# Presentation: 330427

## History Of Nuclear Graphite Research At The Oak Ridge National LaboratoryTim BurchellLeader, Carbon Materials Technology GroupMetals and Ceramics DivisionOak Ridge National LaboratorySeptember 29th, 2003 

## Historical Context

**1942 Manhattan Project, X-10 Reactor at Clinton Engineering Works (ORNL)**
**1940s-1980s - Supported Production Reactors at Hanford WA**
**1950s-1970s - Aircraft Reactor, Molten Salt Reactor Experiment (MSRE), Experiment Graphite Reactor (EGR)**
**1960s-1980s-High Temperature Gas Cooled Reactor (HTGR) [Dragon, Peach Bottom (GA)] and Large HTGR [Fort St. Vrain (GA)]**
**1980s-1990s-Modular High Temperature Gas Cooled Reactor (MHTGR); New Production Reactor (NPR) – a variant of the MHTGR; Gas Turbine-Modular Helium Reactor (GT-MHR)**
**2000 onwards-Gen IV Reactor Concepts, Very High Temperature Reactor (VHTR) - a GT-MHR or PBMR**

## Nuclear Graphite Development

**Earliest reactors used purified electrode graphites, e.g., National Carbon AGOT (X-10 and early Hanford Piles) – highly anisotropic**
**Second generation graphites with finer grain structure, improved properties and purity developed in the 1950s, e.g., Union Carbide TSX (Hanford N reactor), AGL/BAEL grade PGA (Magnox Reactors, UK) or Great Lakes H-321 (Early FSV)**
**Third generation graphites, isotropic and near isotropic grades:**
**IM-124-Gilso carbon, molded, isotropic (AGRs)**
**H-451-isotropic pet coke, extruded, near isotropic graphite (FSV-HTGR)**
**ASR-1RS-pitch coke, vibrationally molded, near Isotropic**
**IG-110-green (pet) coke, cold molded, isotropic graphite (HTTR)**
**Current status: recreation of third generation graphites**
**GrafTek PCEA (isotropic pet coke, extruded, near isotropic)**
**SGL NGB-10 (isotropic pitch coke, extruded, near isotropic)**

## ORNL Graphite Irradiation Experiments

**Oak Ridge Research Reactor**
**OG series (dimensional and physical property changes)**
**OC 1-3 series (irradiation creep experiments)**
**High Flux Isotope Reactor**
**HTK 1-7 series (dimensional change, physical properties), T****irr ****= 600 and 900****o****C med-high dose (beyond turnaround) **
**HTF 1-3 series, fracture toughness samples (Chevron Notched Short Rod)**
**HTU 1&2 series TSX graphite (dimensional change, physical properties), T****irr ****= 600****o****C med-high dose (beyond turnaround) **
**HTN 1-3 series (dimensional change, physical properties), high dose (beyond turnaround), T****irr ****= 600 and 900****o****C**
**HTFC 1&2 series (dimensional change, physical properties), Fusion Energy carbon composites  & graphites, T****irr ****= 600 and 900****o****C**
**Rabbits**
**Fusion carbons and SiC**
**Gen IV VHTR graphites**

## Graphite Development at ORNL

**Very low permeability graphite, grade CGB, developed with UCAR, sealed via CVD to prevent build up of ****135****Xe in porosity for the MSRE (1960s)**
**Near Isotropic Nuclear Graphite (H-451) for FSV jointly developed by Great Lakes Carbon, General Atomics, and ORNL (1970s)**
**GraphNOL N3M, green coke technology developed for the Navel Ordinance Lab REVMAT program.  A fine grain high strength graphite isotropic (with long irradiation lifetime) (1980s)**
**Novel C/C composite for aircraft brakes (improved thermal conductivity & reduced cost) (1990s)**
**High Thermal Conductivity Graphite Foam (2000-)**

## Conclusions

**ORNL has been active in the field of nuclear graphites since the early 1940s**
**ORNL has supported every graphite reactor program in the USA**
**ORNL has >40 years experience in designing, conducting and analyzing graphite irradiation experiments**
**ORNL has developed innovative graphite materials for nuclear, military and commercial applications**