POWER June 2015 - 49

PLANT MOTHBALLING
Watts Bar Unit 2: A " Deferred
Nuclear Plant " Gets Back
into the Game
Construction was suspended on Watts Bar Nuclear Plant Unit 2 in the late 1980s,
and the plant sat idle for more than 20 years. Now, through equipment
refurbishment and replacement, Unit 2 is on track to become the first new
commercial nuclear reactor to come online in the U.S. in the 21st century.
James M. Hylko
E
lectricity consumption during the first
70 years of the 20th century grew at a
steady rate of 7% per year, doubling
every 10 years. To meet that demand, during
the 1960s and early 1970s, commercial
nuclear power plants were steadily increasing
in numbers and size. New reactor orders
were being placed with the expectation that
this trend would continue.
The Tennessee Valley Authority (TVA)
started construction at the Browns Ferry site
in 1966, and the Sequoyah plant followed
in 1969. Construction permits (CPs) for the
TVA's third nuclear site, located in southeastern
Tennessee-Watts Bar (Figure 1)-
were issued in 1973. The plant was slated to
include two Westinghouse four-loop pressurized
water reactors (PWRs) within icecondenser
containments.
All of the TVA's nuclear plant CPs were
issued under the two-step Title 10 Code of
Federal Regulations (10 CFR) Part 50-Domestic
Licensing of Production and Utilization
Facilities licensing process. In the first
step, an approved CP application authorizes
construction, while focusing on the plant's
preliminary design and site suitability. The
second stage evaluates the operating license
(OL) application, final plant design, safety
evaluation, operational limits, and ability to
respond to postulated accidents. The Nuclear
Regulatory Commission (NRC) established
a one-step licensing process under 10 CFR
Part 52-Licenses, Certifications, and Approvals
for Nuclear Power Plants in 1989.
Hiccups Along the Way
By 1976, many nuclear plant proposals were
no longer viable due to a decrease in electricity
demand, rising construction costs as
a result of inflation-exacerbated by schedule
delays, public opposition to projects, and
changing regulatory requirements. By 1983,
June 2015 | POWER
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49
completed nuclear plants, on average, were
costing 10 times their initial projections and
taking 12 years to complete.
Eventually, more than 90 reactor orders in
the U.S. were canceled. The TVA reevaluated
its own nuclear plans. Ultimately, it canceled
construction at Phipps Bend, Yellow Creek,
and Hartsville, while delaying construction
at the Bellefonte nuclear plant.
In 1985, the TVA took Browns Ferry and
Sequoyah out of service and halted construction
at the Watts Bar site. Unit 1 was thought
to be nearly complete and ready to receive
an OL. An NRC review had identified weaknesses
in the TVA's nuclear program, such
as the lack of a sufficient number of experienced
managers to provide leadership and
proper direction, coupled with the absence
of an effective organizational structure to ensure
the safe design, construction, and operation
of the TVA's nuclear plants.
The TVA initiated a vigorous recovery
program in 1986. Its Nuclear Performance
Plan (NPP) was approved by the NRC and
implemented to identify root causes and
implement corrective actions of the aforementioned
issues at the corporate and sitespecific
levels. Elements of the NPP were
implemented at the Watts Bar site, including
an employee concerns program to address
issues at the plant level. Browns Ferry and
Sequoyah were returned to service once necessary
improvements were made.
Deferred-Plant Problems
The NRC issued a policy statement on de1.
Better late than never. Construction on Watts Bar Unit 2 originally began in the
1970s. After a long interruption, the unit is currently forecast to begin commercial operation in
2015. Courtesy: TVA

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POWER June 2015

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