Batch I racks

Though the original information package for the proposed CRP specified six base metals, two crevice sandwiches and four galvanic couples for exposure, the racks of Batch I contained fewer coupons. 

The specimen stacking sequence was as follows, from top to bottom in the racks of Batch I 1100, 1100, 6061, 6061, SZAV-1, SZAV-1, 6063-6063, 6063-6063,SS 316-6063,SS 316-6063. 

The participants were instructed to expose these racks in representative spent nuclear fuel assembly storage basins. They were also encouraged either to add coupons made of site specific alloys to these CRP racks or to fabricate similar racks with site specific alloy coupons. None of the participants added site specific alloy coupons to the racks of Batch I. China, however, prepared and exposed a separate rack with Chinese alloy coupons. This rack was exposed prior to the second RCM. The Chinese rack included coupons of the aluminium alloys 305 and LT24L and of SUS 304-8K the composition of these alloys is given in Table 4.2. A photograph of this rack is shown in Fig. 4.3. Table 4.3 shows the position of these alloy coupons in their additional rack. Brazil manufactured a separate rack (the IPEN rack) of coupons. This included a large number of coupons in different configurations, to allow evaluation of the effect of fuel 

TABLE 4.3. POSITION OF SPECIMENS IN THE CHINESE TEST RACK 

Specimen configuration Position in rack Alloy Size (mm) 

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