Text

Forwards Response to Request for Addl Info Re NUREG-0737, TMI Action Item II.D.1,concerning Relief & Safety Valve Performance Testing
	ML20108A514
Person / Time
Site:	North Anna
Issue date:	10/31/1984
From:	Stewart W; VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton, John Miller; Office of Nuclear Reactor Regulation
References
	RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 107B, NUDOCS 8411150030
	Download: ML20108A514 (130)
	v • d • e

{{#Wiki_filter:, l VIRGINIA ELECTRIC AND Powan CoxPANY Hrcuxowr>,VrmorNIA 20261 W. L. Stuwurr yd'*,"j",*,'**"',,, ' October 31, 1984 Mr. Harold R. Denton, Director - Serial No.1078 Office of Nuclear Reactor Regulation E&C/TLG:jdm:2004N Attn: Mr. James R. Miller, Chief-Docket Nos. 50-338 Operating Reactors Branch No. 3 50-339 Division of Licensing License Nos...NPF-4 U.S. Nuclear Regulatory Conunission NPF-7 Washington, DC 20555 Gentlemen: VIRGINIA ELECTRIC AND POWER COMPANY NORTH Al(NA POWER STATION UNITS 1 & 2 NUREG-0737,. ITEM II.D.1 PERFORMANCE TESTING OF RELIEF AND SAFETY VALVES REQUEST FOR ADDITIONAL INFORMATION In our letter dated May 1,1984, Serial No.107, on the above subject, we noted we were having our vendor (Westinghouse) and architect-enginee. (Stone & Webster) prepare the information requ:::tcd by your February 8,1984 letter. entitled " Responses to USNRC Request for Additional Information TMI Action NUREG-0737 (II.D.1), Relief and Safety Valve Testing for North Anna Power Station Units 1 & 2 Docket Nos. 50-338 and 50-339," provides the additional information. ery t uly yours, \\. d W. L. Stewart cc: Mr. James P. O'Reilly Regional Administrator Region II Atlanta, Georgia 30303 Mr. M. W. Branch NRC Resident Inspector North Anna Power Station L 40 L 8411150030 841031 PDR ADOCK 05000338 P .PDR

(, ' Enclosure 1 RESPONSE TO US NRC REQUEST FOR ADDITIONAL INFORMATION TMIACTIONNUREG-0737(II.D.1) RELIEF AND SAFETY VALVE TESTING FOR NORTH ANNA POWER STATION UNITS 1 AND 2 DOCKET NOS. 50-338 AND 50-339 ---,n.. r--..g, v,-'.

! t< l Question 1 , r 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 f a discussion describing how the single failure considerations are met.

Response

l l The limiting Condition II transient that incurs safety valve actuation is the I loss of external load event (FSAR 15.2.7). The analyses assumed an initial i ~. core power of 102 percent of rated with no direct reactor trip (on turbine l trip). In addition, the pressurizer spray and power-operated relief valves were assumed inoperable., The combined effect from these assumptions produced 6 the greatest { fastest) reactor coolant pressurization rate. r i ? t As the peak pressure is observed within a few seconds of transient initiation, [ single failures within the engineered safeguards systems would have little, or t no effect, on the pressurization rate or peak pressure observed. 4 ! N J l . :i l a 8 r t i 1 .. _ _.., _ _ _ _ _... ~ _ _ _

3: 'Ouestion 2- ] e As pointed.out in the plant specific submittal, results from the EPRI test on the Dresser 31739A safety valve indicates that the test blowdown exceeded the 55 value given in the valve specifications.. If the expected plant blowdowns 4 also exceed 55, an increase in pressurizer water level could occur such that the water level may reach the safety valve inlet line and results in a steam-water flow situation. Also, the pressure might be decreased I sufficiently so that adequate cooling might not be achieved. Blowdown for the North Anna 1 and 2 Dresser 31759A safety valve, at its current ring settings l was not discussed. The submittal did state that the valve manufacturer (Oresser) and the NSSS supplier (Westinghouse) were reviewing the Dresser 31759A ring settings. ! l 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. Resoonse I The recomended ring settings for North Anna 1 and 2 were derived from the i' methodology of Mr. A. Singh of EPRI. The method is described in Mr. Singh's l N m er entitled "A Correlation for Safety Valve 81owdown and Ring Setting" presented 11-16-82 at the ASME Winter Annual Meeting in Phoenix, Arizona. North Anna Unit 1 was adjusted as closely as possible to these recomended l settings in November 1982. North Anna Unit 2 was adjusted as closely as r ~ possible to these recomended settings in April 1983. The recommended settings adjust the blowdown of the (6) valves to an approximate and expected ,( ll value of 12.2% blowdown. This blowdown value was selected because of its di.r. set correlation to the EPRI test results and the conservativeness of its i f magnitude. The refueling outages were taken as an opportunity to make f verification of ring settings and to increase the blowdown settings to a value which would clearly produce top safety valve performance. The recommended l ' ring settings for all (6) North Anna 1 & 2 Oresser 31759A safety ' valves is as I jg follows: I I l l'* ... ~. _,,,., _ -... _.. _., -,. _ _, _. _ _....... _., _.... _.. _.. -.,. _. - _ _ _ _, _. _ _ _. _ _. _ _ ~ _. _ . ~.

e. g.

.; :j. unser rina - 48 notch;s below Enccvering the compsnsattr parts. .s. j =iddic rina - 55 notches below flush with the seat. Iower eine + 11 notches above flush with the seat. l [ For all (6) valves, the upper and middle ring setting values are the same as the reconmended values. For the lower ring setting, each valve was set as o closely as possible to the recommended values. Variation of the lower' ring setting was permitted by Dresser procedure in order to maintain clearance between the disc holder and the lower ring. For Unit 1 the lower ring I- [. settings are A(+5), B(+10), C(+7). For Unit 2 the lower ring settings are A(+2), B(+11), C(-2). Lj A spectrum of analyses utilizing increasing blowdown and the limiting { Condition II event was conducted within the WOG program. For these analyses, a reference four-loop plant was used (see Table 4-4 of WCAP-10105). Blowdowns -l analyzed were 0, 5,10 and 14 percent. The results from these analyses show I that for the reference plant, blowdowns of up to 14 percent have no significant effect on the outcome of the safety analyses, i.e., no safety limits are violated. Subsequent analysis on 3 loop plants provided similar results as those received on the 4 loop plant analyses. 4] l' I I 4

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~.. _g_ Ouestion 3-f: The inlet piping pressure drops for the Dresser 31739A EPRI test valves were compared to the calculated North Anna 1 and 2 Dresser 31759A inlet piping-pressure drops. As stated in the submittal, the Oresser 31709NA pressure drop was not available. The Dresser 31739A pressure drop of the plant submittal, Table 2-3. was taken from Reference 8 of the submittal. Reference 8 "EPRI I 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 for review. As a result, the method used to determine the pressure drops could not be verified. Provide a copy of the report and -i ~ identify how the pressure drops were determined. I j

Response

4 The March 1982 revision 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 North Anna submittal was prepared. A copy of this report is enclosed for your review. The transieni, pressure drop for the inlet piping configuration is provided in I Table 8.1 of the report. I 1 l ~ I f l i t I i. I i 1 i

i L! s-- - l ~. nuestion 4 .The plant specific submittal did not discuss steam relief valve inlet conditions for the cold overpressure transient. If there is a low pressure ~ steam inlet condition possible for the North Anna 1 and 2 relief valves, provide a discussion explaining how the high pressure steam test data bounds the low pressure steam condition.

Response

I The North Anna 1 & 2 Relief Valve Cold Overpressure protection system operates to maintain pressure below the EPRI test conditions. The system limits the j Reactor Coolant pressure to less than 505 psig for a temperature range of 100*F to 320*F for Unit 1 and 100*F to 340'F for Unit 2. The EPRI Cold ,l Overpressure testing conditions therefore bound the North Anna Systems with a maximum test pressure of 665 psig for a temperature range of 100*F to 450*F. i f

I I

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! l~ Ouestion 5 i-The test results of the Dresser 31739A safety valve and the one drained loop seal test of the Dresser 37109NA safety valve were used in the plant specific submittal to demonstrate that the North Anna:1 and 2 Dresser 31759A 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 rate flow was achieved but not reported in the EPRI Test Report Tables. Review of the EPRI Report revealed that the flow was recorded for two of the reference tests for the Dresser 31739A valve but flow was not recorded,ft,r the one loop seal test of the Dresser 37109NA. Provide a discussion explaining how the limited data for the test valves were extrapolated to demonstrate the Dresser 31759A valve , 'i will achieve rated flow. t Reosonse

}

I No extrapolation was conducted to demonstrate the Dresser 31759A valve will -1 achieve rated flow. As discussed, the Dresser 31739A and Dresser 37109NA test - valves sere selected by EPRI to bound the North Anna safety valve. Successful completion of tests conducted on the selected valves is meant to bound and, therefore, demonstrate acceptability of the plant-specific valve. The EPRI i i test results demonstrate functionability of the Dresser design and, therefore, {I meet the intent of the NUREG requirement. Furthermore, demonstration that the ',g Dresser design will pass rated flow is achieved through ASNE Code testing conducted by Oresser. I 1 l ~ l l l I b l i i i

~ < _ y_ Ques' tion 6 Thermal expansion of the pressurizer tank ~ and inlet piping 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 loading would have on valve operability was considered.

Response

Bending moments were induced on the EPRI safety / relief test valves to demonstrate functionability of these valves'.under pipe loading such as deadweight, thermal, safety valve and relief valve thrusts. Induced bending moments for the Dresser 31739A test valve was 241,738 in-lbs. and for the Masoneilan relief valve of 57,000 in-1bs. A review has shown that the maximum predicted bending moments for North Anna Unit 2 of 165,460 in-1bs. for the Dresser saNty valve and 32,280 in-lbs.' for the Masone11an relief valve are less than those induced during the EPRI test, thus demonstrating functionability of these valves as bounded by the tests j-conducted by EPRI. For North Anna Unit 1 the calculated piping loads at the safety and I relief valve inlets have been found to be lower than the EPRI test . loads for similar valves shown in Attachment C. i 1 i i m

k p nn.stien 7 Blowdown and expected valve stability for the North Anna 1 and 2 Oresser 31759A safety valve at its current ring settings were not discussed. The plant specific submittal did state that the valve manufacturer (Dresser) and the NSSS supplier (Westinghouse) were reviewing the Dresser 31759A ring settings. At the completion of their review, provide the recomended ring I' settings along with the expected blowdown and a discussion of the effects on .j. valve stability, rated lif t and rated flow.

Response

4., t^ j .The recommended ring settings and the resulting blowdown value are identified in the response to Item (2). Stable valve performance is expected for these j very-conservative settings. These settir.gs improve valve performance by decreasing the possibility of valve clatter and increase the possibility of l achieving full lift and flow. ! I I I l I l ( I t I I Li t

-9' l l: r Ducstion 8 ,l-During testing of the Masone11an 20000 series PORV, stroke time was found to L be sensitive to actuator supply line size. To achieve the 2 sec stroke time requirement, the line size was increased and the actuator supply pressure was increased to 60 psig. Review of the EPRI safety and. relief valve selected and

justification report for the Masonellan PORY (Orawing A8329 Rev. 8) indicated that a' maximum of 55 psig is allowed to the actuator to prevent component damage. The North Anna Plant submittal stated that adjustments are made as

[

required to the PORVs prior to plant operation to assure the stroke times meet I-the requirements. Provide a discussion of the action being taken to assure that the required stroke time will be achieved without potentially damaging !I components. i f' {

Response

Design changes have been implemented on the pressurizer power operated relief valves at North Anna to provide ccid overpressure protection for the reactor coolant system. Design Change 78-44 modified the valve inlet ports and the ~ associated solenoid valves to increase the openings from 1/4" to 1/2" '{ diameter. An additienal vent hole was added to the pneumatic actuators and the actuator diaphrages were changed to a stronger material to decrease the valve opening stroke time. The piping from the solenoid valves to the pneumatic actuators was replaced with 3/4" tubing. The nitrogen supply

g pressure for cold overpressure protection mode is regulated.'to 55 psig.

'. I j, The combination of equipment modification, tubing size and nitrog'en regulator pressure provide adequate assurance that the PORV's will open within the time requirements stipulated by Westinghouse. The cold overpressurization analyses requires the PORV's to open in less than or equal to 2.14 seconds. The PORV's at North Anna have been tested after maintenance by MMP-C-GV-1 and have been l verified to open in 5 2.14 seconds in a dry, unpressurized condition. L In conclusion, the PORV's at North Anna have the proper nitrogen supply pressure and tubing diameter to provide adequate volumetric flow rate for a 1 2.14 second maximum opening time. The design modifications have been tested and verified that the appropriate open stroke times can be achieved. I i i

-l. Question 9 The Westinghouse 3GM88 EPRI test-valve with a Limitorque'58-00-15 actuator successfully opened and closed on command only after the torque switch was set to the maximum of 3.75 +. The plant specific submittal stated that Westinghouse modified the 3GM88 block valve at North Anna to provide sufficient closing thrust. The details of the EMOV modification were not provided. Provide a discussion of modifications to the 3GM88 ENOV and the l torque switch setting. 2 - r

Response

I Modification of the Westinghouse PORV block valves at North Anna consisted of modifications to the motor gear and pinion to provide the additional thrust { required for closure and to electrically remove the torque switch from the actuator circuit during the final inch of valve stroke. Elimination of the torque switch during closure permits full use of available closing torque j without the possibility of the valve stroke being terminated prior to full closure. Motor cut-out is then achieved by limit switch as the valve disc t ccr. tacts the valve seat. l \\> i 4 I l j i l i \\ I t l

I-Guestion 10 .- l ' The Westinghouse inlet fluid conditions report stated that liquid flow could I 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 EPR1/ Marshall Block Valve Test Program did not test the block valves with fluid media other than steam. Since it is conceivable that the EMOV could be expected to operate with liquid flows, discuss EMOV block valve operability with expected liquid flow conditions. If 4 the Westinghouse Gate Valve Closure Testing Program Report is used to demonstrate EMOV operability for liquid flow for the 3GM80 valve, provide a y l discussion of the test data. ff

Response

ll In a June 1,1982 letter from R. C. Youngdahl to Mr. H. Denton, several block l ' valve test submittals were made which included an explanation as to why block j' valve tests beyond the Marshall tests were not considered necessary, as well as an EPRI sununary report covering Westinghouse gate valve closure testing'. The Westinghouse report, transmitted to the NRC by the Youngdahl submittal, I also includes a section on friction testing of stellited seating parts. j i Friction testing done by Westinghouse on stellite test specimens (note the i 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 0,75 is reached. With 550*F steaa., the i friction factor starts in the 0.5 to 0.6 range (higher than the water tests) ~ d drops to approximately 0.35 over the 200 cycle range. Considering the 21

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test cycles completed at Marshall Steam Station, and in view of the above f frictional data, the thrust required to cycle the valve during the steam tests f 1 I would be similar to that if the test medium were water. l \\ I - ( i 1 ( { t

(.. Question 11 9 i The plant specific submittal stated that the installed velan block valves were siellar to the Velan block valve tested. However, the North Anna 1 and 2 Velan block valve model number and actuator RPM dif fer from the test block valve. discuss the design differences and any effects they may have on block l valve operability.

