Nuclear Plant Journal, May-June 2015 NuclearPlantJournal.com
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3.
Technical Basis for Severe Accident
Mitigating Strategies: Volume 1
. Product
ID: 3002003301. Published April, 2015.
This report describes a risk-informed
technical investigation of severe
accident mitigating strategies for boiling
water reactors (BWRs) with Mark I
containments. This report focuses on
measures that could protect containment
integrity and reduce radionuclide releases
following a severe reactor accident.
The severe reactor accidents at the
Fukushima Daiichi Nuclear Power Plant
in March 2011 showed the significant
challenges that an unmitigated station
blackout (SBO) condition can present
to steel BWR containments with
relatively small volumes (e.g., Mark I
& II containments). Past severe accident
studies (e.g., State-of-the-Art Reactor
Consequence Analyses (SOARCA))
have estimated a high conditional
probability of containment failure in
these containments if certain conditions
(i.e., high containment pressure and
temperatures) cannot be controlled
for prolonged periods of time. The
operational response at the Fukushima
Daini site during this same time period
highlighted the benefit of effective
operator intervention in preventing a
severe reactor accident.
4.
Program on Technology Innovation:
Muon Imaging for Nondestructive
Evaluation
. Product ID: 3002005255.
Published April, 2015.
Naturally-occurring cosmic rays
provide a ubiquitous and safe passive
imaging method for many applications
that could be useful for power industry
applications. Imaging is possible
through significant overburden in
situations where on the order of one hour
or more is available for data gathering
process. Although the current resolution
is limited and the detector used was
difficult to transport, technology exists
for lightweight, low-power systems that
could be easily deployed in field situations
for online monitoring and inspection
needs with sufficient resolution for many
applications.
While muon imaging is not suitable
for all applications, this report identifies
a number of possible applications where
muon imaging could provide some or
significant value for power industry
applications, such as for flow-accelerated
corrosion (FAC) inspection without
removing insulation, some concrete
inspections, and evaluating the open/
closed state of a valve.
5.
GroundwaterProtectionRiskAssessment
and Mitigation for Work Practices and
Systems, Structures, and Components
.
Product ID: 3002004881. PublishedApril,
2015.
Inadvertent leaks and spills during
nuclear power plant operation can lead
to licensed materials such as tritium
migrating into on-site groundwater. Such
inadvertent events have led nuclear power
plant owners to implement groundwater
protection programs. The purpose of this
project is to understand which systems,
structures, and components (SSCs) and
work practices (WPs) have historically
led to leaks and spills of licensed
materials at nuclear power plants in order
to inform risk assessment and mitigation
strategies.
6.
Microwave and Millimeter Wave
Evaluation of Rubber Expansion Joints
and Metallic Materials
. Product ID:
3002005256. Published April, 2015.
Over time, numerous components
experience aging and other forms of
degradation which can lead to failure.
Currently, few inspections are available
for inspecting rubber expansion joints and
many other nonmetallic materials. EPRI
has been developing improved techniques
for the detection of degradation in
metallic and nonmetallic materials, such
as expansion joints. This report provides
information related tomicrowave andmm-
wave inspections that were performed on
simulated degradation, simulated aging,
and actual aging in elastomer materials,
specifically rubber expansion joints.
The results show significant promise in
detecting degradation in expansion joints
and some potential to detect changes in
material properties, however, results were
inconclusive for directly detecting aging
effects using these techniques.
This project also evaluated the
capabilities of microwave and mm-wave
inspection methods for detecting surface
cracks in metals that were either exposed
to the ambient environment or covered by
a coating. The results show promise in
being able to detect cracks in both cases.
7.
Pressurized Water Reactor Shutdown
Activity Releases - 2014 Summary: 2015
Radiation Management and Source Term
Technical Strategy Group Report
. Product
ID: 3002005483. Published May, 2015.
This report presents information
from a research study on releases of
Cobalt-58 (Co-58) from steam generator
tubing during PWR refueling outage
shutdowns. A primary focus of the
project was the assessment of factors
considered to be dominant influences
on Co-58 releases, based on theoretical
considerations and plant observations.
The report updates earlier EPRI reports
1024947 and 1025187 (both published in
2012), incorporating available new data,
and adds trending as a function of time as
well as providing an assessment of long-
term release rates.
The above EPRI documents may be
ordered by contacting the Order Center
at (800) 313-3774, Option 2, or email at
.
