Design of the Online Gross γ Monitoring Instrument at the Exit of the Helium Purification System in HTR-PM

Table 2

Specific activity and other relevant information on the fission products at the exit of the HPS (which has 99.9% purification efficiency).

Nuclides	Half life	Specific activity in the coolant at the exit of the HPS (Bq·L^–1)	Number of emitted γ rays with energy higher than 100 keV	γ ray energy (higher than 100 keV) where the emission probability is maximum (keV)	Maximum emission probability of γ ray (energy higher than 100keV)		Status
Kr-83m	1.83 h	1.40E + 01	0			0.00E + 00	Negligible
Kr-85	10.72 a	1.80E – 01	1	513.99	0.0043	7.81E – 04	Negligible
Kr-85m	4.48 h	6.00E + 01	4	151.18	0.7528	4.52E + 01
Kr-87	76.3 min	6.70E + 01	22	402.58	0.4950	3.32E + 01
Kr-88	2.84 h	1.40E + 02	50	2392.10	0.3460	4.84E + 01
Kr-89	3.16 min	2.00E + 01	141	220.90	0.2000	4.00E + 00
Kr-90	32.32 s	5.00E + 00	64	1118.70	0.3730	1.87E + 00	Negligible
Xe-131m	11.84 d	4.10E + 00	1	163.93	0.0196	8.04E – 02	Negligible
Xe-133	5.245 d	8.50E + 02	1	177.70	0.0007	6.05E – 01
Xe-133m	2.19 d	2.80E + 01	1	233.22	0.1030	2.88E + 00
Xe-135	9.11 h	1.30E + 02	6	249.79	0.8990	1.17E + 02
Xe-135m	15.36 min	1.40E + 01	1	526.56	0.8100	1.13E + 01
Xe-137	3.83 min	4.20E + 01	12	455.49	0.3070	1.29E + 01
Xe-138	14.13 min	9.30E + 01	43	258.31	0.3150	2.93E + 01
Xe-139	39.68 s	9.10E + 00	≥3	218.59	0.5600	5.10E + 00	Negligible
I-131	8.04 d	1.80E – 01	9	364.48	0.8116	1.46E – 01
I-132	2.3 h	2.30E + 00	65	667.69	0.9870	2.27E + 00
I-133	20.8 h	9.20E – 01	22	529.87	0.8632	7.94E – 01
I-134	52.6 min	4.70E + 00	69	847.02	0.9541	4.48E + 00
I-135	6.61 h	1.40E + 00	46	1260.40	0.2861	4.01E – 01
Sr-89	50.55 d	6.60E – 05	1	909.10	0.0002	9.90E – 09	Negligible
Sr-90	28.6 d	4.30E – 07	0			0.00E + 00	Negligible
Cs-134	2.062 a	3.80E – 04	10	604.70	0.9760	3.71E – 04	Negligible
Cs-137	30.17 a	4.90E – 04	≥2	661.66	0.8495	4.16E – 04	Negligible
Ag-110m	249.85 d	3.20E – 04	22	657.75	0.9439	3.02E – 04	Negligible
Co-60	5.271 a	1.10E – 04	3	1173.20	1.0000	1.10E – 04	Negligible
				1332.50
Fe-55	2.7 a	4.90E – 06	0			0.00E + 00	Negligible
Cr-51	27.704 d	1.60E – 06	1	320.08	0.0983	1.57E – 07	Negligible
Na-24	15 h	1.00E – 06	3	1368.50	1.0000	1.00E – 06	Negligible
Si -31	157.3 min	4.50E – 09	1	1266.10	0.0007	3.15E – 12	Negligible
K-42	12.36 h	8.20 – 08	3	1524.70	0.1790	1.47E – 08	Negligible
V-52	3.75 min	4.30E – 10	4	1434.10	1.0000	4.30E – 10	Negligible
Mn-54	312.7 d	7.00E – 08	1	834.83	0.9998	7.00E – 08	Negligible
Mn-56	2.5785 h	1.30E – 07	8	846.75	0.9887	1.29E – 07	Negligible
Fe-59	44.63 d	8.30E – 08	6	1099.20	0.5650	4.69E – 08	Negligible
Co-58	70.8 d	8.20E – 08	4	810.76	0.9943	8.15E – 08	Negligible
Co-60m	10.47 min	1.00E – 08	2	1332.50	0.0024	2.40E – 11	Negligible
Ni-63	100.1 a	1.10E – 07	0			0.00E + 00	Negligible
Cu-64	12.701 h	5.10E – 07	2	511.00	0.3574	1.82E – 07	Negligible
Cu-66	5.12 min	7.90E – 10	≥3	1039.20	0.0923	7.29E – 11	Negligible
Mo-99	66.02 h	1.20E – 07	7	739.58	0.1280	1.54E – 08	Negligible
Tc-99m	6.02 h	1.00E – 08	2	140.51	0.8907	8.91E – 09	Negligible
Rb-88	17.8 min	7.70E + 00	15	1836.00	0.2140	1.65E + 00
Cs-138	32.2 min	1.60E + 00	48	1435.90	0.7630	1.22E + 00
C-14	5073 a	5.20E – 01	0			0.00E + 00	Negligible
H-3	12.28 a	2.10E + 02	0			0.00E + 00	Negligible