ML18347A686

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Referring CPC Letter of 3/20/1976 Which Responded to NRC Letter of 3/10/1976, Providing Answer to 7 Questions for 4.A.7 Under Section 4.0, Accident and Transient Analysis
ML18347A686
Person / Time
Site: Palisades Entergy icon.png
Issue date: 03/23/1976
From: Bixel D
Consumers Power Co
To: Purple R
Office of Nuclear Reactor Regulation
References
Download: ML18347A686 (12)
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Text

{{#Wiki_filter:consumers

  • Power company.

General Offices: 212 West Michigan' Avenue, Jackson, Michigan 49201

  • Area Code 517 788-0550 March 23, 1976 DOCKET 50-255, LICENSE DPR-20 PALISADES PLANT, ANSWER TO QUESTION ON LOcA*(4.A.7)

By letter dated March 20, 1976, we transmitted answers to questions contained in your letter of March 10, 1976. In answer to Question 4.A.7, we indicated that a response would be provided at a later date. This letter provides that

  • response. Please note that the question responded to is somewhat different from that contained in your March 10, 1976 letter. This response is based on discussion with the regulatory staff which took place prior to receipt of the letter. We believe our response will provide the information required.

SECTION 4.0, ACCIDENT AND TRANSIENT ANALYSES Question 4.A.7 Provide the following information for the calculated worst break case for Palisades.

1. Reactor coolant temperature versus time at the hot spot.
2. Average fuel temperature at the hot spot .
3. Hot assembly flow rate.

4~ Quality at*. the hot spot.

  • 5'. Gap conductance versus tinie at hot spot.
6. Hot rod internal pressure.
7. Rupture time.
  • Response The attached information is for the 1.0 DES/PD case with ENC fuel. For this case, the blowdown maximum temperature node is heat transfer Node 22 f32'g . .

5

r--- 2

  • Figure 3.2 of XN-75-64. Node 22 is also the maximl11Il power node and corresponds to* Node 17 of the TOODEE2 calculation. The hot spot during reflood moves up the rod to TOODEE2 Node 19 (hot channel Node 24). All these heat transfer nodes are bounded by fluid Volume 6 of the hot channel model as shown by Fig-lire 3.l of XN-75-64.

The following information is supplied:

l. The average fluid temperature in Volume 6 of the hot channel model.

(Figure 1).

2. The. volumetric average fuel rod temperature for heat transfer Node 22 of the hot channel model (Figure 2).

3 . . Hot assembly flows at inlet Junction 10 and outlet Junctions ll and 12 for the hot channel model (Figures 3, 4 and 5).

4. Average quality of Volume 6 of the hot channel model (Figure 6).
5. Gap conductance for the maximum power node for both blowdown and reflood and gap conductance for the PCT node during refill and reflood (Figures
7. and 8).
6. The hot rod pin pressure during the entire transient *(Figure 9) .
7. Rupture time for the 1.0 DES/PD was calculated to occur at 49.82 seconds after the break.

The transient gap conductance during blowdown is not an available quantity from the RELAP4-EM runs and was approximated from the fuel rod surface heat flux and the calculated outer fuel surface and inner cladding surface temper-atures. This procedure is valid when pseudo steady state conditions exist across the gap and cladding but may be in error when energy storage terms in the cladding are significant compared to the surface heat flux, as at CHF. During refill and reflood, the gap conductance is available directly from TOODEE2 results. Pressure Distribution Overall system irrecoverable pressure losses were adjusted equal to the pl11Ilp head as given by pump performance data. Loss coefficients through the core were based on experimental data from full scale single assembly flow experi-ments which included modeling of the upper and lower core support structure. Line losses were estimated from standard correlations for expansions and con-tractions. Because of the conservatively low flow rate assUliled, system balancing, particularly across the steam generator, required artifically aug-menting the pressure loss. This was accomplished conservatively by reducing the steam generator effective flow area until a balance was achieved .

  • Flow Distribution The distribution of flow between the two steam generators and four pump flow paths was taken from plant flow measurements made in April 1975.

Assistant Nuclear Licensing Administrator CC: JGKeppler, USNRC 

                                                                                                   * - - * - *. ~ ****..* -- ***~-~-:*--***~"":**-*~*--.. ...................... , .......h
  • Pl=lLISRDES SLOWDOWN WREM/ENC.S/PO CD=lJeO F* RLP4EM/O. 12/05
   . 00   ,--                                         1      *------------.--~~*~.----

O') to a: i FIGURE l RELAP4-Ef.1 HOT CHANflEL HOT SPOT FLUID TEMPERATURE 0 1. 0 DES/PD 0 (X> a Q_* UJ 

                                                                                                                                                                       ~     t i!         !

I I el1 or gi 

     - 0 fill i

L_ **---L---~*,___ L-~-~-~-*---.l _____,_.

  • g 1e.

