Acronyms, Abbreviations, and Definitions

AC	alternating-current
(the) Advisory Group	Advisory Group on Nuclear Event Communications
AFS	auxiliary feedwater system
ANS	American Nuclear Society
BDBA	beyond-design-basis accident
Bq	becquerel
BWR	boiling water reactor
Ci	curie
cold shutdown	RPV water temperature is <100°C.
(the) Committee	The American Nuclear Society Special Committee on Fukushima
containment	refers to the configuration of the structure and associated systems that enclose the nuclear reactor and are the final barrier to the release of radioactive materials into the environment in the case of a severe accident; containment designs are designated Mark I (the oldest), Mark II, and Mark III (the most recent).
134Cs	cesium-134
137Cs	cesium-137
CST	condensate storage tank
DC	direct-current
DOE	U.S. Department of Energy
ECCS	emergency core cooling system
EDG	emergency diesel generator
Gy	gray; the international system unit of measure for the amount of energy deposited in any material from any form of radiation
HPCI	high-pressure coolant injection
131I	iodine-131
IAEA	International Atomic Energy Agency
JAEA	Japan Atomic Energy Agency
JAEC	Japan Atomic Energy Commission
kBq	kilobecquerel
km	kilometer
km2	kilometers squared
LWR	light water reactor
m	meter
Mark I	see “containment”
Mark II	see “containment”
Mark III	see “containment”
MBq	megabecquerel
MEXT	Ministry of Education, Culture, Sports, Science and Technology–Japan
µSv	microsievert; see “Sv”
mm	millimeter
mR	millirad; see “rad”
mrem	millirem; see “rem”
mSv	millisievert; see “Sv”
MWe	megawatt electric
m2	meters squared
m3	cubic meters
MSIV	main steam isolation valve
NEI	Nuclear Energy Institute
NIRS	National Institute of Radiological Sciences (Japan)
NNSA	National Nuclear Security Agency (DOE)
NPP	nuclear power plant
NPS	nuclear power station
NRC	U.S. Nuclear Regulatory Commission
NTTF	Near-Term Task Force
outage	Cold shutdown condition and periodic inspections and/or refueling operations are being conducted; the RPV head may be on or off.
PCV	primary containment vessel
person-Sv	person-sievert
(the) PI Committee	Public Information Committee
(the) Plan	Nuclear Event Communications Plan
PWR	pressurized water reactor
RCIC	reactor core isolation cooling
rad	radiation absorbed dose; the unit of measure for the amount of energy deposited in any material from any form of radiation; the related international system unit is the gray (Gy).
rem	roentgen equivalent man; the unit of measure for the amount of energy deposited in a human body that accounts for the effect of differences in radiation types (alpha, beta, gamma, etc.) on living tissue; the related international system unit is sievert (Sv).
RHR	residual heat removal
RPV	reactor pressure vessel
SAMG	severe accident management guideline
SBO	station blackout
SFP	spent-fuel pool
SRV	safety and relief valve
start-up	RPV head is on, reactor is critical, and primary system is being heated.
Sv	sievert; the international system unit of measure for the amount of energy deposited in a human body that accounts for the effect of differences in radiation types alpha, beta, gamma, etc.) on living tissue
(the) Technical Group	Technical Group on Nuclear Communications
TEPCO	Tokyo Electric Power Company
TMI-2	Three Mile Island Unit 2
Unit	refers to reactor(s) in NPS(s)

Last modified March 9, 2021, 10:21am CST