ML19320B879
| ML19320B879 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 07/11/1980 |
| From: | Moore G FLORIDA POWER CORP. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8007150385 | |
| Download: ML19320B879 (9) | |
Text
{{#Wiki_filter:a r cy, [i, (,f 1
- m. o -r h[..$ck.,.4 s ;
n:g 2,- v m_.. fl:p m e,. %YdB Power CORPOR&TtoN July 11, 1980 File: 3-0-3-a-3 Mr. Robert W. Reid Chief Operating Reactors Branch #4 U.S. Nuclear Regulatory Conmissir Washington, DC 20555
Subject:
Crystal River Unit No. 3 Docket No. 50-302 Operating License DPR-72 NRC Letter Dated February 29, 1980, Requesting Additional Information on Containment Purge and Vent System
Dear Mr. Reid:
By letter dated February 29, 1980, you requested additional information for Containment Purge and Vent System for Crystal River Unit 3. The en-closed response by B&W for Florida Power Corporation is for questions Ic and le of tFe subject letter. Our response to questions la, Ib, Id, and if was submitted to you on June 20, 1980. This transmittal completes our response to the subject letter. Should you have any questions concerning this subject, please contact this office. Very truly yours, FLORIDA POWER CORPORATION 4 / f J flk . C. Moore Vice President Power Production Lobo (R042)DN98-2 8 0 0 715gneral Office 3201 Thirty-fourth street soutn. P O Box 14042, St Petersburg. Florida 33733 813-8 333 )p
r- ~ STATE OF FLORIDA COUNTY OF-PINELLAS G. C. Moore states that he is the Vice President, Power Production, of Florida Power Corporation; that he is authorized on the part of said company to sign and file with the Nuclear Regulatory _Connission the information ttached hereto; and that all such statements made and matters set forth therein are true and correct to the best of his knowledge, information and belief. 7 L, G. C. Modre Subscribed and sworn to before me, a Notary Public in and for the State and County above named, this lith day of July,1980. A g hotary Public Notary Public, State of Florida at Large, My Commission Expires: May 29, 1984 ChisamoreNotary(DN98)
i FLORIDA POWER CORPORATION RESPONSE TO NUCLEAR REGULATORY COMMISSION QUESTIONS ON CONTAINMENT PURGE AND VENT SYSTEM \\ QUESTION Ic { Specify the amount of cantainment atmosphere released through the purge and vent isolation valves, for a spectrum of break sizes, during the 4 maximum time specified for them to close in your technical specifica-tions.
RESPONSE
An assessment of the mass released through the containment purge system has been performed for the spectrum of break sizes set forth in the Crystal River 3 FSAR. The following assumptions were used in this evaluation: 1. The containment pressures presented in the FSAR were assumed to be unaffected during the time period the purge valves were closing and the containment was not isolated. An assessment of the 0.5 ft2 cold leg break was performed to evaluate the effect of the purging system on the 4 psig ESFAS actuation time. The 0.5 ft2 break was chos: for this evaluation as its ESFAS actuation ti.te, approximately 6.5 seconds, is the most delayed for the break specti um considered. Results showed that the delay in actuation time would be approximately 0.5 seconds when accounting for the purging system. To offset this delay, there would be approximately a 20% decrease in pressure at the valve closure time (approximately 11 seconds). This decrease in pressure would have more impact than the ESFAS delay on the mass release. Therefore, the assumption of containment pressures being unaffected by the purging system is conservative for mass release calculations. 2. The time to reach conta ent isolation was accounted for in the following manner; tt number of second(s) to reach ESFAS (4 psig), plus 0.5 seconds signal transmittal time, plus 5.0 seconds valve closure time. No allowance was made for flow reduction while the valves were closing. 3. The flow rates through the purge system is based on the ori-fice equation with a discharge coefficient of 1.0. This co-efficient conservatively neglects flow resistance of the pipes, filters, fan drag, etc. 4. The density of the effluent passing through the purge system is based on the mass of saturated steam at the partial vapor pressure and the initial air mass based on the initial con-tainment conditions listed in the FSAR. This partial vapor pressure, assuming a saturation condition, defines a density which is then used to calculate the vapor mass. This mass is Lobo (R042 Resp)DN98-2 A then combined with the initial air mass and containment volume to obtain the effluent density which is then used in the ori-fice equation to calculate mass release rates. The air mass was held constant throughout the transient. 5. Based on the Gilbert Associates, Inc. report, " Final System Reactor uailding Ventilation System," dated Description 10/7/75, the purge system exhaust rate has been calculated to ' be 62.5 lbm/sec. In the cases where the mass release rate calculated from the orifice equation was lower than this steady-state rate, the 62.5 lbm/sec was used as a lower limit. The above assumptions were used in calculating mass release for the spectrum of break sizes. The method used was to integrate each pressure curve by using one second time intervals and an average pressure over that interval. This average pressure was then used along with the effluent density in the orifice equation to calcu-late the mass release for each curve. The results of this analysis are shown in Table 1. Lobo (R042 Resp)DN98-2 TABLE 1 Break
- size, ESFAS Time Leak Open Maximum Mass ft2 Break Location s, 4 psi Time, s Released, lbm 14.1 Hot leg 1.0 6.5 12810.
