ML20087N853
| ML20087N853 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/16/1984 |
| From: | BECHTEL GROUP, INC. |
| To: | |
| Shared Package | |
| ML20087N849 | List: |
| References | |
| 176567, P-274-1, NUDOCS 8404050088 | |
| Download: ML20087N853 (31) | |
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- 3ygggy EVALUATION OF DRYWELL INSULATION DEBRIS EFFECTS ON ECCS PUMP PERFORMANCE a
J Limerick Generating Station Units 1 & 2 Philadelphia Electric Company b. ? l l L 1 r Bechtel Power Corporation i. H San Francisco, California Revision: 4 8404050000-840402 P-274/1(pl) PDRADOCK05000g Date: 3/2/84 E' 3/16/84
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TABLE OF CONTENTS Page No. 1
1.0 INTRODUCTION
1 2.0~ BACKGROUND 2 3.0 -METHOD OF ASSESSING DEBRIS HAZARD 3.l' Assumptions Used to Determine Maximun 2 LOCA Debris Generation 4 3.2 ' Amount of Debris Generated
~ 3. 3 Insulation Debris Transport-to the 6
Suppression Pool
.Short Tern Transport 6 3.3.1 7
3.3.2 Long Tern Transport
-3.4' 'ECCS Suction Strainer Blockage Due to Insulation Debris Carryover Into 11 Suppression Pool 3.5 Effect of Suction Strainer Blockage on ECCS Pump NPSH 13 14
4.0 REFERENCES
LIST OF TABLES Table-3.1- Summary of Insulation Debris Trans- 15
. port Into the Suppression' Pool Table 3.2 Summary of Calculated ECCS Strainer Head Losses - Due to Fibrous Debris 16 Blockage and Effect on ECCS Pump NPSHA.
P-274/1(p2) 3/2/84 1
LIST OF FIGURES Figure 2-1 Secondary Coniainment Boundary Outline, Plan at Elev. 217 Feet, Re v . O, marked-up copy of Fig. 6.2-29, Limerick FSAR, Vol. 7. f-Figure 2-2 Secondary Containment Boundary Outline, North-South Section View, Rev. O, marked-up copy of Fig. E 6.2-34, Limerick FSAR, Vol. 7. Figure 2-3 Downconer Design Details , Re v . O, marked-up copy l
' of Fig. 6.2-1, Limerick FSAR, Vol. 7.
Figure 2-4 Suppression Pool Suction Strainers, Rev. 4, marked-7. t up copy of Fig. 6.2-51, Limerick FSAR, Vol. Figure 3-1 Main Steam Line Break, Rev. 4 (4 sheets)
- Figure 3-2 Recirc.Line break, Rev. 4 (4 sheets)
Figure 3-3 Flow Zone of Influence Around Downcomer Rin, Rev. O I r P E 5 h, P-274/l(p3) 3/2/84 [ - _ _ - _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
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1.0 INTRODUCTION
1.1 Purpose
There is a concern that a high energy pipe break with-in the primary containment might create insulation
~ debris that would build-up on the Emergency Core Cool-ing Systems (ECCS) pump suction strainers, impairing operation of these pumps. Such debris considerations g-are part of Unresolved Safety Issue A-43; " Containment
- Emergency Sump Performance," Reference 4.1.
In response to this concern, an evaluation was made to estimate the maximum quantity of insulation debris that might be generated by a LOCA, the amount of such debris that might enter the suppression pool and cover the ECCS strainers, the attendant pressure losses and retulting effect on the ECCS pump NPSH margins. In Section 6.2.2.2 of Reference 4.4, it is concluded j that small pieces of fiberglas insulation are the only type of drywell insulation debris that might enter the supression pool and coat the ECCS strainers. Therefore, only shredded fiberglas insulation debris is considered in this evaluation. 1.2 Summary of Results: It has been determined that fibrous insulation debris generated by a LOCA jet impinging on nearby insula-tion will not jeopardize ECCS pump operation at Lime-rick Units 1 & 2. This conclusion is based on the theoretically worst case where 100% of the fibrous insulation debris generated by the LOCA inside the [ drywell is arbitrarily assumed to migrate ontoThe head the ECCS strainers in the suppression pool. loss due to maximum theoretical debris blockage con-current with minimum NPSH conditions, does not cause the available NPSH to drop below that required by the i ECCS pumps. Using more realistic considerations, it has been determined that other transport mechanisms will significantly reduce the actual amount of fibrous insulation debris that could migrate to the suppression 3~- pool and cover the ECCS pump strainers.
