Void coefficient reactor is reduced. In boiling-water reactors with large negative void coefficients, a sudden pressure rise (caused, for example, by unplanned closure of a steamline valve) will result in a sudden decrease in void content: the increased pressure will cause some of the steam bubbles to condense ("collapse"); and the thermal output will possibly increase until it is terminated by safety systems, by increased void formation due to the higher power, or, possibly, by system or component failures that relieve pressure, causing void content to increase and power to decrease. Boiling water reactors are all designed (and required) to handle this
2010 Guatemala City sinkhole Guatemala City. The hazards around the pipe have since then been mitigated, by improved handling of the city's wastewater and runoff. Several rainstorms also contributed to the sinkhole's collapse, as stormwater percolated into the ground, further dissolving the rocks beneath Guatemala City. The 2010 sinkhole was formed for similar reasons. The sinkhole formed due to volcanic pumice deposits, upon which Guatemala City is built. These deposits were unconsolidated and of low density, allowing easy erosion. According to Sam Bonis, a geologist at Dartmouth College, leaking pipes went unfixed long enough to create the conditions necessary for sinkhole formation because of