves in the EPRI test program, it is recom-mended that the plant back pressure be calculated on a realistic, rather than conservative, basis.
Therefore, it is suggested that a hydraulic code such as RELAP or similar method be utilized.
In this regard, EPRI has funded/developed a steady-flow hydraulic code specifically for determining valve backpressures.
Further information regarding this code can be obtained from EPRI.
It is suggested that back pressure calculations be performed assuming simultaneous actuation of either all safety valves or all relief valves on steam.
Also, use the maximum valve flow rates as determined by the valve manufacturer.
Revision l The computed steam backpressures are to be compared to those developed during EPRI steam tests to assess applicability.
EPRI liquid testing was performed with the same discharge piping backpressure orifice as was utilized during a specified steam test.
The backpressures developed during
-the liquid tests correspond to those expected in a plant having the same "steam" backpressure as was developed during the specified steam test. Therefore, if the steam backpressure developed exceeds the expected in-plant steam backpressure, the corresponding liquid backpressures.de-veloped will exceed those expected in the plant under similar conditions
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Revision 1 APPENDIX B PROCEDURE FOR CALCULATION OF INLET PIPING PRESSURE EFFECTS
A.
Revision l Purp*ose.
The purpose of this appendix is to provide a procedure for determining the inlet piping pressure drop associated with spring-loaded safety valve opening for the plant safety valve installation. This plant pressure drop is to be compared with the test pressure drop as discussed in Appendix D.
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Discussion The procedure described below is only applicable to high-quality steam-filled inlet piping installations which have a constant flow area.
The method consists of calculating the inlet piping pressure drop due to flow pressure drop and acoustic wave propagation.
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Inlet Piping Flow Pressure Drop (~Pr:)
The flow pressure drop is given by, l
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=
- where, k
f L o M
9c p
A (k+l+fL) M.2 D
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expansion or contraction loss coefficient.
(dimensionless) friction factor (see Reference l} (dimensionless* f
... 1 piping equivalent length/diameter con~idering effects of fittings and friction (see Reference~,*
for pertinent data) (dimensionless) maximum valve flow rate for steam (as established by the safety valve manufacturer) (lb/sec)
- 1 gravitational constant (32.2 lb-ft/lb-sec2) steam density at nominal valve set pressure (lb/ft3) inlet piping flow area (ft2)
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Revision 1 Acoustic Wave.Amplitude* (6PAw)
The acoustic wave amplitude is calculated based on information in Reference 2.
There are two situations to consider:
- If T
< 2 L/a, op -
aM b.P.,._/'j -A
~ 9c
- If Top >2L/a, 2LM
- where, a= steam sonic velocity at nominal valve set P!essure (ft/sec)
L c inlet piping length (ft)
T op = valve opening time for steam inlet conditions as established from the EPRI testing effort is lOmsec for the Crosby safety valves and lSmsec for the Dresser safety valves.
The other variables are the sam~* as defined in t.~e previous section.
- 3.
Plant-Specific Pressure Drop The plant-specific pressure drop associated with valve opening is equal to the sum cf the friction pressure drop (6PF) and the acoustic wave amplitude (APAW) as determined above.
For certain test valves, valve reopening and/or chatter was observed on valve closure.
For similar valve/installations, the pressure rise associated with valve closure may have to be evaluated.
C.
References
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Flow of Fluids through Valves, Fittings and Pipe, Crane Co., Technical Paper No. 410, 1981.
- 2.
Waterhammer Analysis, John Parmakian, Dover Publications, Inc., 1963.
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Revision l.
Sample Problem Fo~lowing is a sample calculation of plant-specific pres-sure drop for an assumed safety valve/inlet piping co!1figuration.
- 1.
Flow Pressure Drop An isometric of the assumed inlet piping configuration is provided in Figure B-1.
