Frank owns a $$500,000$ life insurance policy on his wife Tonya. Frank's son, Sam, is designated as the beneficiary of the policy. Within $9$M of Tonya's death, Sam disclaims his interest in the policy. No contingent beneficiary is named. Pursuant to the terms of the policy, the policy is paid to Tonya's estate.

Discuss the estate tax consequences to Tonya's estate of these events.