CROCUS

{{Short description|Experimental uranium-fuelled reactor.}}

{{use dmy dates|date=May 2020}}

{{for|the genus of flowering plants|crocus{{!}}crocus}}

{{one source|date=December 2018}}

{{Infobox reactor

| name = CROCUS

| image = Crocus-p1020484.jpg

| image_size =

| alt = CROCUS' core

| caption = CROCUS' core

| location_map =

| location_map_width =

| location_map_text =

| institution = École Polytechnique Fédérale de Lausanne

| location =

| coordinates = {{coord}}

| coordinates_ref =

| type =

| power = {{val|100|u=W}}

| power_therm_elec = thermal

| construct_cost =

| construct_start = January 1, 1970

| construct_length =

| first_crit = July 13, 1983

| shutdown =

| decommission =

| upkeep_cost =

| #_of_staff = 8

| #_of_operators = 2

| refuel_time =

| max_thermal_flux = {{val|7.5|e=8|u=cm{{sup|-2}}s{{sup|-1}}}}

| max_fast_flux = {{val|1.75|e=9|u=cm{{sup|-2}}s{{sup|-1}}}}

| fuel_type =

| cooling = light water

| moderator = light water

| reflector = light water

| control_rods = 2

| cladding_material =

| #_fuel_assemblies =

| fuel_per_assembly =

| rods_per_element =

| source =

}}

CROCUS is a research reactor at École Polytechnique Fédérale de Lausanne, a research institute and university in Lausanne, Switzerland.

The uranium nuclear reactor core is in an aluminium container that measures {{convert|130|cm}} across with {{convert|1.2|cm|adj=on}}-thick walls. The aluminum vessel is filled with demineralized light water to serve as both a neutron moderator and a neutron reflector.

Power output is controlled either by adjusting the water level in the reactor—with a ±{{convert|0.1|mm|adj=on}} level of control, or with the adjustment of two boron carbide (B{{sub|4}}C) control rods—with a ±{{convert|1|mm|adj=on}} level of finesse. The reactor has six separate safety systems: two cadmium shields and four storage tanks, any of which can shut down the reaction in less than a second.

CROCUS has a license to produce {{convert|100|W}} or a neutron flux of ~2.5 × 10{{sup|9}} cm{{sup|-2}}s{{sup|-1}} at the core's center.