The flow pressure drop is given by,
- where, k
f L
D p
A M
=
=
=
=
(k+l+fL)M2 D
o.s(l) (sudden contraction at pressurizer nozzle)
.Ol6(l) 33 *6 (l)+ 6 X 30(1) + 2 X 16(l) = 289.8
.432 7.65 lb/ft3< 2> (saturated steam at 2500 psia) 0.147 ft2 345,000 lb/hr
=
95.8 lb/sec 3600sec/hr The flow pressure drop is, (0.5 + 1 +.016 X 289.8) X 95.82 64.4 X 7.65 X.147 2 X 144 36 psi
- Numbers in parentheses denote references listed at the end of this sample problem
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PRESSURIZER NOZZLE 2'1" Revision 1 6'10" PRESSURIZER TOTAL PIPE LENGTH= 33'7"
- PIPE DIAMETER= 6" SCH. 160 (5.189" INSIDE DIAM.)
- FITTINGS 0
6, 90° ELBOWS 2, 45° ELBOWS
-CROSBY 4Ml6 SAFETY VALVE
- 345,000 lb/hr RATED CAPACITY 0.010 SEC OPENING TIME SAFETY VALVE INLET PIPING CONFIGURATION FIGURE B-l
~ -
4 3'7"
Revision l
- 2.
Acoustic Wave.Amplitude
- 3.
- 4.
For the configuration in Figure B-1, the parameters are, -
.010 sec 2 x 33.6 ft
- _052 sec 1300 ft/sec(J)
-a Since T
< 2L op a
~PAW*
aM 9cA 1300 X 95.8 32~2 X.147 X 144 183 psi Plant-Specific Pressure Drop The plant-specific inlet piping pressure drop is given by,
~p
=
~P
=
36
+ 183 = 219 psi References (1)
Flow of Fluids through Valves, Fittings and Pipe, Crane Co., Technical Paper No. 410, 1981.
(2)
ASME Steam Tables, 1967.
(3)
"A Pressure Pulse Model for Two-Phase Critical Flow and Sonic Velocity," ASME 68-WA/HT-8.
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E.
Test Valve/Inlet Pipe Configuration Inlet Piping Pressure Drop Following are Tables B.l through B.6 entitled "Safety
- Valve Description and Inlet Piping Configuration".
These tables provide a description of the tested safety valves and the inlet piping configurations on which the valves were mounted.
The information contained in these tables are the same as the information contained in Tables 3.1.l.a through 3.6.l~a of Reference 1 (see Sec-tion V) with the addition of the calculated transient pressure drop for each test inlet pipe configuration.
The transient pressure drops listed in each table are the calculated upstream pressure drops associated with valve opening for each test valve/inlet pipe configuration.
Opening (Pop) times used to calculate the pressure drop are defined in footnote (1) of the tables.
These opening times were established based on the opening times measured in the EPRI/PWR Safety and Relief Valve Test Program.
The test data indicated that an opening time of isms for all of the Dresser safety valves tested and an *opening time of
!Oms for all of the Crosby safety valves tested were typi-cal of the fastest opening times measured.
B-6
Since the test valves were selected to represent all participating PWR plant safety valve designs and the data indicated opening times which were consistent across the test valves, it is suggested that the opening times defined for each manufacturer's safety valve tested be used for the valve manufacturer's designs which were not tested.
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IJj co EPRI/CI: SAFET.E TEST PROGRAM TABLE 8.1 SAFETY VALVE DESI RIPTION AND INLET PIPING COUFIGURAT1CIN DRl:SSER 31739A SAFETY VALVE Valve Description Inlet Piptn9 Configuration
- Length, Dresser Industries Manufacturer Type Model No.
Ser1a*1 No.
Drawing No.
Spring loaded Safety Valve 31739 A BN-04372 4CP-2432 Rev. 9 Body Size (inlet/outlet) 2',
in./
6 Bore Area 2.545 in.2 Orifice Designation 3
Design Set Point Pressure 2500 psig Design &lowdown 5
percent in.
Rated Flow 297845 lb/hr. Rated Lift 0.45 in.
Nozzle 17 Venturi 38 Pipe 11 Reducer 6
loop Seal Straight 60 Bends 4-900 Reducer 4*
Inlet Flange 6
"D" in.
I.D., 1n.
6.813 6.813.
