Containment spray storage tank

The CSS achieves the above objectives by spraying a sodium hydroxide solution of borated water throughout a large volume portion of the containment atmosphere. The system consists of a containment spray storage tank (CSST), a spray additive tank (SAT), two... 

The safety improvements use redundancy and diversity to prevent and mitigate lents. The safety injection system (SIS) and emergency feedwater system (EFWS) are dedicated four train systems. Containment spray and safety injection pumps take water from the in-containment water storage tank (IRWST), thus, eliminating the need to switch from an external source and provide a. semi-closed system with continuous recirculation. Emergency core coolant flows direc nto the... 

The compositions may be cast, laid up by hand, sprayed, or molded. The final products are used as corrugated or flat panels, helmets, electric appliances, furniture, containers, automotive housings, boats, house sidings, modular bathrooms, and chemical storage tanks. 

Methanol was added to a reactor containing nitric acid instead of xylene, because the storage tank was wrongly labelled. A reaction ran away out of control and vented via a relief system without a catchpot. Fumes and acid spray spread over a considerable distance affecting about 30 people off site. 

Two principal systems used to mitigate the effects of a 1/3CA are the safety injection system (SIS) [see CESSAR-DC, Section 6.3], and the containment spray system (CSS) [see CESSAR-DC, Section 6.5]. These systems utilize an In-containment Refueling Water Storage Tank (IRWST) as their source of water, which is the equivalent of the refueling water storage tank (RWST) and containment sump of a pre-ALWR plant. 

The System 80+ Standard Design has an in-containment refueling water storage tank (IRWST), as described in CESSAR-DC Section 6.8. The CSS draws water from the IRWST. When spray is initiated during a LOCA, spray water from the upper elevations drains through major openings such as hatches and stairwells to the holdup volume of the IRWST, where it is mixed with water spilled from the break. From the holdup volume, water overflows... 

The bulk storage tank, which contained a 93% sulfuric acid solution, was connected to two tanks, the day tank and an acid regeneration tank (also caUed the dUute tank), by 2.5-cm carbon steel Unes. The valve in the line connecting the bulk storage tank and the dUute tank was located near the dilute tank. The acid spray was caused by a failure in the line where it was connected to the valve. The procedure for transferring acid from the bulk tank to the day tank required that the valve at the dilute tank be closed and a transfer pump be used to facilitate the transfer of acid from the bulk tank to the day tank. When the accident occurred, the valve at the dilute tank was closed and the transfer pump had been started. The pump built up pressure in the pipe, causing the acid to spray out. 

The containment is equipped with sumps to collect the water of the primary circuit and of the ECCS water storage tank after a LOCA in order to recirculate the water in the second phase of the accident. The openings of the containment bottom plate are covered with a screen which is intended to prevent debris penetration to the suction of the ECCS and containment spray system. 

The WWER-1000 plants are equipped with ECCS and containment spray systems that have a similar design basis and similar basic configuration as in western PWRs. These systems have 3 100% redundancy with the exception of the ECCS water storage tank which is common to all subsystems. The same tank serves as a containment sump. The tank is located under the containment and has open connections to the containment through the bottom plate. Each of the three safety system trains has one suction line from the ECCS water storage tank to the residual heat exchangers and further to the low pressure safety injection, high pressure safety injection and spray pumps. The suction line is equipped with one containment isolation valve. 

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