Radioactive Releases from Nuclear Power Plants: A Cause for Concern

By Roger Johnson, PhD, contributing editor 

All nuclear power plants regularly discharge radioactivity into the environment.  They produce large quantities of radioactive materials and some of it gets discharged into the atmosphere, waterways, and surrounding land.  The public needs to know more about these radioactive emissions, especially since they are conducted frequently and in secret.  Ionizing radiation is a known carcinogen, and since cancer is becoming the number one cause of death in the United States, one of the primary concerns is whether these emissions cause cancer.  A good analysis of effluent releases is provided by the National Academy of Sciences (NAS) in its 412 page report, Analysis of Cancer Risks in Populations Near Nuclear Facilities Phase 1.

NRC terminates research into radiation-caused cancer deaths

In 2015, the National Academy of Sciences followed up with a Phase 2 report Analysis of Cancer Risks in Populations Near Nuclear Facilities Phase 2, which proposed new scientific research on populations living within 50 km (about 30 miles) of seven nuclear facilities including San Onofre.

Unfortunately, the research never took place because the Nuclear Regulatory Commission terminated the project just as it was set to begin.  No other research has been conducted in the United States on this important issue since the National Cancer Institute (NCI) study back in 1990.  This research failed to draw any conclusions.  By today’s standards, the report is now considered outdated and heavily flawed.

NCI cancer study considered “heavily flawed” 

The National Cancer Institute study examined cancer deaths but ignored cancer incidence. It studied where people died rather than where they lived or worked. It used political boundaries rather than distance from the source of radiation so that people living near the plant were averaged with people living far from the plant as long as they lived in the same county. The NCI study also failed to examine effects on sub groups based on gender and age even though cancer risks are substantially different. More recent research on cancer risks from radiation releases have corrected these flaws. Studies in Europe have reported cancer effects, especially in children.  In spite of the fact that women, children, and the human fetus are much more vulnerable to ionizing radiation, the nuclear industry continues to standardize risk only with regard to the less vulnerable statistical young adult male.

In order to determine possible health consequences from radioactive discharges, nuclear power plants are required to file annual reports about their releases.  These reports, however, are highly technical documents buried deep in NRC files.  The data are not disclosed at the time of the release but instead are delayed until an annual report the following year.  In general, the public is unaware of these reports or even the existence of radioactive releases into the environment.

BEIR VII proposes the LNT model

The radioactive emissions from nuclear power plants are considered low-level but any human-caused radiation contributing to naturally occurring radiation is worrisome.  Because excess radiation is a cause for concern, the National Academy of Sciences undertook a series of reports on the biological effects of ionizing radiation (commonly known as the BEIR reports).  BEIR VII (2006) was titled  Health Risks from Exposure to Low Levels of Ionizing Radiation.   One of the major conclusions was that there is no threshold below which radiation is harmless.  The report also concluded that there is a linear relationship between exposure levels and biological risks. This has become known as the Linear No Threshold (LNT) concept, now widely accepted by science.  Ionizing radiation damages cell DNA and can result in either acute effects or delayed effects.  Delayed effects may appear after years or decades and may include cancer, genetic effects, effects on the unborn child, and other health risks.

One of the most important considerations is that the damaging effects of ionizing radiation are cumulative.  This means that each potentially harmful exposure adds to previous exposures.  Those who wish to minimize the perception of harm caused by low-level radiation often focus only on single exposures. Attempts to trivialize radiation exposure sometimes results in silly analogies such as comparing a single exposure to flying on an airplane or eating a banana.  Another way to play down the effects of radiation exposure is to examine only immediate effects and ignore long term effects. Cancer and other serious medical conditions often take years or even decades to develop. After Three Mile Island, those who studied only immediate effects reported no cancer effects.  Those who studied long term effects found the opposite.  A good example is what happened in Japan after the atomic bombings in 1945.  The atomic bomb museum in Hiroshima contains a display showing how about 2,000 Japanese continue to die every year, not from old age but from medical effects resulting from their radiation exposure as children living on the outskirts of Hiroshima and Nagasaki in August of 1945.

Types of Radiation Emanating from Nuclear Power Plants

 

            Nuclear power plants conduct both controlled and uncontrolled releases of radiation.  The National Academy of Sciences Phase 1 report mentioned above documents many cases of uncontrolled accidental releases of radiation at nuclear power plants.  At San Onofre, it was the accidental release of radiation from a failed steam generator on January 31, 2012, which led to the permanent closure of the plant.  There were also numerous previous episodes of uncontrolled release such as in August of 2006 when radiation leaked into underground water tables at the plant.  Wells in San Clemente and Camp Pendleton were closed and Southern California Edison (SCE) ended up pumping 10,000 gallons of contaminated ground water into the Pacific Ocean (get NRC Report).