6.813 6.813/3.152 3.152 6 in. radius 3.152/2.125 2.125 Internals Type:
Not applicable Transient Pressure Drop (1) 454 psi Rtng Setting Reference Position:
The ring setting positions refer to the number of notches relattve to the following surfaces; Upper Ring - top holes in the guide Middle Ring-seat plane Lower Ring - seat plane (1) This ts the calculated transient upstream pressure drop associated with valve opening for this valve/inlet piping configuration. The pressure drop was calculated based on an opening time of 15 msec.
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nlet Pp ng Configuration Length, in.
17 38 11 10 I.D., 1n.
6.813 I 6.813 6.813 6.813/2.125 Nozzle Venturi Pipe Reducer Pipe Not applicable Inlet Flange 6
2.125 Transient Pressure Drop (1) 54 psf I
EPRI/CE VE TEST PROGRAM TI\\BLE B.2 iAFETY VALVE DESCRIPTION !\\ND INLET PIPING CotlFIGURATICN DRESSER 31709NA I
Valve Description Manufacturer Type Model No.
Serial No.
Drawing No.
Dresser Industries
. Spring Loaded Safety Valve 31709!\\
BQ07681 4CP-2332 Rev 11 Body Size (inlet/outlet) 6 in./
8 in.
Bore Area 4.34 in.2 ---
Orifice Designation N
Design Set Point Pressure 2500 psig Design Blowdown 5
percent Rated Flow 507918 lb/hr. Rated Lt ft O. 588 f n.
Internals Type:
not applicable Ring Setting Reference Position:
The ring setting positions refer to the number of notches relative to the following surfaces; Upper Ring - top holes in the guide Middle Ring-seat plane Lower Rinq - seat plane (1) This is the calculated transient upstream pressure drop associated with valve opening for this valve/inlet piping configuration.
The pressure drop was calculated based on an opening time of 15msec.
Inlet Pipin9 Configurat'ion "A"
- Length, in.
~ J.D., in.
17
~8 6
6 6.813 6.813 6.813 6.813/4.897 Nozzle Venturi Pipe Reducer loop Seal Straight Bends 48 4.897 2 Bends 1800, 9 11 radius Reducer Inlet Flange not applicable 11 4.897 Transient Pressure Drop (1) NOT AVAILABLE Inlet.Pf ping Configuration Length, in.
. "B" 1.0., tn.
Nozzle 17 6.813 Venturi 38 6.813 Pipe 6
6.813 Reducer 6
6.813/4.897 :'
Pipe not applicable Inlet Flange 11 4.897 Transient Pressure Drop (1)
RR psi
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0 EPRI/CE SAFETY VA~EST PROGRAM TABLE 8.3
!:AFETY VALVE DESCUPTJON AND INLET PIPING CONFIGURATION FOR THE CROSBY HB-BP-86 3K6 (STEAM INTERNALS)
Valve Description Inlet Piping Configuration "F"'
Length, tn.
I.D., in.
Manufacturer Type Model No.
Serial No.
Drawing No.
Crosby Valve and Gage Spring Loaded Safety HB-BP-86 31<6 None SK-3658-V Body She (inlet/outlet) 3 in./
6
- in.
Bore Area 1.841 in.2 ---
Orifice Designatlon K
- Nozzle Venturi Pipe Reducer Loop Seal 17 38 6
6 54 6.813 6.813 6.813 6.813 3.152 Design Set Point Pressure 2485 psig Straight Bends 4-900 6 inches radius Design Blowdown 5
percent Rated Flow 212 1182 lb/hr. Rated Ltft 0.382 in.
Internals Type:
Steam Rtng Setting Reference Posttton:
The ring setting position refers to the number of notches relative to the bottom of the ring disc.
(1) Thh ts the calcuhtert tr~nsie'1t uostrearn pressure drop associated with valve opening for this valve/inlet piping configuration.
The pressure drop was calculated based on an opening time of lOmsec.
Reducer Inlet Flange 7
Trans tent Pressure Drop (1) 321 nsf 3.152/2.624 2.624 Inlet Piping Configuration "E" Length, in.
1.0., in.
6.813 Nozzle 17 Venturi 38 Pipe 6
Reducer 10 Pipe 4
Inlet Flange 7
Transient Pressure Drop (1) 56 pst
' 6.813 6.813 6.813/2.624 2.624 2.624
EPRI/CE SAFETY TABl.