2.0 BACKGROUND
2.1 Limerick Units 1 & 2 are 1,100 MWe, BWR's with Mark II containments. 3/2/84
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2.2 The ECCS pumps take suction from the suppression pool water inventory, which is located below the
,~
'drywell. floor. Water released into the drywell from a LOCA first accumulates on the drywell floor.
As-the level of the drywell floor pool rises, the
~
liquid eventually enters the suppression pool by overflowing into downcomers that extend 18" above - the drywell floor. Limerick has 87, 24" nominal -
. diameter downcomers penetrating the drywell floor.
Four of the downcomers are capped, so there are actually 83 active downcomers. The configuration of the drywell, downcomers, suppression pool and o ECCS suppression pool strainers is shown on Figures 2-1, 2-2, 2-3, and 2-4. 2.3 Insulation Types Employed in the Drywells a) Stainless Steel Jacketed Fiberglas Thermal Insul-ation (Owena-Corning "Nukon"). Fiberglas totally enclosed in woven fiberglas covers is used to e insulate.high temperature piping and the i recirculation pumps. The insulation blankets are protected with 22 gauge, minimum, stainless steel jackets having seismically qualified latches. b) Metallic Reflective (Diamond Power). This type is used for reactor pressure vessel (RPV) insula-tion. c) Jacketed Fiberglas Anti-Sweat ~(Owens-Corning Fiberglas). This type is used on chilled water lines inside the drywell and constitutes r a small percentage, less than 20%, of the insula- 3 tion used in the drywell. d)' Encapsulated Low Conductivity (Johns-Manville Min-k). This type is used at the whip restraints where the clearance does not allow the use of thicker "Nukon" insulation, and constitutes a small percentage, less than 10%, of the insula-tion used in the drywell. 3.0 METHOD OF ASSESSING DEBRIS HAZARD , 1 3 .1 - Assumptions Used to Determine Maximum LOCA Debris Generation: J , ~P-274/1(p5)' 3/2/84
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. 3.1.1 The criteria for selecting the worst case J' pipe break with respect to insulation debris generation is in accordance with the assump-tions outlined in Appendix C of Reference 4.1. These are a) The pipe break is assumed to be circum-terential and the downstream pipe section is assumed to be completely displaced so j there is no shadowing from it. Although y all large high energy lines are restrained at Limerick, this assumption was used ~
V because it results in the largest break jet cone. 1 b) Insulation inside the Region I break jet is assumed to be shredded into small ' f ragments by jet impingement forces. The Region I jet cone is a 7 pipe diameter long cone, expanding 45 degrees on either side of the centerline of the pipe. g c) Insulation inside the Region II break jet is dislodged in the as-fabricated form (i.e., as whole or torn blankets). Region f II is the extension of the Region I jet cone starting at L/D = 7 and extending to - a plane where the Jet thrust divided by the jet area is equal to 0.5 PSIG, with the same 90' expansion angle. d) Credit was taken for the shadowing effect of pipe whip restraints and larger struc-tural steel members that are inside the jet blast cone. This is in accordance g with criteria for modeling jet impingement i forces specified in References 4.9, 4.10,
. and 4.11.
e) Insulation on the displaced pipe down-stream of the break between whip res-traints is assumed to be shredded. f). The protective effects of the stainless steel jackets on the "Nukon" insulation were not considered,'and the "Nukon" in-sulation was considered to be unprotected for this evaluation. This is conservative
' because it is expected that limited l protection against shredding would be provided by the insulation jacketing, which would reduce the volume of shredded insulation debris generated by the LOCA.
