Nuclear Power

Valves isolate and control flow rates, pressure, and direction, enabling functionality, safety, and control for the systems in which they operate. Valves in nuclear power plants play critical roles in both the nuclear island and the balance of plant (BOP) systems and must meet applicable Code and regulatory requirements for design, manufacture and construction to ensure safe and effective plant operation. In the United States, nuclear power plants typically fall into two categories, Boiling Water Reactors (BWR’s) and Pressurized Water Reactors (PWR’s). There are many differences between these two platforms, but in each case, valves are installed in safety-related (required for safe plant shutdown) and non-safety related applications.

Conval is also heavily involved in the development of valves for Small Modular Reactors (SMR’s), participating pressurized water and molten salt-cooled design platforms for a number of reactor developers.

Primary Nuclear Systems That Require Valves

Both the nuclear island and BOP systems require reliable, effective valves for safe operation, desired performance, and maintenance. Nuclear valve applications include:

Main Steam System

The main steam system delivers steam to the turbine and must supply this steam safely and efficiently at specified flows and pressures. Nuclear valves facilitate the following processes:

Regulate steam dump to condensers and steam discharge
Protect against Loss of Coolant Accidents (LOCA) (e.g. line break accident)
Protection against exceeding safe pressure levels

Feedwater System

The feedwater system supplies and heats high-quality water for the reactor or steam generator, requiring precise, effective control.

Control feedwater flow
Quickly protect condensate-feedwater piping and preheaters

Core Cooling System

The core cooling system controls the nuclear core reaction rate, requiring superior performance and reliability.

Protect Residual Heat Removal (RHR) pumps, and relief pumps
Prevent overpressure damage
Keep RHR and reactor coolant systems separate
Control flow and regulate backpressure in CVCS Chemical and Volume Control Systems
Halt core reactions with Safety Injection System (SIS) or Standby Liquid Control (SLC) systems

Turbine Island

Depending on the type of nuclear plant platform (BWR vs PWR), steam to the turbine is either contaminated (BWR) or not contaminated (PWR). In BWR’s, the turbine island is a “protected” area. The turbine island contains the turbine and auxiliary systems to convert steam from the reactor or steam generator into electricity and requires precise control to start, maintain, and shut down power generation.

Protection during low-capacity times such as startup, shutdown, and during load-following operation
Protection against overpressure and reverse flow
Isolation of the main steam system from other systems, including drains, and the moisture separator

Auxiliary Systems

These systems are part of the BOP system to support power generation.

Air conditioning and ventilation
Compressed air
Demineralized water system
Fire protection
Fuel handling and storage
Sampling and monitoring system
Waste control and effluent management

Valves Used In Nuclear Power Plants

We offer a selection of valves with the reliability, functionality, and performance demanded by critical nuclear power operations. Our valves offer customizable, modular valve solutions with easy interchangeability and rapid in-line repairability, providing the industry’s lowest life cycle costs.

Clampseal® Globe Valves

Globe valves are used to regulate flow and pressure (throttle) and provide complete flow shutoff. (isolation). They are used in vent, drain, blowdown and other applications.

Y, angle, and T body styles
ASME pressure classes through 4500
5 standard materials, other materials available
Standard sizes through 4″

Swivldisc® Gate Valves

Gate valves commonly serve as isolation valves for water and steam lines, providing a lower pressure drop than globe valves. Other benefits include:

Swivldisc® gate design with tighter shutoff than standard gate valves for optimum sealing
A broad range of end connections
ASME pressure classes up to intermediate 3500
Low-emission design
Easy servicing with no welds or gaskets to replace due to pressure seal bonnet design
Body-to-bonnet joint for high integrity sealing
Long packing service life with fine-finished stem and packing chamber and high-performance graphite rings

Clampseal® Check Valves

Check valves prevent reverse flow.

Y, T, and angle body styles
Lightweight, compact size
ASME pressure classes through 4500
3 standard materials, other materials available
Designed for high-pressure applications
Pressure seal bonnet allows easy servicing with no welds to cut or seals and gaskets to replace
Standard sizes through 4″
Tailored to customer requirements for installation and performance (e.g. cracking pressure)

Camseal® Ball Valves

Ball valves are used to isolate flow.

Designed for extreme high-pressure, high-temperature applications
Zero-leakage performance
ASME pressure classes through 4500
Standard sizes through 4″
Top-entry design for easy in-line maintenance for ALARA (As Low As Reasonably Achievable) compliance and cost savings
Metal seated for long service life
Forged for superior strength

Steam Whisperjets

Whisperjets protect against damage and sonic flow created by high-pressure drops utilizing multi-staged trim in a designed series of pressure-reducing stages.

ASME pressure classes through 4500
Reduced component wear
Lowered noise level
Engineered/Adjustable pressure reducing multi-stage trim
Mitigates part erosion
Proven performance in high-pressure applications
Cost-effective pressure reduction

The Benefits Of Conval Valves For Nuclear Applications

Our valves are ideally suited to the high-pressure, high-temperature nuclear power applications where reliability, economy, and performance are vital.

Industry’s lowest life cycle costs
Outage time & labor minimized (ALARA), designs are in-line maintainable
Leak-free shutoff minimizes repair & valve replacement
Long service life in tough applications
Rugged leak-free bonnet seal ensures pressure boundary sealing integrity, ASME Classes through 4500 lb.
Reliable performance and designs
Wide range of alloys available

We are committed to ensuring our products are in full compliance with the strict industry requirements for the nuclear power environment. Our valves offer:

Compliance with applicable nuclear Codes, standard and regulatory requirements. (e.g. ASME, NRC, etc.)
High performance
NUPIC audited
Extreme reliability
Ease of in-line maintenance
ALARA requirement compliance

Conval Valves

Both our standard valves and custom valves are designed to exceed industry standards for performance and longevity in tough, high-pressure, high-temperature environments. Offering in-line
renewability and industry-leading low life cycle costs, our versatile, rugged valves are second to none. Contact us today and request a quote to take advantage of our severe service valve solutions.