Consequences of the loss of the residual heat removal systems in pressurized water reactors

  • 153 Pages
  • 4.59 MB
  • 5890 Downloads
  • English
by
Division of Systems Technology, Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission, Supt. of Docs., U.S. G.P.O. [distributor] , Washington, DC
Pressurized water reactors -- Emergency core cooling sys
Statementprepared by L.W. Ward, W. Arcieri, C. Heath.
ContributionsArcieri, W., Heath, C., U.S. Nuclear Regulatory Commission. Office of Nuclear Reactor Regulation. Division of Systems Technology., Idaho National Engineering Laboratory., EG & G Idaho.
The Physical Object
FormatMicroform
Paginationxx, 153, 9 p.
ID Numbers
Open LibraryOL14694601M

Get this from a library. Consequences of the loss of the residual heat removal systems in pressurized water reactors. [L W Ward; W Arcieri; C Heath; U.S.

Nuclear Regulatory Commission. Office of Nuclear Reactor Regulation. Division of Systems Technology.; Idaho National Engineering Laboratory.; EG & G Idaho.]. Generic Issue 99 is concerned with the loss of residual heat removal (RHR) capability in pressurized water reactors during cold-plant outage operations.

The issue focuses on two risk-significant common-cause failure modes of the RHR system: (1) air binding of the RHR pumps during reduced-inventory operations and (2) spurious closure of the RHR.

Loss of Residual Heat Removal (RHR) While the Reactor Coolant System (RCS) is Partially Filled (Generic Letter No. ) UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C.

Download Consequences of the loss of the residual heat removal systems in pressurized water reactors EPUB

July 9, ALL LICENSEES OF OPERATING PWRS AND HOLDERS OF CONSTRUCTION PERMITS FOR PWRS Gentlemen: SUBJECT: LOSS OF RESIDUAL HEAT REMOVAL (RHR) WHILE THE REACTOR COOLANT SYSTEM.

Decay heat of the plant is removed by residual heat removals system (RHRS). The water level in the primary system is maintained at mid-line of the hot leg (Seo and Park, ; Sui et al., ). On loss of RHRS, no other system is immediately available for decay heat removal from the core due to by: 2.

The residual heat removal system (RHR) is a low-pressure heat removal system. In PWRs, it takes water from one or two RCS hot legs, cools it in RHR heat exchangers, and pumps it back to the cold legs or Consequences of the loss of the residual heat removal systems in pressurized water reactors book flooding tank nozzles.

To accomplish RHR heat removal, RHR heat exchangers transfer heat to the component cooling water or service water. This paper presents preliminary technical results from the phase I evaluation of the effects of aging on Residual Heat Removal (RHR) systems in boiling water reactors (BWRs).

The goal of the phase I work is to characterize the aging phenomena by identifying pre- dominant failure causes, modes and mechanisms, as well as time-dependent aging trends.

The analyses have been performed considering the loss of residual heat removal (RHR) system at various times after reactor shutdown for the reactor vessel configuration with the removed upper head. Passive residual heat removal system (PRHRS) for the secondary loop is one of the important features for Chinese advance pressurized water reactor (CAPWR).

To prove the safety characteristics of CAPWR, serials of experiments have been done on special designed PRHRS test facility in the former stage.

The test facility was built up following the scaling laws to preserve the similarity to CAPWR. Dai, Shoubao, Peng, Minjun, and Liu, Jiange. "Optimization and Analysis for Passive Residual Heat Removal System of an Integral Pressurized Water Reactor." Proceedings of the 17th International Conference on Nuclear Engineering.

Volume 4: Codes, Standards, Licensing and Regulatory Issues; Student Paper Competition. Brussels, Belgium. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Available via license: CC BY Content may be subject to copyright.

This paper reports that since the loss of vital alternating current power and the residual heat removal system (RHRS) during shutdown at Vogtle Unit 1 on Mamuch attention has been focused on the need to evaluate system performance following such an event in a light water reactor.

A key feature of the passive core cooling system is the passive residual heat removal heat exchanger (PRHR HX) that provides decay heat removal for postulated LOCA and non-LOCA events.

The PRHR HX is a C-tube heat exchanger located in the in-containment refueling water storage tank (IRWST) above the core promoting natural circulation heat. Get this from a library. Loss of residual heat removal system: Diablo Canyon, Unit 2, Ap [U.S.

Details Consequences of the loss of the residual heat removal systems in pressurized water reactors EPUB

Nuclear Regulatory Commission. Office of Inspection and Enforcement. Region V.;]. A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS), which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper.

Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat. Disclosed is a secondary side passive waste heat removal system, comprising a steam pipeline () and a water supply pipeline (), wherein the steam pipeline () hermetically penetrates a containment vessel and is connected to an outlet of a steam generator () arranged in the containment vessel as well as a cooling water tank () arranged outside the containment vessel, the water.

