305 Test Pile
{{Infobox nuclear reactor|name=305 Test Pile|image=|caption=|headerstyle=|location=Hanford Site|concept=Materials testing reactor|design_label=Designed by|design=Manhattan Project|operation=1944 to 1972|status=Shut down|fuel=Natural uranium|fuel_state=Solid (rods)|spectrum=Thermal|control=Lead cadmium ontrol rods|coolant=Air|moderator=Nuclear graphite (bricks)|spectrum_description=Slow|use=Materials testing|remarks=|criticality=March 1944|thermal=50 W|operator=Hanford Engineer Works|module=}}The 305 Test Pile was the first reactor built at the Hanford Site during the Manhattan Project. It achieved criticality in March 1944, becoming the world's fourth nuclear reactor. It tested the purity of the nuclear graphite and refined uranium used for all subsequent plutonium production reactors at the site during the Cold War, including the B Reactor and N Reactor.{{cite report |title=Multiple missions: The 300 Area in Hanford Site history |last=Gerber |first=M.S. |date=1993-09-01 |doi=10.2172/10116166 |page= |doi-access=free}}
History
The 305 Test Pile was the fourth reactor in the world to achieve criticality, in March 1944, following the Manhattan Project's construction of Chicago Pile-1, Chicago Pile-2, and the X-10 Graphite Reactor. Like these, it was also natural uranium-fuelled, graphite-moderated. It was the world's first materials testing reactor. Specifically, it was used in quality assurance of graphite rods and uranium slugs, which would be used for Hanford's plutonium production reactors, had a sufficiently low concentration of neutron poison impurities, such as boron and cadmium. Like the Chicago Piles, at a very low power level just above criticality, usually around 50 watts.
In 1946, the reactor tested the neutronic properties of "myrnalloy", a Manhattan Project codename for thorium.{{cite report | last=Wende | first=C W.J. | title=Production Test No. 305-9-P, poisoning effectiveness and uniformity of myrnalloy slugs | publisher=Office of Scientific and Technical Information (OSTI) | date=1946-02-19 | doi=10.2172/10186026 | doi-access=free | url=https://digital.library.unt.edu/ark:/67531/metadc1395366/m2/1/high_res_d/10186026.pdf | access-date=2025-05-07 | page=}} In the early 1960s, it tested lithium-6-enriched targets for tritium production in the N Reactor.
Historians agree that an unknown component of the Soviet atomic spies program passed the reactor's design to the Soviet atomic bomb project, which chose to essentially duplicate it in the form of their first nuclear reactor, F-1, critical in December 1946.{{cite journal |last=Reed |first=B. Cameron |date=2021 |title=An inter-country comparison of nuclear pile development during World War II |journal=The European Physical Journal H |volume=46 |issue=1 |page=15 |arxiv=2001.09971 |bibcode=2021EPJH...46...15R |doi=10.1140/epjh/s13129-021-00020-x |issn=2102-6459 |doi-access=free}}{{cite book |last=Rhodes |first=Richard |title=Dark Sun |date=1995 |publisher=Simon & Schuster |isbn=978-0-684-80400-2 |publication-place=New York, NY |page=}}
See also
- F-1 (nuclear reactor), a near-duplication of the pile
- Hanford Site
References
{{Reflist|30em}}{{Manhattan Project}}
Category:Former nuclear research institutes
Category:Manhattan Project sites
Category:Defunct nuclear reactors
Category:Graphite moderated reactors
Category:Military nuclear reactors
Category:Nuclear reactors in Washington (state)
Category:Buildings and structures in Benton County, Washington
Category:Nuclear history of the United States
Category:Nuclear weapons infrastructure of the United States