ML17138A536
| ML17138A536 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 12/14/1973 |
| From: | Becker, Hoffmann PENNSYLVANIA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML17138A531 | List: |
| References | |
| KWU-E3-2840, NUDOCS 7903150322 | |
| Download: ML17138A536 (41) | |
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PROPRIETARY INFORMATION This document has been made NON-PROPRIETARY by the deletion of that information which was classified as PROPRIETARY by KRAFTWERK UNION AG (KWU).
The PROPRIETARY information deletions are so noted throughout the report where indicated by a) Use of the term KRAFTWERK UNION AG PROPRIETARY INFORMAT ION .
b) Use of blocked out areas by cross hatch bands in the report text and figures/tables, e.g.
i) ...." with a mass flow density of L+~~Kg/m2s...";
ii) %%V mm iii) ...." should be kept below ~~ W~~ atm."
iv) 8/17/78
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Frankfurt 14 December 1973 Place Date Technical Report KWU/E 3 - 2840 Pile number R 521 R 113 Author Hoffmann R 521/R 113 Dr. Becker Countersi"na=uze
Title:
Pages of tax= 7 Investigations of condensation with the Figures perforated-pipe quencher with small Circuit diag"a".s water coverage of the quencher arms Diagz./oscillog".:
Key words (max. 12) to identify the report's Tables 1 content: Reference list: 1 Relief system, suppression chamber, perforated-ie encher corn lete condensation Summary In the large-scale test stand in the Mannheim Central Power Plant (GEM),'condensation tests were performed with a perforated-pipe quencher reduced to a scale of 1:5 with respect to the flow rate and with a mass flow density of E~ kg/m s nearly corresponding to the maximum value in the large-scale version and with very small suhnergences of the quencher in the water pool. In addition to the steam flow rate, the temperatures in the water and air spaces and the pressure in the test tank were also recorded. The measure-ment results indicate that for a water coverage of the quencher arms of WWL~ arm diameters the steam is condensed completely in the water pool for pool temperatures up to at least+~~C.-'he tests are extremely conservative because accident-rel'ated extreme)y
,small submergences in the plant are conceivable only for greatly reduced reactor pressures,'.e., for far lower mass flow densities than those in the test.
Promotional Project IB 4 - 5691 - RS 78/A of 20 September 1973
/s/ /s/ /s/ II Hoffmann) Dr. Becker) Dr. Sobottka)
Author s signature Exam.nez Classy aer ~Cass For infozmation Distribution li'st:
(covez sheet only) lx XWV/GA'19 Erl R 1/Ffm
~ lx /PSM 22 Ffm lx R 1/Erl lx Librar Gwh Transmission or duplication of this document, exploitation or cor=uni-cation of,.its content not permitted'nless expressly authoriz&.
Infringers'liable to pay damages. All rights to the award o. patents or registration of utility patents reserved.
"'7-l
NONLIABILITY CLAUSE This report is based on the current technical knowledge of,>
KRAFTWERK UNION AG. However, %%FTWEIU( UNION AG and the Federal Minister for Research and Technology and all persons acting in their behalf make no guarantee. In particular, they are no.
liable for the correctness, accuracy and completeness of the data contained in this report nor for the observance of third"party rights.
This reservation does not apply insofar as the report is de'ivere='n fulfillment of contractual obligations, nor with respect to licensing authorities or the experts appointed by them.
KRAFTWERK UNION AG reserves all rights to the technical information contained in this report, particularly the right to apply for patents.
,Further dissemination of this report and of the knowledge contained therein requires the written approval of KRAFTWERK UNION AG.
Moreover, this report is communicated under the assumption that it will be handled confidentially.
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DISTRIBUTION LIST (internal)
R ~ Ffs RZR 1 RS RS 1 RS 11 RS '1 15/G KT RS 12/RXB RS 12/~
RS 13/~'S 13/Xa'S 14/KKI RS 15 RS 2 RS 21 RS 213 R Il/PfR R 11 /Erl R 111 2 x R 113 3 x R 213 2 x R
R 3 z R 32 R 322 R 5 R 52 R 521 5 x DISTRIBUTION LIST (external)
IRS-1S ~ K Ksrrn Dr Lussersbois, Qln bHFT, a. K. Kerm Dr. Xiegler, Ann 7-3
l Table of contents Page Statement,of the problem 7-5
- 2. Test set-up and execution 7-6
- 3. Discussion of the results 7 7 3.1. Heating of the pool and air space 7 7 3.2. Pressure rise in the test tank 7-1C
- 3. 3. Xnfer ence for the plant 7-12 Tables
.Figures References 7-4
- 1. Statement of the roblem The perforated-pipe quencher of the relief system is suhnerged in the water pool of the suppression chamber of the press'ure suppression system by approximatelyg+m in KRB (Figure 1.1). The suhnergence (ETT) differs only slightly from that value in the subsequent plants. Since the water level is regulated within the range g+3cm and 4++ cm, complete condensation of the steam tha.
might be blown down through those quenchers is guaranteed in the normal case.
