Gadolinium nitrate

Many redundant safety features were provided at the SRP. These included a moderator dump tank, gadolinium nitrate solution as emergency absorber, continuously mnning diesel generators, and a 95 x 10 -L (25 x 10 -gal) elevated water tank for each reactor, for assurance of cooling. 

The relaxation of certain 13C nuclei in some uronic acids and derivatives is affected by Gd3+. For example, on addition of gadolinium nitrate to solutions of heparin or dermatan sulfate in D20, the C-l and C-6 signals of the uronic acid residues are selectively diminished. This property would be expected from a-L-idopyranosyluronic acid residues, as the C-l and C-6 signals of sodium a-D-idopyranuronate are similarly lessened in intensity, whereas those of the j8 anomer are... 

The halogens of gadolinium are very toxic, and gadolinium nitrate is explosive. As with most rate-earths, care should be taken not to inhale fumes or ingest particles of gadolinium. 

A leaching cycle begins by screw metering a batch of waste from the accumulation hopper into the top of the cylindrical bed. Next, a mixture of nitric acid, cerous nitrate and gadolinium nitrate is charged to the thermosiphon. Fluid circulation is induced by steam heating the HEPA bed and the thermosiphon leg. 

Nature and concentration of neutron-absorbing poisons, such as nitrate ion or gadolinium nitrate... 

Soluble neutron absorbers. The preceding limits on critical concentration or dimensions can be greatly relaxed when soluble neutron absorbers, such as boric acid or gadolinium nitrate, are... 

Cei-xGdx02-8 Gadolinium nitrate, cetyl trimethyl ammonium bromide, aqueous ammonia, cerium (111) chloride, sulfuric acid... 

The silicon wafers being used were specially processed to have many tiny holes. Gadolinium nitrate was dissolved in ethanol and added to the porous silicon wafers. After the ethanol evaporated, the gadolinium nitrate remained... 

The reactor protection system comprises of two independent, fast acting, diverse, and physically separate shutdown systems SDS-1 and SDS-2, each of which is capable of performing the above functions independently. SDS-1 comprises of 28 cadmium rods. The second system SDS-2 is capable of high speed injection of gadolinium nitrate solution (in heavy water) directly into the moderator through six horizontal nozzles. There are four cadmium control rods which can be dropped or driven into the core to supplement the negative reactivity capability of the protection system in case of prolonged shutdown. 

Soluble neutron absorber Gadolinium nitrate/boric acid... 

Experiments In progress with this vessel loaded with i wt% borated EaSchtg rings. Experiments planned with gadolinium nitrate solution. 

Criticality of Heterogeneous Systems— UO2-PUO2 Solids in Fissile Solution Containing Gadolinium Nitrate, R. C. Lloyd, E. D. Clayton (BNW)... 

Use of Gadolinium Nitrate for Criticality Control During Fuel Dissolution, R. C. Ashline, W. R. Waltz (AGNS)... 

This paper describes the plans for the use of gadolinium nitrate for criticality control in the dissolver system at the Barnwell Nuclear Fuel Plant (BNFP). The particular aspects this paper addresses include (a) a description of the poison solution makeup system and its safety-related controls, and (b) a summary of the criticality analysis of the dissolver unit. 

Gadolinium oxide is dissolved in 12 M HNOs to prepare a gadolinium nitrate stock solution containing 46 Gd/litre. Prior to processing each lot of fuel, a portion of this... 

The low-pressure, low-temperature moderator contains the reactivity mechanisms and distributes the chemical trim, boron, for reactivity purposes and gadolinium nitrate for shutdown purposes. 

SDS2 utilizes liquid poison (absorber) injection into the moderator. Upon receipt of a reactor trip signal, fast-acting valves between a high-pressure helium tank and the poison tanks open to pressurize and inject the liquid poison into the moderator. Injection occurs from several perforated horizontal tubes in the calandria, through which gadolinium nitrate solution jets into the moderator. An earlier design, the 220-MWe Indian HWRs, employs a set of vertical empty tubes in the reactor core that can be filled with a liquid poison (lithium pentaborate solution). 

The explosive responses shown in Fig. 1 are indicative of the relative energies released by three different oxidants, with the sodium perchlorate explosion significantly more energetic than the oxidants gadolinium nitrate and sulfur (du Plessis 2007). It was demonstrated that a pore size in the region of 3-4 nm was optimal for devices using sodium perchlorate as oxidant (du Plessis and Conradie 2006). Another study concluded that a pore size of 11.8 nm was optimal for the oxidant aluminum nitrate (Plummer et al. 2008). 

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