ASTM D5411-10(2015)
Standard Practice for Calculation of Average Energy Per Disintegration (&xaf;E) for a Mixture of Radionuclides in Reactor Coolant

Standard No.

ASTM D5411-10(2015)

Release Date

2010

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM D5411-21

Latest

ASTM D5411-21

Scope

5.1 This practice is useful for the determination of the average energy per disintegration of the isotopic mixture found in the reactor-coolant system of a nuclear reactor (1).4 The E value is used to calculate a site-specific activity limit for the reactor coolant system, generally identified as

where

K

=

a power reactor site specific constant (usually in the range of 50 to 200).

The activity of the reactor coolant system is routinely measured, then compared to the value of A_limiting. If the reactor coolant activity value is less than A_limiting then the 2-h radiation dose, measured at the plant boundary, will not exceed an appropriately small fraction of the Code of Federal Regulations, Title 10, part 100 dose guidelines. It is important to note that the measurement of the reactor coolant system radioactivity is determined at a set frequency by use of gamma spectrometry only. Thus the radionuclides that go into the calculation of E and subsequently A_limiting are only those that are calculated using gamma spectrometry.

5.2 In calculating E, the energy dissipated by beta particles (negatrons and positrons) and photons from nuclear decay of beta-gamma emitters. This accounting includes the energy released in the form of energy released from extra-nuclear transitions in the form of X-rays, Auger electrons, and conversion electrons. However, not all radionuclides present in a sample are included in the calculation of E.

5.3 Individual, nuclear reactor, technical specifications vary and each nuclear operator must be aware of limitations affecting their plant operation. Typically, radioiodines, radionuclides with half lives of less than 10 min (except those in equilibrium with the parent), and those radionuclides, identified using gamma spectrometry, with less than a 958201;% confidence level, are not typically included in the calculation. However, the technical requirements are that the reported activity must account for at least 958201;% of the activity after excluding radioiodines and short-lived radionuclides. There are individual bases for each exclusion.

5.3.1 Radioiodines are typically excluded from the calculation of E because United States commercial nuclear reactors are required to operate under a more conservative restriction of 1 μC (37 kBq) per gram dose equivalent ¹³¹I (DEI) in the reactor coolant.

E–) for a Mixture of Radionuclides in Reactor Coolant

2010 ASTM D5411-10(2015) Standard Practice for Calculation of Average Energy Per Disintegration (&xaf;E) for a Mixture of Radionuclides in Reactor Coolant

2010 ASTM D5411-10 Standard Practice for Calculation of Average Energy Per Disintegration (E) for a Mixture of Radionuclides in Reactor Coolant

2005 ASTM D5411-05 Standard Practice for Calculation of Average Energy Per Disintegration (E) for a Mixture of Radionuclides in Reactor Coolant

1993 ASTM D5411-93(2005)e1 Standard Practice for Calculation of Average Energy Per Disintegration (E) for a Mixture of Radionuclides in Reactor Coolant

1993 ASTM D5411-93(1999) Standard Practice for Calculation of Average Energy Per Disintegration (E) for a Mixture of Radionuclides in Reactor Coolant