Patents and Trademarks, net, net consisted of the following (rounded in millions):

The Company revised the patent amortization expense by recording a cumulative adjustment to accumulated amortization of $0.6 million as of January 1, 2019 (see Note 2. Revision and Correction of an Immaterial Error in Previously Issued Financial Statements). For the years ended December 31, 2020 and 2019, the Company capitalized approximately $0.2 million each year, for patent filing costs and related legal fees. Amortization expense was approximately $0.1 million for the years ended December 31, 2020 and 2019, respectively.

The Company considered the fourth quarter 2019 deterioration of the Company’s relationship with Framatome, its joint venture partner in Enfission, (See Notes 1, 4, 7 and 12) to be a triggering event for the assessment of possible impairment of its patent assets. The Company performed an impairment test in the fourth quarter of 2019 and no impairment of the patent assets was identified.

During 2020, as discussed in Note 8, the Company began a program to support the development of its fuel in collaboration with Idaho National Laboratory (INL) with funding in the form of a voucher from the U.S. Department of Energy (DOE) Gateway for Accelerated Innovation in Nuclear (GAIN) program. In the fourth quarter of 2020, the Company received information that cutbacks in government funding for certain types of nuclear research is expected and the INL research facilities will only be available on a limited basis. The INL notified the Company that the advanced test reactor would not be available to conduct critical experiments and that the INL laboratories now have limited research capabilities which extended fuel development timelines to 15-20 years, which is beyond the remaining legal lives of the patents. These recent developments regarding future potential DOE funding and INL research facility limitations have caused significant delays in the projected timelines for development and commercialization of the Company’s fuel, which constitutes impairment indicators of the Company’s patent costs.

The extended timelines for the development and commercialization of the Company’s fuel results in the reduced prospects of the existing patents providing the necessary legal protection from competitors over the remaining average legal lives of the patent portfolio, as well as the utilization of the Company’s patents in obtaining substantial research grant funding. The Company performed an impairment analysis and determined that the carrying value of the patents were not recoverable. Using both the income approach and the cost approach, the patent costs were determined to have a fair value of $0 as of December 31, 2020. As a result, the Company recognized a total impairment charge of $1.1 million in the fourth quarter of 2020, which is included in operating expenses in the accompanying consolidated statement of operations.