Building Ventilation System

DOE-HDBK-1129-99

form and is not converted by the tritium removal system to the more radiotoxic tritiated water. The

application for glovebox atmospheres is good; however, severe challenges for removing tritium

from room atmospheres with the required flow rates, while not fouling the getters, appear less

promising. Research into other than metal (e.g., fullerenes) gettering material has been sponsored

by EH; however, results have not been promising to date. It is possible that advances in design

will make room or building-type confinement systems highly desirable, or it may turn out that these

cleanup systems in general are found not to be cost-effective, and that a better use of resources to

decrease environmental releases could be made by upgrading the existing primary and secondary

systems. Additionally, there may be future glovebox decisions in which the oxidation process is

still chosen over the gettering process due to programmatic reasons.

4.1.4 Inspection and Surveillance Requirements

Instrumentation should be provided to monitor the leak-tight integrity of process piping, tanks, and

other equipment. The surveillance measurements may include those of pressure differentials or

flow rates and should relate to the design leak rate. Radiation monitoring instrumentation may be

used to qualitatively assess changes in leak rate.

4.2 Building Ventilation System

If tritium does penetrate its barriers, it can be released into the worker breathing space. In this

scenario, the ventilation system should be designed to meet the following objectives.

Move released tritium from the worker breathing space as soon as possible.

Minimize the contamination of other areas while moving released tritium.

Release the tritium-contaminated gases at an elevation and velocity that will result in massive

dilution and mixing with outside air before the tritium reaches ground level.

The ventilation system should be designed using the following guidelines:

The ventilation system should be a single-pass ventilation system. Outside air is brought in

through a supply fan, conditioned for the comfort of the workers, passes through the ductwork

to the ventilated spaces one time, goes through the exhaust ductwork to an exhaust fan, and is

released to the environment through the facility stack.

The air supply and exhaust systems should be designed to eliminate dead air spaces where

tritium-contaminated gases may accumulate.

The ventilation system ductwork should not be shared with non-tritium operations.

To minimize cross-contamination from one room to another, the exhaust gas from each room

should dump into a central exhaust duct. Exhaust gases from several rooms should not be

combined before being dumped into the central exhaust duct.

To minimize cross-contamination from one ventilation function to another, the gases for each

type of function, such as room ventilation, high velocity air hood ventilation, and glovebox

ventilation, from a single room should not be combined until they reach the central exhaust

duct.