NOVELTY - The high pressure reactor system comprises a primary containment structure, ten internally-heated high pressure apparatuses (110) comprising a growth region and feedstock region, an exhaust system coupled to the primary containment structure, an inlet coupled to the high pressure apparatus, sensors (146) configured within spatial regions of the primary containment structure, a secondary containment structure enclosing the primary containment structure, a drain region coupled to the primary containment structure, a pump coupled to the drain region, and a purge line.    USE - The high pressure reactor system is useful for growth of gallium nitride containing crystalline materials, which is useful for manufacturing optoelectronic devices such as lasers, LED, solar cells, photoelectrochemical water splitting and hydrogen generation, photodetectors, integrated circuits and transistors.    ADVANTAGE - The high pressure reactor system ensures economical and safe growth of gallium nitride containing materials with high quality thus simply and large-scale manufacturing the optoelectronic devices with good optoelectronic device performance and reduced dislocation density and stress, and allows safe containment of toxic gas such as ammonia during the growth of the gallium nitride.    DETAILED DESCRIPTION - The high pressure reactor system comprises a primary containment structure, ten internally-heated high pressure apparatuses (110) comprising a growth region and feedstock region, an exhaust system coupled to the primary containment structure, an inlet coupled to the high pressure apparatus, sensors (146) configured within spatial regions of the primary containment structure, a secondary containment structure enclosing the primary containment structure, a drain region coupled to the primary containment structure, a pump coupled to the drain region, a purge line coupled to the primary containment structure, a hoist operably coupled to the high pressure apparatus, a protective shell configured to enclose the high pressure apparatus, and armor plates (130) placed within a vicinity of an outer region of the high pressure apparatus. The high pressure apparatus: is an autoclave; comprises a high strength enclosure (104); is configured within the primary containment structure; is vertically and horizontally oriented with respect to gravity; is present at an oblique angle between a horizontal orientation and a vertical orientation; comprises an internal heating element and an external heating apparatus; is configured to hold a volume of ammonia liquid, where the volume is larger than 0.3 liters, larger than 1 liter, larger than 3 liters, larger than 10 liters, larger than 30 liters, larger than 100 liters, or larger than 300 liters; and is coupled to portions of the primary and secondary containment structures. The exhaust system is configured to remove all of the ammonia gas derived from 4.5 liters of ammonia liquid, and is configured to remove ammonia gas to a level that is safe for operator exposure within a period less than 24 hours. The primary containment structure: is sealed from an exterior region; is configured within an earth structure that comprises a dirt provided on a portion of a ground; comprises a metal material, a concrete material, steel-reinforced concrete and a liner; and is configured partially within a spatial region within a portion of the earth structure that comprises a pit (120). The sensors are coupled to an alarm system and an electrical control system (148). The steel-reinforced concrete comprises a concrete thickness of 2 inches, 4 inches, 8 inches, 12 inches, 18 inches or 24 inches, and a steel jacket surrounding the concrete. An INDEPENDENT CLAIM is included for a method of operating a high pressure system for growth of gallium nitride containing materials.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a high pressure reactor system.    High strength enclosure (104)    High strength apparatus (110)    Pit (120)    Armor plate (130)    Sensor (146)    Electrical control system. (148)