Bruce Hamilton, Chairman 

Jessie H. Roberson 

DEFENSE NUCLEAR FACILITIES 

SAFETY BOARD 

Joyce L. Connery 

The Honorable James Richard Perry 

Secretary of Energy 

U.S. Department of Energy 

1000 Independence A venue, SW 

Washington, DC 20585-1000 

Dear Secretary Perry: 

Washington, DC 20004-2901 

June 11, 2019 

The Defense Nuclear Facilities Safety Board received the NNSA Administrator's 

response to Draft Recommendation 2019-1, Safety of the Savannah River Tritium Facilities, on 

April 10, 2019. The Board considered the NNSA Administrator's response and appreciates the 

actions DOE/NNSA is taking. The information contained in the NNSA Administrator's 

response, however, does not obviate the need for the Recommendation. The Board concludes 

that there remains an issue of adequate protection of public health and safety in the event of an 

energetic accident at the Tritium Facilities, comprising several defense nuclear facilities, at the 

Savannah River Site. On June 5, 2019, the Board, in accordance with 42 U.S.C. § 2286d(a)(3), 

approved Recommendation 2019-2, which is enclosed for your consideration along with all 

related findings, supporting data, and analysis. 

After you have received this Recommendation, the Board will promptly make the 

Recommendation and any related Secretarial correspondence available to the public as required 

by 42 U.S.C. § 2286d(b). The Board believes that this Recommendation contains no 

information that is classified or otherwise restricted. To the extent that this Recommendation 

does not include information restricted by DOE under the Atomic Energy Act of 1954, as 

amended, please arrange to have this recommendation and any related Secretarial 

correspondence placed promptly on file in your regional public reading rooms. The Board will 

also publish this Recommendation in the Federal Register. 

The Board will evaluate DOE's response to this Recommendation in accordance with 

the Board's Policy Statement 1, Criteria for Judging the Adequacy of DOE Responses and 

Implementation Plans for Board Recommendations. 

Enclosures 

c: Mr. Joe Olencz 

Yours truly, 

Bruce Hamilton 

Chairman 
RECOMMENDATION 2019-2 TO THE SECRETARY OF ENERGY

Safety of the Savannah River Site Tritium Facilities

Pursuant to 42 U.S.C. § 2286a(b)(5) 

Atomic Energy Act of 1954, as Amended 

Introduction. The Tritium Facilities at the Savannah River Site (SRS) consist of several 

defense nuclear facilities, including the 217-H Vault, Buildings 233-H and 234-H, and the 

Tritium Extraction Facility, used for processing and storing tritium. The Defense Nuclear 

Facilities Safety Board (Board) is concerned about adequate protection of the public health and 

safety in the event of an energetic accident at the Tritium Facilities. 

The facilities’ approved Documented Safety Analysis (DSA) and the November 2018 

revision to the DSA awaiting approval by the National Nuclear Security Administration (NNSA) 

of the Department of Energy (DOE) both have analyzed several credible accidents that could 

result in very high doses, creating the potential for acute radiation sickness or fatality1 in a 

significant number of individuals. These energetic accidents include building-wide fires due to a 

variety of initiating events, crane drops, and explosions with the potential to release large 

quantities of tritium. 

The probability of such an event within the lifetime of the facility is not negligible. 

Assuming a 50-year lifetime for the facilities, the probability that an unlikely event could occur 

within that time period ranges from 0.5 percent to about 40 percent. Such an event could lead to 

a significant number of potentially exposed individuals, posing a significant challenge to both 

SRS’s emergency management system and to local emergency and medical facilities.

The current situation at the Tritium Facilities does not adequately address either DOE’s 

standards of care or standards of practice as defined by its own requirements. Consequently, 

adequate protection is not assured. The Board has concluded that DOE needs to take actions to 

improve the safety of the Tritium Facilities, upgrades to safety management programs and the 

implementation of robust controls to ensure adequate protection of public health and safety.

2

 

 

1 Acute radiation-induced sickness and acute radiation fatality, as used in this report, refers to possible outcomes of 

the acute radiation syndrome. This syndrome is the result of an acute, or short duration, exposure to a very high 

level of ionizing radiation. In this context, the word acute does not imply immediate incapacitation or death, as the 

syndrome and its impact on a human body may take hours to months to progress to recovery or death.