Response

Information provided by EPRI with regard to description of the Velan block l valve useo for testing was reprinted from the EPRI-Marshall block valve report to the North Anna plant specific submittal. A review of the test valve I drawing (Velan drawing 88425. Rev. 8) shows the model number to be the same as the North Anna block valve, 810-3548-13MS. The two valves, therefore, must 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 brusts, thus ? making the North Anna block valves similar in design to the Velan test valve. N f . l c l i f I 3 l

1. QUESTION: 12.'

The - submittal indicates that - analyses of the safety and

. relief ' valve piping system are in progress or completed. The information received thus far s contains no presenta-tion - of these analyses. A detailed description of the methods and computer programs used to perform the thermal - ydraulic analysis should be provided when available. h This. should -identify - parameters used in the thermal hydraulic analysis such - as timestep, valve ' flow area, - peak pressures and pressurization rate, node spacing, and valve opening times and should discuss rational for their selection. For loop seal cases, the. assumed water and temperature ' distribution in the upstream and downstream piping at the _ time of valve popping should be given and I the development of this distribution explained.

Further, the method usedl 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 con-taining input and output from the~' thermal hydraulic analysis on a problem such as the locked. rotor accident case should be provided. I RES PONSE: The thermal hydraulic analysis was performed by using the (Unit 1) Stone & Webster Engineering Corporation (SWEC) pro - 2 prietary computer code-WATSLUG. The method and adequacy of this WATSLUG program are detailed in Attachment A which contains general description and verification against'RELAPS/ MODI and EPRI test results. The flow area of 2.074 in.2 for relief valve and 3.341 in.8 for safety valve ' were obtained from the manufacturers whila opening time of 1.5 seconds for relief valve and 0.015 second for kafety valve were based on EPRI test data for the similar valves. Node spacing and tirad step are parameters appli-l- cable to RELAP and are not relevant to WATSLUG Program l used. Pressurizer _ peak pressure of 2575 psia and pres-surization rate of 54 psi /see were selected for loss of s ~- ,,,,m_._,, ..m...,,._~y .,,,,,..,_m.__

_ load transient from the Westinghouse specification G-678838, Rev. 2 (see Attachment B for loss of load transient taken from W specification). Initially, the water slug average temperatures were approximately 190'F for relief valve and 400*F for safety valve based on calculation and EPRI Test No. 917 for a hot water seal. The downstream piping was assumed initially 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 210,000 lbm/hr for relief valve and 380,000 lbm/hr. for safety valve at set pressures of 2335 psig and 2485 psig, respectively, with 3 percent accumulation. The locked rotor accident case was consideredih n the i analysis by comparison with other transients that could actuate the relief and safety valves. The loss of load case was selected for the analysis on the basis that it is postulated in the W specification to occur 80 times while the f aulted cases of feedwater line break, reactor coolant pump locked rotor, and control. rod ejection are postulated to occur only once each. The most rapid or pressurizer rise rate occurs with control rod ejection (470 psi /see rise rate) which our analysis shows will create lower piping forces than the loss of load transient does due to higher safety valve backpressure caused by the incomplete reli.ef valve slug discharge event for the locked rotor case the pressurizer rise rate of 107 psi /sec indicated in the W Specification C678838 Rev. 1 (Attachment B) or 216 psi /sec indicated in EPRI S/RV Test Program EPRI NP-2047LD Volume 3. Table 5.5 will l create forces within 3 percent of those predicted for the loss of load case. i .nw-- ---.w ea - w s e ,n-a -erw .,.m

_ I-' Resconse (Unit 2) T.'.: :de:;;scy of the thermal-hydraulic analyses can be verified by the comparison of anslytical and test results for thermal hydraulic loadings in safety valve discharge piping for EPRI tests 908 and 917 presented in the i. submittal. In that evaluation, node spacing and time-step size were selected on the basis of stable solutions of the characteristic equations and matching ) of the test data. The safety vcive full open flow area of 0.022 ft2,,, used in the model. This area is slightly smaller than th' Crosby M-orifice s 2 area of 0.025 ft for the tested valve, but resulted in a good analytical l match of the tested fully open valve flow rate. Appropriate water temperatures were used. All pertinent data, including friction factors, loss factors and flow areas were based upon representative calculations and the Il system layout. Modeling of the water was conducted with the water seal (- upstream of the valves prior to transient initiation. At time -0*, the I transient was initiated and the slug position was analytically calculated during and subsequent to valve opening. 'i The North Anna Unit #2 Plant specific thermal-hydraulic analysis was conducted Dased upon the same approach as used for the comparison to test data. Node spacing and time-step size were utilized consistent with values utilized in the comparison. Valve flow areas were selected based upon actual valve data with appropriate margins applied to account for flow rate uncertainties. Analyses performed assumed a 100 percent linear safety valve opening time (0.040 seconds) with the pressurizer conditions held at initial valves. All pertinent data, including friction factors, loss factors and flow areas were + i based upon representative calculations and the system layout. Modeling of the l water slug from (a) temperature profile, (b) initial location, and I (c) movement post-transient initiation viewpoint was consistent with the comparison study. The submittal discussed the loop seal temperature f~ profiles. Choked flow is checked internally and automatically every tir.2-step to ensure the proper formulation is applied at every flow path. i _-. _ _. __._ _._~,-

l ~ I L Sf oty and relief valves' are modeled as two-way junctions. The pressure drop 'across the valve, provided the system is sub-cooled is given by: AP = C #' D pressure drop Where AP = Discharge coefficient = f(Cv) C, = p = fluid density velocity through the, valve v = f '~ 'In the case of choking at the valve, the velocity at the valve orifice area is set at the sonic velocity. Upstream and downstream boundary conditions are .iteratively set to conserve mass and energy. Choked flow is internally j checked to ensure the proper formulation is applied. 't. The maximum expected steam flow rate through the Masoneilan PORV's, the valves on North Anna Unit #2, is 210,000 lb/hr at approximately 2350 psia. Values of 228,600 and 230,400 lb/hr, at 2745 and 2780 psia respectively (both tests l- [ conducted at pressures above the valve set pressure) were observed in EPRI/Wyle Tests (EPRI Report NP-2670-LD, Volume 6. "EPRI/Wyle Power Operated Relief Valve Phase III Test Report Volume 6: Sumary of Phase III Testing of the Masoneilan Relief Valve". October,1982). To acrount for all r uncertainties and tolerances.'in the valve flow rate, the valve flow area was 'I adjusted accordingly. The minimum analytically calculated ste'am flow of each of the two PORV's is greater than 255,000 lb/hr. This is a flow of 123% o,f rated. The analysis assumed a 100% linear PORY valve opening in 1.00 seconds. Full open times, based upon tests, averaged 2.77 seconds with a minimum value of 1.64 seconds for opening on steam. The nominal steam flow rating for the Dresser Safety Valves at 2575 psia is ~ 388,000 lb/hr. As with the PORV's, to ensure that adequate margin existed in the valve flow rate to account for all unce.rtainties and tolerances, the analytically calculated steam flow was checked prior to finalizing this phase of the overall effort. The flow used in the analysis (565,000 lb/hr) was 145% { 8 of rated. The safety valves were presumed to open fully in 0.040 seconds. This is based upon an _ effective linear opening time. This valve opening time as illustrated by test 917 and 908 comparisons, results in a very good data match.. i 1

I As discussed in the submittal, the computer code ITCHVALVE was utilized to perform the transient hydraulic analysis for the system. This program . utilizes the Method of Characteristics approach to generate fluid parameters as a-function of time. A discussion of the meth'od of charac'teristics solution te:hnique is presented in the following articles: 5 1. A. C. Spencer and S. Nakamura, " Implicit Characteristic Method for One-Dimensional Fluid Flow" ANS Transaction,-Volume 17 P. 247, November, l '1973. 2. S. Nakamura, M. A. Berger and A. C. Spencer, " Implicit Characteristic Method for One-Dimensional Fluid Flow", Proceedinas of the Conference on l Comoutational Methods in Nuclear Enaineerino, Conference 75040, National Technical Information Service, Springfield, VA. 1975. 4 A. C. Spencer is a full time Westinghouse employee who was and is directly [. involved in the development of the ITCHVALVE Computer Program. ,t I Orce the time-history fluid properties were available, the properties were ' ?' utilized in determining the forcing functions. Unbalanced forces were calculated for each straight segment of pipe from the pressurizer to the relief tank. A discussion of the methodology for generating the thermal hydraulic forcing functions and a comparison of analytically determined hydraulic force results to test data is presented in the following article: L. C. Smith and K. S. Hose, " Comparison of EPRI Safety Valve Test Data with f-Analytically Determined Hydraulic Results". The International Conference on i Structural Mechanics in Reactor Technoloav Chicago, Illinois, August 22-28, 1983, Volume F, 2/6, pp. 89-96. } ' l L. C. Smith and K. 5. Howe are full time Westinghouse employees who were and 1 are involved in pressurizer safety and relief valve and thermal hydraulic issues. Because of the proprietary nature of the ITCHVALVE computer program, a descriptive report is not supplied at this time. Hoyever,ifsodesired,this information could be reviewed at the Westinghouse facility in Pittsburgh. i - - - ~ - - - - = - - - - - - - - - - - - - - - - -

.. QUESTION: 13. 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 structural model 'should' be explained. The methods used a 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. 4 RES PONSE: The structural analysis of the upstream and downstream (Unit 1) piping due to safety valve discharge was performed using SWEC's NUPIPE-SW computer program which performs an elastic evaluation 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, Ilbows, valves, etc, for which force-deformation characteristics can be cate-l gorized. Nodal points ars also placed at all discon-tinuities such as piping supports, concentrated weights, branch lines, changes in cross 'section, and eccentric s ib weights'such as valve operators. ,g 1_ i .,...,..,v.,.. .- ~ .-.,.,,-..e., _.,,._n.--,.- , _,. - ~ -,,

4 4 Loading's such as weights, equivalent. thermal forces, and earthquake inertia forces are applied at the nodal points. Stiffness characteristics of the interconnecting members are related to the effective shear. area and 4 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' Sectio'n III. The methodology used to calculate the' forcing functions is described in the response-to Question 12. The forcing. functions are then applied to the appropriate piping seg-ments and a time history modal superposition analysis is performed using NUPIPE-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 axes or skewed. Supports as well as c,onnec-i tiont +o the pressurizer and relief tank are modeled as elastic springs in the NUPIPE-SW 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. The piping geometry and large number of supports on the pressurizer safety and relief valve piping typically results in closely spaced mass points. g... The cut-off frequency and mode.are selected by a review of the piping geometry and system response character-l 1stics recognizing the fact that the typical modes of excitation in this analysis are the higher. frequency o i u q' l axial modes. The total analysis time and integration (t time steps for the analysis are selected based on a review of the input forcing function and to ensure a O* stable solution.

2-20. The damping values _ utilized for the analysis of the reliefi valve 'and safety valve loop seal clearing events - are_ 1/2 percent and 1 percent of critical damping, respectively.- These. damping values are consistent with -the values of. the respective earthquakes (i.e., OBE and DBE) to which the relief valve and safety valve discharge cases are-combined. 4 The piping _ stress analysis for the - North Anna Unit.1' pressurizer safety and. relief valv't piping is performed in accordance with the USAS B31.7 Nuclear Power Piping Code 1969 Edition. The load combinations and allowables - stress limits - for' the relief valve' and safety ~ valve discharge - conditions are based on the UFSAR and EPRI recommendations. For Q1 (Class 1) piping, the equations are: OCCl) 4 1.5 S S +S + SRSS (SOBEI' S ~ LP DW m 1 S +S + SRSS (S ,S ) 1 2.25 S p S p+SDW * -( DBEI' 00CC3) i 3.0 S, For Q2/3 (Class 2/3) piping, the equations are: S +S p DW OBEI' OCCI 'h i S +S + SRSS (S p DBEI' O C3 h r Where: g- -S = Longitudinal pressure stress p e-S = Deadload stress l- ~ * ** " * #*** i SOBEI i = Seismic stress due to DBE inertia sDBEI +-

_ I 1 S =. Stress due to relief valve. discharge -l OCCl = S = Stress due to safety valve discharge ~

1. 3*#

' 'OCC1 # OCC2 S ~ OCC3 3 S- = Allowable. stress intensity at the design temperature m S = Allowable stress at the maximum operating temperature The pipe supports ' are designed in accordance with the AISC Manual of Steel Construction 7th Edition. The loa' ding conditions and allowables are as follows: UW + THER + SRSS (OBET, OCC1) 4 1.33 (Basic Allowable) i DW + SRSS (DBEI, OCC3) d-1.33 (Basic Allowable) Whare: i 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 OCCI = Loads due to relief valve discharge OCC3 = Large of loads due to relief valve or safety valve ' discharge i The baseplate analysis will meet or exceed the require-ments of I&E Bulletin 79-02. . 1 Tha weld:d attcchmnts to C1 css 1 pips will b2 evolunted in accordance with the ASME code cases N122 and N391. Welded attachments to all other (non-Class,,11. pipes will f be evaluated per ASME code cases N318 and N392. onennse (Unit 2) _l 'As noted in the submittal, the major structural analyses programs utilized in the static and dynamic analyses are described in WCAP-8252. This was reviewed ,j. and approved by the U. S. NRC (NRC letter, April 7, 1981 from R. L Tedesco to I T.M$ Anderson). A discussion of the methodology utilized in performing a safety valve discharge structural analysis and a comparison of analytical results to structural test results are presented in the following article: ~L. C. Smith and T. M.-Adams, " Comparison of Analytically Determined Structural Solutions with EPRI Safety Valve Test Results", 4th National Conaress on 4 I Pressure Vessc1 and Pioina Technoloav Portland, Oregon, June 1g - 24,1983 PVP-Volume 74, pp.193 - 199. 4 Following is a discussion of key parameters used in the structural analyses of the thermal hydraulic events performed for the N' orth Anna M Plant. l I 1. Damoina: A conservative system damping of 2 percent was utilized. This is much lower than the actual expected value n'.A is below the 10 percent damping used in the structural comparison to EPRI Tests 908 and 917. ,5 i-2. Lumoina: Lumped mass spacing was determined to ensure that all j appropriate mode shapes were accurately represented. 3. Suncorts: The structural supports were modeled in sufficient detail to analytically represent the system. The shock suppressors and struts were modeled by inputting a stiffness in series with the piping. A linear i \\ overall system analysis was conducted. t 4. Time Sten: The integration time step is internally determined within the structural program and is based upon convergence criteria that results in stable solutions. The largest time step ever used could be 0.0001 ~ second. The time step is automatically adjusted such that the relative -2 error of each modal coefficient is at least less than 10 ~ -.,---....--..-.--w_..-----_-..-_.---

. - -.5. -Cutoff Frecuency: The cutoff frequency utilized in both the relief valve and safety valve discharge cases was approximately 1000 Hz. The pressurizer was rigidly modeled for the thermal hydraulic analyses. The pressurizer nozzles and pipe connections were represented with appropriate pipe properties. Intensification at the nozzle to pipe welds were included. The downstream piping terminated at the relief tank inlet flange where the J. model was anchored. ~ The valve bonnet assemblies and the relief valve actuators were modeled as extended masses, displaced from the pipe centerline. The valves weight and -center of gravity were selected from the valve drawings. The stem properties ~(diameter and thickness) were then selected to represent the valve frequency. Program FORFUN was utilized to calculate the unbalanced wave forces f'or each segment of piping. The time-history hydraulic forces determined by FORFUN were then applied to the appropriate piping system lump mass points. l The axial extension from the balancing forces (opposing ' blowdown" forces) on each end of the structural segment was considered in the FORFUN evaluation. However, this effect was determined to be negligible relative to the net unbalanced forces. Referring to structural analyses comparisons to test ~ results for Tests 908 and 917, maximum support and pipe loads compared well l with test results. Good comparisons of the maximum displacement values downstream of the safety value were also seen. i The submittal discusses: I l) 1. The load combination and corresponding allowable stress limits l 2. The governing codes and standards 3. The analyses results, and r j' 4. The safety evaluation of the system c _..__,4____._____.___ .. _,~ _._.-.

j J .1 l QUESTION: 14. The' submittal should discuss whether multiple -valve -actuation 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 l 4 sequence of opening -is such that = the initial pressure. wavec from opening of the valves. reach the common header-downstream simultaneously. Thus, the method nused to maximize the loading on the piping should be discussed.

