Spent fuel basin

The spent fuel basin used for the corrosion tests was constructed of reinforced concrete and hned with aluminium. The size of the basin was 3114 mm (length) X 2114 mm (width) x 5430 mm (depth) and the basin contained 31.6 m of deionized water. The racks were suspended in the spent fuel basin water on stainless steel wires. The racks were positioned 2.5 m below the water surface, and were 0.8 m and 1.5 m away from the basin walls, to avoid contact with the fuel racks (Fig. 7.1). 

There are 24 fuel racks in this basin and 14 assembUes in each fuel rack. At present, 236 assemblies with 3628 rods of spent fuel are stored in this basin. 

Rack No. Origin Materials Date of first Duration of test 

Made by CIAE with coupons of site specific material. 

The basin water is mainly stagnant, except during purification. Basin water purification is not periodic and depends on the extent of deterioration of the water quality it is carried out about once a year. The purification system is a mobile mixed ion exchange column 1.5 m high and 200 mm in diameter. 

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COUPONS IN THE SPENT FUEL BASIN AT THE OFFICE OF ATOMIC ENERGY FOR PEACE, BANGKOK, THAILAND. 197... 

In 1996 the IAEA initiated a CRP on the corrosion of aluminium clad spent research reactor fuels to help evaluate the state of the spent fuel assemblies and to inform pool/basin operators regarding maintenance and housekeeping procedures to extend the lives of the FAs. The main activities of this programme are related to exposing racks of aluminium alloy specimens (coupons) in different spent fuel basins around the world. Five racks were suspended in the 1EA-R1 reactor pool and were subsequently withdrawn after different time spans to evaluate the extent of corrosion of the coupons as a function of alloy composition, crevices, bimetallic effects and water chemistry. During this period the pool water was monitored for pH, conductivity, chloride ion content and radiometry (Table 6.3). The IAEA CRP racks are denoted as racks 1,2A, 2B, 3A and 3B. 

CORROSION BEHAVIOUR OF ALUMINIUM ALLOY TEST COUPONS IN THE SPENT FUEL BASIN OF THE CHINA INSTITUTE OF ATOMIC ENERGY, BEIJING... 

Five racks of test coupons were immersed in the spent fuel basin of the swimming pool research reactor at the CIAE. The rack numbers, the coupon materials and the immersion dates are listed in Table 7.1. The coupons were assembled in the rack to evaluate general corrosion, crevice attack and galvanic... 

The last cleaning of the spent fuel basin was in 1995 and included the bottom and the walls of the basin. The basin sludge was not analysed. The materials of the basin components are fuel rack — aluminium graphite rack — aluminium test target — stainless steel and aluminium. 

FIG. 7.1. Spent fuel basin and position of rack. Dimensions in millimetres. 

The experiments carried out in Thailand related to the exposure of standard coupons to spent fuel basin water were based on instructions provided at the first RCM, held at KFKI in Budapest in August 1996, and the second RCM, held in S3o Paulo in March 1998. During the second RCM, a protocol was established to handle, prepare, expose and evaluate standard coupons. 

TABLE 13.1. CHEMICAL PARAMETERS AND RADIOACTIVITY OF THE SPENT FUEL BASIN WATER... 

H. TOFFER, Borated Concrete Use in the Hanford N Reactor Spent Fuel Basin, Tram. Am. Nucl. Soc., 24, 231 (1976). 

N Reactor fuel elements were discharged to the spent fuel basin via a large tunnel-like canal located at the outlet face of the N Reactor. During this transfer process, a large quantity of reactor primary-cooling-circuit water, containing considerable amounts of suspended and soluble metals and metal oxides was added to the spent fuel storage basin. Excess basin water was routed to the 116-N-l and/or 116-N-3 cribs via the basin overflow weirs and a... 

The 1314-N LWLS is a transfer station consisting of numerous valves, pumps, underground and overhead piping and couplings, and underground tanks at the north end of the 100-N Area, approximately 90 m (300 ft) from the Columbia River. The unit received liquid radioactive waste from the 116-N-2 radioactive chemical waste treatment and storage facility and the 107-N spent fuel basin recirculation facility. The waste was transferred into railway tank cars and transported to the 200 Area for processing and disposal. 

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