| Abs |
Absolute |
| ASP |
Accident sequence precursor (PRA term) |
| Acre-ft |
Acre-foot |
| AE |
Action Evaluation |
| AR |
Action Request |
| ALJ |
Administrative Law Judge |
| AL |
Administrative Letter (NRC) |
| ACRS |
Advisory Committee on Reactor Safeguards |
|
Aftercooler |
|
Air-cooled |
|
All-inclusive |
| AVT |
All volatile treatment |
| AOT |
Allowed outage time |
| ARC |
Alternate repair criteria |
| Ac |
Alternating current |
| ACI |
American Concrete Institute |
| AIEE |
American Institute of Electrical Engineers |
| AISC |
American Institute of Steel Construction |
| ANSI |
American National Standards Institute |
| ANEC |
American Nuclear Energy Council |
| ANI |
American Nuclear Insurers |
| ANS |
American Nuclear Society |
| API |
American Petroleum Institute |
| ASTM |
American Society for Testing and Materials |
| ASCE |
American Society of Civil Engineers |
| ASME |
American Society of Mechanical Engineers |
| ASA |
American Standards Association |
| AWS |
American Welding Society |
| AWG |
American wire gauge |
| A/amp |
Ampere |
| A/cm2
|
Ampere per square centimeter |
| A-hr/amp-hr |
Ampere-hour |
| AM |
Amplitude modulation |
| A.m. |
Ante meridiem–before noon |
| ATWS |
Anticipated transient without scram |
| ATWT |
Anticipated transient without trip |
| Antilog/log-1
|
Antilogarithm |
|
Antireverse |
| AVB |
Antivibration bar |
| ALARA |
As low as is reasonably achievable |
|
As-built (adj or noun) |
| Atm |
Atmosphere |
| AEC |
Atomic Energy Commission |
| AIF |
Atomic Industrial Forum |
| At. no. |
Atomic number |
| At. % |
Atomic percent |
| ASLAB |
Atomic Safety and Licensing Appeal Board |
| ASLB |
Atomic Safety and Licensing Board |
| At. wt |
Atomic weight |
| AMSAC |
ATWS mitigation system actuation circuitry |
| AFR |
Audit Finding Report |
| AIT |
Augmented inspection team (NRC) |
| ANI |
Authorized Nuclear Inspector |
| ACI |
Autoclosure interlock |
|
Autostart |
|
Autostop |
| AB |
Auxiliary building |
| AFW |
Auxiliary feedwater |
| ASW |
Auxiliary saltwater |
| Avg |
Average |
| AO |
Axial offset |
| AOC |
Axial offset control |