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O 3.2 Amount of Debris Generated: 3.2.1 A review was made of the postulated pipe rupture locations (PRL) on the high energy lines in the drywell in order to locate those breaks where the jet cone would be oriented towards fibrous insulation. High energy piping systems with small diameter lines g ( are not expected to generate significant
- amounts of debris because of the small break .
jet cone size. The review was reduced to the @ following large diameter high energy piping i systems: , Reactor Recirculation Main Steam Feedwater
- RHR Shutdown Cooling Due to separation of high energy lines, the shadowing effect of numerous whip restraints on these lines, surrounding structural steel and other obstacles, none of the actual PRL's listed in Reference 4.4 is a significant insu-lation debris producer as compared to other non-PRL break locations. Consequently, our review was expanded to include all fitting welds on the above listed piping systems.
Study of the isometric drawings of these systems contained in Section 3.6 of the Limerick FSAR, in conjunction with visual examination of the e scale model of the primary containment (1/2" =
. l'-0"), was used to locate the break locations that caused the largest insulation debris generation.
3.2.2 Whip restraints and separation of high energy lines would prevent pipe whip and pipe impact, respectively, from being significant mechanisms - of debris generation. Further, any debris
- generated by these mechanisms would be in as fabricated whole blanket form, and this debris form does not jeopardize ECCS pump operation .
per Section 6.2.2.2 in Reference 4.4. In this , review, it was assumed that one length of g' insulation upstream of the break is blasted off by the LOCA, and shredded in the Region I blast cone. ; P-274/l(p7) 3/2/84
3.2.3 The two break locations that would generate the largest amounts of insulation debris are: (1) The 26"5 main steam line "D" where it crosses over the 26"# main steam line "C". The break weld = lucated inside the whip restraint at approximate elevation 282 ft, and is oriented so the jet cone intercepts main steam line "C". Figure 3-1 shows the ! specific break location and targets. The same basic geometry exists where main steam line "A" crosses over main steam , line "B". However, dif f erences in the ;i main steam relief valve piping makes the main steam line "D" cross-over the largest debris generator. (2) The second break is at the end cap weld on the 22"# recirculation line half ring ' header, approximate elevation 269 f t. Figure 3-2 shows the specific break location g and targets. There are two end caps on each d half header. The jet cone from each of the four recirculation line end caps intercepts a similar portion of the vertical 28"9 recircu-lation pump suction line. The jet cone from the south-west end cap also intercepts a portion of the 20"S RHR shutdown supply line, so this end cap location was selected for analysis. - 3.2.4 A geometric analysis was performed to determine the amount of insulation that could be affected , by the two selected break jet cones. It was observed that both of these selected break jet cones intercept almost exclusively "Nukon" c type fiberglas insulation, with the remainder being a very small amount of encapsulated min-k insulation. Encapsulated insulati n is resistant to jet impingement forces and will not be broken-up into small pieces. Since only shredded fibrous insulation is of concern in this evalua-tion, only the volume of "Nukon" insulation exposed to jet impingement inside the Region I , jet cone was quantified. A review of the geometry of the Region II jet cones showed that j shadowing from structures, pipe whip restraints and structural steel would provide protection against jet effects in Region II so that only n ( few whole or torn blankets would be expected to be dislodged. However, the LGS FSAR, (Reference 4.4) Section 6.2.2.2, discusses the physical P-274/l(p8) 3/2/84
s . barriers that will prevent whole or torn blankets and encapsulated insulation from entering the suppression pool. As a result, these types of insulation were not considered to be a concern, and insulation removed by the Region 11 portion of the jet cone was not quantified. 3.2.5 Our analysis determined that the main steam line h break would produce the largest amount of fibrous > insulation debris. The results of our analysis are tabulated below:
. Amount Fibrous Insulation Dislodged (1) Main steam line break
- M . S . " D" , 26" 5 16 ft3
- M.S. "C", 26" 7 20 ft3
- MSRV lines, 8"$, 12"E 18 ft3 .
S4 ft3 (2) Recirc line break
- Recirc hdr end caps, 2 x 22" # 3ft3 ?