11.0 Hot leg 1.0 6.5 11900. 8.55 Hot leg 1.0 6.5-10960. .5.0-Hot leg 1.0 -6.5 8690. 3.55 Cold leg P.S. 1.0 6.5 11900. 7.0-Cold leg P.S. 1.0 6.5 10330. 5.13 Cold leg P.S. 1.0 6.5 9090. 3.0-Cold leg P.S. 1.5 7.0 8090. 2.0 Cold leg P.S. 2.0 7.5 7470. 0.5 Cold leg P.S. 7.0 13.0 8650. s 4 1 ! Lobo (R042 Resp)DN98-2' -
QUESTION le - Provide an analysis of the reduction in the containment pressure result-ing from the partial loss of containment atmosphere during the accident for ECCS backpressure determination. RESPONSE-An analysis of the minimum containment pressure, including the effect of the purge system, was performed for Crystal River 3. A CONTEMPT model was developed, using the basic approach listed in Section 4.4 of BAW-10103A, specific to the Crystal River 3 contain-ment. Heat sink data is based on the Gilbert Associates Report GAI-1889, dated August 1975, and Branch Technical Position CSB6-1. All other data is based on the generic CONTEMPT model utilized for BAW-10103A, Revision 3. The following assumptions were used in performing the containment evaluation: 1. Mass and energy release was obtained from the worst case break, the 8.55 ft2 double-ended break at the pump discharge with a CD = 1.0, determined in BAW-10103A, Revision 3. 2. Leakage through the purge system was assumed for 6.5 seconds. This accounts for a one second time to reach the 4 psig ESFAS signal, a 0.5 second signal transmittal time, and 5 seconds for the purge valves to close. No allowance was made for flow reduction while the valves were closing. 3.- The flow rates through the purge system is based on the ori-fice equation with a discharge coefficient of 1.0. This co-efficient conservatively neglects flow resistance of the pipes, filter, fans, etc. 4. Initially, the reactor building is at 110F, 13.7 psia, and 100% relative humidity. These values are defined ia BAW-10103A, Revision 3. 5. The outside air temperature is 40F. 3 6. The containment volume is 2050550 ft. This is the Crystal River 3 specific volume as reported in the Gilbert Associates Report GAI 1889. 7. All heat removal systems and their actuation times are used as reported in BAW-10103A, Revision 3. As reported by Gilbert Associates, Inc. in Report No.1889, these heat removal sys-tems are conservative relative to the specific systems in the CR-3 facility. 8. Complete mixing of the spilled ECCS water with the containment atmosphere is-considered. The HPI injecting in the broken . loop is considered part of the spilled ECCS water. Lobo (R04 Resp)DN98-2 m
9.- Rainout of susperded water is assumed, and a high heat trans-2 fer coefficient of 1000 Btu /h-ft _oF between the liquid and vapor regions is used. 10. The building is modeled with five heat sinks: a. The reactor building walls including the concrete wall, steel liner,- and anchors: Exposed area, ft2 63,304.0 Paint thickness, ft 0.0005 Steel thickness, ft 0.03125 Concrete thickness, ft 3.5 b. The reactor building dome including concrete, steel liner, and anchors: Exposed area, ft2 18,138 Paint thickness, ft 0.0005 Steel thickness, ft 0.03125 Concrete, ft 3.0 c. Painted internal steel: 2 409,817.0 Exposed area, ft Paint thickness, ft 0.0005 Steel thickness, ft 0.017738 d. Unpainted stainless steel: Exposed area, ft2 46,059.0 Steel thickness, ft 0.0227 e. Internal concrete: Exposed area, ft2 105,941.0 Paint thickness, ft 0.00083 Concrete thickness, ft 1.4350 11. The following thermophysical properties are used: Thermal Conductivity Heat Capacity 3 Material Btu /h-ft-F Btu /ft _op Concrete 0.92 22.62 Steel 27.0 58.8 Stainless Steel. 