Abstract. The design, selection, and calculation of the Army Package Power Reactor shielding are described. The APPR-1, a prototype of a package reactor for remote locations, has a primary shield of iron and water. this shield has been adopted to permit fast erection and to provide low transported weight. economically, including transportation cost, the iron water shield is better than a lead water shield and is competitive with a concrete shield for a remote site. Because of the location at Fort Belvoir,Va., the shielding requirements for the APR-1 are considerably more stringent than those for a reactor at a remote base. Since the secondary shielding which surrounds the entire primary system must provide protection for personnel at any location outside the vapor container, concrete is provided for this need.

Abstract: The reactor analysis of the critical experiment and the APPR-1 resulted in a loading of the APPR-1 of 31.096 gm of B-10 with 22.5 kg U-335. This loading will result in adequate reactivity for a core life of 13 MWYR based on uniform burnup of U-335 and B-10. Calculations indicate that five of the seven control rods provided are more than adequate to shut the reactor down at any time. The temperature coefficient of reactivity should be at least -2 x 10-4 [delta] K/0F.

Abstract: The reactor analysis of the critical experiment and the APPR-1 resulted in a loading of the APPR-1 of 31.096 gm of B-10 with 22.5 kg U-335. This loading will result in adequate reactivity for a core life of 13 MWYR based on uniform burnup of U-335 and B-10. Calculations indicate that five of the seven control rods provided are more than adequate to shut the reactor down at any time. The temperature coefficient of reactivity should be at least -2 x 10-4 [delta] K/0F.