Dear Mr. Kiester,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located 1 photographic series, 2 file units, and 51 items related to Operation Castle in the Records of the Defense Threat Reduction Agency (Record Group 374) that may be relevant to your research. Many of these images have been digitized and can be viewed online using the Catalog. For assistance with the non-digitized records, please contact the National Archives at College Park - Still Pictures (RDSS) at firstname.lastname@example.org.
Next, we located the series Correspondence and Other General Administration Files Relating to Organization and Joint Participation in Operation Castle, 1951-1954 in Record Group 374 that may be of interest to you. The series Records Relating to Nuclear Testing, Contamination, and Exposure, ca. 1947-1978 in the Records of the Bureau of Medicine and Surgery (Record Group 52) includes 12 files related to Operation Castle, and the series Secret Administrative Files with Incoming, Outgoing, and Registered Logs, 1950-1954 in the Records of Naval Operating Forces (Record Group 313) that contains some information about Operation Castle as well. These records have not been digitized. Please contact the National Archives at College Park - Textual Reference (RDT2) at email@example.com for access to these records.
Plus, we located the series Program Files Relating to the Development of Enewetak Atoll, ca. 1949 - ca. 1951 in the Records of the Atomic Energy Commission (Record Group 326) that includes some records related to Operation Castle. These records have not been digitized. You may contact the National Archives at Riverside (RW-RS) at firstname.lastname@example.org with questions about these records.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDSS, RDT2, and RW-RS. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!