Westinghouse Electric Corporation

Robert J Leduc

Michael F Hankinson

Louis J Malandra

Edward Jean Lahoda

Edward F Kowalski

Joseph W Richard

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.

Process for producing a dried fertilizer from sewage sludge

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). Thermocouple electrical connector and control rod drive mechanism coolant air exhaust port access panels (68) (74) are respectively provided within the radiation shield (10), and an emergency water-gas vent line (76) is likewise accommodated by an access panel (78) also defined within the radiation shield (10). The shield (10) is vertically spaced above the closure head (12) so as to define a gap (82) therebetween, and auxiliary hinged shield panels (192) may be secured along the bottom of the shield (110) to close the gap (182).

Reactor vessel head permanent shield

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). The air ducts (140) pass through the seismic support platform (128) and the missile shield plate (134), and a centralized cable connector plate (164), to which all electrical cables from the CRDMS, thermocouples, and control-rod rod-position-indicator coils are routed and connected, is mounted upon the seismic support platform (128) and is interposed between the seismic support platform (128) and the missile shield plate (134). By means of the modular head assembly (110) of the present invention, all of the aforenoted components may be lifted or lowered along with the closure head (112) as one integral unit, all components are physically located within the peripheral envelope of the closure head (112), and existing facilities can be accordingly modified.

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Columbia, MD, United States of America

Robert J Leduc