VE TEST PROGRAM 4
SAFETY VALVE OE 'iCRIPTIOtl AND INLET PIPING CONFIGURATION FOR THE CROSBY llO-BP-86 3K6 (LOOP *sEAL ltlTERrl/\\LS)
Valve Descrtptton Inlet Ptpin9 Configuration "f*,
Length, tn.
I.D., tn.
Manufacturer Type Model No.
Ser1a*1 No.
Drawing No.
Crosby Valve and Gage Spring Loaded Safety llB-BP-86 3K6 None SK-3658-V Body She (inlet/outlet) __
l __ in./ __
6._in.
Bore Area
- 1. 841 in. 2 Orifice Designation K
Nozzle Venturi Pipe Reducer Loop Seal 17 38 6
6 6.813 6.813 6.813 6.813/3.152 3.152 Design Set Potnt Pressure 2485 pstg Straight Bends 54 4-900 6 inches radtus Design Blowdown 5
percent Rated Flow 212,182 lb/hr. Rated Ltft 0.3B2 in.
Internals Type:
(
Ring Setting Reference Posttton:
The reported measurements are relative to the bottQm of the disc ring.
(1) This ts the calculated transient upstream pressure drop associated with valve opening for this valve/inlet piping configuration.
The pressure drop was calculated based on an opening time of lOmsec.
Reducer Inlet Flange 4
7 3.152/2.624 2.624 Transient Pressure Drop (1) 321 pst Inlet Piping Configuration "E*
Length, tn.
1.0,, tn.
Nozzle Venturi Pipe Reducer Pipe Inlet Flange 17 38 6
10 4
1 Transient Pressure Drop (1) 56 ps1 6.813 6.813 6.813 6.813/2.624 2.624 2.624 I
td
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I i.ABLE B.~
. SAFETY VALVE DESCRIPTJOtl AND INLET PIPING CONFIGURATION FOR TJIE CROSBY HB-OP-86 6:16 ( LOOP SEAL INTERNALS)
Valve Description Manufacturer Crosby Valve and Cage Company Type Spring Loaded Safety Valve Model No.
HB-BP-86 6H6 Serial No.
N56964-00-0086 Drawing No.
Crosby DS-C-56964 Rev. C Body Siz~ (inlet/outlet)
Bore Area 3.644. in.2 Orifice Designation. M 6
in./
6 in.
Design Set Point Pressure 2485 psfg Design Blowdown __ _.;;.5~~ percent Rated Flow 420,006 lb/hr. Rated Lfft 0.538 I
Internals Type:
Loop Seal Ring Setting Reference Position in.
The ring setting position refers to the number of notches relative to the bottom of the disc ring.
Inlet Piping Configuration "G"
length, in.
1.D., 1n.
Nozzle Venturi Pipe Reducer loop Seal Straight-Bends 17 38 13 6
48 2-1800 6.813 6.813 6.813 6.813/4.897 4.897 9 in. radius I
Reducer Not Applicable Inlet Flange 10 4.897 Transient Pressure Orop (1) 251 nsf (1) This is the calculated transient upstream pressure drop associated with valve opening for this v~lv@/lnlet pipinq configuration.
The pressure drop was calculated based on an opening time of 10 msec.
EPRI/CE SAFETY V~ TEST PROGRAM TABLE..
6 SArETY VALVE DESCRIPTION ANO INLET PIPING CONFIGURATION FOR THE CROSBY HB-RP-86 6N8 (STEAM INTERNALS)
V~lv~ Description Manufacturer Inlet Piping Configuration "H",
Length, tn.
J.0 0 fn.
Type Model No.
Crosby Valve and r,age Company Spring Loaded Safety Valve HD-DP-86 6N8 Nozzle 17
- 6.813 Serial No.
Drawing No.
N61894-00-0006 Venturi Not Appltcable Crosby DSC-61894 Rev. D Body Size (inlet/outlet) _____ 6~~in./
Bore Area ~.381 in.2 8
in.
Orifice Designation N
Design Set Potnt Pressure 2485 psig Design Blowdown 5
percent R~ted Flow 504,952 lb/hr: Rated ltft n 591 in.