RESPONSE

All safety and relief valve discharge events are bounded (Unit 1) by the respective loop seal clearing cases. Se thermal ' hydraulic forcing functions for these cases are developed using SWEC's WATSLUG computer code which is described in the response to Question 12. The valve sequencing for the respective events are selected such that the water slugs from one, two or three safety valve loop seals, whichever creates the maximum force in particular segment of pipe are considered. They all join in the common a j discharge piping and continue through the system as a combined mass. In the case of the relief valve event, w two water slugs will join, and for the safety valve i event, three water slugs will join. The phasing of pressure waves are not significant for the water slug loop seal clearing event. l l l t c [ l

I l l - l Response (Unit 2) f" Two valve opening cases were addressed in the submittal, 1) the three safety l valves opening simultaneously and discharging without PORV flow and 2) the two PORV>s opening simultaneously without safety valve flow. The three safety valves are identical and have the same set pressure (i 1 percent). It was, therefore, assumed for the analysis that all three safety valves open simultaneously without PORV flow. Because of similarity, the two PORV's were also assumed to open simultaneously without safety valve flow. Maximum comon header (area of piping comon to both safety and relief valve discharge piping) forces theoretically could be expected when valve sequencing is such that the initial pressure waves from valve opening reach a comon downstream junction simultaneously. Based upon engineering judgment: 1. The simultaneous opening of the safety valves results in practically simultaneous peak loads at the safety valves comon branch point. The t As a I peak forces occur within approximately.04 seconds of each other. f, result, no significant impact in the comon header region, due to safety valve discharge, is expected, if the valve sequencing is adjusted such that the peaks of the initial pressure waves reach a comon downstream l header point simultaneously. I 2. The total lengths of effective piping between each valve out1'et and the comon junction point are not exactly the same. The likelihood of the valve phasing being such to compensate for the different lengths is very I small; therefore, the peaks of the initial pressure waves from valve 8-( -l-opening, either safety or relief, would not reach a common downstream junction at exactly the same time. 3. There is a significant amount of piping and dynamic supports between the valve outlets and the comon point. In the unlikely event that increased { loadings from this common point to the relief tank were to occur, the effects would be limited primarily from near the comon point to the rel,tef tank. Significant isolation of the comon region from the upstream region because of the support configuration exists. Th'erefore, the operability and integrity of the valves, the inlet lines to the valves, or the nozzles on the pressurizer would not be jeopardized. l

. 1 l l Considerable margin exists between the conservatively calculated maximum stresses'and the allowable stresses for the safety valve event. Tables 6-4 and 6-11 of the submittal report illustrate this for the upstream piping and Tables 6-8 and 6-15 demonstrate this for the downstream piping. ~ 4 o 1

J Ouestion 15_ tg i 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 i moments resulting from the piping dynamic effects due to the fluid pressure cscillations 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 i I included. ~ q 1

Response

' l The piping system response including the safety valve loop seal region is due to frequencies less the 100 Hz. The frequency of the forces and moments in the 170 - 260 Hz range potentidlly induced by the pressure oscillations is l' significantly greater than this frequency. The upper limit of significant ie frequency content for similar systems is much less than this (170 - 260 Hz) [l range. Jndustry data indicates that frequencies of 100 Hz or less are meaningful. The EPRI test data confirms this. Consequently no significant bending moment daring the pressure oscillation phase of the transient will occur. l ~ i In the submittal, pressure stresses based upon a design pressure of 2485 psig l ivere included with the bending moments resulting from the. safety valve discharge piping loads. Because of the time phasing of the pressure oscillation (during water slug discharge through the safety valve) and the I discharge piping loads (subsequent to water slug discharge thru the valve) this pressure term and moment term were not added. They do,'not occur g coincidentally. A comparison of the intensified bending moments Yrom the stress evaluation and the allowable moment presented in WCAP-10105 shows that I all values are below the allowables. Specifically, the maximum allowable iI i ~

e- [ moment from Tabis '4-7 cf WCAP-10105 fcr 6 inch'schedulo 160 piping fer en internal pressure of 5000 psi is 516 in-kips. The bending moments for water slug discharge for the components (straight run, butt weld and elbow) listed i in Table 6-11 of the submittal are 84.75, 84.74, 84.74 in-kips, respectively. ~! 1 i i -I 9 .I h f s I f i l l : 1 i I i I 'i

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[ -3 0-EATETY EVALUATION OCESTIOTS-NUREG 0737 NORTH ANNA UNITS 1 & 2 WATSLUG. ATTACH?!ENT A '1. General Description Th,e. purpose of WAISLUG (Ref. 1) is :s istermine forcing func:icas on. piping sys:e=s during waterjslug -discharge events for subsequent input to piping _ dynamic analysis. t The analysis is based upon rigid body action of the generally subcooled water slug and. ideal gas represents:1ons of the steam or air using rigid column :heory to facilitate tracking the several water-steam or water-ai interfaces. The driving force. is :he steam pressure between :he valve and the slug, less friction and other losses, and back pressure. Densi:7 changes due to possible local flashing of :he water slug are considered. -Having recourse to the control volume theory, the_subsecuent segnant force. calculation iz carried out. The input consists of complete piping systam gecastry, pipe dimensions, valve flow :haracteristics, valve opening time, detail upstreca steam conditicus, and initial downstream steam or air. conditions, while :he output contains forcing functions for each piping segment based upen-i flow veloci:1es, pressures, and densities during the water slug discharge event. Torces are writ:en on : ape for direc: input to NUPI?E-3W (ME-110). (Ref. 2). i l 2. Program Verification The WATSLOG model of the cast problem is diagrammed in Figure 3A.3. A-1 and the NUPIPE-5W model is diagrammed in Figure 3A.3.A-2. WATSLOG is verified I by comparing the solution of this :est problem to the resul:s for :he same problem obtained by an independent analy:ical approach (RELAPS, MOD 1, Ref. 3) i as shcwn in Figures 3A.3.A-3 and 3A.3.A-4 and by comparison :f predicted versus measured support reactions. NU?!?E-3W - (ME-110) genera:ed - suppor: reactions due to the WAISLUG forcing fune:icas were compared with experimental i measurements frem a test run of this preblem (EPRI Tes: 908, Ref. 3) as shewn in Figures 3A.3. A-5 and 3A.3. A-6. The WATSLUG generated forcing functions and the resultant NUP!?I-SW support reactions compara favorably with the RELAPS/ MOD 1 predic:ed forcing functions and the EPRI measured support reactions, respec:ively. 3. References 1. "WATSLUG" (ME-212) compu:er code by J. S. Hsieh and D. A. 7an Duyne, Ver. O, Rev. 3, December 1982 and :he related documentatica calculation 576.470.1-NP(3)-038-FD. Rev. 2, " Water Slug Discharge in Piping System (WATSLUG) - Preproduction Version 3", dated March 3, 1932. 2. NUPI?I-SW,'MZ-110, V03,L14 (created 32.095), " Computer code for Stress Analysis of Nuclear Piping". 3. " Application of RELAPS/ MOD 1 for calculatien of Safety and Relief 7alve . Discharge ?iping Hydrodynamic Loads", Interim Report, March 1982, by In:ermountain Technologies, Inc., Idaho Falls, Idaho, Proj ec: Manager R. K. House. ._ _ _ _. _ _ _.,_. _._ _. _ _. _ _ _ _ _ _. _ _ _ _ _ - _. - ~..,

.. _31 TA3LE 3A.3.A-1 INPUT DATA 70R *ATSLUG

TOTAL I'ISIDE FRICTION PI?E NO.
ENG H (7t)

DI.UIE ER (7t) 7 ACTOR 1 16.125 0.408 0.015 2 12.563 0.5054 0.015 3 63.562 0.948 0.013 VALVE CHARAC*IRISTICS ORITICE., OPENING DISCHARGE FLOW AREA (Ft") TIME (Sec) COE77 CIENT RA*I ('bm/ sec) 0.0253. 0.013 0.805 120.33 UPSTREAM STIAM CONDIT!ONS PRESSURE pm DENSI Y ( 3 ) 3 gg gg g (PSI) PRESSURE (?SIA) EMPERA'"URE sec 2690. 679 7 (1139 R) 3.862 -40. DOICISTREAM GAS CONDITIONS ?RISSURE (?SI.O TEMPERATURE DENSITY (1bm)

ta 15.

80 7 (540 R) 0.09975

JATERSI.UG ~4E!GET = 69.3 Lbs.

i NOTES: l SEE FIGURE 3A.3.A-1 FOR SKITCH OF '4ATSLUG MODEL

- -?RESSURE IS DECREASING AFTER VALTE OPENS

TABLE 3A.3.A-2 INPL"' DATA FOR NUP!?E-S'.T

CUTOFF CU'0FF INTEGRAT!ON MODE TREQUENCY TIME STE?

TOfE DAMP!NG RATIO 53 433 H, 0.0009 Sec. 0.5 Sic. 10" ?!?E TOTAL CU* SIDE SEC !ON-LINGTH (Fe) DIAMI ER (!N) 3ICKNESS (IN) ~4E:GHT (D/ye) 1 a.73-8.625 0.906 74.7* 2 12.31 6.625 0.364 53.16 3 12.43 6.625 0.23 13.97. 4 69.0 12.75 0.688 38.60 5 1.1 12.75 1.5 6 1.0 3.625 0.322 23.55 7 0.83 6.625 0.432 23.57 6 = YOUNG's MODULOS OF ?!?E = 23.f x 10 ?SI E.,o = E,.0LD ni v i l i l I NOTE: SEE FIGURE 3 A.3. A-2 FOR SKETCH OF NU?IPE-S*4 MODEL i l

STEAM Le P IX1 a GAS j l ' 1 a V O WATER [ PRESSURIZER 7 VESSEL 1 A r -LF 4 if 3 ~ DISTANCES FRCM PRES 3URIZER VESSEL: Le 3AFETY/ RELIEF yALyt LG :0OWNSTREAM AREA CHANGC j LF s PlPE EXIT IXt aTRAILING EDGE CF SLUS 1 e FORCING FUNCTION DIRECTION,+ EPRI TEST (REF.3) SEGMENT NO, WATSLUG MCOEL PIPE NUM0ER 1 - PRESSURIZER TO Le 2-Le TO LG 3 - LG TO LF FIGURE 3A.3. A - I WATSLUG MODEL OF EPRI SAMPLE PROBLEM 4 v, e-esew ,-w, --,,r-~~+ ,-~~-e ,we,,,-r,~ww-vrm-

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ATTAC10!E"T 3 0 25 50-75 190 LOO I 8 J 3:s e s. e~ } y ,o -t f l =. O in w as => we art U -200 a. sOTE: l O AFTER : ut s;TES. Mts-E -400 - sunt i: acTunsto to int g ist711:. va*.:t AT 1 8171 g Con:117 tat v TM scau t Pats. -473 L sta Zta NEATUP. -600 TIME (SECONUS) i l I. Figure 8 - Loss of Load - Pressuri:er Pressure Variatien l (30 cycles) l Ex:5 acted from *4estinghouse Equipmen: Specification G-675838. Rev. 2,10/19177, " Pressurizer Safety Valves, ASME 3ciler and Pressure Vessel Code, See:1cn I:!, Class 1." l 1 f Rsv. 2. G-e73S33 Page 11 of 23

1 ATTACIDiENT C MAXIMUM CALCULATED EPRI APPLIED RATED BENDING BENDING FLOW-MOMENT MOMENT ' VENDOR MODEL LBS/ER (IN.-LBS) (IN.-LBS) DRESSER ~31739A 298.000 86,207 242,000 SAFETY VALVE I 3 MASONEILAN 38-20771 230,400 24,537 35,600 RELIEFE VALVE NOTES: 1. a. SWEC Calculation No. 14248.02-NP(B)-003-XC Rev. O dated December 22, 1983, Vepco North Anna Unit i Stress Analysis for Pressurizer Safety and Relief System Problem 700. b. SWEC Piping System Stress Analysis Report No. 12050-SSR-4 Rev. 0 dated December 21, 1978, Vepco North Anna Unit 2 Pressurizer Safety and Relief System 2. EPRI/C-2 Pur. Safety Valve Test Report Vol. 3 of 10, Test Results for Dresser Safety Valve Model 31739A EPRI Research Project V102-2 Interim Report, July 1982. 3. EPRI/W,le Power-Operated Relief Valve Phase III Test Report Volume 6, Summary of Phase III Testing of the Masoneilan Relief Valve NP-2670-LD, Volume 6 Research Project V102-11 Interim Report, October 1982 314/3R

{ POWER R' E S E A R C H INSTITUTE SE L E C T R'I C f 'pi EPRI + April 5,1982. I 1 TO: - UTILITY TECHNICAL AND LICENSING CONTACTS. PWR NSSS VENDOR FRIMARY CONTACTS-

SUBJECT:

~" GUIDE FOR APPLICATION OF VALVE TEST PROGRAM RESULTS TO PLANT SPECIFIC EVALUATIONS"- REVISION 1 Q'

i s 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 4 4 of. TMI-1 Action Plan Requirements") Saction II.D.1.A Requirements. Attached to this letter is a' copy of the subject report. A drafti copy of this report was transmitted for your, review on February 23, Y 1982. All coments have been' incorporated into the attached. 1 If you have any questions regarding the attached, please contact me. 1 .f Sincerely. f = I l Warren J. Bilanin Program Manager Safety and Analysis Department g WJB/11 Attach. l i o 4 j I m s s 'Neadauarters 3412 lii!!vew Avenue. Port Offes Box 10412. Pajo Alto. CA 94303 (415) 855 2000 ~ o' .... ea.. ..en....... .........w -)-- v. . - - -. -.,, - - ~ .-,.-,.,--.--.,.~,y. ..m.. +---e

Revicicn 1 {- ~ - - I - s, 1 \\ EPRI PWR SAFETY AND RELIEF VALVE TEST PROGRAM GUIDE FOR APPLICATION-OF VALVE TEST PROGRAM RESULTS TO PLANT-SPECIFIC EVALUATIONS l ~ - INTERIM REPORT, MARCH 1982 -(RESEARCH PROJECT V102) i i 1 I 1, Prepared by: l MPR Associates, Inc. 1140 Connecticut Avenue, N.W. Washington, D.C. 20036 Prepared for l 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 i i i ..+e -e y e w-r,,-.emIw,=- .-e --.m-,.emc*-g3 w -mey----ye gw-w-ww-,.--+w--qg.wm'---e.-eg,e-4--r-g-ger--w -w --g--up--f-> -e m g-w---ww -w ges ye_ T-w w WM nu v 4 vere 3s'-9-Pop *,e4--_v.yyy

c: - _p ; - l I: PREFACE ] :- This guide has been developed to assist participating PWR e Utilities in determining the applicability'of the various-test results from the EPRI program for their plant-specific evalu-4 - 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- ' taken not to overlook the results of any test for possible, l, 11 applicability, i.e., each test conducted on a representative 9 valve type may have some generic or indirect applicability. However, the closer the tie between specific EPRI tests and the l Plant. installation, the more direct the applicability of the t resulhs. It is expected that the approach developed in this [ guide will be useful for virtually all of the plant evaluations. e OO I C 4

6. 9

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Cevioita 1-1D } ^ t TABLE OF CONTENTS l Z. 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 l' A. Identification of Pertinent Plant Parameters B. Procedures for Evaluation of Test Results 1. Safety valve Performance and Associated l' ' Piping / Support Adequacy 2. Relief Valve Performance and Associated Piping / Support Adequacy C. Identification.of Potential Problem Areas and Possible Alternatives to Address Undesirable r 3 Valve Performance 4 IV. SUGGESTED FORMAT FOR JULY 1, 1982 PLANT-SPECIFIC SUBMITTAL V. REFERENCES i 1 ! 1 i 1 k .m ,m

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R;vicisn 1-q g. l -TABLE OF CONTENTS (Cont'd) VI. APPENDICES A. Procedure'for Calculation of Valve Back Pressure B. Procedure for Calculation of Inlet Piping ~ Pressure Effects Procedure for Verification of-Alternative Methods to C. '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 Ir I 0 o I se t' \\ \\ l e 6** h ii l-f ~ _.. -.., - -,...,,. _ _..,. .. m.--.

