ML20136F473
| ML20136F473 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 12/31/1985 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | Noonan V Office of Nuclear Reactor Regulation |
| References | |
| SBN-916, NUDOCS 8601070394 | |
| Download: ML20136F473 (5) | |
Text
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M SEABROOK STATION Engineering Office Pub 5c Service of New HampsNro December 31, 1985 Now Hampshire Yankee Divh SBN-916 T.F. P7.1.2 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Mr. Vincent S. Noonan, Project Director PWR Project Directorate No. 5
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNH Letter (SBN-513), dated May 31, 1983, "Open Item Response (SER Section 7.3.2.3; Instrumentation and Controls System Branch)"
Subject:
Level Measurement Error (SER Outstanding Icsue No. 10)
Dear Sir:
Reference (b) submitted the results of our analysis or the level measurement error caused by reference leg heatup resulting from high energy line breaks inside containment. During the November 20, 1985 meeting at Bethesda to discuss the Instrumentation and Controls review, the staff requested additional information relating to our response.
In the telephone conversation on December 23, 1985 with the staff, we clarified our analytical methods. At the staff's request, we are providing, as Attachment 1, the technical description of the HESITET computer program that was used in the analysis.
Other concerns relating to the use of the high containment pressure signal and manual action to mitigate certain feedwater line breaks will be addressed by February 15, 1986.
Very truly oura, 8601070394 851231 PDR ADOCK 05000443 NA E
PDR 0
(),0 John DeVincentia, Director V
1 Engineering and Licensing
{
Attachment cc: Atomic Safety and Licensing Board Service List NQb',
Af) -J. RM f GIT (ltr only.
LB (RALLARD)
P.O Box 300 Seobrook.NH 03874. Terophone (603)474 9521
- ygg, HSB (BENLINGER)
FOR (BENAROYA)
SBN-916 December 31, 1985 e
ATTACHMENT 1 From - HESITET - Temperature Transient in Containment Passivo Heat Sinks and 1
Equipment, ComputerDocumentationandVhificationPackage I
i 2.0 TECHNICAL DESCRIPTION 2.1 Theoretical Basis and Matheestical E _deling The heat conducting structure or equi; ment absorbs heat due to-high 4
containment temperatures produced by the rupture of a high energy line in the coutainment. Tha heat transfered to-the passive heat sinks'is a combination of condensing heat! transfer ant. convective heat transfer as long as the haat sink temperature remains balow the vapor saturation temperature. When the heat sink temperature exceeds the vapa curation temperature the heat transfer is due to convection only.
I 2.1.1 Best Transfer Coefficient 1
1 The condensing heat transfar coefficients are supplied to the program as an input as a function of time. The convective heat transfer coefficients are calculated assuming turbulent flow on a flat plate.
The convective heat transfer can be forced or natural depending on the velocity of the fluid past the exposed surface. If the velocity is negligible the heat transfer will be due to natural convection. The l
following correlationa have been employed to compute the heat tranafer coefficients:
Forced Convection h = 0.036 g (NRE)0 8 (Nyg)1/3 K
l Natural Convection 1/3 h=0.13f(NGR.NR) heated plate P
- 000 h = 0.024 g (NPR)1.17 K
NGR/{1+.494 (NPR))
cold plate
1 f
^
- whers, f
Esat transfer coefficient due to convection h
=
Grashof Number ggg
=
Prandel Number yyg
=
l Reynolds Number NEE
=
Thermal conductivity of the mixture of gases K
=
Characteristic length L
=
The velocity (v) used in evaluation of Nes may be determined as follows:
V = 25 (Mbd/Yeon) where:
V = Velocity in ft/sec bd = Blowdown rate in Ibs/hr M
3 V
= Containment volume in fc con 2.1.2 Mixture Properties The mixture properties needed to calculate the heat transfer coefficients are calculated as follows:
i
^
2.1.2.1 Conductivity The conductivity of a mixture of gases is calculated using Lindsay a*:d Bromley formulation as follows:
a K / {1+
A; (yjfyg)]
K
=
i Jpi i
- where, 5 1 (N)374 (1 + 81/T )
(1 + Sij/T )
i A ij = Ig 1+
X 1 + Si/T 1 + Si/T
(
Ali dynamic viscosity of component i
=
conductivity of component i Ei
=
mole fraction of component i 71
=
molecular weight of component i mi
=
i 1.5 Tbi Si
=
b boiling point of component i Ti
=
Cs (Si + Sj)b Sij
=
~
i C, = 0.733 for very polar gases
= 1.0 otherwise T = absolute temperature 2.1.2.2 Viscosity 2
The viscosity of a mixture of gases is calculated by Wilke formulation.
n 1
M = E{ A1/F1+%
8d (YJ 71}H
~
/
gg
.l J i=1 L
- where, g
g2 (h_
2.[ l + -)f, k = _1 +(
)
2.1.3 Heat Conduction The temperature distribution through a heat conducting structure is determined by solving the following one-d4==naional, unsteady heat conduction equation.
g(x)
(T (x,t)
K (x) e
=
- where, temperature in the heat conducting structure T
=
space variable x
=
time t
=
g volumetric heat capacity
=
thermal conductivity of the material K
=
e l
1
---+--~--+----r,,
.-...-~
. -. -..... ~
., o e
The heat transfer rate from the cone =4-t atmosphere to the structure is given by:
4 = f(h
- h) (T
+"
~
ed sat wall stm wall
- where, 4
= heat flux desntiy h
= condensing heat transfer coefficient g
T
" at208Phere saturation temperature sat Ta = atmosphere dry bulb temperature st Tg = surface temperature f
= 1 if T,,g y T,,17
= 0 otherwise For maximum heat t rans fe r hcond can be obtained from Uchida or Tagami correlations (as appropriate) and multiplying them by a factor of 4.
s e
6 6
-~
=+m---
---w.
-y-n--.,,-
y.
+ -,. - -. - + - - - - - -. -
-,,m_,,-n--
-w--,
--.--,,,-m.
- - - - + - - - - - -
,-y w
-g----