A 2,400 MW(t) plutonium sodium-cooled fast reactor has the following characteristics:
W = 14,000 kg /s τ = 4.0 s c_p = 1,250~J/(kg °C)
M_ƒc_ƒ = 13.5 × 10^6 J/°C M_cc_p = 1.90 × 10^6 J/°C T_i = 360 °C
Λ = 0.5 × 10^{-6} s α_ƒ = -1.8 × 10 ^{-5} /°C α_c = +0.45 × 10 ^{-5} /°C
The reactor undergoes a loss of flow transient with { W}(t)={ W}(0)/(1+t/t_{o}) where t_{o}=5.0\,\mathrm{s}\,. Employ appropriate software to Eqs. (8.36) through (9.40) to analyze the transient: Make plots of the reactor power, fuel and coolant outlet temperatures for 0 < t < 20 s ( Hint, note that \tilde τ cannot be approximated by τ in this problem.)
β1 := 0.00021 \operatorname{c1}:=\mathbb{\beta 1}\cdot {\frac{\operatorname{P0}}{(\lambda1\cdot\Lambda)}} \mathrm{c}2:=\beta 2.{\frac{\mathrm{P}0}{(\lambda2\cdot\Lambda)}}
β2 := 0.00142 \operatorname{c3}:=\mathbb{\beta 3}\cdot {\frac{\operatorname{P0}}{(\lambda3\cdot\Lambda)}} \mathrm{c}4:=\beta 4.{\frac{\mathrm{P}0}{(\lambda4\cdot\Lambda)}}
β3 := 0.00128 \operatorname{c3}:=\mathbb{\beta 3}\cdot {\frac{\operatorname{P0}}{(\lambda3\cdot\Lambda)}} \mathrm{c}4:=\beta 4.{\frac{\mathrm{P}0}{(\lambda4\cdot\Lambda)}}
β5 := 0.0007 \operatorname{c5}:=\mathbb{\beta 5}\cdot {\frac{\operatorname{P0}}{(\lambda5\cdot\Lambda)}} \mathrm{c}6:=\beta 6.{\frac{\mathrm{P}0}{(\lambda6\cdot\Lambda)}}
β6 := 0.00027
Sample calculations shown for $0.10 below using the stiff differential equations solver Radau (Mathcad) to obtain the vector Y.
\mathrm{Rf}:={\frac{\tau}{\mathrm{MfCf}}}=0.296 \alpha_{\mathrm f}:=-1.8\cdot10^{-5}
\mathrm{Tf0}:=\mathrm{Rf.P0}+\mathrm{Ti}=1.071\times10^{3} \alpha_{\mathrm c}:=0.45\cdot 10^{-5}
C=({2 \cdot \operatorname{Rf}\cdot{{W}}_{0}\cdot{{C}}{{p}})}^{-1}C = 0.096
\mathrm y := \begin{pmatrix}P0 \\ c1 \\ c2 \\ c3 \\ c4 \\ c5 \\c6 \\ \mathrm {Tf0} \end{pmatrix}
Y := Radau (y , 0 , 100 , 10000 , DD)
n := 0 .. 10000
Below is an algebraic equation to obtain the coolant outlet temperature using the fuel temperature and the inlet temperature.
\mathrm{Y_{n,9}} :=\mathrm{Ti}+\mathrm{C} \cdot\bigg (1 + \frac{Y_{n,0}}{t_0}\bigg) \cdot Y_{n ,8}