-.1 b' <j) Revicisn 1 ~ ?.1 i ) o I.. INTRODUCTION I A. 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 ) i submittals in response to NUREG-0737 (" Clarification of I TMI-Action Plan Requirements") Section II.D.1-A, .l i Requirements. Specifically, NUREG-0737 requires the !j l following: i :

1..

An evaluation of safety and relisf valve function-I I ability for plant-specific operating and accident t i conditions. l 2. An evaluation of piping and support adequacy for I plant-specific conditions. x-l 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 9 evaluations. Specifically, it was assumed that: 1. The utilities (with possible assistance from architect-engineers at other piping designers) will perform the eval untions of piping and support adequacy. ~ 2.~ The valve manufacturers will perform the evaluations t 4 ~ of valve performance. l l 1 i 0 L ._,...~ m _ _,_._,...,_.-..r_......__.., - _ ~.... -,, ~,

Va h R;vicien 1-f 't ~ 3. The NSS5' vendors will perform.the evaluations of overpressure protection system performance. ~ - 4. The utilites will-coordinate the overall evaluation. j 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 b organization (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 1 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. I s l 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. l l by EPRI which most closely matches the plant installation. It is expected this approach will be useful for virtually i l' all of the plant evaluations. The guide assists in de-1 i fining the limits of applicability of the EPRI data. l

I I-2 F

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~ [ w Revicicn_1 ti 5-4 .p 7 3. l Contents of the Guide' The contents of the application guide are summarized in' 'the-following: Section II -- Procedure to be Followed in Plant-Specific Evaluations A. Flow Charts for the Evaluations' This section describes the overall approach -f to be followed in performing _the evaluations I of valve performance and piping / support adequacy. l B. Workscopes'for the Evaluations This section discusses the workscopes for the evaluations to be performed by the utilities, the valve manufacturers, the NSSS vendors and 1 EPRI. 4 section III -- Evaluation of Test Results for Plant-Specific Conditions k I A. Identification of Pertinent Plant Parameters ^ This section identifies the pertinent plant-t 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. O O i I-3 f w, .-~-, mesop, s e m e.- . ew -pew,~w, -,-,--sw.,wmm,w e-, -s,. e e w-y mm ,,n m m e w,4--m-o-w_ -_m-e._,e-iww- - e - - + -m +----we -,e

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. c. t. D. - -Pracnduran far Evaluntien'nf Tant'R7sult7 i. ti ~ This section provides the procedures to be used - in performing the evaluations of valve performance e and piping / support adequacy.- For.the valve per- [ 'formanca evaluation, it provides-guidelines for identifying applicable valve tests, a table to be-used by the valve manufacturer.to document' valve performance characteristics, and a suggested set of acceptance criteria for valve performance. f For the piping / support adequacy evaluation,'it j ~ l provides suggested guidelines fpr the evaluation and a suggested set of structural acceptance i . criteria. i ( Identification of Potential Problem Areas and I C:. Possible Alternatives to Address Undesirable Valve Performance .g i 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 mise discusses possible alterna-tives to be considered by the utilities to address ~ undesirable valve performance features. I, Section IV -- Suggested Format for July 1, 1982 j Plant-Specific Submittal

i This section of the guide provides a suggested format for the July 1, 1982 plant-specific submittal to the NRC.

l 2-4 l ... - - =.- - -.. - a

l ! 8 Revicica 1 section V -- References [ 6-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 ~ i A. -Procedure for Calculation of Valve Back Pressure 8 -This appendix outlines a suggested procedure and guidelines for the calculation of valve back pressure. I I B. Procedure for Calculation of Inlet Piping y Pressure Effects ) This appendix provides a suggested procedure' l and guidelines for the calculation of inlet j piping pressure effects. C. Procedure for Verification of Alternative Methods to be used in Evaluation of Piping / Support Adequacy This appendix provides a suggested procedure to I verify.the adequacy of the alternative methods to i l be used to evaluate the structural adequacy of the piping and supports. i l D. Procedure for Assessment of Applicability of j Specific EPRI Safety Valve Tests l This appendix outlines a procedure to assist in l i determining the applicability of EPRI safety valve tests to specific plant evaluations. l 1 i 'O I-5 .,,-.....y.% h - ,y_ -..,-_,._,---..,__....__,,,mm,__m...~,,,,,......,,_,,.._,...,,,.__,,,.,___.,...ml....

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Icad ' Combinations and Acceptance Criteria for

~

the Safety and Relief Valve Piping Evaluation 1 ec This section provides recommended load combinations L and acceptance criteria to be used by the utilitiest +33 in evaluating the adequacy of the safety and re-- ~ t lief valve piping and supports. l t I ) I f. l 9 l 9' i ! g I I I e I-6 ..,._,..,_,_,I '"O""T'"'**'TF9e-v mp9 ,ew,,,,,

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Revicien 1. i i' II. PROCEDURE TO'BE FOLLOWEDIN-PLANT-SPECIFIC EVALUATIONS l A. Flow Charts'for the Evaluations j la Evaluation of Valve' Performance safety valves The flow chart provided in Table II-1 illustrates j the overall procedure to be followed in performing l 1 the evaluations of safety valve performance. The ] input for the evaluations consists of: EPRI valve program reports as listed in ~ section V of this guide. i List of pertinent plant parameters as g identified in Table III-1. l The evaluations to be performed consist of the 1 3 following: i ' l. e An evaluation of test results by the valve ! i manufacturer to identify any potential i 4 l problem areas regarding valve performance. l An evaluation by the NSSS vendor to identify-any. potential problem areas regarding overpressu )I protection system performance. e W e i i

n. -l 'T: R;vicisn 1 1 E i An evaluation by the utility of possible alternatives to address undesirable valve -l. performance features. i 4 The output from the evaluation's~ consists of: 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 t j 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, t 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 responsibility for coordinating the overall evaluation effort. i 1 1 l" I l II - 2,

Revicien'1 F - 1 Relinf valv,n The evaluation of relief valva performance l should also be performed lfollowing the procedure shown in Table II-1. However, this evaluation f ~ should be acre straightforward than the safety valve performance evaluation and it is expected that the utilities would perform the bulk of the evaluation. 2. Evaluation of Piping / Support Adequacy The flow chart provided in Table II-2 111ustrates the overall procedure to be followed in performing the evaluations of piping / support adequacy. The input g) ! [f for the evaluations consists of: l g Verified computer codes for determination of hydraulic loads and EPRI valve program reports I as listed in section V of this guide. 3 l a List of pertinent plant parameters as identified in Table III-1. The evaluations to be performed by the utility consist t i I j of the following: An evaluation of the piping stresses and support loads using the EPRI-provided codes or other t method which has been verified by comparison of predictions with EPRI test data provided in .o Reference 7. A comparison of calculated Dining stresses and support loads with allowables and identification L of any potential problem areas. ~ - gr _ 3 9 w w w -<---em-,+---e m we v- ---wm3-.w - - - - - -- - - -,%www.-+.----.-,mwwwwwww e.,e,w-----**- _4.-=,ww.=~w__ .e-m

y-m L ~ An evaluation of possible alternatives to address. potential piping / support problem ~ t'l. areas. . 1. The output of-the evaluations consists of a report for submittal to the NRC which provides the results I of the plant-specific evaluations. The report.may e ac include, if required, the selection and implementa-tion schedule of modifications to the piping and f, supports. B. Workscopes for the Evaluations Tables-II-3 through II-8 summarize the workscopes for the 4' various evaluations to be performed by the utility, the valve manufacturer, the NSSS vendor and EPRI. The. tables are identified as follows: Table Organization Evaluation 4 II-3 Utility Safety and Relief Valve l, Performance L II-4 Utility Piping / Support Adequacy II-5 Valve Manufacturer Safety Valve Performance 'l II-6 Valve Manufacturer Relief Valve Performanca 1 I II-7 NSS Vendor Safety and Relief Valve Performance II-8 EPRI Valve Performance and t' ~ Piping / Support Adequacy l, 4 l. i I 'l II - 4 l .v., s-+-e,,-_-a.--~--e..,,-m,n-,-- -,.-,,.-,-.,~-,4,,m,,-e-m--e-,- ,,.,--m-~.,--w,s- ,,,_ w.e,--- m e ,m.m.~.w,. wa m ,.,,,,,e,--.

TABLE 11-I m:vicien 1 j APPLICATION OF VALVE TEST RESULTS TO: PLANT - SPECIFIC EVALUATIONS OF VALVE PERFORMANCE UTILITY VALVE MANUFACTURER NSSS VENDQR EPRI-L i ~ ASSEMBLES PROVIDES VALVE pgggggggy PROGRAM REPORTS M P2 ANT INFORMATION FOR WAI,UATIONS (SEE TABLE III-1) t 3 I 1 r 1r EVALUATES TEST EVALUATES TEST RESULTS AND RESULTS AND l 2DENTIFIES ANY

2DENTITIES ANY i

POTENTIAL PROBLEM PCTENTIAL PROBLEM AREAS REGARDING AREAS RECARDING VALVE PERTORMANCE SYSTEM PERTORMANCE l l 1r 1r IDENT2FIES ZDENTIFIES I ALTERNATIVE ALTERNATIVE VALVE SYSTEM / ANALYSIS MODITICATION5' MODITICATIONS AS REQUIRED AS REQUIRED 1, 1r l 1 r

PROVIDES, EVALUATES ASSISTANCE l

ALTERNATIVES TO UTILITY IN* AND SELECTS EVALUATION MODITICATION5' 1 AS

REQUIRED I

I i i r SCHEDULES 1 IMPLEMENTATION 0F SELECTED I MODITICATIONS 4 AS REQUIRED 1r PREPARES PIANT-SPECITIC 7 SU5MITTAL FOR TME NRC II - 5

w R3vicicn 1 TABLE 18-2 APPLIC.ATION OF VALVE TEST RESULTS TO PLANT - SPECIFIC EVALUATIONS OF. PIPING ADEQUACY EPRI ' UTILITY l- .+ ASSEMBLES PROVIDES VER2 TIED COMPUTER CODE AND PERTINENT f-VALVE PROGRAM W PLANT 'l. REPORTS FOR 2NFORMATION e UTILITY EVALUATIONS (SEE TASLE !!!-1) ~ s v USING EPR2-PROVIDED CODE OR OTHER VERIFIED METNOD EVALUATES STRESSES AND SUPPORT 2AADS IN P2 PING '1 i 1 1 r I' COMPARES LOAD 5 AND STRESSES WITH A2LOWASLZ5 AND 2DENTIFIES ANY POTENTIAL I ( PROBLEM ARIAS .i 1 P i EVALUTES. SELECTS { AND SCNEDULES IMPLEMENTATION OF i i* MODITICATIONS TO P172NG AND SUPPORTS AS RIOV2 RID i 1 P PREPARES PLANT SPECIT2C l SUBMITTAL FOR TSE WRC l l l 4 I e 11 - s e 7---,,,n.e.,.,,-n.e----.-egn.r,-c---..,,-,,,,,-~,..n-m-,,,,,.an,,,,,.-nn,m-,wmv,m.ww,.,-w--,--~--,~~-------

~ - .l Revicien 1 l e, 1 e I TABLE II-3 ~ WORKSCOPE FOR UTILITY EVALUATION OF ) SAFETY AND RELIEF VALVE PERFORMANCE. l The utility will perform the following: 1. ' Identify pertinent plant information listed in Table III-1, including: l Valve parameters Inlet piping parameters ~ Discharge piping parameters Valve actuation transient parameters s 2. Evaluate alternative modifications identified by valve manufacturer and/or NSSS vendor and select modifications for implementation. j 3. Schedule implementation of selected modifications to 1 valves. t 4. Prepara plant-specific submittal for the NRC. I I \\ i % l 'l j II-7

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~' TAB'E II * ' WORKSCOPE FOR-UTILITY EVALUATIONS OF PIPING / SUPPORT ADEQUACY c.. The utility _will perform the following: L 1. Identify pertinent plant information listed in Table III-1, including:- valve parameters 1 Inlet piping. parameters Discharge piping parameters g Valve actuation transient parameters with valve test results) method, evaluate stresses and Using EPRI-provided code or other verified (by comparison 2. support loads in inlet and discharge pipin,g. Compare loads and stresses with allowable values and I i 3. identify any potential problem areas. i

4. g Evaluate, select and schedule implementatio'n of modifica.-

~' 4. tions to piping and supports as required.

i l

l 5. Prepare plant-specific submittal for the NRC. l 3 i i 1 i i ! 1. 11 - s .-t ~ .I

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) TABLE II l WORKSCOPE FOR VALVE MANUFACTURER EVALUATION g OF SAFETY VALVE PERFORMANCE l A. - Bases for Evaluation \\ The following will be provided to the valve manufacturer for his use in the evaluations: 1. Applicable EPRI test program. outputs. 2. Plant information listed in Table III-1 { N. Scope of Evaluation .The valve manufacturer will perform the'following: Define performance for as-installed valve ring settings g 1. based on: g EPRI test data I Valve manufacturer's test data Valve manufacturer's supporting analysis i The evaluation should: 3 Determine which fluid conditions result in stable 4 or unstable valve performance. j Establish valve performance characteristics (e.g., blowdown, lift, flow opening time, etc.). l' Define performance for optimal valve ring settings in 2. accordance with the steps identified in:1 above. 1 Recommend valve modifications to provide improved 3. performance, if needed (e.g., to provide reduced blowdown, stable water performance,.etc.). 4. Document performance recommendations and bases for* recommendations to the utilities. 1 e

1 I

II - 9 . _,. -.. ~ _ _. _ _ _.. _. _ _ _. -..... _ _ _ '

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I TABLE II-6 WORKSCOPE FOR VALVE MANUFACTURER.

