0ASystems, Equipment and Components

0A Systems, Equipment and Components

0A001 “Nuclear reactors” and specially designed or prepared equipment and components therefor, as follows:

a. “Nuclear reactors”;

b. Metal vessels, or major shop‑fabricated parts therefor, including the reactor vessel head for a reactor pressure vessel, specially designed or prepared to contain the core of a “nuclear reactor”;

c. Manipulative equipment specially designed or prepared for inserting or removing fuel in a “nuclear reactor”;

d. Control rods specially designed or prepared for the control of the fission process in a “nuclear reactor”, support or suspension structures therefor, rod drive mechanisms and rod guide tubes;

e. Pressure tubes which are specially designed or prepared to contain both fuel elements and the primary coolant in a “nuclear reactor”;

f. Zirconium metal tubes or zirconium alloy tubes (or assemblies of tubes), specially designed or prepared for use as fuel cladding in a “nuclear reactor”, and in quantities exceeding 10 kg;

N.B.1: For zirconium pressure tubes see 0A001.e.

N.B.2: For calandria tubes see 0A001.h.

g. Pumps or circulators specially designed or prepared for circulating the primary coolant of “nuclear reactors”;

h. ‘Nuclear reactor internals’ specially designed or prepared for use in a “nuclear reactor”, including, for example, support columns for the core, fuel channels, calandria tubes, thermal shields, baffles, core grid plates, and diffuser plates;

Note: In 0A001.h. ‘nuclear reactor internals’ means any major structure within a reactor vessel which has one or more functions such as supporting the core, maintaining fuel alignment, directing primary coolant flow, providing radiation shields for the reactor vessel, and guiding in‑core instrumentation.

i. Heat exchangers as follows:

1. Steam generators specially designed or prepared for the primary, or intermediate, coolant circuit of a “nuclear reactor”;

2. Other heat exchangers specially designed or prepared for use in the primary coolant circuit of a “nuclear reactor”.

Note: 0A001.i. does not apply to heat exchangers for the supporting systems of the reactor e.g. the emergency cooling system or the decay heat cooling system.

j. Neutron detectors specially designed or prepared for determining neutron flux levels within the core of a “nuclear reactor”.

k.  ‘External thermal shields’ specially designed or prepared for use in a “nuclear reactor” for reduction of heat loss and also for containment vessel protection.

Note: In 0A001.k. ‘external thermal shields’ means major structures placed over the reactor vessel which reduce heat loss from the reactor and reduce temperature within the containment vessel.