2 The Board has raised concerns regarding the safety posture at the Tritium facilities since 1992. The Board’s 

concerns over the potential for energetic accidents with very high calculated dose consequences have been 

frequently communicated to DOE. DOE has routinely responded to the Board’s concerns with improvements in the 

safety controls, only to allow those controls to be downgraded after a number of years. (See the Attachment for a list 

of previous Board correspondence.)
2 

Recommendations. The Board recommends that DOE:

1. Identify and implement near-term compensatory measures at SRS to mitigate the 

potential for high radiological consequences to individuals who would be impacted 

by a release from the Tritium Facilities. (For example, potential near-term 

compensatory measures could include, but are not limited to reducing the material at 

risk (MAR) and/or limiting the number of potentially exposed individuals or other 

physical or administrative controls.)

2. Identify and implement long-term actions and controls to prevent or mitigate the 

hazards that pose significant radiological consequences to acceptably low values 

consistent with the requirements of DOE directives. 

3. In parallel with the above recommendations, evaluate the adequacy of the following 

safety management programs and upgrade them as necessary to ensure that SRS can 

effectively respond to energetic accidents at the Tritium Facilities, and that it can 

quickly identify and properly treat potential victims:

a. The staffing and training requirements for individuals expected to take 

specific actions in response to alarms, abnormal operations, and emergencies;

b. The adequacy of the Emergency Preparedness programs in H-Area to account 

for all individuals in the vicinity and ensure that all potentially affected 

individuals understand their responsibilities and required actions in the event 

of a large tritium release from the Tritium Facilities and are prepared to 

implement them;

c. The ability of the site’s Fire Department to respond to fires, explosions, and 

other accidents at the Tritium Facilities that could lead to a large tritium 

release;

d. The capability of the site-wide radiological protection and occupational 

medicine programs to respond to an accident and monitor a large number of 

people with potentially serious uptakes of tritiated water vapor; and 

e. The ability and preparedness of community emergency and medical resources

to support the site in such situations. 

Background. 

Effects of Tritium Release: Much of the in-process tritium at the Tritium Facilities may 

be in the form of gas, and material in storage is either in pressure vessels or deposited on hydride 

beds. Exposure to tritium gas does not result in significant doses to individuals, as the gas is not 

retained by the human body after inhalation. However, any significant release of tritium gas 

during an energetic accident or upset condition has a high potential of resulting in a fire, even if a 

fire did not initiate the release. In the energetic accidents of concern to the Board, tritium, an 
3 

isotope of hydrogen, may be ignited, converted into water by oxidation, and then dispersed as a 

vapor. 

Tritiated water vapor represents a significant risk to those exposed to it, as its dose 

consequence to an exposed individual is 15,000 to 20,000 times higher than that for an 

equivalent amount of tritium gas.3

 As with normal water vapor, tritiated water vapor is quickly 

absorbed into the lungs and through the skin, and rapidly mixes with the water in the body. The 

target organ for the exposure is the whole body, with a biological half-life4

 of 10 days [1]. The 

combination of a rapid intake and a short biological half-life means a large fraction of the 

radiological dose is acutely delivered within hours to days rather than chronically delivered over 

many months to years. Tritium’s chemical and radiological characteristics also create difficult 

challenges that complicate the approaches to responding to such accidents and providing medical 

assistance to exposed individuals. A tritium release becomes even more challenging when 

considering that hundreds of workers in the SRS H-Area occupy the defense nuclear facilities 

and other administrative and training buildings surrounding the Tritium Facilities.