- Recirc line "B", 28" 5 24 ft3
- RHR supply, 20" 9 7 ft3 _
- Recire hdr, 22" g (upstm break) 6 ft3 40 ft>
3.3 Insulation Debris Transport to the Suppression Pool. 3.3.1 Short term transport: 3.3.1.1 Short term transport is caused by the pipe break jet, pipe whip and pipe impact and terminates at the i i end of blowdown. As indicated in l section 3.2.2, pipe whip and pipe I impact are not considered to be a ' significant factors in this review. l 3.3.1.2 It was assumed that all shredded debris generated at the selected line break would fall onto the drywell floor. This is considered conserva-tive because some shredded debris (and most dislodged whole blankets) would be trapped or sieved by floor ! gratings and other horizontal surfaces below the selected break. l l 3/2/84 P-274/1(p9) i i
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176567 3.3.2 Long term transport: 3.3.2.1 Long term transport is caused by operation of ECC systems. For long term operation after a main steam line break, it is probable that the RHR system will be operated in the shutdown cooling mode with no additional ECC sys-tems operating. Therefore, water would not accumulate on the drywell floor to the level of the downcomer, such that there would be no water flow from the drywell to transport the insulation debris to the suppresion pool via the downcomers. However, to be conservative for this analysis, it is assumed that full ECCS_ flow spills onto the drywell floor from the line break, for the entire accident duration. 3.3.2.2 It is expected that the shredded debris is distributed over a large floor area by blast effects and large concentrations adjacent to a few downcomers do not l - occur. Consequently, it is assumed the debris is uniformly dispersed over a large floor area and the overall bulk properties of the drywell floor apply to the region where insulation debris is scattered. Refer to section 2.2 of'this report for a description of the arrangement of the drywell, suppression pool and downcomers. 3.3.2.3 The maximum possible ECCS flow condi-tion was used in order to maximize the flow velocities into the drywell downcomers and to minimize the resi-dance time available for slow-sinking debris to settle. Specifically, the evaluation is based on simultaneous operation of the following ECCS pumps all operating at their runout flow-rates. 4 RHR Pumps ' 4 x 10,750 GPM = 43,000 gpm 4 Core Spray Pumps 4x 3,950 GPM = 15,800 apm Total ECCS Flow ---------------------58,800 gpm 3.3.2.4 Based on data contained in Reference 4.3, the long term transport evalua-tion considered the behavior of three types of shredded fibrous debris after it falls onto the drywell floor:
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- 1) Debris that immediately sinks upon contact with hot water.
- 2) Debris that floats for an inde-finite period.
- 3) suspended debris that slowly -
sinks. 3.3.2.5 The shredded fiberglas insulation debris that falls to the drywell floor will initially come into contact with hot water released from the LOCA. Test data contained in Refe- ' rence 4.2 shows that shredded fiber-glas fragments rapidly become wetted and sink in 20 to 30 seconds in 120*F water. Per . Re f erence 4.7, Owens-Corning tests show that the same sinking characteristics apply to fibrous "Nukon" fragments. Ref erence 4. 5 shows that "Nukon" . i
. fragments will sink even more rapidly when the insulation is hot, which would be the case for any insulation dislodged from high energy lines. Since the -
initial water build-up on the drywell floor will be reactor inventory that is hotter than 120*F, and the insulation debris will be hot, it is expected most "Nukon" insulation fragments will rapidly sink. 3.3.2.6 There is sufficient volume below
- the downcouer overflow level (i.e.,
18" above-drywell floor) to contain 6 the maximum water release by a design
- basis LOCA (which would be from a j
' recirculation line break). No liquid overflow into the downcomers occurs until after the ECCS pumps are operating for any high energy line break. Based on accident chronology i data for high energy line breaks con-tained in Reference 4.4, the insulat-ion debris will have substantially more than 30 seconds exposure to hot water r-before the start of drywell water < overflow into the downcomers. L It can be assumed there will be sufficient time to permit most f l debris to sink to the bottom of the drywell_ floor pool before overflow l l starts.
