The recovery of fission products from Hanford wastes has for some time been under investigation by various HAPO workers. Flowsheets for the recovery of cesium have been demonstrated, and one for the recovery of cerium is ready for full-level testing. Several tentative flowheets have also been proposed for the recovery of other fission products and of waste plutonium and uranium. The {open_quotes}Integral Flowsheet{close_quotes} developed by Chemical Research Operation is based primarily on the work of G.B. Barton. The present work is a continuation of that begun by Barton. The primary objective has been the recovery of long lived fission products, other than cesium, with particular emphasis on cerium-144 and strontium-90. Secondary objectives of importance include: (1) the isolation of uranium and plutonium into solutions suitable for recovery by recycle into appropriate Purex plant streams, and (2) gathering data that may be useful at some later date on the recovery of the remaining fission products (other than cerium and strontium) should these become valuable. Precipitation procedures were principally considered since idle plant facilities already exist which were designed for this type of process. It is also desirable that the processes developed be compatible with the already demonstrated cesium recovery flowsheet.

Corrosion studies indicate that digest liquors presently in use at the Mallinckrodt Uranium Refining Center should not be excessively corrosive to the digesters, which are constructed of Type 347 stainless steel. Experimental tests have shown that the digest liquors resulting from some of the more recent sources of uranium concentrates might become corrosive if the fluoride, chloride, or free nitric acid contents of these liquors should reach abnormal levels. If such constituents are present, there are corrective procedures that may be employed to prevent excessive corrosion of the stainless steel. It has been demonstrated that aluminum additions to the digest liquors will reduce the attack in both the liquid and vapor phases when relatively high concentrations of fluoride are involved. Iron additions may be used to some extent to combat corrosion arising from high chloride levels. Type 304 ELC stainless steel appears to have comparable corrosion resistance to Type 347 and Carpenter No. 20 stainless. Haynes Alloy No. 25, which showed a somewhat lower rate of penetration tended to form a loose insoluble corrosion product which may be objectionable in service. (auth)

A rough calculation shows that a flux of 10/sup 16/ n/cm/sup 2/ sec can be obtained in the internal thermal column (island) of a reflector-moderated circulating fluoride-fuel reactor. Existing NaZrF/sub 5/ base fuels and a graphite moderator are used. The average power density in the reactor is 1 kw/ cc, and the total pcwer is 444 Mw. Inner radius of the fuel region is 50 cm. (auth)

The feasibility of the electronic-explosive safety device was demonstrated in KEWB-I reactor excursions. It was shown to be a fast, efficient safety system for reactor protection. The safety devices inserted 1.5% negative reactivity into the core region of the KEWB-1 reactor to produce rapid shutdown. The system response time, i.e., that time interval between trip and insertion times, was found to be 4.2 msec. The complete freedom in choice of trip level and the flexibility of device geometry makes the system applicable to many types of reactor and critical assembly. The system does not offer the ultimate in reactor safety because it is not completely self-contained, but it is a practical, workable system for reactor protection. (auth)

The equations, numerical values, and results of the calculation are given. The assumptions involved and the known uncertainties are listed. (M.H.R.)