TIME 16 

                                                           ~-__J*~--~-*~'---\---------~--------------------j
                                                                ~o
                                                          ~PTER*BRE~K
                                                                         ~4 IN SECONDS is         32.                        36                                       40

~--------------------------

N I 

 ."\l (j) 0
. PRLIS~DES
  • SLOWDOWN WREM/ENC DES/PO CD=l.O F RLP4EM/003 * *12/05
                                                             ~-----....,,..----.-.F-I-GU_R_E_2__,,,~-EL-AP-4--E-M_H_O....-~-C-HA_N_riE--L---.1, 0
      ~  - - - - - - --*--.--*          r*
                                                                                       .~          HOT SPOT AVERAGE FUEL
                                                                                         ;         ROD TEMPERATURE                              1.

l

  • 0 DES/PD -I I

0 0... I 

                                                                                                                                        .~

~J) g 

      ~

0 -L 

                                                                                                                                            ~. I 4i I

j 

                                                                                            . (
                                                                                               ~

8 ____ _ t _ _ _ _:__t _ _ _ _ _L _ ---* . ----**-*--*-..l___ 

                                                                        ..__L _ _ _....._._

II 

      ~          4         s          lf.        16              w        2.4        2.8          32.                                      40 TIME     ~FTER        GRERK IN SECONDS

                                                                                                       .. -- *-"' .  '.'... '-'*'~ . . * . . . * . * -.*: **.*--:.-... -:-*~.::"":":".!~*-** *~**""!~ . . ..
                                                                                                                                                                                                           *~-

PRLISROES -----r-*--- BLOWOOWN WREM/ENC~S/PO CD=l.O F 12/05 

                                                                                            ;. FiGURE 3    RELAP4-EM HOT CHANNEL
  • HOT ASSEMBLY INLET FLOW

{Jur~cnm~ 10) 1 .0 DES/PD I li 

                                                                                                                                                                                                  !i
                                                                                                                                                                                               -{

I eli I I I i I I I I g L. ___......_1_ ~-*---*- _ _J ___ .__ ,___ _J _ _ _ _ _ _ ...J__._~--- i - __..-1~. - - " - ' - - -_ ____.,____,_ ____.._ _ ____. ~ 4  ! 8 tt Y M ~ H 36 

                 !                                 TIME AFTER BRERK IN SECONDS

419-PRLISRDES 

    *-,      I .

SLOWDOWN WREM/ENC Its/PD co~1.o F RLP4EM/OO' 12/0~/ 

                                                                                          ~-I FIGURE 4 RELAP4-EM HOT CHANNEL HOT ASSEMBLY OUTLET FLOW

( JUflCTION 11 ) l .0 DES/PD i i I 

                                                                                            ~

r 

                                                                                           .I 1

I I i I 

                                                                                            -{
                                                                                          *I
                                                 "**~.                                     I!'

8 re m w ~ ~ 32. 36 40 TIME RFT~R BR~~K IN StCONDS 

                                                                                          . --. ... - .. ..  ... **- --*--~*** -*-**~*~*
  • PALTSr:lDES SLOWDOWN WREM/ENC,S/PD CD=l.O F RLP4EM/01 12/0.5
                             --*-          I
                                                                         .FIGURE 5 RELAP4-EM HOT CHANUEL HOT ASSEMBLY OUT FLOW (JUNCTION 12)
1. 0 DES/PD l1

_J

)

>-:\ ~ ,. r . 

~ ~ .[l1 ! I
~ '*![)~
.I   0 11!~w- - - - - - - - -* *- -

L.1;,l~,:\yJ~'I i~ I lf .* . i,r :!

  • 0 ------~--'----~-----~----~--------------_._-----------1*~~~__,_~~~~~~~-'-~~~--~~~
     )l>                 t.._ . .-* - s          16     io     e4     ~s         . 3~                       36 TIME RFTER BRERK IN SECONDS

RLP4EM/ 12/05 w  : FIGURE 6 RELAP4-EM HOT CHANNEL x HOT SPOT FLUID QUALITY a:"-' 1. 0 DES/PD 

       -I*

t-o n... (f)o 

       -I*

t-o I CI <n II 0 t~ >- H _J a:

> tO CJ *
  . 0

(.!) a: 0 0

  • plL-~~---'-~~~--'-~----~-'-~~~...1-~~*----"--~~--l~..;.._~--..J..~~~-'-~~~-'-~~__._J J) 4. 8 1s ~o ~4 ~s ~6 40 TIME RFTER BRERK IN SECONDS

l'

  • 1000 900 800 700 u..

0 I  :.**-;.** (\J 

       .µ
       ..s...

LI- 

               . 600
      ..c:
s
      -+->

co Cl) u c: 

               '500 It:!
       +->
  *~  u 0

0. 400 It:! t!:I 300 Rupture at 49.82 200 lOO 0 l-~-1.~~-L-~--1~~...J-~~L-.~-1-~--1~---l-~~.i.-~--&..~--- 

                       -   4     8     12 Bl owdown FIGURE 7 16 30 60    lOO     140 180 220 Refi 11 + Re flood Time After Break (Sec)

PEAK POWER NODE GAP CONDUCTANCE VS TIME 1.0 DES/PD ENC FUEL 

  *              . 700
                   .600 N

u. 0 I 500 

      .µ
      '+-

S- 

      .c: '
I
       .µ co            400 I        QJ u

I c: 1! 'J 

  *~     c:

0 c....> 300 c.. rel (,!) 200 100 O._.....,__.___,__iL-.,.__.._._.....,___.......,_.....,_...1-__..---1......,_-.--'-~-1--.-~i.--:---L..~--' o 20 40 60 ao 1oo 120 140 160 mo . 200 Time After Break (Sec) FIGURE 8 HOT SPOT GAP CONDUCTANCE

  • VS TIME 1.0 DES/PD ENC FUEL

T--- 1~-- ... l1* . l \ I ' i: j: j; 900 l. 

~i t*

800 200 100 8 12 Slowdown --1--*-- 20 60 l 00 Refill + 140 180 Ref~ood 220 

                                                           ~

Time After Break (Sec) FIGURE 9 MAX. POWER FUEL ROD PRESSURE VS TIME 1.0 DES/PD ENC FUEL}}

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