Ionizing Radiation

Ionizing radiation produced by nuclear reactors can cause different levels of biological damage depending on the type, energy, and access to the human body. Transuranic elements (those with atomic numbers greater than 92) are synthetic elements that do not exist in nature but are created in nuclear reactors.  They emit alpha particles which some like to portray as harmless because they do not easily penetrate human skin.  But they are massive in size and can be very damaging if inhaled or swallowed.  Airborne effluent releases are therefore potentially very dangerous not only because the winds carry them over populated areas but also because if ingested the radiation becomes an internal emitter which can cause extensive damage to many organs of the body. Beta particles have a smaller mass but greater energy which allows them to penetrate the skin.  Gamma radiation has very high energy but no mass so it easily penetrates the human body (and everything else including lead and several feet of concrete).  Gamma radiation can cause considerable damage to tissue and cell DNA.

“Allowable” radiation levels are not necessarily “safe” 

Some radionuclides are difficult or impossible to contain which can lead to continuous releases.  Nuclear reactors produce large quantities of Tritium, a radioactive isotope of Hydrogen. Tritium is a beta emitter. Since it cannot be filtered, what is allowable is regulated by an NRC standard called “ALARA” which means “As Low As Reasonably Achievable.”  This motivational standard encourages plants to do the best they can. The words “allowable” and “permissible” often appear but it should be remembered that the words “allowable” and “permissible” mean they comply with regulations. They do not mean that they are “safe.”

The five sources of ionizing radiation:

According to the NAS, nuclear power plants typically release from several to a few hundred curies of radioactivity into the environment per year however some plants have been known to release several hundred thousand curies.  Airborne and liquid effluent releases come from five sources within a nuclear plant:

*   Fission of residual uranium contained on the exterior of the fuel rods, referred to as tramp uranium.

*   Leaks from failed fuel rods.

*   Diffusion of radioactive gases through intact fuel rods.

*   Activation of materials in reactor cooling water.

*   Erosion and entrainment of activated materials from pipes, valves, and pumps in the cooling system.

Batch releases of radiation

Controlled releases are called “batch” releases because the liquids or gases are held in containers and then pumped into the environment.  Gaseous effluent releases are blasted into the atmosphere. NRC tables list dozens of radionuclides released into the air including 27 radioactive isotopes of Krypton, Xenon, Argon, Iodine, Bromine, Cobalt, Cesium, Chromium, Carbon, Manganese, Niobium, and Tritium. Decay time of these radionuclides vary considerably in their half-life, the time it takes for half of the radioactivity to decay.  Radionuclides cannot be considered safe after a half-life since the other half can remain lethal.  Most of the radiation is gone only after 10 half-lives.  Deadly Cesium 137 has a half-life of 30.2 years but it will be relatively safe only after 302 years (2322 AD, for example).  The beta emitter Carbon 14 has a half-life of 5,730 years and will be relatively safe in 57,300 years (the year 59,320 AD).

Monitoring of Radiation in the Environment Outside the Plant

Nuclear power plants are required to have Radiological Environmental Monitoring Programs (REMPs) to monitor radioactivity in the environment around their sites.  The NAS report states:

“It is important to note that REMPs at nuclear facilities are not intended to provide a comprehensive assessment of radionuclide distributions and concentrations in the environment surrounding the facilities.  Instead, their purpose is to demonstrate that the facility operations are in compliance with regulations.”

To demonstrate regulatory compliance, water monitoring typically involves taking samples of surface water, groundwater, and drinking water at various locations. Foodstuff monitoring analyzes samples from milk, fish, food products, and vegetables.

Regulatory compliance also requires periodic air samples collected from monitors miles from the site boundary.  Because radionuclides are spread in prevailing winds over populated areas, extensive meteorological reports have to be included.  Dozens of technical tables show wind speed and direction at different times of the year for different Pasquill stability classes. The monitoring is periodic rather than continuous. Radiation samples can be taken as often as twice a day or as infrequently as once every 184 days. Some of the sites outside of San Onofre where monitoring used to take place include the Mobil gas station on El Camino Real in San Clemente, a San Clemente school, the San Clemente Town Hall, the Fallbrook and Escondido fire stations, Aurora Park in Mission Viejo, Newport Beach, and the Oceanside City Hall.  Since San Onofre is now being decommissioned, it is no longer required to do environmental monitoring (or provide warning sirens).  The NRC has also permitted SCE to reduce its security presence and its participation in responses to emergencies.

