of a large database, prudence is required for applications that
involve variable values beyond the ranges specified in 1.1. Due
to strong correlations with other exposure variables within the
database (that is, fluence), and due to the uneven distribution of
data within the database (for example, the irradiation tempera-
ture and flux range of PWR and BWR data show almost no
overlap) neither neutron fluence rate nor irradiation time
sufficiently improved the accuracy of the predictions to merit
their use in the embrittlement correlation in this guide. Future
versions of this guide may incorporate the effect of neutron
fluence rate or irradiation time, or both, on TTS, as such effects
are described in (1).
4
The irradiated material database, the
technical basis for developing the embrittlement correlation,
and issues involved in its application, are discussed in a
separate report (ADJE090015-EA). That report describes the
nine different TTS equations considered in the development of
this guide, some of which were developed using more limited
datasets (for example, national program data (2,3)). If the
material variables or exposure conditions of a particular
application fall within the range of one of these alternate
correlations, it may provide more suitable guidance.
1.3 This guide is expected to be used in coordination with
several standards addressing irradiation surveillance of light-
water reactor vessel materials. Method of determining the
applicable fluence for use in this guide are addressed in Guides
E482,E944, and Test Method E1005. The overall application
of these separate guides and practices is described in Practice
E853.
1.4 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
provided for information only and are not considered standard.
1.5 This standard guide does not define how the TTS should
be used to determine the final adjusted reference temperature,
which would typically include consideration of the transition
temperature before irradiation, the predicted TTS, and the
uncertainties in the shift estimation method.
1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
5
A302 Specification for Pressure Vessel Plates, Alloy Steel,
Manganese-Molybdenum and Manganese-Molybdenum-
Nickel
A508 Specification for Quenched and Tempered Vacuum-
Treated Carbon and Alloy Steel Forgings for Pressure
Vessels
A533 Specification for Pressure Vessel Plates, Alloy Steel,
Quenched and Tempered, Manganese-Molybdenum and
Manganese-Molybdenum-Nickel
E185 Practice for Design of Surveillance Programs for
Light-Water Moderated Nuclear Power Reactor Vessels
E482 Guide for Application of Neutron Transport Methods
for Reactor Vessel Surveillance
E693 Practice for Characterizing Neutron Exposures in Iron
and Low Alloy Steels in Terms of Displacements Per
Atom (DPA)
E853 Practice for Analysis and Interpretation of Light-Water
Reactor Surveillance Neutron Exposure Results
E944 Guide for Application of Neutron Spectrum Adjust-
ment Methods in Reactor Surveillance
E1005 Test Method for Application and Analysis of Radio-
metric Monitors for Reactor Vessel Surveillance
E2215 Practice for Evaluation of Surveillance Capsules
from Light-Water Moderated Nuclear Power Reactor Ves-
sels
2.2 ASTM Adjunct:
2
ADJE090015-EA Technical Basis for the Equation Used to
Predict Radiation-Induced Transition Temperature Shift in
Reactor Vessel Materials
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 best-estimate chemical composition—the best-
estimate chemical composition (copper [Cu], nickel [Ni],
phosphorus [P], and manganese [Mn] in %) may be established
using one of the following methods: (1) Use a simple mean for
a small set of uniformly distributed data; that is, sum the
measurements and divide by the number of measurements; (2)
Use a weighting process for a non-uniformly distributed data
set, especially when the number of measurements from one
source are much greater in terms of material volume analyzed.
For a plate, a unique sample could be a set of test specimens
taken from one corner of the plate. For a weldment, a unique
sample would be a set of test specimens taken from a unique
weld deposit made with a specific electrode heat. A simple
mean is calculated for test specimens comprising each unique
sample, the sample means are then added, and the sum is
divided by the number of unique samples to get the sample
weighted mean; (3) Use an alternative weighting scheme when
other factors have a significant influence and a physical model
can be established. For the preceding, the best estimate for the
sample should be used if evaluating surveillance data from that
sample.
3.1.1.1 Discussion—For cases where no chemical analysis
measurements are available for a heat of material, the upper
limiting values given in the material specifications to which the
vessel was built may be used. Alternately, generic mean values
for the class of material may be used.
4
The boldface numbers in parentheses refer to a list of references at the end of
this standard.
5
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
E900 − 21
2