Europium-155

Medium-lived fission products
t^½(y)		Yield%	KeV	β
¹⁵⁵Eu	4.76	.0330	252	γ
⁸⁵Kr	10.76	.2717	687	γ
^113mCd	14.1	.0003	316
⁹⁰Sr	28.9	5.7518	2826	β
¹³⁷Cs	30.23	6.0899	1176	γ
^121mSn	43.9	.00003	390	γ
¹⁵¹Sm	90	.4203	77

halflife of 4.76 years. It has a maximum decay energy of 252 KeV. In a thermal reactor (almost all current nuclear power plants), it has a low fission product yield, about half of one percent as much as the most abundant fission products.

Eu-155's large Sr-90, so Eu-155 is not a significant contributor to nuclear waste.

Some Eu-155 is also produced by successive neutron capture on Eu-153 (nonradioactive, 350 barns thermal, 1500 resonance integral, yield is about 5 times as great as Eu-155) and Eu-154 (halflife 8.6 years, 1400 barns thermal, 1600 resonance integral, fission yield is extremely small because beta decay stops at Sm-154); however the differing cross sections mean that both Eu-155 and Eu-154 are destroyed faster than they are produced.

Europium-155

See also