Читать книгу Industrial and Medical Nuclear Accidents - Jean-Claude Amiard - Страница 70

The incident involving the breach of radioactive effluents in the sea at La Hague was the subject of a reconstruction of the radiological impact, based on the consumption of marine products by the GRNC [GRN 99]. The calculations were based on two assumptions, and the differences between the results were in the order of a factor of 7 for the collective ex utero dose and a factor of 8 for the collective risk. Whatever the calculation hypothesis considered, the predicted number of leukemia cases, which was in the order of 0.0014 cases between 1978 and 1996 (taking into account only the consumption of marine products), increases to 0.002 if we look at all the exposure routes to discharges from nuclear installations in North Cotentin. This result illustrates the significant sensitivity of the risk of leukemia down to discharges from nuclear installations, particularly with regard to the incident of pipe breakage [BAR 00].

The consequences on exposure ex utero of the two major incidents that occurred at the site of the La Hague spent fuel reprocessing plant (breaking of the offshore discharge pipe in 1979–1980 and fire at silo 181 containing high-level waste on January 6, 1981) were estimated and are presented in Table 2.2.

Table 2.2. Type and level of exposure of the population of Beaumont-Hague caused by incidents at the La Hague spent fuel reprocessing plant (modified according to [GRN 99]. For each of the accidents, the percentages of the various causes are provided

Incident	Type of exposure	Dose (myear.Sv)	Percentage
Breaking of the pipe	Ingestion (90Sr, 106Ru)	0.04	48
External (106Ru, 125Sb)	25
Inadvertence (244Cm)	16
Spray and spreading (90Sr)	11
Silo fire	Ingestion (137Cs)	0.14	64
External (137Cs, 134Cs)	35
Inhalation	1