Document: NUREG-0800
Document ID: 545a669a-51a1-4b1f-9d90-78ee08ca0845
Document Type: srp
Title: COMBUSTIBLE GAS CONTROL IN CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070463.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.5
CFR Part: 
CFR Title: 

Content:
ergy absorbed in coolant outside core due to fission products dissolved in coolant, s ev/sec-MWt. The quantity E (t) is defined by: c E (t) =(f ) H (t) c q c q where (f ) = fraction of fission product gamma energy absorbed by coolant in core region c (H )(t) = gamma energy production rate, ev/(sec-Mwt). Similarly, E (t) is defined by: s E (t) = (f ) H (t) + f H (t) s + s ( + ) I I where (f ) = fraction of total solid fission product energy absorbed in coolant outside core + s H (t) 1022(5.1912e 9.8×10 5t 0.8743e 6.5×10 6t 0.6557e 5.7×10 7t 0.4098e 7.4×10 8t 0.0150e 8.0×10 10t) H (t) 1022(5.1912e 9.8×10 5t 0.8743e 6.5×10 6t 0.6557e 5.7× 7t 0.4098e 7.4×10 8t 0.0150e 8×10 10t) HI(t) 1022(0.8197e 6.1×10 5t 0.3279e 1.1×105t 0.0574e 1.0×10 6t) 6.2.5-19 DRAFT Rev. 3 - April 1996 H (t) = total solid fission product energy production rate, ev/sec-MWt + f = fraction of iodine isotope energy absorbed in coolant outside core I H (t) = iodine isotope energy production rate, ev/sec-MWt I The equations for oxygen generation by radiolysis are identical to those above describing hydrogen evolution except that the yield is one-half that of hydrogen. These equations have been incorporated into the COGAP program. For calculational purposes, the reactor decay profiles (H (t), H + (t), and H (t)) specified by the ANS-5.1 draft standard for two-year reactor I operation have been fitted by several finite exponential series expressions and also incorporated into the program. The resulting equations are: H (t) = 2.0H (t) + where t = time after reactor shutdown, sec. Between 400 and 4 x 10 seconds, the equations overpredict the standard curve by 20%. The 7 equations underpredict the standard curve soon after shutdown. However, this does not seriously affect the results due to the short time period involved. The equations are equivalent to the afterheat decay curve in BTP ASBSPLB 9-2 over the times of interest for post-accident hydrogen generation. Sc(t) ApBC(t) 12×3.15×107