~ EVALUATIONS OF RELIEF VALVE PERFORMANCE l A.~. Bases for Evaluation m The following will be provided to tho valve manufacturer for his use in the evaluations: ) - 1. Applicable EPRI test program outputs. ~ 2. Plant information listed in Table III-1 1 s, B. Scope of Evaluation

i The valve manufacturer will perform the following:

.I 1. Establish valve performance characteristics I (e.g., opening time, flow, closing time) i , 'l* ~ 2. Recommended valve modifications to provide improved l, performance, if needed. i i( 3. Document performance recommendations and bases for recommendations to the utilities. g. 1 O i ( I s. i II - 10 \\ .---e -w e -,-e--,, - -.,e_-,e ev,--,,.,--,-e, ww,-----e-.w-,em,.m,w.,.e,n,--m,.,,,,m--.ve,wwn,.,m,m,y-- --go,ym,,,em-m cem,p4--ew,.g,,,, emum.,---

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g e; - - TABLE II-7 r WORKSCOPE FOR NSSS VENDOR EVALUATION'OF 5AFETY AND RELIEF VALVE PERFORMANCE \\ '~ i A. . Bases for Evaluation e The following will be provided to the NSSS vendor for l his use in;the evaluations:

1. -

Applicable EPRI. test program outputs. l 2. Plant information listed in Table III-1. f 8 3. Valve performance characteristics (e.g., blowdown, l lift,. flow, opening time, etc.), as established by 4 the valve manufacturer. 7 i B. Scope of Evaluation I The NSSS vendor will perform the followings. j 1. Evaluate test results and document system acceptability or identify any potential problem i areas regarding NSSS overpressure protection sys-tem performance. 4 2. If Potential problems are identified: l Identify alternative modifications to NSSS 4 overpressure protection system and/or overpressure '[ i i transient analysis parameters to resolve un-l acceptable performance. l l I Concur with system / analysis modifications selected i l by utility for implementation. I Prepara report which justifies acceptability l a j of system / analysis modifications selected for l 1 implementation. f i i i I i ej i i II - 11 j i l s lo

men cisa 1 [, .r t ti s ~ I TABLE II-8 WORKSCOPE FOR'EPRI EVALUATIONS L A. Valve Performance 1; Provida valve program reports for utility evaluations.- 2. Provide on-going assistance to utilities in the understanding and use of program outputs as

required, l'

3. Piping / Support Adequacy 1 Provide verified computer code and valve program reports for utility evaluations of inlet and discharge piping and support adequacy. The code provided by EPRI is to be used for the calculation of the time-dependent hydraulic loads applied by the fluid on the piping. l t Ii i !

1. -

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Revioita 1 , (. ' " I i III. EVALUATION OF TEST RESULTS FOR -l PLANT-SPECIFIC CONDITIONS I A. -Identification of Partinent' Plant Parameters , l A 15st of pertinent plant' parameters to be identified by 3 the utility ils provided in Table III-1. Possible sources to be used by the utility in compiling.the required in-formation are listed below: l 1. Plant Final Safety Analysis Report / Cold Overpressuri-' l zation Analysis Report

t 2.

Plant Technical Specifications l 3. Plant installation drawings'and system isometrics. ~ b 4. Valve Documentation and Nameplate Information 5. Initial valve manufacturer's test data and periodic i set pressure verification test data. J In addition, the EPRI valve program reports (see Section V) I and the appendices to this guide should be useful as follows: f The test conditions justification report (Reference 3) { i and plant conditions justification report (References 4, l i t 5 and 6) should be useful in assembling the valve j l actuation transient information. Appendix A provides a procedure to be used for the 1 calculation of valve back pressure. i f 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. { ll j 4 ---y e ,m, r-,s. -e ,.#---+.--%._,., ,, +. - --,,y-wes,,e,yr,,,-,n,--e-. - =,., _,w-wm,y-.,----,m._y.

95 Procedures for Evaluation of Test Results 0 3. safety valve Performance and Associated 1.s Piping / Support Adequacy .l: The procedure to.be-used -to. evaluate safety valve ) performance for plant-specific conditions is as ~ follows: l-Step 1 The utility-provides the assembled plant in-J. formation (Table III-1) - and the applicable EPRI 1 f[ 1. valve test program output to both the valve manufacturer and the NSSS vendor. c, i f f Step 2 The valve manufacturer identifies the specific EPRI tests which are applicable for the plant-I }, specific safety valve evaluation being performed. An outline for conducting this type of evaluation is provided in Appendix D to this report. i Step 3 l Based on the information provided by the utility i* (see Step 1 above) and the valve manufacturer's l j, l own test data and supporting analyses, the valve manufacturer determines the valve performance !lL characteristics and completes the performance summary sheet provided in Table III-2 for both l as-installed and optimal ring settings. 1 l III - 2 i' l _-,-__-.4

Revicihn 1 A 1 g Step 4 The utility performs an evaluation of safety valve-i - inlet and discharge piping stresses and_ piping sup- ' l Port and valve loads. } Step 5 The NSSS vendor compares the valve performance _ , i characteristics listed in Table III-2 with the valve-l characteristics assumed in the FSAR (or other design),l, _ overpressure protection system analyses and identifies-any conditions for which the actual and assumed valve,l t performance characteristics are not consistent (see I Table III-3 for performance characteristics to be considered). Where not consistent, the NSSS vendor i should judge the acceptability of the deviation ) and provide the basis for his judgment. (' t-i Step 6 j The utility comparas the safety valve piping / support i loads and stresses with the allowable values and { li identifies any conditions for which the allowable 4 I values are exceeded (see Table III-3 for definition of piping and support allowable loads and stresses). Step 7 The utility (with assistance from the valve manufacturer and NSSS vendor as required) identifies ' ~ ~ any conditions for which acceptable valve performance l I is not obtained. The utility then evaluates III - 3' ~ ~.~r.n- ,.n- ,-,,..-----,,~,,,-n----n.,,.~,---,,n..,, ~..-------v_-,,.nn_.,~e.,,..,,--._~,,,,,n..

N 7 P.- Ipo00iblo citOrnativ2O which could provida P. acceptable valve performance and selects any needed modifications-to be made to the valves or piping. .i i~. 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, i. 2. -Relief valve Performance and Associated Piping / Support i Adequacy The procedure to be used to evaluate relief valve per- ~ g 4 "l formance for plant-specific conditions is outlined in j the following. It is noted;that these evaluations should be straightforward and it is expected that the lI utility could perform the bulk of the evaluations. t Step 1 l The utility assembles the plant information (Table III-1) and the applicable EPRI valve. test program L l outputs. i 3 g.

l Step 2 j

Based on the plant information and the EPRI valve tes f .l data, the valve manufacturer (or utility) determines I, the valve performance characteristics and completes f the performance summary sheet provided in Table III-4' This evaluation should consider any differences in th j air and/or electrical supply and,for pilot-operated .I ! I valves the pilot vent discharge tubing for that in-i stalled in plants compared to that tested. I ZZI - 4 3 l y .-r. .--.___-_-...._..~_~..d.,,.. _ _ ~ _

.Revicitn 1-Y f-l .l Step 3 The utility performs an evaluation of relief i -valve inlet and discharge piping stresses and piping support and valve loads. Step 4 The Nsss vondor (or utility) compares the per-formance characteristics listed in Table It;-4 } with the valve characteristics assumed in the cold overpressurization analyses n'n'd identifies any conditions for which the actual and assumed valve i I' performance characteristics are not consistent (see Table III-3 for performance characteristics j to be considered). t I step s The utility compares the relief valve piping / ,l 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 1 l and stresses). Step 6 l The utility identifies any conditions for which acceptable valve performance is not obtained, and then evaluates possible alternatives III - 5 l ~

~

M 'y i [,1~ t. which could provide acceptable valve performance L f O' and select's any needed modifications: ,p c Step 7 r + . The utility, valve manufacturer, and NSSS vendor O prepara reports which document their evaluations 't im and justify the acceptability of any modifications selected for implementation. i, j, 1 Identification of Potential Problem Areas and l C. Possible Alternatives to Address Undesirable Valve Performance Based on the results of the EPRI valve test's, it is apparent i 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 r previous sections, the first step in addressing these poten-tial concerns is to perform analyses to attempt to demonstrate i that the observed valve performance can be accommodated in r Should these efforts be unsuccessful, several I the plant. alternatives are available to resolve these potential t A list of potential problem areas and some possible problems. I alternatives to be considered to address the undesirable It should be valve perforrance is provided in Table III-5. 1 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 performed by the p> .utilitiaskvalvemanufacturersandNSSSvendors. III - 6 t I J. L -. 1....

i Rovicica 1 7- ?... j. 1 o I l l Table III-6 provides a general summary of the safety valve ) 1 i test results obtained in the EPRI program. Some cons $dera-t o s to be taken into' account in evaluating off-normal ( valve performance for various conditions as noted in ~ I Table III-5 are discussed below: 1 Safety valves i 1. Performance with Steam Flow l For virtually all safety valve / inlet piping combinations tested, ring settings were established 'l 'in the EPRI tests which provided stable valve per-i 4 formance with steam inlet conditions.

However, s

these ring settings resulted in valve'blowdoyn outside of normally accepted limits (i.e., greater than five percent). Therefore, re-evaluatioE of selected NSS system overpressure transients should be performed by the NSSS vendors to show that in-i 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 blowdown (i.e., near five percent). 2. Performance with Subcooled Water Flow For some of the safety valves tested, the valves l - ~ chattered with subcooled water inlet' conditions. 1 III - 7 l .,,y .w q.. cw-- ---_e.- y- __p ,y-- eq9my.,,._.,e,weocme-amw++wo-e.-e-er-m*-e-- e---

~ Far thoco cococ, if tho fluid conditiens fer. t a specific plant include subcooled watcr, tho j i ~ utility /NSSS vendor could show that the subcooled - l water can be handled by other than safety 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 f 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. 3. Performance with Cold Loop Seals L 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 i discharge piping. (Elevated temperature loop seal tests resulted in reduced piping loads.) Possible alternatives to aliminate 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 9 III - 8 ~ ~ -. - _. =

R;vicien I c i 4 performance with the loop seal. However, before a decision'to drain or heat loop seals is made, 1 careful consideration should be given to the l.; potential consequences, e.g., increased potential' - for valve seat degradation and resulting steam / I hydrogen leakage. l' 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 1 (Dresser Electromatic and Target Rock) with fluid i conditions that result from loop seal installations. 1 For plants which utilize these valves with loop seals, i d possible alternatives to consider include' heating or draining of the loop seal, or utilizing an alternative l vafve 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. g -e 1 5 III - 9 4 4-a,-. e e-,e.. .--w..%-v%7,ww-.ar-w w-weeme-,e----s-m+---s+ -we-u-eraoreEvwc-w-W-cev-w-sy,*- ---te-wwe-s---e-ar- -w-+-w-e-*+w-va-es W-w- + ve e r

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~ L.- l TABLE III-1 L PLANT INFORMATION TO-BE ASSEMBLIED BY VTILITY Followl g is a list of valve / piping information to.5e assembled by the utility for the evaluations: E 1.

Safety Valve Information Number of valves Manufacturer l'

Type I' Size -(inlet, outlet, orifice) j ' ~ Steam flow capacity (rated and maximum) Design pressure'and temperature Inlet flange rating Discharge flange rating Allowable applied load (should consider the applied load t which'resulted during testing) I' Se't pressure l Accumulation ispecified and existing, if available) 1 Blowdown (specified and existing, if available) Ring settings (specified and existing, if available) original valve procurement specification original valve quality assurance package i Maintenance documentation package for valve 2. Relief Valve Information i f ~ Number of valves i 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) .I I III - 10 i y w--+-+ y

O-pg7*-

g ti'---weem---g-* "-w' * - - - - mu-rt-V--'g%g ggeva.-g-'w= yv e q-w't y9P-==N -T w er e - py-twF--=-*eei-e-*ewp-7e-1-Ww-wWw-teges'w+ w e w -ee=wm-e 'e ww-w ene& w ee r**' eh*s-a'tw-'er-**-**-

- - --- - - - -- -- TT i TABLE'III-1 (Cz't'd)' q n l Opening pressure (include all settings) Closing pressure (include all settings) ~ ' Original valve-procurement specification Original valve quality assurance package p intenance documentation package for valve For air-operated valves: Air supply system pressure and system 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, l i configuration, etc.) \\ 3. Inlet Piping Information ] Design pressure . I Design temperature Configuration from pressurizer to valve (include an isometric-i drawing of the installation showing piping diameter, length and orientation) Pressurizer nozzle configuration Loop seal (include volume and temperature of water in .I loop seal) 1 Piping supports (show location on isometric and list type and capacity of individual supnorts in a-table) steady-state flow pressure drop (including velocity head) III Acoustic wave pressure amplitude (1) l 4. Discharge Piping Information i Design pressure Design temperature Configuration (include an isometric drawing of the installation showing piping diameter, length and orientation) I Pressurizer relief tank design pressure Piping supports (show location on isometric and list ty.pe and capacity.of individual supports in a table) Note s - (1) See Appendix B, applies to safety valves only. } III - 11 .I o -a m rwm w-r es- -*--,-s-wwn-es ow-w<g sp-mm-e u v w~ we W9w r ww-MTgr e -++Eywev-e-+pemNe-eg-Eee wc-me me.- ew Dmem ee ah air a w _ehw o N-99*we reF m

.~ j; fReviDign 1 en .n- ~. ~ T .-t' I ' TABLE III' .1 (Cont'd) l' 5. valve Actuation Transient Information ~ i. '._FSAR Transients Pressure (opening, peak, closing) Temperature Pressurization rate at valve opening 5 ' Maximum back pressure (2) (steam condition) Fluid range' (e.g., saturated steam, saturated water, l ]. steam to water transition, subcooled water) Valves actuated (number and type). III ' Cold Overpressure Transients Pressure ranges (opening, peak, closing)

1 Corresponding temperature ranges Pressurization rate at valve opening Maximum back pressure (2) (steam condition)

Fluid range valves actuated (number and type) ~ Extended High-Pressure Injection Transients Pressure range (opening, peak, closing) Corresponding temperature range Initial pressurization rate Maximum back pressure (2) (steam condition) l Fluid range valves actuated (number and type) / t . t -{ Notes: (1) -Applies to relief valves only -(2) See Appendix A l i i I III - 12 1 ..__.,...._..__,._,2___._.~____.__.___..___._._________.__

R;vicion 1 j - g.. o TABLE III-2 .j SAFETY VALVE PERFORMANCE

SUMMARY

-SHEET ~

l-A.

Parameters for Safety 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 / piping configuration 1 L most nearly corresponding to the plant configuration. j-l 1. Safety Valve Manufacturer Type Size 1 2. Inlet Piping g Piping length 4 Piping diameter Dry or loop-seal j 3. Discharge Piping r Back pressure range (for steam actuation) 4. Inlet Piping Pressure Drop (Steam Actuation) { Steady-state Acoustic (after icop seal discharge) .l 8 5. Applicable Test Numbers (Selected by comparing preceding information with EPRI test data) 6. Valve Ring Settings I Ring Settings Ring As-Installed Optimal Upper ~ ~ Middle Lower-1, l III --13 l ~. _.. -.,,,..., _ _,. - - -, -..,..,.,.,. - - -. _. -,. _.. _.,..., _ _... _ _ _.. _ _ _ _. _ _ _ _. -. _ _. _ _ _ _ _ _ _ _. _

Q Revicisn 1 E' TABLE III-2.(Cont'd) 3. . valve Performance. Summary u , The following valve performance characteristics are to be ~ determined from the data for the applicable tests for both as-installed and. optimal ring settings. 1. - Behavior Mode Fluid Condition Stable Chatter Other 1 Saturated steam Loop seal 1: Transition I Water j - 650*F I - 550*F l - 400*F I i 2. Performance Characteristics

i

{ Flow Closing Fluid Opening Opening Capacity Pressure Condition Pressure (psia) Time (sec) (1b/sec) (psia) Saturated steam ( Loop seal i Transition Water l 4 - 650*F. - 550*F - 400*F i In addition, determine maximum back pressure for l.[ saturated steam condition. g l c1 III - 14 s ,.w-e- ...m......-...,r.4._,..e....e-.-,-.s, --y e,e-.-..--..~-e-+.- .-+-.-.,w.we,,,-w-._...i..,,,e--.--..w.-.-,,w--w.,--w,-

R vicien 1 l TABLE III-3 f: DEFINITION OF ACCEPTABLE PERFORMANCE FOR SAFETY AND RELIEF VALVES AND INLET AND DISCHARGE PIPING l I Following.is a definition of acceptable performance for safety and relief valves and inlet and discharge piping: i A. Safety Valves Valves open and close in a stable manner. (A minimum 1 ,1 1. amount of. valve chatter or flutter is permitted pro-vided no change in critica1' valve dimensions or wear of seating surfaces results.) See Note (1). ) l Valve performance characteristics are consistent with 2. FSAR (or other design) overpressure analysis assumptions, g 1 including: i opening pressure l opening time 1 flow capacity closing pressure (i.e., blowdown) i B. Relief Valves valve performance characteristics are consistent with i cold overpressurization analysis assumptions, including: l 5 opening time flow capacity closing time I C. Inlet Piping (see Note 2) Piping stresses during valve discharge transient 1. less than design stresses. l 8 Pipingsuphortloadslessthandesignloads. 2. Applied load on valve less than design load. (The design 3. loads should consider the applied loads which resulted during testing.) I It should be noted that when valve chatter occurrea curing non,g ~ loop seal tests, the valve was assisted open to terminate the (1) Therefore, the degree of valve internals degradation during an actual in-plant event under similar conditions may event.

