Abstract: Sewage sludge is subjected to a treatment with an acid in order to form stable ammonium compounds before thermal drying of the sludge which would otherwise volatilize ammonia and diminish the nitrogen content of the sludge.

Abstract: A radiation shield (10) is comprised of three, equiangularly extending, arcuate sections (14) which are secured to the nuclear reactor pressure vessel closure head (12) so as to annularly surround the nuclear reactor control rod drive mechanisms (26) and thereby prevent radiation emanating from the mechanisms (26) from reaching maintenance personnel who may be operatively working within the peripheral section (20) of the closure head. The shield sections (14) are bolted together by fasterners (18) and are secured to closure head lift lugs (30) by means of mounting brackets (38) and transversely extending pins (36). Clevis assemblies (34) are also pinned to the mounting brackets (38) and lift lugs (30), and lift rods (32) are threadedly engaged with the clevis assemblies (34). In this manner, when the closure head (12) is lifted from its associated pressure vessel, the radiation shield (10) remains with the closure head (12).

Abstract: A modular head assembly (110) for a nuclear reactor pressure vessel includes a closure head (112) having control rod drive mechanisms (116) mounted therein and projecting thereabove. Cooling baffles (118) provide air paths for cooling air for the CRDMs (116), and a lower air manifold (120) is fluidically connected to the cooling baffles (118) as well as to vertically upwardly extending air ducts and manifolds (136, 138, 140). Axial flow exhaust fans (126) are fluidically connected to the ducts (140) through means of plenum chambers (162) with the latter mounted upon a missile shield plate (134). The missile shield plate (134) is fixedly mounted upon closure head lift rods (144) as is a seismic support platform (128).