nucdata.tools

Nuclear data
in a browser tab.

756 isotopes across ENDF/B-VIII.1, JEFF-3.3, JENDL-5, and TENDL-2021.

Cross sections, angular distributions, outgoing-neutron spectra, fission yields, MF=33 covariance bands, decay chains, group meshes, and material mixtures — side by side, shareable by URL. Build runnable NJOY-2016 decks for SHEM-281, SHEM-370, WIMS-69, and OpenMC CE. Nothing to install.

Open the Viewer →Build an NJOY deckUpload ENDF
Example: U-238 capture · 4 libs · 900 K · SHEM-370 →
loading catalogue…
Isotopes covered
hover any element or material — the background nucleus follows
Hover any element to preview · click a lit element to open its isotope picker
1
H
2
He
3
Li
4
Be
5
B
6
C
7
N
8
O
9
F
10
Ne
11
Na
12
Mg
13
Al
14
Si
15
P
16
S
17
Cl
18
Ar
19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
55
Cs
56
Ba
57
La
58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
87
Fr
88
Ra
89
Ac
90
Th
91
Pa
92
U
93
Np
94
Pu
95
Am
96
Cm
97
Bk
98
Cf
99
Es
100
Fm
101
Md
102
No
103
Lr
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
111
Rg
112
Cn
113
Nh
114
Fl
115
Mc
116
Lv
117
Ts
118
Og
57–71
89–103

Common materials

Click any material to open σmix(E) in the viewer. Hover swaps the hero nucleus to the molecule.

UO₂(n,γ)
3 atoms · natural uranium dioxide
UO₂ 3.5%(n,f)
3 atoms · LWR enriched fuel
MOX(n,f)
4 atoms · mixed-oxide fuel (7% Pu)
H₂O(n,el)
3 atoms · moderator + coolant
Zr (nat.)(n,el)
1 atoms · natural Zr; not Zircaloy (no Sn/Fe/Cr/Hf alloy trace)
SS304(n,γ)
5 atoms · stainless (atom-% ≈ wt-% 70/18/10/2)
B₄C(n,α)
5 atoms · absorber (natural B; enrich for engineering)
Gd₂O₃(n,γ)
5 atoms · burnable poison
open →

Plot

Log-log σ(E) for any (isotope, MT, library) tuple. Resonance peaks auto-annotated. Doppler-broaden between cached temperatures with a slider. Multi-library overlay; deep-link the URL to share.

open →

Overlay

41 group meshes (SHEM-370, WIMS-D 69, XMAS-172, SCALE-238, ECCO, ANL …) dropped on any curve with live resonance-coverage metrics. ±1σ MF=33 covariance bands. EXFOR overlays coloured by year.

UO₂open →

Mix

Type a chemical formula → atom-weighted σ_mix(E) across all four libraries. Enrichment overrides (3.5 % LEU, MOX, HALEU). σ_th / RI / σ̄_M / σ̄_χ benchmark integrals computed on the fly.

open →

Generate

Form-driven NJOY-2016 input deck builder. SFR · SHEM-370 (custom IGN=1) and LWR · WIMS-D 69 (IGN=9) presets. Per-stage download + bash runner.sh that pipelines PENDF → GENDF → DRAGR with tape handoff.