ASTM D5411-10(2015)
计算反应堆冷却剂中放射性核素混合物的每次衰变 (&xaf;E) 平均能量的标准实施规程

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

被代替

标准号

ASTM D5411-10(2015)

发布

2010年

发布单位

美国材料与试验协会

替代标准

ASTM D5411-21

当前最新

ASTM D5411-21

 

 

引用标准

ASTM D1066 ASTM D1129 ASTM D3370 ASTM D3648 ASTM D7282

适用范围

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.

讨论：太先进无法展示？核能新技术ADS靠谱吗

为此在九十年代初，曾对P-T方法处置核废物作出过否定结论的以A.G.Croff 为首的同一组人对P-T方法处置核废物作了重新评价，得出一些新的结论:乏燃料元件中的锕系核素通过分离回收，只要分离后的α放射性丢失在废液中的量达到EPA规定中C类废物的释放标准，则残留放射性废物再衰变1000年就可以达到EPA 规定的高放废物埋藏和低放废物处置标准。因而有可能解决长寿命核废物的远期风险问题。...