}
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C....._.,...__... -- 176567 3.3.2.7 Although there is considerable test data supporting the conclusion made in section 3. 3. 2. 6, that most "Nukon" frag-ments will immediately sink to the bottom of the drywell floor pool, it is acknowledged there is no specific LOCA test data available describing the post-LOCA buoyancy characteristics of "Nukon". In the absence of specific LOCA f test data for "Nukon", the conservative approach is to assume less than all the "Nukon" fragments immediately sink. In order to arrive at a credible and ~ conservative factor for the lesser ' amount of debris that immediately sinks, comparable test data contained in section 4.7.2 of. Reference 4.3 describing the post-LOCA buoyancy characteristics of mineral wool insulation was used in the analysis. This data is considered conservative because fragments of as- . c manufactured fiberglas insulation, and "Nukon" in particular, will become wet and sink faster than mineral wool (i.e., 6 fiberglas has a greater tendency to sink compared to mineral wool). This conclusion is based on data contained in References 4.2, 4.5, and 4.7. There is no reason to believe LOCA effects would change the buoyancy characteristics of "Nukon" debris so that it would be more buoyant ' than mineral wool. Reference 4.3 states that 40% to 50% of the fibrous insulation l (mineral wool) dislodged by a LOCA can - L be expected to immediately sink. The calculation, therefore, used the conser-vative factor of 40% to determine the - amount of "Nukon" fragments that immediate-ly sink. 3.3.2.8 Obstacles between the main steam line break and drywell floor pool will L protect the pool from agitation due to ! direct break jet impingement. Liquid released from the line break during y blowdown and later during ECCS pump j operation will tend to fall onto drywell [ floor pool. In consideration of the plan area of the drywell floor, only I comparatively small localized regions of liquid turbulence may exist in the floor pool, where larger streams of falling i liquid impact the floor pool. Since P-274/1(p12) 3/16/84
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.'- . liquid is being displaced at these locations, the flow direction will be away from the disturbed zone. This outward flow pattern will be especially pronounced during the initial build-up of liquid on the drywell floor, and insulation debris that landed in these disturbed zones will be swept into quieter regions where it can settle. Thus, floor turbulence will f not interfere with the overall insulation sinking process, but, instead, will assist in wetting the insulation debris which accelerates p sinking.
3.3.2.9 Transport test data co.ntained in Reference 4.2 indicates that a flow velocity exceeding 0.3 ft/sec is required to entrain fibrous insula-tion shreds lying on the bottom of the drywell floor pool. Due to the ; elevated downcomer pipe ends, the L flow velocity profile approaching the downcomers is maximum on the surface and minimum on the bottom. During maximum ECCS flow (58,800 gpm) into the 83 downcomers, the maximum flow velocity at the bottom of the drywell floor pool is less than 0.06 ft/sec. Thus, sunken insulation debris will not be re-entrained by the flow into the downcomers when the ECCS pumps are operating. l 3.3.2.10 It is assumed that all floating debris
- is carried by the flow into the down-comers and enters the suppression pool.
Citing post-LOCA data for mi,neral wool in reference 4.3, 20% to 30% of the mineral wool debris remained afloat during ECCS operation. As l noted in section 3.3.2.6 of this report, fiberglas has a greater L ~ tendency to sink than mineral wool, j ' so this data is considered conser- [ vative when applied to fiberglas I debris. For additional conservatism, the highest stated mineral wool $ L i floating percentage (30%) was used in the analysis. (P-274/1( pl 3) 3/2/84
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'3.3.2.11 The remaining 30% of the original
,- shredded insulation volume is considered to be slow-sinking debris dispersed evenly in the water on the drywell floor. A calculation was performed to determine the flow zone around each downcomer that could draw the slow sinking debris into the downconer before it settles to the bottom of the floor pool. This calculation was based on a settling velocity of 0.012 ft/sec which is the median settling rate between individual fibers and very small clumps of "Nukon" insulation f based on data contained in Reference 4.5. Calculation results. indicate that a carryover factor of 50% for the slow-sinking debris would be conservative. In terms of the original shredded insulation volume, : this results in approxinately ISS entering the downcomers due to the _ slow-sinking phenomena, and coating ( the ECCS strainers. 3.3.2.12 Based on the forgoing transport analy-sis, the maximum expected fibrous debris migration into the suppression pool is 24.3 ft.(45%) 3 out of the original 54 ft3 of insulation shredded by the LOCA. A summary of the fibrous insulation transport phenomena is shown on Table 3.1. 3.4 ECCS Suction Strainer Blockage Head Losses Due to Insulation Debris Carryover into the Suppression