However, it is possible to conceive of accidents in which the water level in the suppression chamber drops distinctly relative to the normal value. The function of the pressure suppression system must be maintained then. Accordingly, we investigated the smallest submergence of the quencher for which complete conden-sation of the blownmut steam in the water pool is guaranteed.
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- 2. Test set-u and execution The tests were performed in the KWU condensation test stand in GKM with perforated-pipe quencher BS 1, 4 (Figure 2.1). A more
. detailed description of the quencher can be found in /2/. Fig re 2.2 shows the utilized pipe geometries C and D. The stea=
flc-'ate in all cases corresponded to the maximum value reached in the test stand between g++++Q t/h. The mass flow density relative to the outlet area was approximately j~4kg/m s.
Figure 2.3 shows the test set-up in the GKM test stand. More detailed information concerning the test atand can be found in
/1,2/. The most important measurement values for the tests being discussed here are the water temperature 8 17> which is measured at the height of the center line of the perforated arm laterally at the wall< and the temperature, in the air space, which is measured by the measurement transducers 818 and 819 approximately 1 and 3 m above the water level, respectively, and by averaging those values. Finally, pressure changes .in the air space were recorded by the measurement point PK.
The tests were performed with suhnergences of ++++~ m. Th-'s corresponds to a water coverage of the quencher arms of EWE% a. ..
diameters, respectively (Pigure 2.4) ~ The measurement results a e compiled in Table 1, Sheets 1-6. The test duration was between jMMMQseconds. After each test, clean initial conditions with respect to the water level and tank pressure were restored.
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- 3. Discussion of the results, I 3.1. Heating of the pool and air apace In Pigures 3.1 and 3.2, the variation 'of the water and air tem-perature versus the test time is plotted for average and higher pool t<<nperatures and a submergence of,'<W3m. Beginning at a test time of approximately 1 second, the temperature of the air clea"ly exoeeds that of the water.
Tests resu)ts for comparable initial conditions but a suhnergence of k~~m are plotted in Figures 3.3 and 3.4. Beginning at a test time of approximately 2 seconds, the water and air have practically the: sane temperature.
Another type of plot is chosen in Pigures 3.5 and 3.6 in which several tests are combined for submergences of h%%%%> m. The air temperature is plotted 'along the ordinate,'and the water tem-perature along the, abscissa. The two temperatures are equal along the orientation line running at 45; in the graph. The direction of the test sequence is identified by an arrow for the chains of measurement points connected by line segments.
Por a submergence of Q~m it is again clear from Figure 3.5 that the 'air is heated up very quickly after the beginning of the test to a temperature approximately+QK above the measured water te.-..-
perature. As the test proceeds, this temperature differcncc remains approximately constant. Por a submergence of 44m< Figurc 3.6 7-7
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shows that, after an equilibrium is-adjusted, the air and water have practically the same temperature.
Figure 2.4 provides a scale representation of the correlation between quencher arms and pool vater level. We see that the steam jets are blown out of the test quencher in the immediate vicinity of the water surface and are blown upward vith an impulse componcnnt.
According to optical observations in the model test stand in the le Nuclear Energy Test Facility in Grosswelzheim, for such a small vater coverage of the quencher arm we may expect an intense movemcnt of the vatcr surface vith a good transfer of heat to the air space. Accordingly, vater is flashed at the pool's surface, whereby the air is saturated with steam and is heated.
Because of the heat transported upward vith the emerging steam pulse (see Figure 2.4}, a higher temperature is probably sct at the vater surface than laterally at. the tank wall at the height of the arm's center linc, where thc vater temperature is measured P'igure 2.3}. In fact, for a submergence of i%3 m the air is heated 'to a higher value than would correspond to the temperature measurement point 8l'> in the vater. However, since the temperature difference relative to the vater remains constant and does not rise steadily further, ve 'may conjecture that ve are dealing with the temperature that is set near the surface of the pool. According to this analysis, for a suhnergencc of g~m none of the steam emerging from the quencher breaks through the surface of the vate..
A break-through of thc steam vith a suhnergence of LXm can be 7-8'
ruled out vith certainty. For those tests, the air temperature rises only to the temperature at, the measurement point 8 17 at the height of the quencher arm.
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3.2. Pressure rise in the test tank To reinforce the conclusions drawn from the measured temperatures, we shall now consider the pressure rise 'measured in the air space during the test. It is plotted versus the test time in Figure 3.7.
The measured variation is compared with the variation calculated from the measured air temperature. It was assumed in the calcu-lation that a quantity of steam corresponding to the saturation state is contained in the air. The calculated curve lies above the measured pressure variation, which indicates that in reality a smaller amount of steam is contained in the air.
