Encyclopedia of Environmental Science and Engineering, Volume I and II

306 ENERGY SOURCES—ALTERNATIVES

by calcination or fixation in glassy materials, which would be

stored underground in isolated geological formations such as

salt domes, shale, or rock.^26 Two long-lived radioactive iso-

topes that cannot be easily captured and concentrated for such

disposal are krypton-85 and tritium. Krypton-85 is a chemi-

cally inert fission product with a 10.76-year half-life. Tritium,

with a half-life of 12.26 years, is produced both by fission

and by neutron irradiation of boron and lithium contained

in the reactor coolant and ends up in aqueous form in waste

treatment systems. Both of these isotopes are discharged to

the environment in liquid and gaseous effluents but are first

diluted to permissible concentration levels.

Fossil-fuelled power plants release small quantities of

radioactive material that are attributable to trace amounts of

uranium and thorium in coal and oil. A study performed by

Department of Health, Education, and Welfare personnel^27

compared potential exposures to the population in the vicin-

ity of coal fired and nuclear power plants. The only radia-

tion sources attributable to either type of plant that could

be detected above background levels were emissions to the

atmosphere. A plant fired with a specific coal containing 9%

ash and with 97.5% effective fly ash removal could lead to

an exposure of 3.08 
 40 −4 millirem of radiation annually

per MW of electrical power produced. The exposure poten-

tial from a typical pressurized water reactor (PWR) plant

was 1.05 
 10 −5 millirem on the same basis. A boiling water

reactor (BWR) included in the study had a higher exposure

value but is not representative of plants of this type that are

now being built. In any case, the maximum off-site exposure

attributable to any nuclear plant was in the 5 to 15 millirem/yr

range. The difference between the BWR and PWR in this

study is attributed to the fact that the PWR had the ability to

store gaseous wastes for about 60 days prior to release to the

atmosphere, while the BWR had only a 30 minute hold-up.

Larger volumes of waste gases must be handled in the BWR

even though the total quantity of radioactive materials pro-

duced are comparable in the two reactor types.

Solid Wastes^28

In 1969 over 30 million tons of fly ash were recovered from

power plants burning coal and lignite. About 20% of this is

used commercially as a soil conditioner and as an additive

to concrete and asphalt mixes. Bottom ash, which accounts

for about one-fifth of the ash produced in coal-fired plants,

is used in the manufacture of cinder blocks, as road ballast,

and on highways in icy weather. Unused portions of these

materials represent a solid waste disposal problem and are

dumped in spoil areas which occupy land are unsightly.

Large amounts of solid wastes are generated in coal

mining, uranium mining, and shale oil recovery. The residual

wastes from the processing of coal are put in culm banks and

coal waste piles. These contain a high content of carbonaceous

material and besides their unsightly appearance and the land-

slide hazard that they represent, they can ignite spontaneously

and emit air pollutants. A survey has located waste piles from

470 bituminous coal cleaning plants and 800 culm banks each

containing 10,000 tons or more of waste material from the

cleaning of anthracite coal. In 1964 about 495 refuse deposits

located in 15 states and containing about 500 
 10 6 yds^3 of

material were found to be burning.

Overburden material from strip mines is piled in spoil

banks which may be thousands of feet long and over 100

feet high. These are a source of acid water, will generally not

support vegetation, and render the land unsuitable for recre-

ation or industrial use. A thickness of overburden material

averaging about eleven times the coal thickness was handled

in US strip mining activities during 1970.

Control of the solid waste problem in these activities will

require increase utilization of ash from coal burning power

plants and of mill tailings from coal and uranium ore treat-

ment. An obvious disposal method for the portions of these

wastes that cannot be used and for spoil bank material is

to replace them in depleted strip mining areas and thereby

assist in restoration of the land whenever this is feasible.

Noise^14

Energy conversion devices, particularly those used for

mobile applications, are noisy in operation. Noise can impair

hearing and has physiological and psychological effects on

people.

The average level of sound at normal conversation

amounts to 55 db (A) in a distance of 3 feet, the sound of elo-

cution amounts to 70 db (A). For the noise in a living room a

TABLE 11

Long-lived radioactive materials generated in typical nuclear reactor fuel

Material Half-life (in years)

Activitya (megacuriesb/10^15

Btu of thermal energy

produced by fission)

Tritium 12.26 0.146

Krypton-85 10.76 3.4

Iodine-129 1.6 
 107 1.03 
 10 -5

Other fission products

Cesium-137 30 40.2

Strontium-90 28 28.5

Technetium-99 2.1 
 105 4.2 
 10 -3

Transuranium isotopes

Americium-241 458 0.091

Curium-244 18.1 1.34

Plutonium-238 89 1.27

Plutonium-239 2.4 
 104 0.116

Plutonium-240 6760 0.212

Plutonium-241 13 55

a After 90 days of cooling time following operation of a typical batch of

2.84% U-235, non-recycle, PWR fuel at a specific power of 40 kW/kg U to

a burnup of 35,000 MW-days/long ton.

b A curie is the amount of a given radioactive substance which undergoes

3.7 × 10^10 radioactive transformation/sec (equivalent to 1 g of radium).

Derived from data presented in: Safety Analysis Report, Barnwell Nuclear

Fuel Plant, Allied Chemical Nuclear Products, Inc., Amendment 2, Docket

No 50–332–4, March 21, 1969.

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