. Pool:
3.4.1 It is assumed that all pieces of fibrous insula-tion that enter the suppression pool eventually deposit on the 8 sets of active ECCS strainers. No credit was taken for quiet zones in the suppression pool where insulation could settle-out without being drawn onto one of the strainers. Each of the operating pumps identi-fied in section 3.3.2.3, has two conical type suction strainers in a " Tee" configuration in the suppression pool. Figure 2-4 shows The total details of these conical strainers. ECCS strainer surface area is 157.0 ft2, 3/2/84 P-274/1(pl4)
3.4.2 Per Reference 4.1, calculation of strainer screen head loss due to fibrous insulation debris blockage is based on the equivalent insulation blockage thickness, ti, as defined below: tg = Transported debris volume AvailaoAe screen area The total transported debris volume is distributed g between the RHR and Core Spray strainers : J based on the ratio of individual pump flowrates to s total ECCS flow. t 3.4.3 Reference 4.12 contains a head loss formula developed specifically for a bed of shredded "Nukon" insulation. It is noted the maximum debris bed approach velocity tested in - Reference 4.12 is 0.5 ft/sec, while the strainer approach velocities at Limerick are closer to 1.0 ft/sec. Review of test .. data contained in Reference 4.12 indicates 3 it is reasonable to assume the straight line [ logrithmic relationship between head loss and approach velocity can be extended to approach velocities of 1.0 ft/sec. Thus the "Nukon" fragnent bed head loss formula developed in Reference 4.12 is considered The valid"Nukon" for the Limerick service conditions. specific head loss formula was approved for ~ use in this review by the NRC during the Reference 4.6 telecon, and is given below: ZiH = 68,3 (ti)l.07 gy)1.79 c where: I liH = screen loss, ft of H 2 O ti = equivalent blockage thickness, ft V = screen approach velocity, ft/sec r 3/2/84 2-274/1(p15)
- i 3.4.4 Using the above formula, the strainer head lossen due to the deposition of LOCA genera-ted fibrous insulation materials were calcu-
-lated for two transport conditions:
3.4.4.1 Assume 100% debris migration to ECCS i strainers. This condition will esta-
- blish the maximum theoretical strainer f loss due to fibrous debris.
3.4.4.2 Debris migration to ECCS strainers is reduced by transport losses. This condition establishes the maximum expected strainer loss due U to fibrous debris. The calculated ECCS strainer head losses for
' 3.4.5 the two transport conditions are shown in Table 3.2.
t 3.5 Ef fect of Suction Strainer Blockage on ECCS Pump NPSH: c 3 . 5 . l' Minimum NPSH is available for the ECCS pumps when the suppression pool temperature is 212*F, f the drywell pressure is 14.7 psia, and the suppression pool is at minimum level. This minimum NPSH is further reduced by the strainer blockage loss to obtain.the actual NPSH avai- ' lable. The calculated actual NPSH available at the pump suction was compared to the NPSH g required by- the pump to determine if strainer blockage could cause pump cavitation problems. 3.5.2 Table 3.2 shows that the theoretically worst 2 case strainer blockage, (100% migration to ! stainers), concurrent with the minimum available NPSH operating condition, still leaves more ' NPSH than required by the ECCS pumps. The NPSH required values used in this evaluation are taken from pump manufacturer certified pump performance data. When certain debris transport losses are taken into consideration, the NPSH L margin becomes significantly larger. (The NPSH required values stated by G.E. in the FSAR Process Flow Diagrams contain a large safety margin over the NPSH required values given by the pump manufacturers). I t i ',
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4.0 REFERENCES
4 .1 Serkiz, A.W., " Containment Emergency Sump Perf ormance," NUREG-0897 (for comment), NRC, April, 1983. 4.2 Brocard, D.N., " Buoyancy, Transport, and Head Loss of Fibrous Reactor Insulation," NUREG/ CR-2982, SAND 82-7205, Alden Research Laboratory, November,1982. 4.3 Wysocki, J.; Kolbe, R., " Methodology for Evaluation of ; Insulation Debris Effects," NUREG/ CR-2791, SAND 82-7067, Burns & Roe, Inc., September, 1982. y 4.4 Bechtel, " Final Safety Analysis Report (FSAR), Limerick Generating Station, Units 1&2, Philadelphia Electric , Company," FSAR Vol.4 and Vol.7. - 4.5 Owens-Corning Fiberglass Corporation, " Topical Report ' OCF-1, Nuclear Containment Insulation System, NU'K'ON," January, 1979. 4.6 Telecon between Messrs. Serkiz (NRC); Tutton, Phillabaum (PECo); Schlueter, Lewis, Blakely, Klein, and Bielanowski (Bechtel); July-21, 1983. 4.7- Owens-Corning letter to Bechtel, January 26, 1984,
" Sinking Characteristics of Glass Fibers," Limerick Project Document No. 174363.
