NN = 50;
ra = 4*10^3;
h = 120;
alpha = 2.5;
m = 2;
x0 = 500;
betadB = 0;
beta = 10^(betadB/10);
sp = ra + x0;
sm = ra - x0;
wp = Sqrt[sp^2 + h^2];
wm = Sqrt[sm^2 + h^2];
d = Sqrt[ra^2 + h^2];

thet1[w_] := ArcCos[(w^2  + x0^2 - d^2)/(2*x0*Sqrt[w^2 - h^2])] ;
phi1[w_] := ArcCos[(x0^2 + d^2 - w^2 )/(2*x0*ra)] ;

Fw1[w_] := ((w^2 - h^2)/ (ra^2));
fw1[w_] := ((2 w)/ (ra^2)) ;

Fw2[w_] := (((w^2 - h^2)/(Pi*ra^2))*(thet1[w] - 1/2*Sin[2*thet1[w]])) + (1/Pi *(phi1[w] -  1/2*Sin[2*phi1[w]]));
fw2[w_] := ((2 w)/(Pi* ra^2)) *ArcCos[(w^2  + x0^2 - d^2)/(2*x0*Sqrt[w^2 - h^2])];

fRa1[rr_] := NN*(1 - Fw1[rr])^(NN - 1)*fw1[rr];
fRa2[rr_] := NN*(1 - Fw2[rr])^(NN - 1)*fw2[rr];

AA[ss_, rr_] := (Integrate[(1 + (ss ua^-alpha)/m)^-m (fw1[ua]/(1 - Fw1[ua])), {ua, rr, wm}] + Integrate[(1 + (ss ua^-alpha)/m)^-m (fw2[ua]/(1 - Fw1[ua])), {ua, wm, wp}])^(NN - 1);
BB[ss_, rr_] := (Integrate[(1 + (ss ua^-alpha)/m)^-m *(fw2[ua]/1 - Fw2[ua]), {ua, rr, wp}])^(NN - 1);

FAfinal[ss_, rr_] := Sum[((-1)^k/Factorial[k])*D[AA[ss, rr], {ss, k}], {k, 0, m - 1}];
FBfinal[ss_, rr_] := Sum[((-1)^k/Factorial[k])*D[BB[ss, rr], {ss, k}], {k, 0, m - 1}];

s1[rr_] := m*rr^alpha*beta;
FA[rr_] := FAfinal[s1[rr], rr]*fRa1[rr];
FB[rr_] := FBfinal[s1[rr], rr]*fRa2[rr];

Pc = NIntegrate[FA[rr], {rr, h, wm} ] +  NIntegrate[FB[rr], {rr, wm, wp} ]