Internals Type:
Steam Ring Setting Reference Position:
The ring setting position refers to the number of notches relative to the bottom of the disc ring.
Pipe 9
Reducer 6
Pipe 76 Inlet Flange 7
Transient Pressure Drop (1) 270 psi (l) This ts the calculated transient upstream pressure drop associated with valve op~ning for this valve/inlet piping configuration.
The pressure drop was calculated based on an opening time of 10 msec.
6.813 6.813/5.189 5.189 5.189
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l Revision l APPENDIX C PROCEDURE FOR VERIFICATION OF ALTERNATIVE METHODS TO BE USED IN EVALUATION OF PIPING/SUPPORT ADEQUACY
Revision l As discussed in Section II of this guide, the utility may elect to use ~n alternative method to perform the evaluation of piping/support adequacy.
In this event, it is recommended that the adequacy of the alternative method be verified by comparison with the EPRI test data provided in Reference 7 (see Section V).
This can be accomplished by one of the following approaches:
0 0
By direct comparison between the analytical method pre-dictions and the data measured in the CE Facility tests.
By comparison between the hydraulic forcing function determined by the alternative method with the forcing function determined by the EPRI-provided code {RELAPS) *
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Revision 1 APPENDIX D PROCEDURE FOR ASSESSMEtlT OF APPLICABILITY OF SPECIFIC EPRI SAFETY VALVE TESTS
A
- B.
Revision 1 Purpose The purpose of this appendix is to provide a procedure fo~* use by the valve manufacturers (or utilities) in dssessing the applicability of specific EPRI tests to
- plant safety valve installations. This procedure is based on directly using test results from the EPRI program in the plant-specific evaluation. Thus, the key is to establish that one or more of the represe~-
tative valve/piping configurations tested by EPRI closely matches the plant installation. It is expected this approach will be useful for virtually all the plant evaluations
- Discussion The results of the EPRI safety valve tests indicate that there are a number of key parameters which effec-tively control the response of the safety valves.
These parameters are:
0 0
0 Valve ring settings (for spring-loaded safety valves only)
Discharge piping backpressure Inlet piping pressure effects associated with valve opening (for spring-loaded safety valves only)
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0 Revision l Inlet fluid conditions (e.g., saturated steam, saturated water, subcooled water).
A suggested procedure for assessing the applicability of specific EPRI tests to various plant installations is provided in Tzible D-1.
This procedure involves following four steps to determine the applicability of a particular test or test series. Note that if tests are not found to be directly applicable to the plant valve evaluation, the EPRI test data base combined with other existing test data and/or analysis would have to be used to establish the expected valve performance in the plant.
Sample Evaluation I
Table D-2 provides the results of a sample test appli-cability assessment for a Dresser safety valve, Model 31759A u~ing test data for Dresser safety valve Models 31739A and 31709NA.
This case is the more complex of the two options identified in Table D-1:
a valve not directly tested, but one for which the valve manufacturer can identify ring settings which provide similar performance. Further, the *evaluation requires comparison to two different representative valve/piping configuration tests to assess the expected performance of the valve.
D -
2
Revision l.
- The results of the sample evaluation are discussed in
- the following:
o Tes.!...! -- The test is directly applicable because the valve ring settings, plant backpressure, inlet piping pressure and fluid condition requirements specified in Table D-1 are satisfied.
0 0
Test 2 -- The test is directly applicable because the valve ring settings, plant backpressure, inlet piping pressure and fluid condition requirements specified in Table D-1 are satisfied
- Test 3 -- This test is not directly applicable because the plant backpressure is greater than the test backpressure.
o Test 4 -- This test is not directly applicable because the plant inlet piping pressure drop is greater than the test inlet piping pressure drop.
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I Revision 1 Test S -- This test is not directly applicable because the plant valve ring settings do not correspond to those specified by the valve manufacturer to ~ovide similar performance to the test valve.
Test 6 -- This te~t is directly at>plicable becanc;e the valve ring settings, plant backpressure, inlet piping pressure and fluid condition requirements speci-fied in Table D-1 are satisfied~
In this sample assessment, the Dresser Model 31759A safety valve is determined to provide acceptable performance for steam inlet conditions *(at a plant backpressu~e of 400 psia ~nd an inlet piping pressure drop of 150 psi), and unacceptable performance for 550°F water inlet conditions.
