Double-ended guillotine

Venting area currently included in the design of the Reactor Building is that for the blowdown from a double-ended guillotine break of a main steam line. 

A circumferential pipe rupture may result from a failure of the piping by a stochastic, spontaneous double ended guillotine break damage by a degradation failure mechanism such as corrosion or fatigue (i.e. a crack... 

The phenomenon of pipe whip in its classical form can occur only as a consequence of a double ended guillotine type pipe break in high energy... 

Purification of the secondary sodium after a sodium-water reaction As the safety design criteria for a DBL, 4DEG (Double Ended Guillotine) breaks are specified based on the result of leak propagation analysis using conservative conditions... 

A double-ended guillotine rupture of an inlet header reverses the flow in the downstream core pass. On the other hand, a small break at the inlet header will maintain the flow in the normal flow direction. Therefore, it is possible to select a break size that leads to a period of sustained very low-flow in the downstream core pass. This low-flow arises from a balance between the break flow and the flow delivered by the upstream pump. Such breaks, referred to as critical breaks, tend to more limiting with respect to cooling of the fuel and fuel channels than other large breaks and are therefore analyzed in detail. After a short period of about <30 s of very low-channel flows in the affected pass, voiding at the pump suction degrades the pump head causing channel flows in the downstream pass to reverse toward the break. 

Intermediate leak 0.05 - 2 kg/s. This is a leak which engulfs many other tubes in reaction products and produces significant excess pressures in the secondary circuit. It might be caused by a complete failure of a single tube so that steam flows unimpeded from both the broken ends (this is sometimes known as a "Double-Ended Guillotine Fracture", DEGF). However, if water rather than steam flows from a DEGF, flowrates of 10 kg/s may be possible. 

The safety design criteria for a DBL, 4xDEG (double ended guillotine rupture of the heat... 

Actually, a range of break sizes is considered, the largest being the hypothetical severance of the largest pipe in the system in such a way that reactor coolant would discharge unimpeded from both ends of the severed pipe. This type of break is referred to as a "double-ended guillotine break" and usually leads to the most severe calculated conseq Because... 

The design basis accidents for the ECS are a loss of coolant accident from a double-ended guillotine break (DEGB) of a large process water line (D20) and a loss of pumping accident from a cooling water line break. Section 6.2.3.3.1.1 of the Safety Analysis Report (SAR) states that the ECS addition rate for a... 

The enveloping nature of the design basis event relative to other events will be confirmed. The design basis event shall be a double-ended guillotine break (DEGB) loss-of-coolant accident (LOCA), unless an alternative basis is demonstrated to be... 

According to the US NRC point of view, a Double Ended Guillotine break (DEG) or an equivalent axial crack must be postulated for the High Energy Fluid stem (HEFS) piping. In contrast, for the Moderate Energy Fluid stem (MEFS) piping, a slit-like defect of D/2 in... 

The PSAR of the CEFR was finished in May of 1998, but the review lasted 2 years. The primary pipe rupture accident is the key accident and the most important topic in this review. The owners (us) think that the 0.25DT (D is the diameter of the pipe and T is the thickness of the pipe) size break initial event should be a DBA (Design Base Accident), but the double-ended guillotine break instantaneous should be a BDBA (Beyond DBA). However, the reviewer was of the opinion that the double-ended instantaneous guillotine break should be DBA. The owner should calculate the break position spectrum in order to find the most serious case. 

In spite of the fact that the safety cases for Monju, CRBRp, SPX, and BN-600 have all considered that the double-ended guillotine instantaneous break should not be a DBA (Design... 

Pessimistic hypotheses for the LIPOSO accident scenario (double-ended guillotine break in 1 s) ... 

Double-ended guillotine break 1 s of a pipe joining a pump to the core grid plate in ... 

The purpose of the analysis is to check, whether a double ended guillotine rupture (DEGR) in any of the four pipes can be detected by knowing the associated core flow reduction and temperature rise across the core. 

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