U.S. Nuclear Corp. has received orders totaling more than $400,000 for its new tritium monitors, the company announced Thursday.

The Canoga Park manufacturer received a $93,150 order from Schlumberger Ltd., an oil and gas technology services provider in Houston, and a $307,922 order from Korea Hydro & Nuclear Power.

The tritium monitors will be made by Overhoff Technology Corp., a subsidiary of U.S. Nuclear in Milford, Ohio. Overhoff is the only company in the U.S. specialized in tritium monitors.

Tritium is a radioactive isotope of hydrogen. Clients for tritium monitors include nuclear power reactors, biomedical and academic researchers, water treatment facilities and groundwater monitoring firms or agencies.

Shares in U.S. Nuclear (UCLE) closed up 24 cents, or 13.7 percent, to $1.99 on the over-the-counter market.