Based on the six tests listed in Table D-2, no direct indication can be obtained of the safety valve performance for the 650°F and 4S0°F water inlet conditions.
However, from a review of the safety valve test results summarized in Table III-6 of this guide, it is apparent that valve performance would be acceptable for 650°F water and unacceptable for 450°F water.
D - 4
0 For
- 1.
- 2.
- 3.
0 For
- 1.
- 2.
- 3.
- 4.
Revision 1 TABLE D-1 PROCEDURE FOR ASSESSMENT OF APPLICABILITY OF SPECIFIC EPRI TESTS
- STEP A -- VALVE RING SETTINGS Valves Tested in the EPRI Program:
Are t*he ring settings for the plant valve the same as for the tested valve?
If the answer to the above question is yes, proceed to Step B.
If the answer to the above question is no, the test is not directly applicable to the plant evaluation.
Valves not Tested in the EPRI Program:
-Is the *plant valve represented by a test valve per Reference 2 (see Section V)?
Do the ring settings for the plant valve correspond to those specified by the valve manufacturer to obtain similar performance as observed for the test valve?
If the answers to Questions 1 and 2 are both yes, proceed to Step B.
If the answer to either Question 1 or 2 is no, the test is not directly applicable to the plant evaluation.
D -
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- i Revision 1 TABLE D-1 Cont'd STEP B -- DISCHARGE PIPING BACKPRESSURE (See Appendix A for the procedure for calculating plant backpre~sure)
- 1.
is the plant backpressure less than the backpressure in the test?
(This comparison should be made for steam discharge condition as discussed in Appendix A.)
- 2.
If the answer to the above question is yes, proceed to Step C.
- 3.
If the answer to the above question is no, the test is not directly applicable to the plant evaluation.
(How-ever, if unacceptable valve performance was observed in the test, it is highly probable that unacceptable valve performance would also result at the plant backpressure condition.)
D -
6
Revision 1 TABLE D-1 (Cont'd)
STEP C -- INLET PIPING PRESSURE EFFECTS*
(See Appendix B for tfie procedure of calculating plant inlet piping pressure effects)
- l. -Is the plant inlet piping pressure drop due to valve opening less than the corresponding value for the test?
(This comparison should be made for the steam discharge condition as discussed in Appendix B.)
- 2.
If the answer to the above question is yes, proceed to Step D.
- 3. If the answer to the above question is no, the test is not directly applicable to the plant evaluation.
(However, if unacceptable valve perforamnce was observed in the test, it is also highly probable that unacceptable valve perfor-mance would also result at the plant inlet piping pressure drop condition. )
The procedure outlined in this step should only be used for those plant installations which have the same or smaller valve nozzle and the same inlet nominal piping diameter as those tested.
For other cases, a different evaluation method may be required.
In this regard, EPRI has funded/developed an* analytical method that can be used for these evaluations.
Further information regarding this method can be obtained from EPRI.
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I I Revision 1 TABLE D-1 (Cont'd)
STEP D -- INLFT FLUID CONDITION
- 1. *Is the inlet fluid condition for the plant (see list in Table II-l of this guide) the same as the inlet fluid condition for the test?
- 2. If the answer to the above question is yes, the applicability assessment is complete and the test is determined to be applicable to the plant evaluation.
- 3. If the answer to the above question is no, the test is not directly applicable to the plant evaluation.
D -
8
VALVE MAKE/MODEL I
RI Nii SETTINGS BACKPRESSURF
<STEAM> CPSIG)
PLANT A DRESSER 31759A T.~BLEji SAfiPLE, TEST APPLI. ITY ASSESSMEMTS * *
- TEST 2 TEST 3 TEST It TEST 5 TEST 6 DR31739A DR31709NA DR31739A DR31739A DR3I739A DR31739A I
+x,-v,+z*
... ~8,-'IO,
... so,-21,
... qs,-qo,. +qs,-qo,
+100.,-30,
...,1s,-qo,
+11
+10
+11
+11
-10
+11 qoo 650
- 600 300 650 650 INLET PIPING PRESSURE UROP (PSI) ]50 250 300 250 40 250 250 IHLET FLUID COND.
on~ERVED PERFORf1f\\NCE TEST APPLICA3LE?
