HTR-PM (Shidao Bay) by China Huaneng Group: status and timeline

HTR-PM (Shidao Bay)

Demonstrate that Gen-IV pebble-bed reactors can operate safely, produce heat for process industry applications, and enable China's energy transition while proving the design to other countries.

DeployStage 4 of 5

Commercial operation since Dec 2023. HTR-PM600 variant in development.

Updated Dec 2023Checked 11 Oct0 updates this week

Milestones

Next · HTR-PM600 variant in development

First reactor achieves criticalitySep 2021Complete.
Operating permit grantedAug 2021Complete.
Grid connection achievedDec 2021Complete.
Commercial operation beginsDec 2023Complete.
HTR-PM600 variant in developmentTarget 2026Current milestone.

Most important updates

Upcoming

2026HTR-PM600 variant in development (next)
2027HTR-PM600 planned deployment at multiple demonstration sites

Current obstacles

Pebble handling and dustPebble circulation generates dust and causes attrition. Detecting cracks without disrupting operation is challenging.
First-of-a-kind operational learningWorld's first commercial pebble-bed; procedures and maintenance established.

Physics limits

Outlet temperature limited by materialsHigher outlet temps improve efficiency but materials degrade above 800°C; coatings help but add cost.
Pebble packing densityPebbles cannot pack denser than ~65% of the core volume due to geometry. This inefficiency is trade-off for the continuous refueling advantage.

How it works

3 parts

Pebble fuel

Graphite spheres carry uranium

Graphite pebbles contain TRISO particles, drop through the core as they burn, recycled continuously.

Moderation and absorption

Graphite slows neutrons

Graphite slows neutrons for capture by uranium and conducts heat away from fuel.

Passive heat removal

Radiation and conduction cool the core

Heat flows to vessel and radiates away, needing no active cooling.

Spec sheet

Spec	HTR-PM (Shidao Bay)
Thermal power per module	250 MWt^R (reported)
Electrical output (both modules)	210 MWe^R (reported)
Outlet core temperature	750°C^R (reported)
TRISO fuel temperature limit	1,600°C+^R (reported)

^R reported by the company

Papers & demos

1 item

2023demo
Safety demonstration: passive cooling under loss-of-coolant conditions (opens world-nuclear-news.org)Proof that HTR-PM can cool itself without pumps or human intervention, the core safety advantage of the design.

Update log

3 updates

About China Huaneng Group

The team behind HTR-PM (Shidao Bay)

China Huaneng Group

HTR-PM pebble bed reactor, nuclear power

China Huaneng is a state-owned power generation company operating coal, hydro, wind, solar, nuclear and gas plants. In 2026 it achieved commercial operation of the world's first Gen-IV pebble-bed reactor at Shidao Bay.

One of China's largest power producers with 130,000 employees operating diverse power sources.
Leads HTR-PM at Shidao Bay: first Gen-IV reactor; commercial operation January 2026.
HTR-PM uses TRISO fuel and passive cooling; no meltdown risk if active systems fail.

chng.com.cn (opens chng.com.cn)Company profile →

Founded: 198937 yrs
Headquarters: China
Status: Public
Valuation: public
Staff: ~130,000Jan 2020
Works in: EnergyFission
Coverage: 1 program · 3 updateslatest 1 Dec 2023checked 11 Oct
Partners: China Nuclear Engineering Corporation (opens cnnc.com.cn)INET, Tsinghua University (opens inet.tsinghua.edu.cn)

Spec

HTR-PM (Shidao Bay)

Thermal power per module

250 MWt^R (reported)

Electrical output (both modules)

210 MWe^R (reported)

Outlet core temperature

750°C^R (reported)

TRISO fuel temperature limit

1,600°C+^R (reported)

HTR-PM (Shidao Bay)

Milestones

Most important updates

Upcoming

Current obstacles

Physics limits

How it works

Graphite spheres carry uranium

Graphite slows neutrons

Radiation and conduction cool the core

Spec sheet

Papers & demos

Update log

Dec 2023

Mon 20 Dec 2021

Dec 2021

About China Huaneng Group

Current obstacles

Physics limits

How it works

Graphite spheres carry uranium

Graphite slows neutrons

Radiation and conduction cool the core

Spec sheet

Papers & demos

Update log

Dec 2023

Mon 20 Dec 2021

Dec 2021

About China Huaneng Group