>e_more severe than was observed in the testing.

~ Load combinations and allowable piping stresses and l i (2) support loads listed in Appendix E. III - 15 c

y. 5 s-P.svicien 1: f 4' I TABLE III-3 (Cont'd) D. Discharge Piping (see Note 1) l Piping stresses during valve discharge transient t 'less than design stresses. j 2. Piping support loads less than design loads. 3. _ Maximum pressure less than maximum acceptable g-valve back pressure. 1 4. Applied load on valve less than design load. which resulted during testing,)(The design loads shou I1 i e I (1) ] Load combinations and allowable piping stresses and support loads listed in Appendix E. \\ Ii I . ~.. ..,,,,-.......----.-,:---....,-,.......,...--..-...---..---___~~----1------

. f. R vicien 1 TABLE III-4 -RELIEF VALVE PERFORMANCE' SUM 2iARY SHEET. .A. Parameters for Relief Valve-Installation in Plant The following parameters are to be tabulated for the plant } l I ihstallation. They are to be:used to identify the tests i with the representative valve. 1. Relief Valve -Manufacturer l ~ Type size 2.- Inlet Piping-Dry or loop-seal ,f 3.- valve Operator } Air supply system details or electrical voltage / current Other (size, force capacity) j I 4. Applicable Test Numbers I \\ i 4 l',) j 1 III - 17

'~ TABLE III-4 (C:nt'd) ~ . {- .A 1 B. ~ valve Perfor'mance Summary The following valve performance characteristics are to .. j be' determined from-the data for the applicable tests. ' Fluid: Opening-Flow: ~- - Condition Time (see) Capacity (1b/sec) Closing Time (sec) Saturated steam Water Seal Transition - Steam to water - Nitrogen to water s Water' (at high pressure set-Point) - Maximum temperature - Minimum temperature 4-l Wats.r (at low pressure set-point) - Maximum temperature - Minimum temperature 1 J s. l ( ..I ) III - 18 {. ~ i

R vicicn 1 '{ . e. r-1 I, 6 TABLE III-5 LIST OF POTENTIAL PROBLEM AREAS AND POSSIBLE ALTERNATIVES TO ADDRESS UNDESIRABLE VALVE PERFORMANCE (v Potential Problem Areas Possible Alternative o Safety valves and -Associated Piping g. lL. valve blowdown required Re-analyze selected NSSS system I to provide stable valve overpressure transients to.show performance for steam flow that increased valve blowdown is j is not within FSAR/ Tech acceptable fro.T. the standpoint of Spec limits. plant operation considerations. 'l (Note, since all plants are de-l signed;to accommodate losses of j 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 y smaller blowdown. g Relocate valve closer to pressur-izer to allow stable performance to be obtained with reduced blowdown. 4

2. valve chatters with subcooled h" Show that subcooled water condi-i

~ water flow conditions and ' tions can be handled by other i bl wdown cannot be adjusted than safety valve actuation, to provide stable valve e.g., operator action or use of r PORVs. performance Utilize alternative valve which performs in a stable manner with subcooled water, (e.g., Framatore/ Crosby 6M6, or Target . Rock 69C) or utilize an auxiliary j 4 lift device with the existing i l valve. ) l i l 6 i ~ III - 19 v l.

3 . TABLE III-5.(Cant'd). 3 Possible Alternative U' / Potential Problem-Area

3. With cold loop seal arrangement, Provide a. drain at-low point

) valve provides unacceptable per-in loop seal piping back to o

thepressurizer-togrevent formance, e.g.:

water accumulation ( ). pressure oscillations.(water - Provide heaters to increase ]- hammer)-in upstream piping. temperature of loop seal delayed valve opening until watertonearsaturatigp loop seal clears (approximately 650 F). high pressures and loads in Utilize alternative valve -- + discharge piping which provides better performance with loop seal. ~ j Relief Valves Provide a' drain at low point With cold loop seal arrangement, in loop seal piping to prevent valve-closure following discharge . water accumulationtl). is delayed' Provide heaters to increase temperature of loop seal water. (1) Utilize. alternative. valve which is less sensitive-to the thermal transient. ~ 1 setore a decision to drain or heat the loop seals NOTE: (1) is made, careful consideration should be given to the potential for valve seat degradation and result-ing steam / hydrogen leakage. I fI i III - 20 ~ L

.5 j ) TABLE III-6 EPRI PWR S UETY AND REllEF VALVE TEST PROGRAM ~ SAFETY VALVE TEST RESULTS

SUMMARY

(1). - (CRITERIA: 1STA5LE PERFORMANCE /NO CHATTER) l 1 TESTED VALVES INLET FLUID CONDITIONS STEAM LOOP SEAL TRANSITION WATER 650 F 550 F ' 400 F 0 0 0 e DRESSER 31739A YES' N/A (2) YES YES YES YEs (!' !' SHORT INLET LONG INLET _. YES .YES (4) YES YES NO e DRESSER 31709NA YES N/A YES YES YES NO SHORT INLET LONG INLET (3) NO e CROSBY 3K6-YES N/A YES 'YES NO SHORT INLET i LONG INLET YES YES NO a CROSBY SMS YES YES YES YES .NO. LONG INLET e TARGET ROCK 69C YES YES YES YES(6) YES (6) YESl-LONG INLET 4 e CROSBY 6N8 YES N/A, YES YES NO LONG INLET e FRAMATOME/ CROSBY YES YES YES YES YES YES 6M6 LONG INLET summary is for valve performance after reference test ring l NOTES: The settings had been established and does not generally reflect ex- ; j -(1) performance with current in-plant ring settings. pected Indicates the condition is not applicable to the valve / piping (2) combination tested. (3) P.lants which utilized this valve / piping combination have been modified and now have a short inlet. Chatter observed on loop seal portion of test. (4) The valve had a limite'd lift and did not relieve the transient. (5) (6) Observed inlet pressure fluctuations indicated possible } valve flutter. III - 21 .e. v. ,--,.,*,-,-y%~w.m. ,,.-..-..v..-- ,,,,.-mv.-- -.-.m-,,--.,.-e-.--=.-.-.~

e IV.

SUGGESTED FORMAT FOR.-

JULY 1, 1982 PLANT-SPECIFIC SUBMITTAL t.. _ A1 suggested format for the July 1, 1982 plant-specific submittal to.the'NRC is provided in the following. It should be noted that 'the'eubmittal outline is provided only as a_ general guideline for utility consideration ~and it is' recognized that more or less information mayLneed to be included in a particular plant-specific submittal. l. 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 u 'l provide a list of key plant parameters as listed in Table IV-1, including: ll I Safety valve parameters Relief valve parameters Inlet piping parameters Valve actuation transient parameters 'l RESULTS OF PLANT-SPECIFIC PERFORMANCE EVALUATIONS 8 II. 1 A. Safety and Relief Valve Performance This section should discuss the following: 1. Evaluation of pertinent test results and i l identification of condition's which could result in unacceptable valve performance. 2. Identification of modifications selected for implementation to provide acceptable performance. I 1 i M -*1 e------e-- -tm-w-y-%---w w um - m we w e. -w e-es-wy+-sowam.* w w y o w'w wy.g.,,,--ww.y.,,,g,w-, y,ggy, ,,,wm,- 9 y--,,pse,-w+,w,yyw+9ey o. gy,- 9 y- -.9,e-,,,.,9p-g.,u y

~ ~ ~ ~ '~" Revicisn 1 1j w I L.G. : gg

3. -

Inlet and Discharge Piping Adequacy This section should discuss: --.l. Evaluation of stresses and support loads in -inlet and-discharge piping and identification-by 30 of any overstressed piping or overloaded l @' ' ' c. supports. 2. Identification of modifications? required to provide acceptable stresses and loads in piping } l and supports. l III. CONCLUSIONS g IV.~ REFERENCES I This section should include a listing of all references utilized in the evaluations, including: A. Safety and Relief Valve Test Reports } s I B. Valve Selection / Justification Report' C. Plant and Test Condition Justification Reports 1 i D. Discharge Piping Load ModelD eport R i ii V. _ APPENDICES 1 The following appendices should be included: Sum: nary of report by valve manufacturers which justi-A. fies the acceptability of ' valves or the modification (s) ,f selected for implementation. B. Summary of report by NSSS vendor which justifies the acceptability of the existing system or modification (s) selected for implementation. 1i ( IV - 2 i. i -.~.

.j^ -.g. 4~ C. Summary results of calculations of inlet and discharge piping loads.and stress,es. D. Schedule for evaluation and implementation of modifications (if modifications are.-required). I I-4 . e e l l 1 I I-IV - 3

i l

.... -.... - -,.. - -.. -, -.. - - - - - - - - -. -. ~.. -.. ~. - - - - -

mov$dLEoin.5 ~ T, -

-j-t i

l . TABLE IV-1 LIST OF REY PLANT PARAMETERS ~ I safety valve Information 1. l Valve-Parameters -l ) .y . Number of valves I Manufacturer Type size' (inlet, outlet orifice) Rated capacity (steam) i l Inlet Piping Parameters I Diameter }i l Length Type (dry, loop seal /tettperature) 1 Actuation Transient Parameters Fluid range (e.g., saturated steam, saturated I water, subcooled water, etc.) l Maximum back pressure (steam condition) I, i 4 Relief Valve Information I 2. Valve Parameters L Number of valves Manufacturer ~ .. Type l size (inlet, outlet, orifice) Capacity (steam) }! I IV - 4 .I -s 1 -,-,-,.-._.........._.,_._-.~........-.._.-_-,,m

-g ~,, LD3EU3iliRs 1 g.. r

L.

TABLE IV-1 (Cont'd) Inlet Piping Parameters Type (dry, loop, seal / temperature) ~ Actuation Transient Parameters Fluid range (e.g., saturated steam, saturated water, subcooled water, etc.) I Maximum back pressure (steam condition) I' I / 4 e l h 4 k i f I I 1 6P I L i ce 1 3g. IV - 5

c'i l s V. REFERENCES Following is a list of' reports issued by EPRI to document the Also noted results of the safety and relief valve-test _ program. 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. Report - Date Draft Final Submitted to NRC EPRI Report d. 1. Safety and Relief Valve Test 8 3/1/82 4/1/82 4/1/82 Report . f' 2. Valve Selection / Justification Report . 9/81 12/81 4/1/82 Test Condition Justification 3/5/82 4/1/82 4/1/82 } 3. Report ) 4 4. B&W Plant Fluid Condition 10/8/81 3/17/82 4/1/82 Justification Report

5.. CE Plant Fluid Condition 11/18/81 3/10/82-4/1/82 Justification Report 6.

W Plant Fluid Condition Justification Report 10/8/81 1/29/82 4/1/82 7. Application of RELAP5/ MOD 1 l for Calculation of Safety and .) Relief Valve Discharge Elping Hydrodynamic Loads (includes Discharge Piping Data) 3/5/82 4/1/82 4/1/82 8. Marshall Relief Valve 8/81 10/81 N/A Test Report 9. Wyle Phase II Relief 9/81 12/81 N/A Valve Test Report 10. Wyle Phase III Relief 3/9/82 4/1/82 N/A Valve Test Report 6/1/82 7/1/82 N/A 11. CE Safety Valve Test Report These reports contain supplementary i l N/A Not Applicable. ,information. l 1 ~ V f -- a v- -s m +----,c-w---eve.-

-en-oe-m-m---,---we+-.--

e+,s4 w--we ew- = -Tw w eree-,e-w e -ww w ee, m ow-e w w-w -e*ar-a wv w-e-e.g.or**w%+m+ee w ww ew*v ei-wo w r e'we

4 rwmFT-******-e

r.. t i 1 j i. O 9 %D e e G G I I O VI. APPENDICES !~ l 1 i f i I i I, 1 SP I -l i e-em

c Rivicica.1 i 1 I. -l ,. APPENDIX A PROCEDURE FOR CALCULATION OF VALVE BACK PRESSURE l 6 I l ) 1 I I I e I, I l

-- g., e p .~ -i JL A. Purpose The purpose of this appendix _is to provide-a.sug'gented o ~ procedure and_ guidelines for the calculation -of-safety and relief valve backpressure.for-tho' plant.' This backpressure j . is to be compared with the test backpressure as discussed in l ) 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 REIAP or i 'l similar method be utilized. In this regard, EPRI i has funded / developed a steady-flow hydraulic code specifically for determining valve backpressures. Further information regarding this code can be i obtained from EPRI. It is suggested that back pressure calculations be performed ) i assuming simultaneous actuation of either all safety valves l o_r,all relief valves on steam. Also,.use the maximum r valve flow rates as determined by the valve manufacturer. E l I i I* i ,+,-w-n--,.em.,,,,----e-w-r--,a,,, ,w-we,,-o,,,---w+,-mn ,,--,,,-.-mww eo,,,--w -mw_,mwo,-me-,w-e,n-m,v-gwwwwm,wm,,,,,+,,, un m w w-e- wow--

sf :.** Thacomputh:dctccmbackproccuroacrotobeocmparcotothoco i ' developed during EPRI steam tests to assess applicability, i EPRI liquid testing was performed with the same disch'arge piping backpressure orifice as was utilized during a specified steam test. The backpressures developed during -the liquid' tests correspond to those expecte'd in a plant having the same " steam" backpressure as was developed during the specified' steam test. Therefore, if the steam j backpressure developed exeseds the expected in-plant steam backpressure, the' corresponding liquid backpressures.de-veloped'will exceed those expected in the plant under similar conditions. 1 l 1 ) l I. i 8 D ~ ~ l A-2 9 =, e -..r.. ---m- ,,--,--,--...,,,...-,----,----,-.~e--.- -.-,,..,~,-ww..e -.e.-,

a I~ -- Revici+2n 1 . 4- .s :. .I .~ i s e 8 e e, e e D T d ' APPENDIX B PROCEDURE FOR CALCULATION-OF' I INLET PIPING PRESSURE EFFECTS !I E 0 \\ y T = J 4 e i i j m ? t a l p e 9 y-.-,

y g

v.---gwte- +-,---eyw yve-%*-T --e-w g-gey,g--g,y-gg e.9-F-e g eg g ry-pq.-g---gmh wn-pea ywrye-ve-rg-d -wg,99-%p-w+,wp % w-- - g,-v ey - w e e-ge-v-y-r

^ ,j { 4 O .\\ A. Purpose Th'e purpose of this appendix is to provide a procedure for ~ determining the inlet piping pressure drop associated with i spring-loaded safety valve opening for the plant safety valve i installation. This plant pressure drop is to be compared l with the test pressure drop as discussed in Appendix D. B. 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. 1.