4.8 Deleted 4.9 U. S. Nuclear Regulatory Commission, Standard Review v Plan 3.6.2, " Determination of Rupture Location and Dynamic Effects Associated with the Postulated D Rupture of Piping, Rev. 1 - July 1981." 4.10 ANSI /ANS-58.2-1980, " Design Basis for Protection of Light Water Nuclear Power Plants Against Effects of Postulated Pipe Rupture." 4.11 ANSI /ANS-58.3-1977 (N182), " Physical Protection for Systems and Components Important to Safety." 4.12 Brocard, D. N., " Transport and Head Loss Tests of Owens-Corning NUKON Fiberglas Insulation, "Alden Research Laboratory, September, 1983. I, P-274/1(pl6) - 14 - 3/2/84
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- TABLE 3.1
SUMMARY
OF INSULATION DEBRIS TRANSPORT INTO THE SUPPRESSION POOL I; Amount i Transported $ Original to 4 Amount Supp.gool g ft3 ft p i a) Short term transport: Shredded insulation debris 54.0* N.A. generated by LOCA i Shredded insulation debris 54.0* N.A. $ falling onto drywell floor a b) Long ' term transport: Breakdown of shredded debris types - on drywell floor:
- Immediate-sinking (40%) 21.6 0.0
- Floating (30%) 16.2 16.2
- Slow-sinking (30%) 16.2 8.1 54.0 24.3 a
- Does not include volume of ethole, "as-fabricated" blankets of insulation generated by LOCA (Region II blast cone),
i 3-274/1(pl7) 3/2/84
.. ,.c TABLE 3.2 StPMUW OF CAIIIJLATED ECG S"IRAINER HEAD IIESES DUE 'IO FIBROUS DEBRIS BTIXXME AND EFFECT ON ECCS PUN NPSHA .
ESTIMATED MIN ACIVAL ECC FIIM '1UI'AL DEBRIS DEBRIS DEBRIS NPSHA NPSHA SYSTEM STRAINER VOllME BtIXXAGE BIIXXEE WI'lH WI'lH SURFACE REACHING ON HEAD CLEAN BtiXXED Pt N AREA STRAINERS SIRAINERS IOSS S'IRAINERS S'IRAINERS NPSHR gpn ft2 ft3 in ft ft ft ft 100% fibrous RHR 43,000 105.7 39.5 4.5 20.0 27.0 7.0 6.0(2) Debris Migration to ECCS strainer CS 15,800 51.3 14.5 3.4 9.1 28.0 18.9 10.0(2) Maximun expected RHR 43,000 105.7 17.8 2.0 8.5 27.0 18.5 6.0(2) fibrous debris migration to CS 15,800 51.3 6.5 1.5 4.5 28.0 23.5 10.0(2) ECCS strainers N0lES (1) FIDID 'ITN4:RA'IURE IS 212*P (2) VAwES FROM SUPPLIER CEIRIFIED PUMP tulORMANCE CURVES. P-274/1(p16) 3/2/84 L -- o s -1 -, ,m e m. m
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