STEAM, '
\\11\\TER.
STEAK STEAH (650,550~
qoo°F>
ti/A GOOD GOOD.
NIA YES VES STEAM STEAM.
GOOD GOOD NO NO STEM BAD.
NO WATER (550°F>
DAD YES RING SETTINGS RECOMMENDED BY VALVE VENDOR BASED ON REVIEW OF EPRI TEST DATA AND INTENDED TO PROVIDE SIMILAR PERFORMANCE TO THE 31739A AND THE J1709NA TEST VALVES.
SAME DISCHARGE PIPE ORIFICE USED WHICH RESULTED IN A 650 PSIG BP ON STEAM VALUES SHOWN FOR ILLUSTRATION ONLY, ACTUAL VALUES SHOULD DE OBTAINED FROM REF£RENCE 1.(SEE SECTION V).
TifE INLET PIPING PRESSURE DROP INFORMATION IS CONTAINED IN APPENDIX B (PARAGRAPH E).
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r I Revision 1 APPENDIX E LOAD COMBINATIONS AND ACCEPTANCE CRITERIA FOR THE SAFETY AND RELIEF VALVE PIPING EVALUATION
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B.
Purpose The purpose of this appendix is to provide suggested load combinations and acceptance criteria for the pressurizer sa:-fety and relief valve piping system.
j D':ring the course of the EPRI valve program, an ad hoc group
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.was established to help insure analysis consistency regarding discharge piping.
The recommended load combinations and acceptance criteria provided in ~he following section were developed by this group and are being supplied to you for your consideration.
Discussion The recommended load combinations and acceptance criteria for the pressurizer safety and relief valve piping system and supports are shown in Tables 1, 2A and 2B.
Tables 2A and 2B are for the discharge, or downstream, piping and supports.
Table 2A applies to the portion for which seismic requirements apply.
There are two possible approaches to this requirement.
The entire downstream portion may be seismically designed, in which case, only Table 2A need be used.
If only a portion of the down-stream system is seismically designed (e.g., to the first downstream anchor, or enough supports and piping to effectively isolate the seismic and non-seismic portions), tpen Table 2A would apply for that portion,*
while Table 2B would apply to the rest of the downstream system.
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L Revision 1 For the seismically designed downstream piping and supports, less restrictive allowables are suggested. Since satisfac-tion of allowable valve loading is part of the-acceptance c~iteria, this would appear to be acceptable.
For the non-seismically designed portion of the downstream piping, it is reconunended that the pipe support system be seismically designed to assure overall structural integrity of the system. It is suggested that Service Level D limits be applied for all pipe support load combinations contain-ing OBE or SSE.
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LOAD COMBINATION:; AND ACCEPTAN*~E CRITERIA FOR PRESSURIZER SAFJ-:TY AND RELIEF VALVE PIPING AND SUPPORTS - CLASS l PORTION Plant/System Service Stress Combination O~eratin2 Condition Load Combination Limit 1
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4 5
NOTES:
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Normal N
A Upset N + OBE + SOTu B
Emergency N + SOTE C
Faulted N + MS/FWPB or DBPB D
+SSE+ SOTF Faulted N + LOCA + SSE + SOTF D
1.) Plants without an FSAR may use the proposed criteria contained in Tables 1-l.
Plants with an FSAR may use their original design basis in conjunction with the appropriate system operating~ranslent definitions in Table 31 or they may use the proposed criteria contained in Tables 1-3.
2.)
See Table J for SOT definitions and other *toad abbreviations.
3.) The bounding number of valves (and discharge sequence if setpoJnts are signifi-cantly different) for the applicable system operating transient defined in Table 3 should be used.
4.J Verification of functional capability is not required, but allowable loads and accelerations for the safety-relief valves must be met.
5.)
Use SRSS for combining dynamic load responses.