The NAS report concludes that data collected by nuclear power plants are not sufficient to support detailed reconstructions of doses to specific individuals living nearby. The environmental monitoring data have limited usefulness for estimating doses around nuclear power plants.  Typically, most environmental measurements get reported at below minimum detection limits, partly because the measuring instruments are not sensitive enough to provide dose estimates.

Radioactive Releases at San Onofre

          Like all nuclear power plants, San Onofre conducts periodic deliberate releases of radioactivity into the air and water after which radiation then passes into the environment.  Gaseous releases are discharged through air ejectors. Liquid releases are diluted with sea water and pumped into the ocean through giant pipes 18 feet in diameter typically with a volume of 740,000 gallons per minute. The discharge pipes extend over a mile into the ocean but along the way there are 63 large portholes five feet in diameter.  Pumping at almost three-quarter of a million gallons per minute, a considerable volume of water can be quickly discharged through 63 large portals.

The discharge area is directly offshore of one of the most popular state parks in California visited by over 2.5 million people every year.  San Onofre State Beach is not only a Mecca for surfers and swimmers but it also attracts campers, kayakers, birders, fishermen, and bicyclists. The location is the sacred Native American site of Panhe.  A healthy marine environment in this area is considered of high importance. The 3,000 acre park with 22 public parking areas completely surrounds the nuclear power plant.  The Independent Spent Fuel Storage Installation (ISFSI) is only 108 feet from the beach where anyone can walk. A public road is a few hundred feet above the ISFSI as is an interstate highway right next to it.

Summaries of the release data are filed with the NRC the year after they take place (see below).  The exact dates and times of the releases are never disclosed. Summaries can be found by searching the NRC website.  The NRC reports focus on quarterly averages which are used to summarize the data so there is no way to determine the contents of any particular release.  Yearly summaries are also posted. For example, in 2009 at San Onofre there were 221 ocean discharges which released 23.3 billion gallons of radioactive water.  Some liquid batch releases went on continuously for over 28 hours.

San Onofre becomes the only nuclear power plant to provide advanced warnings

Historically, the releases at San Onofre have been conducted regularly for a half-century.  They have been carried out in secret with no public warnings before and no disclosure dates afterward. All this suddenly changed in 2019 when the California Lands Commission (following up on a request by the Surfrider Foundation) ordered SCE to issue 48 hour advance warnings.  The only notification has been a note on the SCE website that few people were aware of.  After 52 years,  many residents learned about these releases for the first time. Between December of 2019 and early August of 2020 there were 11 releases.  When one ocean release was scheduled for Memorial Day weekend, SCE was asked to delay the release until after the holiday.  SCE refused.  Many locals became incensed and starting placing warning signs on the beach just before the releases. In early summer, the releases were taking place weekly or biweekly.  After the signs went up in early August, there were no more releases as of the end of September. The last release to date was August 6, the exact 75^th anniversary of the bombing of Hiroshima.  No one knows if the releases have actually stopped or whether SCE reneged and no long discloses them.

Release frequency was quite consistent over the years but tended to decline following the plant closure.   More alarming statistics come from prior years. In the five years before closure, there were 1,041 radiation releases into the ocean and atmosphere.  In 2011, SCE pumped radiation releases for 518 hours at about 740,000 gallons per minute.  That makes 23 billion gallons pumped into the ocean that year.  Releases have continued after the plant closure and some worry that they might increase when the contaminated fuel pools are drained and the contaminated domes are demolished.

For ocean releases, the dangers to the marine ecosystem are both heat and radioactivity.  With “once through cooling,” sea water (and marine life) is sucked in to cool the reactors after which it is heated and pumped back into the ocean in enormous volumes at much higher temperatures.  The Diablo Canyon nuclear power plant, for example, sucks in 2.5 billion gallons of coastal water (including fish and marine life) a day and returns it 23F higher, thus causes enormous damage to marine life and the coastal habitat.

Because of the harm to the marine environment at San Onofre, SCE was required to construct an artificial reef to mitigate the damage. According to the California Coastal Commission, the once-through cooling returned water to the ocean at San Onofre 19F higher than the ocean temperature. At the time, SCE claimed that the new reef would make marine life thrive and fish populations soar.  This never happened.  The reef failed on 9 of 14 marine life criteria.  SCE was then required to build a second reef which was just completed in 2020.  These reefs ended up costing about $65 million, all costs paid for by the public.

