GEOGRAPHIC AND SEGMENT INFORMATION - Schedule of Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Long-term assets by reportable segments
Net property, plant and equipment	$ 20,414		$ 20,414		$ 20,337
Restricted cash	3,807		3,807		3,797
Operating lease right-of-use assets	424		424		484
Total long-term assets	24,645		24,645		24,618
Statement of Operations, Loss before taxes
Mineral property expenses	576	$ 808	1,178	$ 1,426
Product development expenses	175	16	301	32
General and administrative	1,659	1,700	3,438	3,405
Arbitration expenses	28	354	697	485
Accretion of asset retirement costs	32	30	138	156	390
Depreciation and amortization	17	25	30	48
Total operating expenses	2,487	2,933	5,782	5,552
Loss from operations	(2,487)	(2,933)	(5,782)	(5,552)
Other income (loss)	20	158	28	(397)
Loss before taxes	(2,467)	(2,775)	(5,754)	(5,949)
Corporate
Long-term assets by reportable segments
Net property, plant and equipment	102		102		114
Operating lease right-of-use assets	407		407		463
Total long-term assets	509		509		577
Statement of Operations, Loss before taxes
General and administrative	1,094	1,216	2,283	2,364
Arbitration expenses	28	354	697	485
Depreciation and amortization	12	1	24	2
Total operating expenses	1,134	1,571	3,004	2,851
Loss from operations	(1,134)	(1,571)	(3,004)	(2,851)
Other income (loss)	28	158	28	(397)
Loss before taxes	(1,106)	(1,413)	(2,976)	(3,248)
Uranium
Long-term assets by reportable segments
Net property, plant and equipment	11,340		11,340		11,251
Restricted cash	3,797		3,797		3,787
Operating lease right-of-use assets	17		17		21
Total long-term assets	15,154		15,154		15,059
Statement of Operations, Loss before taxes
Mineral property expenses	570	805	1,172	1,358
General and administrative	442	433	868	825
Accretion of asset retirement costs	32	30	138	156
Depreciation and amortization	5	24	6	46
Total operating expenses	1,049	1,292	2,184	2,385
Loss from operations	(1,049)	(1,292)	(2,184)	(2,385)
Other income (loss)	(8)
Loss before taxes	(1,057)	(1,292)	(2,184)	(2,385)
Lithium
Statement of Operations, Loss before taxes
Mineral property expenses		2		3
Total operating expenses		2		3
Loss from operations		(2)		(3)
Loss before taxes		(2)		(3)
Graphite
Long-term assets by reportable segments
Net property, plant and equipment	8,972		8,972		8,972
Restricted cash	10		10		10
Total long-term assets	8,982		8,982		$ 8,982
Statement of Operations, Loss before taxes
Mineral property expenses	6	1	6	65
Product development expenses	175	16	301	32
General and administrative	123	51	287	216
Total operating expenses	304	68	594	313
Loss from operations	(304)	(68)	(594)	(313)
Loss before taxes	$ (304)	$ (68)	$ (594)	$ (313)