5

 

Emergency Preparedness: Since 2011 the Tritium Facilities have conducted several 

seismic and/or multi-facility drills and exercises. The Board’s staff have observed these drills 

and exercises and found that they have improved communications and coordination among the 

tritium facilities, as well as coordination of protective actions with other nuclear facilities within 

the H-Area. However, neither DOE nor the site contractor, Savannah River Nuclear Solutions 

(SRNS), has conducted exercises involving the evacuation of large numbers of individuals from 

an area due to a large tritium release, nor have they planned for the related logistical issues or for 

monitoring large numbers of individuals to identify those who might be at risk of a significant 

tritium intake and would require immediate medical intervention. While reliance on the 

Emergency Preparedness programs is not a long-term solution, this program will be essential in 

mitigating the consequences of a significant tritium release until an adequate control set can be 

implemented. 

Past Communication: During a June 16, 2011, public hearing in Augusta, Georgia, the 

Board raised concerns regarding high consequences due to a potential fire in the Tritium 

Facilities. The Board further communicated this concern to NNSA in an August 19, 2011, Board 

correspondence in which it identified a shift in the safety philosophy applied to the Tritium 

Facilities at SRS. The Board noted that downgrading of safety related controls at the Tritium 

Facilities has “weakened the safety posture, reduced the safety margin, and increased the 

potential for both the workers and the public to be exposed to higher consequences.” 

 

3 The ratio of the dose conversion factors for inhalation between tritiated water and tritium gas is a factor of 10,000; 

additionally, a factor of 1.5 is applied for the workers, and a factor of 2.0 is applied for the public, to account for 

tritiated water absorption through the skin [1]. 4 The biological half-life is defined as “the time required in a given radionuclide for its activity to decrease, by 

biological clearance and radiological decay, to half its original activity” [8]. This half-life is a function of the 

radiological half-life of the radioactive material and how rapidly it is removed from the body by metabolic 

processes.

5 A training building with a cafeteria is about 300 meters from the Tritium Facilities; the building hosts a significant 

transient population. 
The Deputy Administrator for Defense Programs replied to the Board's concerns on 

November 14, 2011, stating that NNSA would develop new analytical models to better 

understand the risk posed by the Tritium Facilities' operations, and at the same time NNSA 

would pursue "additional interim safety controls for Tritium Facilities, such as MAR 

segregation" to reduce the consequences of a potential accident. The attachment to the NNSA 

letter identified a series of analytical and administrative activities that SRNS would conduct and 

stated that, "A review of the control selection for the design basis events considering the new 

analysis will be performed. Emphasis will be placed on utilizing existing passive and active 

engineered controls vice administrative controls. Any changes to controls will be reflected in a 

future update to the Documented Safety Analysis." 

A letter from SRNS to NNSA dated July 12, 2018 [2], indicates that SRNS is considering 

a number of engineering controls, but the Board is not aware of any formal actions or 

implementation of any near-term compensatory measures based on this strategy. SRNS's 

proposed strategy mainly consists of performing analyses. These analyses may result in SRNS 

proposing revisions to the Tritium Facilities DSA to credit existing engineered controls or may 

lead SRNS to pursue installation of new engineered controls. Any physical modifications or 

additions would likely take years to implement under SRNS's proposed strategy. Furthermore, 

the Board is not aware of any commitments made by NNSA to implement engineered controls 

based on the contractor's strategy. 

Conclusion. The Board has concluded that adequate protection of public health and safety 

currently is not assured, should an accident, such as an earthquake or large fire, occur at these 

facilities and there continues to be a risk of exposure to significant radiological consequences in 

case of an energetic event at these facilities. 

4 

/~e 

~i~ Hamilton 

Chairman 
5 

Recommendation References

1. Canadian Nuclear Safety Commission, Health Effects, Dosimetry and Radiological 

Protection of Tritium, Minster of Public Works and Government Services Canada, INFO0799, April 2010. 

2. Spangler, R. W., Senior Vice President NNSA Operations and Programs, SRNS, letter to 

N. N. Nelson-Jean, NNSA Savannah River Field Office, Transmittal of the Schedule for 

Implementing the Strategy for Risk Reduction to the Co-Located Worker in Tritium 

Facilities (U), SRNS-T0000-2018-00227, July 12, 2018. 
Risk Assessment for Recommendation 2019-2 

Safety of the Savannah River Site Tritium Facilities

In making its recommendations to the Secretary of Energy and in accordance with 42 

U.S.C. § 2286a.(b)(5), the Board shall consider, and specifically assess risk (whenever sufficient 

data exists). Risk is generally defined as the quantitative or qualitative expression of possible 

loss that considers both the likelihood that an event will occur and the consequences of that 

event. For Recommendation 2019-2, Safety of the Savannah River Site Tritium Facilities, 

sufficient data does not exist to precisely determine the likelihood that an event will occur and 

the consequences of that event. However, the Board can use information from the Tritium 

Facilities’ DSAs to develop a qualitative risk assessment. 