SONGS RADIOACTIVE RELEASE REPORTS 2005-2015

Nuclear power plants are required by the NRC to submit what is called the Annual Radiation Effluent Release Report.  Details of some of the batch releases can be found on the NRC website.  Currently, the NRC includes only reports from 2005-2015:    https://www.nrc.gov/reactors/operating/ops-experience/tritium/plant-specific-reports/sano2-3.html  Because the plant is now closed, the NRC stopped posting these reports after 2015.  They also stopped posting reports prior to 2005 even though these reports supposedly go back to 1968.  The annual reports are sometimes quite lengthy, often over 300 pages long. The exact dates and times of releases as well as the quantities of individual releases are never disclosed. Instead, data are organized around quarterly averages.  The information below is copied directly from the NRC website. These summaries are for GASEOUS EFFLUENT BATCH RELEASES and LIQUID EFFLUENT BATCH RELEASES.  Both gaseous and liquid release data summarize the total number of releases and the total duration of the releases.

2005

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT (2005) S.O.N.G.S. 2 and 3 TABLE iF GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 6 releases; 2. Total time period for batch releases: 2070 minutes; 3. Maximum time period for a batch release: 470 minutes; 4. Average time period for a batch release: 345 minutes; 5. Minimum time period for a batch release: 39 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT (2005) S.O.N.G.S. 1 TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 9 releases; 2. Total time period for batch releases: 12875 minutes; 3. Maximum time period for a batch release: 1722 minutes; 4. Average time period for a batch release: 1431 minutes; 5. Minimum time period for a batch release: 990 minutes; 6. Average saltwater flow during batch releases: 13222 gpm

2006

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT (2006) S.O.N.G.S. 2 and 3 TABLE IF GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 11 releases; 2. Total time period for batch releases: 4164 minutes; 3. Maximum time period for a batch release: 547 minutes; 4. Average time period for a batch release: 379 minutes; 5. Minimum time period for a batch release: 206 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT (2006) S.O.N.G.S. 2 and 3 TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 132 releases; 2. Total time period for batch releases: 20275 minutes; 3. Maximum time period for a batch release 522 minutes; 4. Average time period for a batch release: 154 minutes; 5. Minimum time period for a batch release: I minute 6;  Average saltwater flow during batch releases: 737197 gpm

2007

ANNUAL RADIOACTIVE RELEASE REPORT (2007) S.0.N.G.S 2 and 3 TABLE 1F GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY I\ 12 month period 1. Number of batch releases: 7 releases;  2. Total time period for batch releases: 2567 minutes;  3. Maximum time period for a batch release: 518 minutes;  4. Average time period for a batch release: 367 minutes;  5. Minimum time period for a batch release: 233 min

ANNUAL RADIOACTIVE RELEASE REPORT (2007) S.O.N.G.S. 2 and 3 TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 202 releases;  2. Total time period for batch releases: 29363 minutes;  3. Maximum time period for a batch release: 455 minutes;  4. Average time period for a batch release: 145 minutes;  5. Minimum time period for a batch release: 1 minute 6;  Average saltwater flow during batch releases: 731000 gpm

2008

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2008 SAN ONOFRE NUCLEAR GENERATING STATION -10- TABLE 1F GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 5 releases;  2. Total time period for batch releases: 1849 minutes;  3. Maximum time period for a batch release: 485 minutes;  4. Average time period for a batch release: 370 minutes;  5. Minimum time period for a batch release: 282 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2008 SAN ONOFRE NUCLEAR GENERATING STATION -18- TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 164 releases;  2. Total time period for batch releases: 26116 minutes;  3. Maximum time period for a batch release: 522 minutes; 4. Average time period for a batch release: 159 minutes;  5. Minimum time period for a batch release: 50 minutes;  6. Average saltwater flow during batch releases: 738000 gpm

2009

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2009 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 1F GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 6 releases;  2. Total time period for batch releases: 2138 minutes;  3. Maximum time period for a batch release: 447 minutes;   4. Average time period for a batch release: 356 minutes;  5. Minimum time period for a batch release: 271 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2009 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 221 releases;  2. Total time period for batch releases: 31779 minutes;  3. Maximum time period for a batch release: 456 minutes;   4. Average time period for a batch release: 144 minutes;   5. Minimum time period for a batch release: 64 minutes;   6. Average saltwater flow during batch releases: 734000 gpm

