Grade construction

Figures 31.3 through 31.5 illustrate typical radon entry routes found in basement, crawlspace, and slab-on-grade construction, respectively.

FIGURE 31.5 Typical radon entry routes in slab-on-grade construction. (Adapted from U.S. EPA, Radon-Resistant Construction Techniques for New Residential Construction—Technical Guidance, EPA/625/ 2-91/032, U.S. Environmental Protection Agency, Washington, DC, February 1991.)... 

Excavation by Means of Explosives is described in Blasters Hdb (1966), pp 385—92 (under Grade Construction) and pp 473—74 (Excavating in Hard Ground)... 

Construction work, which includes grade construction(Ref 35a,pp 413-23) and ditch blasting for pipeline construction(pp 423-28) Coyote turmelingfpp 215-20 390-92)... 

High processing temperatures cause corrosion problems. High-grade construction materials such as nickel or nickel alloy are needed for the reactor. 

A lower-grade construction material such as stainless steel is used for the reactor. 

In the millisecond range, say from 25—1000 msec, the delay action provides for effective blasting in quarries, salt mines, and numerous other commercial applications of explosive charges. Staggering the explosions in series of boreholes reduces vibration and improves fragmentation. It has special advantages in grade construction work. ... 

For wood railings Wood components shall be minimum 1500 Ib-ft/in2 fiber (stress grade) construction grade lumber the posts shall be at least 2-inch by 4-inch (5 cm X10 cm) lumber spaced not more than 8 feet (2.4 m) apart on centers the top rail shall be at least 2-inch by 4-inch (5 cm X 10 cm) lumber, the intermediate rail shall be at least 1-inch by 6-inch (2.5 cm x 15 cm) lumber. All lumber dimensions are nominal sizes as provided by the American Softwood Lumber Standards, dated January 1970. 

In the routine inspection of reactor-grade construction materials, a tube, pipe, plate, or rod is rejected if a void is detected that is larger than 5% of the thickness of the part being inspected. In the inspection of a weld, the integrity of the weld must be better than 95% of that of the base metal. 

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