Inlet Piping Flow Pressure Drop ( APF.)

The flow pressure drop is given by, I 3 4 L (k+1+fL)g2 't i 7 l 3p F 2 2geoA t

where, expansion or contraction loss coefficient.

k = (dimensionless) friction factor (see Reference 1) (dimension 4 f = ~ piping equivalent length / diameter considering effects of fittings and friction (see Reference. L 5 for pertinent data) (dimensionless) maximum valve flow rate for steam (as established -A by the safety valve manufacturer) (1b/sec) = 2 gravitational constant (32.2 lb-ft/lb-sec ) 9c i al valve set pressure

(1b/ftgensityatnomn steam l

A = ) 2 ' inlet piping flow area (ft ) A = I ..,---.,-,--..4_-,.._----.-.__._-.,..m.m--..-__-.~,-...-.-----...-.--,_,._--------._-_-..,-4--

~ q , 9... 4.. 3. $fi AJ 1 2.

Acoustic ' Wave Amplitude- (AP w)

A .The acoustic wave amplitude'is. calculated based on-I, ' nformation in Reference 2..There are two situations. i l-to considers: - If T,,< 2-L/a, '= aM AP g IcA - If T,p >2L/a,. AP = gcA T,p AW

where, a = steam sonic velocity at nominal valve set cv'

~ . pressure (ft/sec). L = inlet piping length (ft) = valve opening time for steam inlet conditions ToP as established from the EPRI testing effort is 10msee for the Crosby safety valves and 15msee for the Dresser safety valves. The other variables are the. same as defined in the previous section. 3. Plant-Specific Pressure Drop The plant-specific pressure drop associated with valve ,l opening is equal to the sum of the friction pressure' drop (AP ) and the acoustic wave amplitude (APgy) as dete M ned F For certain. test valves, valve reopening and/or above. chatter was observed on valve closure. For similar valve / installations, the pressure rise associated with j valve closure may have to be evaluated. C. ' References j ) Flow of Fluids through Valves, Fittings and Pipe, 1. Crane Co., Technical Paper No. 410, 1981. 2. Waterhammer Analysis, John Parmakian, Dover Publications,.Inc., 1963. 3 <,.( k sl-B-2 b$.. l.-.. -__ _._.._; _ ______

!~! . y :. ; -['l D. Sample-Problem t- 'Following is a sample calculation of plant-specific pres- .I sure drop:for an' assumed safety' valve / inlet piping' -l co,nfiguration. 1. ' Flow Pressure Drop An isometric of the assumed inlet piping configuration is provided in Figure B-1. The flow pressure drop is lll I' given by,. (k+1+fL)A2 l. g I APy 2 = 2ge A o

where, 0.5(1)* (sudden contraction at pressurizer k.

= nozzle) III .016 f = + 6 x 30(1) + 2 x 16(1) = 289.8 h = 3 (2) (saturated steam at 2500 psia) 7.65 lb/ft o = 0.147 ft2 l A- = 345,000 lb/hr 95.8 lb/sec A = = 3600 sec/hr g .I The flow pressure-drop is, 2 (0.5 + 1 +.016 x 289.8) x 95.8 3p 2 i 64.4 x 7.65 x.147 x 144 36 Psi APy = i

Numbers in parentheses denote references listed at the end of this sample problem.

B-3 \\ ...-............,.-..---~a:.--.-....-....-. .. - - - -. -. - ~.

l Revioitn l " ~ ~ ~ ic e ? *- a ~ 7'10" '10" SAFETY VALVE - 2'1" 6'10" PRESSURIZER -NOZZLE 2'3" 4,2" 3'7" PRESEURIZER - TOTAL' PIPE LENGTH = 33'7" l - PIPE DIAMETER = 6" SCH. 160 (5.189" INSIDE DIAM.) - FITTINGS 6, 90' ELBOWS' 2,.45' ELBOWS -CROSBY 4M16 SAFETY VALVE

345,000 lb/hr RATED CAPACITY

'.010 SEC OPENING TIME i. e [ SAFETY VALVE INLET PIPING CONFIGURATION FIGURE B-1 M-4 . i= .. ~ m-. -,m..,,,v.--w.-%,..,,4.y --,e,e ,,,,-,_.,yv .,,.y,-,.y,, ,,,,,,,,,,re.#,.m,

-W .R;vicica 1 I .' ~ 1l 2. Acoustic wave Amplitude 'l For 'the configuration in Figure B-1, the parameters ~

_.. are, TP

.010.see = o ^ 2,k 2 x 33.6 ft =.052 sec -1300 ft/sec(33 sinceT,p<h, $A 1300 x 95.8 3 PAW, 32.2 x.147 x 144 .q I APAW " 183 Psi 3. Plant-Specific Pressure Drop The plant-specific inlet piping pressure drop is t given by, AP = APy + AP w A l 36 + 183 = 219 psi AP = t 4. 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 i Flow and Sonic velocity," ASME 68-WA/HT-8. + f t l. B-5 I a ,._,,,,.._--._..,,,,,--m-,,..w ,,.,,,.-,._,,,,,-,--..-.2 .,_im..,... _.w,,_..,, _. - _.m..., ,..,, ~., _,'

-o. . p. W. t' . E.. Test valvn/Inlot Pip 7 Configurntien Inint Piping-7 Pressure' Drop 4 i Following-are Tables B.1~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 3.1.1.a through 3.6.1.a of Reference 1 (see Sec-tion V) with the addition of the calculated transient pressure drop for each test inlet pipe configuration. Thz transient pressure drops listed in each table are the, n 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-l times were established based on the opening times measured The in the EPRI/PWR Safety and Relief Valve Test Program. J for all test data indicated that an opening time of 15mm,

l of the Dresser safety valves tested and an opening time of I

for all of the Crosby safety valves tested were typi-i 10ms 3 l cal of the fastest opening times measured. e \\ ~ 1 1 B-6 I 2 ----. - -+ -v-.--5-+-..w,-, -,--.-.-,,,,-...~me+-.--._-,--.,.**-.-w,%.,.e#. .r--,.w-e4o-~w-, -... .,,-,-,.w. ,,w .- w n.,--*%.,,,,e y. -.e,

l I Since the test valves were colceted'to rcyrocGnt oil l-participating PWR plant safety valve' designs and the data indicated opening times which were cons'istent-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. i 4 ^* l 4 e T e i I e e a B-7 l

l EPRI/CC SAFETY VALVE TEST PROGRAM r TABLE 8.1 }. l l SAFETY VALVE DEStRIPTION ANO INLET PIPING C0HFIGURATION DRl:SSER 31739A SAFETY VALVE i i. i Valve Description Inlet Piping Configuration "D" l Length, in. 't.D.. in. I Manufacturer Dresser Industries Nozzle 17 6.813 j l Type Spring Loaded Safety Valve Model No. 31739 A Venturi 38 6.813' i l Serial No. BN-04372 j Drawing No. 4CP-2432 Rev. 9 Pipe 11 6.813 l-Body Size (inlet / outlet) 2% in./ fi in. Reducer 6 6.813/3.152 Bore Area 2.545 in.2 i Orifice Designation 3 Loop Seal i Straight 60 - 3.152' w Design Set Point Pressure 2500 psig 8 ends 4-g68 6 in radius-Design Blowdoun 5 percent Reducer 4-3.152/2.125 en Rated Flow 297845 lb/hr. Rated Lift 0.45 in. ' Inlet Flange 6-2.125 l Internals Type: Not applicable Transient Pressure Drop (1) 454 psi Inlet Piping Configuration "C" Ring Setting Reference Position: The ring setting positions refer to the number of Length,in. 1.D.. in. notches relative to the following surfaces;

gorgi, 17 6.813 Upper Ring - top holes in the guide

',6.813 Middle Ring-seat plane Venturi 38 Lower Ring - seat plane ~ 3

pgp, 11 6.813 10 6.813/2.125 This is the calculated transient upstream Reducer l

(1)' pressure drop associated with valve i-1 opening for this valve / inlet pipin9 Pipe Not applicable configuration. The pressure drop was j calculated based on an opening time of Inlet Flange 6 2.125 15 usec. [ Transient Pressure Drop (1) 54 psi

EPRl/CE SAFETY VALVE TEST PROGRAM TA8LE 8.2 37 i iAFETY VALVE DES (RIPTION 4ND INLET PIPING CONFIGURATION DRESSER 31709NA 4 - "A"

~

Inlet Piping Configuration. Valve Description. Length,in. ! I.0.. in. Nozzle 17 6.813-l Manufacturer Dresser Industries l Type . Spring Loaded Safety Valve Venturi 38 6.813 Model No. 31709A 6 6.813 Serial No. 8Q07681 Pipe Drawing No. 4CP-2332 Rev 11 Redher '6 6.813/4.897 SodySize(inlet / outlet)' 6 in./ 8 in. I Bore Area 4.34 in.2 Loop Seal 48 4.897 Orifice Designation N Straight 2 8 ends 1808 ~9" radius Bends 2500 psig 8 Design Set Point Pressure not app 11 cable t Reducer _ ercent l Design Slowdown 5 p Rated Flow 5079181b/hr. Rated Lift 0.588 in. " Inlet Flange 11 4.897' TransientPressureDrop(1)NOTAVAILABLE not applicable f. Internals Type: Inlet Piping Configuration "8" Length,in. I.O. in. Ring Setting Reference Position: l II 0 8I3 The ring setting positions refer to the pus 6er of Nozzle I notches relative to the following surfaces; - 38 6.813 l Upper Ring - top holes in the guide Venturi l Middle Ring-seat plane l Lower Rinq - seat plane pipe 6 6.813 l 6*813/4*897i l (1) This is the calculated transient upstream Reducer 6 pressure drop associated with valve opening for this valve / inlet piping configuration.' pjPe e t applicable i l The pressure drop was calculated based on l an opening time of 15 msec. Inlet Flange 11 '4.897 Transient Pressure Drop (1) 88 (wat ~~~ l ~

. _ r..Q --.c j EPRI/CE SAFETY VALVE TEST PROGRAM TABLE 8.3 .;. ?, 2 i !AFETY VALVE DESC11PTION AND INLET PIPING CONFIGURATION. i FOR THE CROSitY H8-8P-86 3K6 (STEAM INTERNALS) ) Valve Description inlet Piping Configuration "F" j Length. in. .I.D.,in.. Manufacturer Crosby Valve and Gage Nozzle 17 6.813 i Type Spring Loaded Safety Model No. HB-8P-86 3K6 Venturi 38 '6.813 Serial No. None Drawing No. SK-3658-V Pipe 6 6.813 I i L SodySize(inlet / outlet) 3 in./ 6-in. Reducer 6 6.813 Bore Area 1.841 in.2 Orifice Designation K' loop Seal 4 Straight 54 3.152 ^ w Design Set Point Pressure 2485 psig Bends 4-g08 6 inches redius. [ g Design Blowdown 5 percent Reducer, 4 3.152/2.624 f i Rated Flou 212.182 lb/hr. Rated Lift 0.382 in. Inlet Flange 7 2.624 I internals Type: Steam . Transient Pressure Drop (1)~ 321 est Inlet Piping Configuration "E" Ring Setting Reference Position: ength.'in. I.D.. in. f The ring setting position refers to the number of l notches relative to the bottom of the ring disc. porzie 17 6.813 (1) This is the calculated transient unstrean Venturi 38 6 813-pressure drop associated with valve opening a l for this valve / inlet piping configuration. Pipe 6 6.813 l The pressure drop was calculated based on i an opening time of 10 msec. Reducer 10 ,6.813/2.624 l 4 2.624 Pipe i 7 2.624 Inlet Flange Transient Pressure Drop (1)- 56 ost

EPRl/CE SAFETY V'ALVE TEST PROGRAM TABLE B.4 SAFETT VALVE DEiCRIPT10tl AHO INLET PIPING CONFIGURATION C I - FORTHECROS8YHB-BP-863X6(LOOP'SEALINTERtlALS)' I Valve Description Inlet Piping Configuration' 'T" Length. in. c ~I.O.. in. i i i i-Manufacturer Crosby Valve and Gage Nozzle-17. 6.813 l Type Spring Loaded Safety Model No. HB-BP-86 3K6 Venturi 38 6.813 Serial No. None 6.813' Drawing No. .SK-3658-V Pipe 6: j Body Size (inlet / outlet) 3 in./ 6 in. Reducer 6 6.813/3.152 Bore Area 1.841 in.2 K Loop Seal y Orifice Designation Straight 54 3.152 j -Design Set Point Pressure 24ss psig Bends 4-908 6 inches redius-l ~ Design Blowdoun 5 percent Reducer 4 3.152/2.624 ) l U 0.382 in. Inlet Flange 7 2.624 Rated Flow. 212.182 1b/hr. Rated Lift Transient Pressure Drop (1) ~ 321 psi ~ Internals Type: Loop Seal Inlet Piping Configuration "E" Ring Setting Reference Position: Length,in. I.0,. in. The reported measurements are relative to 17 '6.813 the bottom of the disc ring. Nozzle 38 6.813 i l (1) This is the calculated transient upstream Venturi pressure drop associated with valve opening 6' .6.813 Thepressuredropwascalculated$ ration. for this valve / inlet piping confi Pipe l sed on 10 6.813/2.624 Reducer 4 2.624 pipe 7 2.624 Inlet Flange Transient Pressure Drup (1) 56 pst u } ~~~ ^ ~

~ ~ ~ ~~ EPRI/CE SAFLTY VALVE TEST Pfl0 GRAM TABLE 8.5 SAFETY VALVE DESCRIPTION AND IIR.ET PIPlflG CONFIGlitATION ) FOR THE CROS8Y HB-BP-86 6:15 (LOOP SEAL INTERNALS) i 1 Valve Description inlet Piping Configuration "Ga .I.D.,in. Length,in. 2 ?

