In the absence of any relevant detail, the best anyone can advice you would be to go to the following site and look up the contact details of the different manufacturers.
Once you have done that, send a email to the technical support department of each manufacturer describing in detail everything you know about the reactor i.e. volume, operating temperature & pressure, physical dimensions, operational process etc. Send them a picture of it as well. Maybe the manufacturer might recognize the technical specifications and be able to advice you accordingly.
__________________
If only you knew the power of the Dark Side of the Force