Sodium pools

Noyes, R. C., 1963, An Experimental Study of Sodium Pool Boiling Heat Transfer, Trans. ASME. J. Heat Transfer 85 125-131. (2)... 

Some medical researchers claim in vivo activation analysis is an excellent nondestructive method that can be used to either (a) measure the total-body content of trace elements considered important to man s health or (b) determine the total amount of a particular element in an organ. Studies carried out by Anderson et al. (23,24), Battye et al, (60) and Newton (645) have measured the total sodium, calcium and chlorine contents of the whole body. In similar studies Chamberlain et al. (168) and Palmer et al. (680,681) have demonstrated the feasibility of the method for total body sodium and calcium. Chamberlain et al. (167) have used living subjects to develop further evidence for nonexchangeable sodium pools in the body. 

EVST shielding above the sodium pool consists of 22 in. of steel including the closure head, plus 2 in. of borated polyethylene neutron shielding attached under the striker plate. This shielding will ensure that the radiation level above the striker plate will not exceed 0.2 mrem/hr under the design basis conditions. 

Corticoids are also called corticosteroids they are physiologically divided into mineralocorticoids acting during the metabolism of electrolytes (sodium and potassium) and glucocorticoids acting during saccharo-metabolism, the antiinflammatory response, and the sodium pool. 

Based on the VOF method (Volume of Fluid) proposed by U.S. LANL, another computer code for calculating the free Na surface wave motion in the CEFR primary sodium pool has been developed in Qinghua University. ... 

The model describing the deviation of a light beam above a sodium pool due to thermal heterogeneities was completed and is now optimized. The problem of aerosols remains to be resolved. 

Sodium coolant has very good thermal conductivity. In the event of failure of the main sodium pumps, heat can be transferred to the vessel boundary by conduction and natural convection without large increases in temperature. Provided the reactor is small enough, decay heat can then be transferred through the vessel wall to a natural convection air flow. Alternatively a small additional heat exchanger in the sodium pool can be used to take heat to an external heat sink by natural convection. Thus the sodium and the small size permit a passive decay heat removal system. 

The body sodium is distributed into intracellular and extracellular pools. The sodium contained in these pools exchanges readily with the exogenous sodium. Isotope studies demonstrate that the intracellular sodium is rapidly exchanged with the extracellular sodium. In addition to the two large sodium pools, a smaller sodium pool is located in the skeleton. The sodium in bone is only slowly exchanged with exogenous sodium. The presence of sodium in the bone has been discussed in the chapter on calcification. 

There were multiple barriers between fuel and the environment. The fuel in each fuel pin was hermetically sealed within a strong stainless steel clad the fuel pins were immersed in a sodium pool able to retain chemically a number of important fission products, should a fuel pin fail the coolant was contained within the primary contaiiunent (the reactor vessel, the biological shield roof and, surrounding the reactor vessel, the leak jacket) over the biological shield roof was the secondary containment building which incorporated a post-incident cleanup plant. The latter ensured that any radioactive release to the environment, even following a major incident would be kept to a minimum. 

Pool fires A sodium pool fire will not normally ignite below about 250°C (if the pool is at rest). Since the fire occurs only at the pool surface it is appropriate to characterize the reaction rate on an area basis. A standard rate for a pool fire is 25 kg/nuh. 

In the event that the electric drives fail to actuate the dampers there is difficulty with manual opening, an emergency passive drive could be provided. It would be based on natural effects such as gravity and a "shape-memory" effect in special alloy structural materials manifesting itself as temperature changes. The passive drive could be installed in the reactor sodium pool or in the expansion tank of the mr cooler. It would actuate as the primary sodium temperature approached 600°C. 

Argon gas from an auxiliary argon circuit covers the sodium surface to prevent any contact with air. The sodium contained in the primary vessel is operated at a pressure slightly higher than atmospheric. The hot and cold sodium pools are separated by an inner vessel. An upper core structure is suspended from the small rotating plug and contains control rod guide ducts and thermocouples. 

The thermal capacity of the bucket Is sufficient to maintain fuel cladding at less than the on-power operating temperature during the time taken for normal transfer between the reactor vessel and the CCS. To cater for the risk that a hold up occurs while the fuel Is out of the sodium pools, the bucket will be finished with a profile which enables the heat to be transferred to the ramp tubes by radiation. A steady state heat removal capacity of about 35 KW can be achieved within a temperature limit which will not jeopardise the fuel pin Integrity. By switching on a gas cooling system the heat removal capacity can be enhanced. 

The CEFR block is shown in Fig. 14.3 (Xu, 2008). It is mainly composed of a reactor cover, a sodium pool, and internal structures. The reactor cover is an approximately 2-m-thick steel-concrete structure that acts as the reactor upper shielding and provides support for the plug, main pumps, intermediate heat exchangers (IHXs), residual heat removal heat exchangers, and the circuits and pipes of various auxiliary systems. The driving mechanisms of control and safety, the fuel manipulator, and various measurement instruments are all fixed on the small plugs of the plug system. 

The sodium pools are mainly composed of a main vessel and guard vessel, with a temperature and pressure measurement instrument on the wall and a sodium leak detector in the gap of the vessels. The main vessel acting as the boundary of the primary circuit is a very important item of safety equipment. The internal strucmres involve the inner pool used to separate the hot and cold pools, the reactor core and its pressure header, and supports and shieldings. 

The primary circuit of the CEFR in the sodium pool has two primary sodium pumps, which drives the 360°C cold sodium from the cold pool into the core and cools it. The average core outlet temperature can be as high as 530°C. Via the hot... 

The primary circuit of the CEFR is composed of two main pumps, four intermediate heat exchangers, reactor core support diagrid plenum, pipes, and cold and hot sodium pools. In the cold pool, the two primary loops are separated from each other, but in hot pool they are linked up. In normal operation the average sodium temperature in the cold pool is 360°C and in the hot pool it is 516°C. Figure 2 shows the CEFR primary pipe. 

Access for maintenance and repair is generally considered much easier with the loop system since the components are separate and not closely coupled to the reactor vessel. The loops of a multiloop system can be located in individual cells to allow repair operations while the reactor is operating at reduced power on the remaining loops. Since in the pool system, pumps and heat exchangers are suspended from the reactor vessel cover into the sodium pool around the reactor core, they must be designed for high reliability to avoid excessive downtime for removal and replacement. It would probably not be feasible either technically or... 

---