2010

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2010 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 1F GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 6 releases;  2. Total time period for batch releases: 2653 minutes;  3. Maximum time period for a batch release: 650 minutes;  4. Average time period for a batch release: 442 minutes;  5. Minimum time period for a batch release: 303 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2010 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 212 releases;   2. Total time period for batch releases: 32971 minutes;   3. Maximum time period for a batch release: 1573 minutes;   4. Average time period for a batch release: 156 minutes;   5. Minimum time period for a batch release: 86 minutes;   6. Average saltwater flow during batch releases: 739127 gpm

2011

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2011 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 1F GASEOUS EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 3 releases;   2. Total time period for batch releases: 2654 minutes;   3. Maximum time period for a batch release: 1564 minutes;   4. Average time period for a batch release: 885 minutes;   5. Minimum time period for a batch release: 476 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2011 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 215 releases;   2. Total time period for batch releases: 31073 minutes;   3. Maximum time period for a batch release: 657 minutes;   4. Average time period for a batch release: 145 minutes;   5. Minimum time period for a batch release: 79 minutes;   6. Average saltwater flow during batch releases: 740000 gpm

2012

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2012 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 1F GASEOUS EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 6 releases 2. Total time period for batch releases: 2585 minutes;   3. Maximum time period for a batch release: 521 minutes;   4. Average time period for a batch release: 431 minutes;   5. Minimum time period for a batch release: 349 minutes

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2012 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 65 releases;   2. Total time period for batch releases: 20104 minutes;   3. Maximum time period for a batch release: 1685 minutes 4. Average time period for a batch release: 309 minutes;   5. Minimum time period for a batch release: 52 minute;  s 6. Average saltwater flow during batch releases: 612000 gpm

2013

2013  ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT (2005) S.O.N.G.S. 2 and 3 TABLE iF GASEOUS EFFLUENTS-BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 6 releases;   2. Total time period for batch releases: 2070 minutes;   3. Maximum time period for a batch release: 470 minutes;   4. Average time period for a batch release: 345 minutes;   5. Minimum time period for a batch release: 39 minutes

2013 TABLE 2E LIQUID EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 56 releases;   2. Total time period for batch releases: 14564 minutes;   3. Maximum time period for a batch release: 681 minutes;   4. Average time period for a batch release: 260 minutes;   5. Minimum time period for a batch release: 6 minutes 6. Average saltwater flow during batch releases: 387000 gpm

2014

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2014 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 1F GASEOUS EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: releases 0;  2. Total time period for batch releases: 0 minutes;   3. Maximum time period for a batch release: 0 minutes;   4. Average time period for a batch release: 0 minutes;   5. Minimum time period for a batch release: 0 minutes.  There were no batch releases in 2014

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT – 2014 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS BATCH RELEASE SUMMARY 12 month period 1. Number of batch releases: 8 releases;   2. Total time period for batch releases: 1725 minutes;   3. Maximum time period for a batch release: 262 minutes;   4. Average time period for a batch release: 216 minutes;   5. Minimum time period for a batch release: 118 minutes;  6. Average saltwater flow during batch releases: 29500 gpm

2015

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT- 2015 SAN ONOFRE NUCLEAR GENERATING STATION TABLE1F GASEOUS EFFLUENTS BATCH RELEASE SUMMARY* 12 month period Number of batch releases: 0 releases;  Total time period for batch releases: 0 minutes; Maximum time period for a batch release: 0 minutes;  Average time period for a batch release: 0 minutes;   Minimum time period for a batch release: 0 minutes *There were no batch releases in 2015

ANNUAL RADIOACTIVE EFFLUENT RELEASE REPORT- 2015 SAN ONOFRE NUCLEAR GENERATING STATION TABLE 2E LIQUID EFFLUENTS BATCH RELEASE SUMMARY 12 month period Number of batch releases: 1 release;   Total time period for batch releases: 80 minutes;   Maximum time period for a batch release: 80 minutes;   Average time period for a batch release: 80 minutes;   Minimum time period for a batch release: 80 minutes;  Average saltwater flow during batch releases: 29,800 gpm,

ATMOSPHERIC AND OCEAN RADIOACTIVE RELEASES AT SONGS

Compiled from NRC Files 2005-2015

Year	No. Gaseous Releases	Hours per Year	# Liquid Releases	Hours Per Year	Gallons dumped into  Ocean
2005	6	35	9	215	170.2 million
2006	11	69	132	338	14.0 billion
2007	7	43	202	481	21.5 billion
2008	5	31	164	435	19.3 billion
2009	6	36	221	530	23.3 billion
2010	6	44	212	559	24.4 billion
2011	3	44	215	517	23 billion
2012	6	43	65	335	12.3 billion
2013	3	44	56	243	5.6 billion
2014	0	0	8	262	50.9 million
2015	0	0	1	1.3	2.4 million