In a small modular Pressurized Water Reactor (PWR) the decay heat is removed by the Residual Heat Removal System (RHRS) shown in Figure 3. The RHRS consists of an external water loop, which removes heat from the Reactor Pressure Vessel (RPV) via the RHRS heat exchanger and discharges it to an atmospheric pool at a higher elevation.

The system. cleanup (e.g., hydrogen removal system) d. systems2 or portions thereof that are required for (1) reactor shutdown, (2) residual heat removal, or (3) cooling the spent fuel storage pool e.

those portions of the steam systems of boiling-water reactors extending from the outermost containment isolation valve up to but not including the turbine. and various alternative and support systems is important to assuring that the decay heat removal (DHR) function can be performed reliably during shutdown.

There have been 52 events at U.S. Pressurized-Water-Reactors (PWRs) involving the loss of a residual heat removal systems (RHRS) during mid-loop conditions. Three. (2) General containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs).

(3) Emergency core cooling systems (ECCS) for pressurized water reactors (PWRs) including: High-head, intermediate-head, and low-head injection systems and the low pressure injection function of residual (decay) heat removal systems.

The residual heat removal system 3 in each safety division has enough capacity for % of removing heat capacity (twice the removing heat capacity of the residual heat removal system of a conventional ABWR) required for cooling the nuclear reactor core and the containment 15 at a loss of coolant accident, which is a design basis accident.

of a compensating tank pressurized by nitrogen, a heat exchanger immersed in an in-containment refueling water tank, valves and piping for steam and condensate.

The compensating tank makes up the water volume change in the passive residual heat removal system and holds the water inventory for the filling system pipelines during a cooldown. Passive decay heat removal system.

Remove residual/decay heat and cool down the plant during normal shutdown, in the event of anticipated operational occurrences and DBA.

Description Consequences of the loss of the residual heat removal systems in pressurized water reactors FB2

Overpressure protection system • Primary & Secondary: Protect the primary side equipment and pipelines from excessive pressure under DBA and BDBA conditions. decay heat removal, the total decay heat removal by hybrid control rod is MW.

The heat removal rate is about 3 % of decay heat when the decay heat removal from the secondary system is ended by depletion of water in the steam generator at SBO accident. Thus, the enhancement of heat removal capacity of hybrid control rod system is required.

A pressurized water nuclear reactor system includes a vortex mitigator in the form of a cylindrical conduit between the hot leg conduit and a first section of residual heat removal conduit, which conduit leads to a pump and a second section of residual heat removal conduit leading back to.

Reactor Startup. A reactor startup is a procedure, that comprises many points and changes of operational parameters and significantly differs according to certain reactor type.

For example, any startup of zero-power reactors (e.g. research reactors) can be classified into three categories. Buy Residual Heat Removal Experience Review and Safety Analysis: Pressurized Water Reactors (NSAC/ January ) on FREE SHIPPING on qualified orders.

Although all three of the reactors that were operating were successfully shut down, the loss of power caused cooling systems to fail in each of them within the first few days of the disaster.

Rising residual heat within each reactor’s core caused the fuel rods in reactors 1, 2, and 3 to overheat and partially melt down, leading at times to. ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering ASME Letters in Dynamic Systems and Control Journal of Applied Mechanics.

A nuclear meltdown (core meltdown, core melt accident, meltdown or partial core melt) is a severe nuclear reactor accident that results in core damage from overheating. The term nuclear meltdown is not officially defined by the International Atomic Energy Agency or by the Nuclear Regulatory Commission.

It has been defined to mean the accidental melting of the core of a nuclear reactor, however. Reactor protection system (RPS) A reactor protection system is designed to immediately terminate the nuclear reaction.

By breaking the nuclear chain reaction, the source of heat is systems can then be used to remove decay heat from the core. All nuclear plants have some form of reactor protection system. An investigation on the thermal hydraulic characteristics of the passive residual heat removal system (PRHRS) which is used in an integral pressurized water reactor (INSURE) is presented in this paper.

The main components of primary coolant system are enclosed in reactor vessel. Primary fluid flow circle is natural circulation.After Fukushima accident, decay heat removal in station blackout (SBO) accident is concerned for different NPP design.

Advanced passive PWR relies on passive systems to cool reactor core and containment, such as the passive residual heat removal system (PRHR), passive injection system and passive containment cooling system (PCCS).

In a control apparatus for residual heat removal system for a nuclear reactor in which the steam generated in the reactor vessel is cooled and condensed into water through a heat exchanger and the condensed water is fed back by a feedwater pump driven by the reactor steam so as to cool the reactor core, the pressure of the condensed water at the exit of the heat exchanger is increased with .