9.1836 54.263 Paint 0.6215 40.42 Lobo (R04 Resp)DN98-2 9 ~ 12. The condensing heat transfer coefficients given in Sec-tion 4.3.6.1 of BAW-10104 are used: a. At the end of the blowdown, assume a maximum heat trans-fer coefficient four times higher than that calculated by Aerojets' Tagami correlation: h ax = 72.5 (Q/Vt )0.62 m p where 2 hmax = maximum heat transfer coefficient, Btu /h-ft -F, Q = primary coolant energy deposit to containment at end of blowdown, Btu, 3 V = net free containment volume, ft, tp = time interval to end of blowdown, s. Before the end of blowdown, assume a linear increase from 2 h nitial = 8 Btu /h-ft - F i to the peak value specified above, b. During the long-term stagnation chase of the accident, characterized by low turbulence in the containment atmo-sphere, assume condensing heat transfer coefficients equal to 1.2 times the one obtained from the Uchida data. The Uchida heat transfer coefficients are shown in Table A-1 of BAW-10095. c. During the transition in phase of the accident between the end of blowdown and the long-term, post-blowdown phase, a reasonably conservative exponential transition with a decay constant of 0.0255 is used. The results of the CONTEMPT evaluation is depicted on Figure 1. As shown, the influence of the purge system is to reduce the contain-ment pressure by 1.5 psig. However, even with the purge system assumed operational at the start of the event, the resultant con-tainment pressure is still higher than the value obtained from the generic 177-FA lowered-loop containment pressure evaluation used for demonstrating ECCS conformance to 10 CFR 50.46. Lobo (R04 Resp)DN98-2 %s ., _ eg g S._ N 7 , l.. ..q. e g s 1 g .S.... l. f Q g 4 s3 -E l 4 __ 'i U b 4 3..___. l./,) q .g - g 2... ....__....g.-._.___.._.j .p___ . 7... .. k.d.~._. g . p....._ _. m ._..... q ___ . b __. l... C%. 9_,
== 8. ~ .._.j .Q Q. ..--\\.-..--.._. 1 .L. 4 6. i _....._J.. __.,g %1 si... _. p> - -... ~ 1... i ... n >1.,,
- M.
9" m N 4._.-. y 3 Q ~~ ' ~ Q...!. / .Q..Q.g.. p 1 ..,, f. .s, g 2 I Q -. I ,g..1__._.___, \\. 1 .l____.;.._.. g. l s .I y
- l.. i I.
sJ L._.. . N;. a. 3 g.. 9.. .__.._. _ _...... _ _.N ( g 8 .u.._... I_~.I L_. .._..N.~~.l.'..._T..t__..- ~ ~ ~ ~ ~ ~ $ :-~ ~ ~Z_ __'.Z_.T.T__ _Z.~. I _.. :.. _ _.'. l.. _.j. S____. s 4_ ^ R s 3_ t .. Q. _.:.._ _: k z._.. t' t Q \\ y. I_..._.. I f.1. q ..'~.__._.; _.. t g....T g. g 1 1. 3* -_[.~. ...l.._ g Q y C ^ g r ...-l ....i. l' \\ t 3 V a.. .l l jj
- 1. -.... _... -(%...
Q CE 8 ~3
- f 7_
? (? e ~ 6_. M g44 s q 'T 5a g 3.'.._...._..__.- ._____u_____......_.._...._..._...._.-._p.__... ...,.__....._..... -......_ _ _. _ -..l.... _.. 3 __ d ._....D l a F-i d .) . l 2 .i a l l I,' 4. ,a s s. ._b .L_.._. I. F. ......___.__..p....I h s. 7. _.___.__.._...._....j.._.......;.-.._.____p_.. C...-..........;..... -.._ __r.......... j._.__.. _ .y....._..__..[....... 5. n _._... 4. I I A L -._ l. 3 ... _. a 1 3.._.a.... q 7 r. } y .W .o. w o w 0 o y. o w ,I n u i__,, ..(D.._.I..gd.). _..n m3Ud._._"....__"__D i " w w
- 3.
_ -...._ I qw w 3 D 1. 1 es s =}}