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. TAB1,E 2A LOAD COMBINATIONS AND ACCEPTANCE CRITERIA FOR PRESSURIZER SAFETY AND RELIEF VALVE PIPING ANO SUPPORTS - SEISMICALLY bESIGNED DOWNSTREAM PORTION Plant/System Combination 1
Operating Condition Normal toad Combination N
Service s'tress Limit A
B C
C D
2 3
4 5
6 Upset Upset Emergency Faulted Faulted N + SOTU N + OBE + SOTU N + *sOTE N + MS/FWPB or DBPB
+SSE+ SOTp N + LOCA +SSE+ SOTp D
NOTES1 1.) Plants without an FSAR may use the proposed criteria contained in Tables 1-3.
Plants with an FSAR may use their original design basis in conjunction with the appropriate system op~rating transient definitions in Table 31 or they may use the proposed criteria contained in Tables 1-3.
2.) This table is applicable to the seismically designed portion of downstream non*
Category I piping (and supports) necessary to isolate the Category I portion from the non-seismically designed piping response, and to assure acceptable valve loading on the discharge nozzle.
l.) See Table 3 for SOT definitions and other load abbreviations.
4.) The bounding number of valves (and discharge sequence if setpoints are significantly different) for the applicable system operating transient defined in Table 3 should be used.
5.) Verification of functional ca~7~ility is not required, but allowable loads and accelerations for the safety/:-*.*.def valves must be met.
6.)
Use SRSS for.combining dynamic load responses.
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TABLE 2B Revision *l LOAD COMBINATIONS AND ACCEPTANCE CRITERIA FOR PRESSURIZER
. SAFETY AND RELIEF VALVE PIPING AND SUPPORTS -
NON-SEISMICALLY DESIGNED DOWNSTREAM PORTION lii PIPING l
Combinatlon l
2 3
4 Combination l
2 3
4 5
6 NOTES:
l.)
2.)
3.)
.4.)
PJ..ant/System Operating Condition Normal Upset Emergency Faulted SUPPORTS Plant/System 0Eerating Condition Normal Upset Upset Emergency Faulted Faulted Load Combination N
N + SOT0 N + SOTE N + SOTF Load Combination N
N+ SOTu N + OBE + SOTu N + SOTE N + MS/FWPB or DBPB +SSE+ SOTF N + LOCA + SSE
+
1 Service Limit I
A B
I C
D T
Service l
Limit 1
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D D
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Plants without an FSAR may use the proposed criteria con-tained in Tables 1-3. Plants with an FSAR may use their,
original design basis in conjunction with the appropriate!
system operating transient definitions in Table 3; or thei may use the proposed criteria contained in Tables 1-3.
I Pipe supports for the non-seismically designed down-strea.J piping should be designed for seismic load combinations.
to assure overall structural integrity of the system.
j The bounding number of valves (and discharge sequence if setpoints are significantly different) for the applicablf l system operating transient defined in Table 3 should be 1 /
Verification of functional capability is not required, but allowable loads and accelerations for the safety/
~1 relief valves must be met.
5.)
Use SRSS for combining dynamic load responses.
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I Revision l TABLE 3 DEFINITIONS OF LOAD ABBREVIATIONS N
- Sustained Loads During Normal Plant Operation SOT
- System Operating Transient f-OT0
- Relief Valve Discharge Transient(l)
SOTE h
(1)
- Safety Valve Disc arge Transient SOTF
- Max (SOT0 ; SOTE): or Transition Flow
- oBE
- Safe Shutdown Earthquake MS/Fh"PB c Main Steam or Feedwater Pipe Break DBPB
- Design Basis Pipe Break LOCA e Loss of Coolant Accident (1)
May also include transition flow, if determined that required ope~ating procedures could lead to this con-dition.
(2)
Although certain transients *(for example loss of load) which are classified as a service level B conditions may actuate the safety valves, the extremely low probability of actual safety valve actu-ation may be used to justify this as a service level C condition with the limitation that the plant will be shut down for examination after an appropriate number of actuations (to be determined on a plant specific basis).
NOTE:
Plants without an FSAR may use the proposed criteria contained in Tables 1-3. Plants with an FSAR may use their original design basis in conjunction with the appropriate system operating transient definitions in*
Table 3: or they may use the proposed criteria con-tained in Tables 1-3 *