| Schedule of Disaggregation of Revenue | The following tables
present further disaggregation of our revenues by different categories for our Services and Treatment Segments:   
    | Revenue by Contract Type |  |  |  |  
    | (In thousands) |  | Three Months Ended |  |  | Three Months Ended |  |  
    |  |  | March 31, 2019 |  |  | March 31, 2018 |  |  
    |  |  | Treatment |  |  | Services |  |  | Total |  |  | Treatment |  |  | Services |  |  | Total |  |  
    | Fixed price |  | $ | 9,905 |  |  | $ | 428 |  |  | $ | 10,333 |  |  | $ | 8,959 |  |  | $ | 90 |  |  | $ | 9,049 |  |  
    | Time and materials |  |  | ― |  |  |  | 1,375 |  |  |  | 1,375 |  |  |  | ― |  |  |  | 3,609 |  |  |  | 3,609 |  |  
    | Total |  | $ | 9,905 |  |  | $ | 1,803 |  |  | $ | 11,708 |  |  | $ | 8,959 |  |  | $ | 3,699 |  |  | $ | 12,658 |  |    
    | Revenue by generator |  |  |  |  
    | (In thousands) |  | Three Months Ended |  |  | Three Months Ended |  |  
    |  |  | March 31, 2019 |  |  | March 31, 2018 |  |  
    |  |  | Treatment |  |  | Services |  |  | Total |  |  | Treatment |  |  | Services |  |  | Total |  |  
    | Domestic government |  | $ | 7,913 |  |  | $ | 686 |  |  | $ | 8,599 |  |  | $ | 6,536 |  |  | $ | 3,118 |  |  | $ | 9,654 |  |  
    | Domestic commercial |  |  | 1,879 |  |  |  | 758 |  |  |  | 2,637 |  |  |  | 2,423 |  |  |  | 402 |  |  |  | 2,825 |  |  
    | Foreign government |  |  | 57 |  |  |  | 337 |  |  |  | 394 |  |  |  | ― |  |  |  | 153 |  |  |  | 153 |  |  
    | Foreign commercial |  |  | 56 |  |  |  | 22 |  |  |  | 78 |  |  |  | ― |  |  |  | 26 |  |  |  | 26 |  |  
    | Total |  | $ | 9,905 |  |  | $ | 1,803 |  |  | $ | 11,708 |  |  | $ | 8,959 |  |  | $ | 3,699 |  |  | $ | 12,658 |  |  | 
| Schedule of Contract Assets and Liabilities | The following table
represents changes in our contract assets and contract liabilities balances:   
    | (In thousands) |  | March 31, 2019 |  |  | December 31, 2018 |  |  | Year-to-date Change ($) |  |  | Year-to-date Change (%) |  |  
    | Contract assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Account receivables, net of allowance |  | $ | 7,341 |  |  | $ | 7,735 |  |  | $ | (394 | ) |  |  | (5.1 | )% |  
    | Unbilled receivables - current |  |  | 3,316 |  |  |  | 3,105 |  |  |  | 211 |  |  |  | 6.8 | % |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Contract liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Deferred revenue |  | $ | 5,443 |  |  | $ | 6,595 |  |  | $ | (1,152 | ) |  |  | (17.5 | )% |  |