The Tritium Facilities’ DSAs use risk binning to estimate the frequencies of several of 

the energetic accidents discussed in the Recommendation to be Unlikely, which DOE Standard 

3009, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility 

Documented Safety Analyses, assigns a frequency range of 10-2 to 10-4 per year. Assuming a 50-

year lifetime for the facility, and given the broad frequency range, the probability that an event 

could occur within that time period ranges from 0.5 percent to about 40 percent. 

The large-scale release of tritium postulated for these accidents has a significant potential 

to result in acute injuries or fatalities. Such an event could lead to a significant number of 

potentially exposed individuals, resulting in a mass casualty situation that would pose a 

significant challenge both to the Savannah River Site’s emergency management system and to 

local emergency and medical facilities.

Therefore, the Board has determined the qualitative risk at the Savannah River Site’s

Tritium Facilities is significant enough to require the Department of Energy to take action. 
Findings, Supporting Data, and Analysis 

Degradation of Safety Posture. 

Introduction—In December 1991, Congress amended the Defense Nuclear Facilities 

Safety Board’s (Board) enabling legislation, expanding its jurisdiction into defense nuclear 

facilities and activities involved in the assembly, disassembly, and testing of nuclear weapons. 

According to the Board’s 1992 Annual Report to Congress [1]: 

As a consequence, additional technical activities were conducted at the following plants, 

sites and laboratories:

• Pantex Plant, 

• Oak Ridge Y-12 Plant, 

• Los Alamos National Laboratory, 

• Tritium Facilities at the Savannah River Site, 

• Building 991 at Rocky Flats, 

• Nevada Test Site, 

• Sandia National Laboratories (Albuquerque and Livermore), 

• Lawrence Livermore National Laboratory, and

• Pinellas Plant

As part of these additional technical activities, in 1992 the Board and its staff began to 

review safety basis documents for Building 233-H (known at the time as the Replacement 

Tritium Facility, RTF) [2-9]. At that time the facility had been built but had not commenced

operations. Later, the Board reviewed the design and safety basis of the Tritium Extraction 

Facility from the conceptual design stage to its final startup. In both cases, the Board identified 

safety issues that were remediated by design modifications or administration of operational limits 

to ensure that the public and the workers were adequately protected. 

Since the Board’s initial interactions with the Tritium Facilities in 1992, the Board’s 

concerns over the potential for energetic accidents with very high dose consequences have been 

frequently communicated to the Department of Energy (DOE). A listing of those 

communications is provided in the Attachment. These communications and the DOE responses 

to them illustrate a pattern that, in itself, is a concern to the Board. The Board’s early 

involvement in the safety of the Tritium Facilities prompted DOE to implement a range of safety 

improvements; however, those improvements either were downgraded or were found to be 

ineffective by 1999. After the Board’s interactions with DOE in 1999, improvements were again 

identified and implemented. By 2011, those improvements had been downgraded and the Board 

found it necessary to raise the subject again. Today, the Board has determined that its concerns 

are such that a formal Recommendation is needed to ensure prompt action is taken and sustained.

As noted, in 2011 the Board identified a degradation in the facilities’ safety posture that 

appears to have begun in the period between 1999 and 2011. The Board initially communicated 

those concerns in 2011, and the National Nuclear Security Administration (NNSA) responded on 

November 14, 2011, with a series of commitments that included updating the methodology and 

assumptions to meet current DOE requirements and expectations for conservative analyses, as 

reflected in Subpart B to 10 CFR 830 and its safe harbor methodology in DOE Standard 3009-
2 

94. NNSA also stated that “A review of the control selection for the design basis events 

considering the new analysis will be performed. Emphasis will be placed on utilizing existing 

passive and active engineered controls vice administrative controls. Any changes to controls will 

be reflected in a future update to the Documented Safety Analysis (DSA).” The current 

Savannah River Site (SRS) contractor, Savannah River Nuclear Solutions LLC (SRNS), 

submitted that DSA update to NNSA’s Savannah River Field Office (SRFO) in July 2017. 

