Nuclear Power

Industries: Valves for Nuclear Power Applications

Valves 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.

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, powerful 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 byhigh-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, designs are in-line maintainable.
  • Leak-free shutoff minimizes repair & valve replacement
  • Long service life in extreme temperature services
  • Rugged leak-free bonnet seal ensures pressure boundary sealing integrity SME 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:

  • Nuclear Code Requirement compliance (ASME N/NPT and 10CFR50 Appendix B programs)
  • 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.