Radiological Hazards Comparison of SNAP 9A to SNAP 10A

STATEMENT OF PROBLEM Review SNAP 9A radiological h^^«f4s, safety features, and criteria and develop criteria which limit SKAP lOA hazards to the same level.f ABSTRACT SNAP lOA radiological hazards are compared to those from SNAP 9A as presented in the final safeguards report for the transit mission.The SNAP 9A hazard is based on a 900 year decay in orbit plus reentry burnup.It is shown that the SNAP lOA hazards are always less than those from SNAP 9^, for the same orbit life, provided: 1. Reactor shutdown is achieved prior to & years operation at full power.2. Reentry burnup is achieved.n the event that reentry burnup of SNAP lOA cannot be ensured, 400 years shutdown is required to reduce the external radiation hazard from one year of reactor operation to a safe level.Internal radiation hazards would have been reduced to the 9A level in 200 years.Post reentry criticality must also be prevented to allow meaningful comparison as criticality produces direct radiation hazards as well as short-lived radionuclides that otherwise would not be present in the case of radioisotope power source.It is, therefore, concluded that for those missions where long decay times in orbit cannot be ensured it is imperative that reentry burnup be achieved in order to eliminate external radiation hazards.^ r/