INL FACT SHEET

INL’s Unparalleled

Advanced Test Reactor

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Based on nearly 40 years

of operating experience

and a well-documented

record of continuous upgrades, Idaho National

Laboratory scientists, engineers and safety professionals

are confident the Advanced

Test Reactor and other INL

site facilities can safely

support the proposed consolidation of nuclear operations

related to the production of

Plutonium-238 for space

batteries and national security.

Beyond this professional

perspective, though, the U.S.

Department of Energy is

implementing its standard

practice of seeking public input

before proceeding with major

projects that have the potential

of impacting the environment.

As part of this involvement

process, questions have been

asked about the design,

operating record, geographic

location and age of the Advanced Test Reactor (ATR),

which would be part of the Pu238 mission at INL.

Design

• The ATR is one of the world’s

most versatile and bestdesigned test reactors. It is

used to study the effects of

radiation on materials. This

reactor also produces rare and

valuable medical and industrial isotopes that safeguard

and improve American lives

every day. As such, the ATR

has the capacity and capability to support the production

of Pu-238 without any

physical modifications or

changes to its safety posture.

• A highly flexible reactor, it

is designed and operated to

be shut down as often as

needed to support the

reactor’s missions, including the need to retrieve

experimental results from

the reactor’s materials

testing missions or when

maintenance is scheduled. It

is also designed to automatically shut down in

response to power outages

and experiment instrument

irregularities that would

result in the loss of experiment data. When this

happens, there is no impact

on the environment and the

reactor’s shutdown system –

commonly known as a

“SCRAM” system – has not
INL FACT SHEET

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05-GA50506

failed. In fact, it is doing

exactly what it is designed

to do.

• ATR does not require a

containment dome. Comparable operating test reactors –

licensed by the NRC, or

authorized to operate by

DOE – do not have and do

not require a containment

structure, no matter where

they are located. The ATR

simply does not have the

inventory of radioactive

material – 1/60th the inventory of a U.S. commercial

power reactor – or the

amount of stored energy

(high pressure and high

temperatures) that would

make a containment dome

necessary. The ATR operates

at temperatures and pressures

that are essentially the same

as a home hot water heater.

Nonetheless, the ATR is

enclosed in a “confinement

structure” which would

prevent the release of

radioactive materials in the

very unlikely event of an

accident. Given the low

temperatures and pressures at

which the ATR operates, the

confinement structure is

entirely adequate to protect

public health and safety.

• The frequently cited statement

that this reactor is capable of

dispersing 175 million curies

of radiation is reflective of

analysis done on what

amounts to a “perfect storm”

accident that assumes the

worst imaginable event, at the

worst imaginable time, in

combination with a set of

circumstances that are, at best,

incredible. INL regularly

analyzes for such improbable

events to ensure all scenarios

have been considered. Recent

INL safety analyses show

such an ATR accident would

not occur in more than once

in one million years – or one

million years of reactor

operations – which is

consistent with NRC siting

criteria. The ATR bears no

design or operational resemblance to the Chernobyl

reactor and comparing this

hypothetical accident scenario

to the Chernobyl accident is

not valid

Operating Record

• The Advanced Test Reactor

has an exceptional operating

record — it has operated

safely and without any

reactor or nuclear accident

since it started up in 1967.

INL has full confidence in

the continued safe operations

of the reactor on the INL

Site. It will be a safe source

of irradiation services for

many years to come.

• ATR complies with the

federal safety rules and U.S.

Department of Energy orders

established for DOEregulated reactors. The rules

that govern the design and

operation of ATR are

commensurate with the rules

the Nuclear Regulatory

Commission applies to test

reactors it licenses.

Geographic Location

• The ATR is not located, as

some have suggested, in a

seismically active zone

similar to San Francisco. The

ATR is located on the eastern

Snake River Plain, which is

seismically quiet relative to

the surrounding seismically

active mountainous region.

INL seismic monitoring has

recorded 30 small-magnitude

earthquakes since 1972. The

best and most important

A U.S. Department of Energy

National Laboratory

John Lindsay

208-526-9078

John.Lindsay@inl.gov

Teri Ehresman

208-526-7785

Teri.Ehresman@inl.gov

For more information:

measure of how well the INL

facilities have been designed

and built to perform in these

types of earthquakes is

obtained from the Advanced

Test Reactor. In 1983, when

one of the largest U.S.

earthquakes in memory

occurred at Borah Peak, ATR

performed exactly as

designed, immediately

shutting itself down and

placing itself in a safe

configuration.

Age

• Since it began operating in

1967, the ATR has been

regularly updated with plant

upgrades to maintain and

improve its performance and

safety posture. For example,

every 8 to 10 years, ATR

crews replace all the internal

reactor core elements subject

to wear and tear by irradiation – thus eliminating the

concern that limits the life

span of a commercial reactor.

To put plant life in perspective, the useful life of a

commercial reactor is limited

by the effects of neutron

irradiation on core structural

components. INL completed

a core internal change-out

this year, returning the ATR

core internals to as-new

condition.

INL leaders and employees

value the environment and are

committed to the safety and

well-being of ourselves, our

neighbors in Idaho, Wyoming

and other Western states, and

the cherished national treasures

we find in such places as

Yellowstone and Grand Teton

national parks.

We welcome further questions,

comments and public discussion on this important topic.