US 11,837,375 B2
Testing subterranean water for a hazardous waste material repository
Richard A Muller, Berkeley, CA (US); and John Linus Grimsich, Berkeley, CA (US)
Assigned to Deep Isolation, Inc., Berkeley, CA (US)
Filed by Deep Isolation, Inc., Berkeley, CA (US)
Filed on Feb. 12, 2021, as Appl. No. 17/175,106.
Application 17/028,667 is a division of application No. 16/796,798, filed on Feb. 20, 2020, granted, now 10,921,301.
Application 17/175,106 is a continuation of application No. 17/028,667, filed on Sep. 22, 2020, granted, now 10,940,512.
Claims priority of provisional application 62/934,894, filed on Nov. 13, 2019.
Claims priority of provisional application 62/911,560, filed on Oct. 7, 2019.
Claims priority of provisional application 62/833,285, filed on Apr. 12, 2019.
Claims priority of provisional application 62/808,523, filed on Feb. 21, 2019.
Prior Publication US 2021/0333256 A1, Oct. 28, 2021
Int. Cl. G21F 9/34 (2006.01); B09B 1/00 (2006.01); G01N 33/00 (2006.01); G01T 1/167 (2006.01); G01N 1/08 (2006.01)
CPC G21F 9/34 (2013.01) [B09B 1/008 (2013.01); G01N 1/08 (2013.01); G01N 33/0036 (2013.01); G01T 1/167 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method, comprising:
identifying a drillhole from a terranean surface through a first rock layer at a first depth below the terranean surface and a second rock layer at a second depth below the terranean surface, the second depth being deeper than the first depth;
determining a first concentration of a radioisotope in a first fluid sample from the first rock layer;
determining a second concentration of the radioisotope in a second fluid sample from the second rock layer;
determining that the radioisotope in the second fluid sample is at a secular equilibrium based on a ratio of the first concentration to the second concentration;
based at least in part on determining that the radioisotope in the second fluid sample is at the secular equilibrium, determining that the second rock layer is suitable as a hazardous waste repository; and
based on the determination that the second rock layer is suitable as the hazardous waste repository, forming an access drillhole of the hazardous waste repository from the terranean surface toward a depth in or under the second rock layer.