F -

Manufacturer Crosby Valve and Cage Company Hozzle 17 6.813 I \\ I.. Type Spring Loaded Safety Valve Model No. HB-BP-86 6M6 Venturi 38 6.813 i Serial No. 1156964-00-0006 Drawing No. Crosby DS-C-56964 Rev. C Pipe 13 6.813 g U [ Body Size (inlet / outlet) 6 in./ 6 in. Aeducer 6 6.813/4.897-l Bore Area 3.644 in.2 i j Orifice Designation M Loop Seal Straight. 48 4.897 l Bends 2-1808 9 in. radius l Design Set Point Pressure _ 2485 psig 5 percent l Design Blowdown _ lb/hr. Rated lift 0.538 in. Rated Flow 420.006 \\ Internals Type: Loop Seal ht Weble i Ring Setting Reference Position Inlet Flange 10 4.897 The ring setting position refers to the number of notches relativefo the bottom of the disc ring. Transient Pressure Drop (1) 251 est i (1) This is the calculated transient upstream pressure drop associated with va 1.sinlet ninina confiouration. t l =

^ 'i EPRI/CE SAFETY VALVE TEST PROGRM TABLE 5.6 }. SAIITY VALVE DESCRIPTION AND INLET PIPING CONFIGURATION FOR THE CR058Y N8-RP-86 6N8 (STEAMINTERNALS) i Inlet Piping Configuration "H" Valve' Description Length,in. 1.D.. in. l ) Manufacturer Crosby Valve and Gage Company l Type Spring Loaded Safety Valire Norrie 17 6.813 Model No. HB-BP-86 6N8 Serial No. N61894-00-0006 Venturi Not Applicable ~ i Drawing No. , Crosby DSC-61894 Rev. D Pipe 3 6.813 4 i Body Size (4.381 inlet / outlet)6 in./ 8 in. i Bore Area in.2 Reducer 6 6.813/5.189 l-Orifice Designation N ~ Pipe 76 5.189 } Design Set Point Pressure was psig O Inlet Flange 7

5.189 Design 81owdown 5

sercent I u l Rated Flow 504,952 lb/hr. Rated lift a son in. 1 l Internals Type: Steam Transient Pressure Drop (1) 270 psi i l Rine Setting Reference Position: y The ring setting position refers to the number of notchet relative to the bottom of the disc ring. 3 (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 10 usec. 9 9 i 1

7t; levioita 1 ' 5-Q.. .? 1 G + ,1-O d b '9 I e = APPENDIX C PROCEDURE FOR VERIFICATION OF ALTERNATIVE METHODS TO BE USED IN [- EVALUATION OF PIPING / SUPPORT ADEQUACY I i. I I I i I l i9 i t .) 6e i t 4 WD + l t 9 99

LDFtDJEITB p [ ', - i u I, As discussed in Section II of this guide, the utility may elect-q,. to use kn alternative method to perform the evaluation of In thi's event, it is recommended that piping / support adequacy. 'the adeg'uacy of the alternative method be verified by comparis,on 4 with the EPRI test data provided in Reference 7. (see Section V). hs ,This can be accomplished by one of the following approac e : By direct comparison between the analytical method pre-dictione 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 (RELAP5). 1 ,h l l a e e i 9 t [' t

'Ve 'm; mov'icion 1 i - . e a e e e O APPENDIX D PROCEDURE FOR ASSESSMENT OF APPLICABILITY OF SPECIFIC EPRI SAFETY VALVE TESTS I i r 1 I 9

9 b

$ P I 4 o -,-._.,,-..,_-,-.--,__...--,._-,-.--,..._....w,, ,--,n,.-- n-

4 f7 Revicita 1 'l 1 l, A. Purpose The purpose of this appendix is to provide a procedure ' for use by the valve manufacturers (or utilities) in assessing 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 represen-tative valve / piping configurations tested by EPRI closely matches the plant installation. It is expected this approach will be useful for virtually all the i plant evaluations. l i } B. Discussion i l l The results of the EPRI safety valve tests indicate that there are a number of key parameters which effec-l tively control the response of the safety valves. I These parameters are Valve ring settings (for spring-loaded safety valves only) Discharge piping backpressure s - Inlet piping pressure effects associated with valve opening (for spring-loaded safety valves only) ,-,-.,,----,n--,-nn-,n-,---n-,--n-,,,-w,m,---n,-,.- ,w..,.,_,-.,--n,-n-en_

~ _v a . Revicitn~1 -? l i e-Inlet fluid. conditions (e.g., saturated steam, 1 saturat'ed water, subcooled water). A suggested procedure for assessing the applicability of specific EPRI tests to various plant installations is provided in Table D-1. This procedure involves f 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 I the plant. C. Sample Evaluation Table D-2 provides'the results of a sample test appli-cability assessment for a Dresser safety valve, Model f 31759A using test data for Dresser safety valve Models 31739A and 31709NA. This case'is the more complex of i 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 1 of the valve. 1 D-2 i ee rv -, e--- ,r, ..+-,,e-#_.,,e--r*. -..-wm-www,*->+,ww.e~. w . % - we.e v m-. .,v-em_ .w.

q eqi F q$f t-c4 d ', i, A*- i j;- - movicion 1. 9 t The results of the sample evaluation'are discussed in " the followings. + Test 1 ---The test is directly applicable-because o-the valve ring, settings, plant backpressure, inlet piping pressure and fluid condition requirements specified in Table D-1 are satisfied. g;i t,f- >lI. I Test 2 -- The test is directly applicable because o the valve ring settings, plant backpressure, inlet piping pressure and fluid condition requirements specified in Table D-1 are satisfied. l, Test 3 -- This test is not directly applicable o I because the plant backpressure is greater than l the test backpressure. Test 4 -- This test is not directly applicable o because the plant inlet piping pressure drop is I greater than the test inlet piping pressure drop. l '4 9 + O l i l D-3 i

0; Revicirn 1 N . ff- -t f: Test-5 -- This test-is not directly applicable because thepla$t'valveringsettingsdonotcorrespondtothose ff.~ specified by the' valve manufacturer to provide similar

m performance to the test valve.

d n ,A .l Ebb. Test 1 - This test is directly acclicable because the valve ring settings, plant backpressure, inlet piping pressure and fluid ~ condition requirements speci-o .s 4':'. fied in. Table.D-1 are satisfied,- In this sample assessment, the Dresser Model 31759A safety valve is determined to provide acceptable r NA performance for steam inlet conditions (at a plant backpressure of 400 psia and an inlet piping pressure drop of 150 psi), and unacceptable performance for 550*F water inlet conditions. Based on the six tests 4 p, @E l listed in Table D-2, no direct indication can be m k obtained of the safety valve performance for the 650*F j t and 450*F water inlet conditions. However, from a A ! 3 'in 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 i unacceptable for 450*F water. l O M i l , i 's D-4 1 s, x, 3.i {; m -._____.-..,_,_,,,,._,.m.

.( -' R;vici:n 1 TABLE D-1 PROCEDURE FOR ASSESSMENT OF' APPLICABILITY OF SPECIFIC EPRI TESTS - STEP A -- VALVE RING SETTINGS .NorvalvesTestedintheEPRIPrograms 1. Are the ring settings for the plant valve'the same-as for the tested valve? 2. If the answer to the above question is yes, proceed to step 3. If the answer to the above question is no, the 3. test is net directly applicable to the plant evaluation. For Vsives not Tested in the EPRI Programr i 1. -Is the ' plant valve represented by a test valve per Reference 2 (see section V)? I 3 2. Do the ring settings for the plant valve correspond to'those specified by the valve manufacturer to obtain similar performance as i observed for the test valve? L 3. If the answers to Questions 1 and 2 are both yes, proceed to Step B. [.. 4. If the answer to either Question 1 or 2 is no, the I test is not directly applicable to the plant } ~ 1 evaluation. i i / \\ l l 1 l l f D-5 'i ( t ._.2,___-.._.____..__. J

MM .C & jr. -\\ 7 4 wh y t /- 1 u n e, y i ! TABLE D-1 Cont'd p - STEP B -- DISCRARGE PIPING BACKPRESSURE . (See Appendix A for the procedure for calculating plant backpressure) 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. ll 3. If the answer to'the above question is no, the test is ~ not directly applicable to the plant evaluation. (How-

I 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.)

i l O . e - l i D-6

we---

.-s-.w-ee-,---.---,,,ng m-m,,,, ,--g,w,m.wan a s - m e -ww r w-- w .. w wwwmv w.wn, m, p, w n_, m w ww mw m e m-o,-o --o-

y N l Revicien l' .- ^ ' 1 l, ' TABLE D-1 (Cont'd) STEP C -- INLET PIPING PRESSURE EFFECTS * ~ (See Appendix B for the procedure of _a-calculating plant inlet piping pressure effects) 1. -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.) s li - 2. If the answer to the above question is yes, proceed to Step D. I 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 . a 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 i 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. 4 i e l i 1 1 r D-7 m m-m- - - w,-,+-.---E.----,<% ,-e-w-m..--..<,r, ,-w w w,,-,-ee.,. _..,__ew,-mm-ye--,.-,w--.., ,% -,,w cw r-m y

I;.-- Revision 1 i TABLE D-1 (Cont'd) ~ - STEP D -- INLFT FLUID CONDITION ~ .1. Is the inlet fluid condition for t e p ant (see list in h l Table II-1 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. 4 t OO e 6 D=8

i E 5 i E c j E e =g 3 R g' E' 8 w M m m ~ w E. . =5 =, g = I Ud 5' N E WE m e g g g E 3 eg a N A Em W 5 g 5 27 E E Egf em

a" m

8 C. E W EW5 N o g 4-g 5 a .m= o er g, eng o 2 8 % m 55 tua = y a e s R R E R 8 m:..- E-s-swg y W m

== Wg <R* g

+

el-[al = E C = E" s' m.E 3 v E s s. [ g 9' s :- =N 5 m W m g. = = gg WE, s .x mm wd c~ ={ =M* p W M' R S g g ~ E~ g h 9 g5 S$5 W M 2 m W: sgs W E9 m 2" gBy=$ ~b~ B .T E =M8 s iudC "E Esa 1 N QR %e "W$) a a Em Na Nsg e om v mv _E$ Wl E ~ g U, e ~ "Y D e C )W N e c -g g "e 5 s-rg 8 m s .g 8 um gWW g g ma w wg a E. - a g5 =s 9e

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Revidion 1 3

- h O .xl. ll/ l APPENDIX E LOAD COMBINATIONS AND ACCEPTANCE CRITERIA FOR THE SAFETY AND RELIEF VALVE PIPING EVALUATION I i 1 4 ~ l i j l O e 9P 'I k '-~ '- - - ~ - + - - -,,,, _ _,., _ _ _ _ _ _ _

Revidica 1-p e. n A. purpose ~. Tho purpoco cf thic typendix 10 to pr;vida cuggact d leco-l combinations and acceptance criteria for the pressurizer-safety and relief valve piping system. Du ing the course of the EPRI valve program, an ad hoc group , as established to help insure analysis consistency regarding w discharge piping. The recomunended load combinations and acceptance criteria provided in the following section were developed by this group and are being supplied to you for your consideration. 4 3. Discussion The recommended load combinations and acceptance criteria for the pressurizer safety and relief valve piping system j and supports are shown in Tables 1, 2A and 25. Tables 2A and 23 are for the discharge, or downstream, piping and supports. Table 2A applies to the portion for i which seismic requirements apply. There are two possible i 8 approaches to this requirement. The entire downstream l 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 I downstream anchor, or enough supports and piping to i effectively isolate the seismic and non-seismic portions), then Table 2A would apply for that portion, - I I while Table 23 would apply to the rest of the downstream I system. l' l -..,--,,,,_...,w...- y,--www--_-_y, _---_.,m.- _..~---.. _ _ -,-----

8 p I For the seismically designed downstream piping and supports, i less restrictive allowables are suggested. Since satisfac-J 1 tion of allowable valve loading is part of the-acceptance criteria, this would appear to be acceptable. 4 . F$r the non-seismically designed portion of the downstream piping, it is recommended that the pipe support system be ) seismically designed to assure overalli structural integrity of the system. It is suggested that Service 1,evel D limits be applied for all pipe support load combinations contain-ing OBE or SSE. ) s 1 i .j ) j l r I l l r, i { l I E-2 !i I e -,.-,-vs.. vy--- --m,-.-.-gy-e,w.,,~y- ,,re_-.- ..,wm,----,.---- 4 e p--

e l TnnLE 1 LOhD COMBINATION:1 AMD ACCEPTANCE CRITERIA POR FRESSURIEER SUPPORTS - CLASS 1 PORTION AND RELIEF VALVE PIPING A!K) i, l Service Stress ! ~ ) Limit Plant / System Load Combination _ operating condition _ Combination _ A N Normal j 1 I N + OBE + SOTU 2 Upset l C N + SOT Emergency E 3 D M + MS/FWPB or DBP8 4-Faulted + SSE + SOTy f 4 D g N + LOCA + SSE + SOTy Faulted 5 i 1-3. Plants without an FSAR may use the proposed criteria co l ith , MOTES: 1.) they may the appropriate system operating transient definitions in Table.3r or i ~ use the proposed criteria contained in Tables 1-3. l l See Table 3 for Sor definitions and other load abbreviations. 2.) i ifi-The bounding number of valves (and discharge sequence if setpoints f 3.) l cantly dif ferent) verification of functional capability is not required, but allowable loeds 3 should be used. j and accelerations for the safety-relief valves must be met. I 4.) l l g Use SRSS for combining dynamic load responses. t 5.) ( 8 E ~ ~~ ~ oeme

.t TABLE 2A LOAD COMBINATIONS AND ACCEPTANCb CRITERIA FOR PRESSURIZE AND RELIEF VALVE PIPING AND SUPPORTS - SEISMICALLY DESIG i Service Stress Limit Plant / System Load combination Combination _ Operating Condition A N Normal 1 B N + SMg Upset i 2 C N + OBE + SMg Upset f 3 U N + 'SM E Emergency 4 D N + NS/FWPB or DBPB Faulted + SSE + SMp 5 D i N + LOCA + SSE + SMy Faulted 6 1-3. plants without an FSAR r.ay Ese the proposed criteria contained in Tables i ith Plants with an FSAR may use their original design basis in h NOTES: 1.) h 1 use the proposed criteria contained in Tables 1-3. i This table is applicable to the scismically designed portion of dow 2.) ble valve Category I pipingthe non-seismically designed piping response, and to assure accepta I loading on the discharge nozzle. i See Table 3 for SOT definitions and other load abbreviations. 3.) i ificantly [ The bounding number of valves (and discharge sequence if setpo l 4.) different) verification of functional ca;. '?ility is not required, but allowable loads and l-be used. accelerations for the safety /7. lief valves must be met. I 5.) l I-Use SRSS for. combining dynamic. load responses. i 6.)

BevioN ~ !, 5~ l-TABLE 2a LOAD _ COMBINATIONS AND ACCEPTANCE CRITER I ' SAFETY AND RELIEF VALVE PIPING AND SUPPORTS - l NON-SEISMICALLY DESIGNED DOWNSTREAM PORTION _ PIPING Service Limit __ Plant / System Load Combination Operating Condition A combination N Normal B 1 N + SOTg 2 Upset N + SOTE Emergency D 3 N + SOTy Faulted 4 SUPPORTS Service Limit _ Plant / System Load Combination Operating Condition A Combination N Normal ? 1 N + SOTg C Upset N + OBE + SOTy 2 Upset C 3 N + SOTg D Emergency 4 N + MS/FWPB er Faulted DBPB + SSE + SOTF 5 D N + LOCA + SSE Faulted 6 + SOT i y I Plants without an FSAR may use the proposed criteria c Plants with an FSAR may use their I NOTES: 1.) i original design basis in conjunction with the appropr tained in Tables 1-3. h system operating transient definitions in Table 3; or may use the proposed criteria contained in Tables a Pipe supports for the non-seismically designed dow i piping should be designed for seismic load combina 2.) to assure overall structural integrity of the system. f The bounding number of valves (and discharge sequ licable setpoints are significantly different) for t 3.) be 1 i d Verification of fE:ntional capability is not requ re, but allowable loses and accelerations for the safet 4.) relief valves must' be met. Use SRSS for combining dynamic load responses. 5.) l e ,-u-+ ,,,--,,r.,-..,v.w..,,--~w.

e

q q

g i TABLE 3 e 1 DEFINITIONS OF LOAD' ABBREVIATIONS N = Sustained I, cads During Normal Plant Operation SOT = System Operating Transient III SOT = Relief Valve Discharge Transient y l = Safety Valve Discharge Transient (1) SOTE 50T = Max (SOTg SOTg): or Transition Flow F OBE = Operating Basis Earthquake SSE = Safe Shutdown Earthquake f MS/FWPB = Main Steam or Feedwater Pipe. Break DBPB = Design Basis Pipe Break LOCA = Less of Coolant Accident 1 May also include transition flow, if determined that (1) required operating procedures could lead to this con-dition. I (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). t l 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 ,l appropriate system operating transient definitions in l l Table 3r or they may use the proposed criteria con-tained in Tables 1-3. t I 1 i ,,,.,.,,as ,.g- ,.,,,m p,,.g_,,.-_- n., -,L,.n.w -}}

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