Por test 369 illustrated in Figure 3.1, in which the temperature in the air space is clearly higher than the temperature measured in the water, we shall also determine the amount of water flashed.
~ An air volume of imam 3 is enclosed in the air space. At the beginning of the test, a temperature of %'C prevails. If we assume air saturated with steam, then this corresponds to an air
.mass of ~~kg and a steam mass of Q~ kg. After a test duration of 10 seconds, the temperature has risen to %~C. Zf we again assume air saturated with steam, then the steam mass is then+% kg ~
From that we calculate a total pressure of the mixture of iL%kg/c-(absolute) . This pressure is compared with a measured value of LW kg/cm (absolute). Thus, as indicated above, the stoa=,
content was overestimated. This might be due to a partial conden-sation of the steam at, the colder wall of the tank. On the othe" hend, it is also possible that in the air space there is a temperate e
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gradient having a larger value near the ~ter surface an" a smaller value in the upper region. The measurement values listed in Table 1 for 818 and 8 hint at such a possibility. In that case, the air temperature vith an averaging from those too values I
would be assumed too high.
If ve use as a basis the higher calculated steam content, then L~W kg/s of eater is flashed from the pool during the test time interval under consideration. In contrast, approximateiy L4 kg/s of steam +as injected into the pool through the quencher. The tvo values differ by a factor of gg. From this ve may conclude that, for the suhnergence of)LWm Ponsidered here also, the steam blown out of the quencher does not break through the water surface, but rather is condensed completely inside the pool. The quantity of eater emerging into the air space is flashed out of the pool, as already described previously.
7-11
3.3. Inference for the plant Prom the measurements vith the experimental quencher ve reach the conclusion that, beginning vith a water coverage of the quencher
-arms of Q~+~ arm diameters (corresponding to a submergence of Q+++~ m for an arm diameter of QQm) with high flow rate (mass flow density g~Qkg/m 2 s), the steam is condensed completely in the vater pool for pool temperatures up to at least+WC, i.e.,
there is no break-through of steam through the water surface. We may therefore assume that with the large-scale quencher installed in the plant the steam flow rate of z~% t/h blown out at the reactor rated pressure (the mass flow density corresponding approximately to that in the test stancl) is also completely condensed in the water pool if the pool temperature does not substantially exceed )ERIC and there 'is a minimum vater coverage of LMM5. arm diameters above the quencher arms. For an arm diameter of 4~ m, that corresponds to a minimum submergence of
%%%Km.
If the water level in the suppression chamber has dropped by
'% below the normal level (signifying a quencher submergence of ca. g~Wm in KKB), then measures are initiated to lower the pressure in the reactor pressure vessel. According to /1/, for the design-basis leak of the suppression chamber the flov rate through one quencher in the event, of a lowering of the water level by an additional hj%m .(in other words, for a quencher suhnergence of ca, m) is still only abouti% of the rated flow rate, Based 7-12
on the results obtained in the test stand with the high stea=.
flow rate, we can expect that such low steam flow rates are also completely condensed in the water pool when the quencher arms are covered with less water than would correspond to an arm diameter.
7-13
KRAFTJERK UNION AG PROPRIETARY INFORMATION Tzb1e 1 sheets 1 to 6 7-14 to 7-20
l KET
- 1. Safetylrelief valve 5. Protective tube 2~ Pitting vith orifice plate 6. blovdoun pipe
- 3. Restraining structure 7.
- 4. Connection for snifter valve Perforated-pipe quencher S. bottom mount (total of 2)
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Fillkll 2,1 8 I21 Perforated-pipe quencher HS 1 Model quencher for GKM test stand Locm.rchrdUse HS 1 i~loci=-tt~Qse fur GKM- Versuchss'.and 7.-22
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KEY FOR FIGURE 2 ~ 2
- l. Relief valve
- 2. Blowdown pipe
- 3. Cladding tube
,.4. Central tube I
- 5. Centering (3 adjusting screws)
- 6. Perforated-pipe quencher
- 7. Bracing to hold the pressure transducers
- 8. Minhole 9., Hole diameters are inside diameters 10 KRAFTWERK uNION
, AG PROPRIETARY INFORMATION 7-24
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Arrangenent of perforated-pipe quencher HS 1,4 in the CKH teat stand Anordnung der LochroI".r-duse HS 1,4 im G KVI-Yersuchsston J Hanhole Mon~Ioeh Figure 2.3 Bolo 7 25
KRAFTWERK UNION AG PROPRIETARY INFOKIATION Figure...,... 2.4 3.7 7-26 7-33
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References
"/1/ Backer, Prenkel, Melchior, Slegers Construction and design of the relief system with perforated-pipe quencher 3-2703, July 1973 'WU/E
/2/ Backer, Hoffmann, Knapp, Kraemer, Melchior, Meyer, Schnabel KKB - Vent clearing vith the perforated-pipe quencher KMU/E 3-2796; October 1973 7 34
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