SRFO requested and the contractor submitted a revised version of that DSA on November 2018, 

and it is currently undergoing DOE’s review and approval process. Consequently, the currently 

approved safety bases still contain many of the weaknesses that concerned the Board in 2011. 

The following discussions briefly describe some of the original activities and the controls 

applied to for Building 233-H. This building contains the majority of the process tritium 

inventory and poses the most unmitigated risk in case of an energetic accident. 

Building 233-H’s Past Safety Basis—The Board and DOE worked through several issues 

with the hazards analysis and control set in the original Final Safety Analysis Report (FSAR)1

 [2-

9] during the early 1990s, prior to startup of Building 233-H. The fire event analyzed in the 

FSAR was based on 0.1 percent oxidation of the tritium released during the accident. The site 

contractor at the time, Westinghouse Savannah River Company2 (WSRC) performed a

conservatively bounding analysis assuming that 100 percent of the tritium would be oxidized in a 

facility fire and documented this analysis in an addendum to the FSAR. Furthermore, WSRC 

performed a seismic analysis that indicated that a stack would collapse on top of the tritium 

reservoir storage vault. DOE and WSRC designed and constructed more than a dozen safes 

known as HIVES (Highly Invulnerable Encased Safes) to protect the storage reservoirs from the 

impact load of a stack and vault roof collapse. The bounding scenario conservatively calculated 

the consequences of a seismic event that triggers a fire involving the entire inventory from the 

reservoirs and the process systems [9]. The maximum individual dose at the site boundary for a 

two hour exposure was estimated to be about 5.1 rem total effective dose equivalent (TEDE3

, an 

ionizing radiation dose unit in use at the time). The corresponding value for onsite dose was 328 

rem TEDE. [This value was calculated prior to the issuance of DOE Standard 3009; the 1993 

calculation used an older methodology and different assumptions than those currently accepted 

for safety analyses. Consequently the results cannot be compared to the values in the current 

safety bases.] 

The FSAR control set ultimately established by WSRC was a mixture of administrative 

operational limits and engineered controls. An administrative control limited the total amount of 

tritium in the facility, including the reservoirs in the seismically qualified areas. Four limiting 

 

1 Final Safety Analysis Reports were a predecessor to the current Documented Safety Analysis documents. 2 The current SRS contractor, Savannah River Nuclear Solutions assumed responsibility for the site in August 2008. 

The prior contractor at the site, Westinghouse Savannah River Company, assumed responsibility for the site in 1989. 

In 2005, Westinghouse Savannah River Company changed its name to Washington Savannah River Company.

3 There are two basic components to an individual’s radiation dose, the dose from internal emitters and the dose 

from external emitters. Prior to 2007, the dose from internal emitters such as tritiated water was measured in rem 

Committed Effective Dose Equivalent (rem CEDE); the dose from external radiation sources such as an X-ray 

machine was measured in rem Effective Dose (rem ED); and the sum of the two components was the Total Effective 

Dose Equivalent (rem TEDE). In 2007 the units were changed to committed effective dose (rem CED) and total 

effective dose (rem TED), but they are numerically equivalent to doses in rem CEDE and rem TEDE.
3 

conditions for operations (LCO) limited the system pressure for the relief tanks, contaminated 

nitrogen tanks, and the Z-bed recovery tanks to sub-atmospheric conditions to protect their 

inventory from a system rupture. An additional three LCOs limited the inventory of the mix 

tanks, deuterium storage beds, and the tritium reservoirs, which were stored in non-seismically 

qualified areas [7]. WSRC classified the HIVES as safety related4 to protect the reservoirs in the 

vault from impacts. Finally, WSRC used a tritium storage seismic detection and isolation system 

to further reduce the amount of tritium released during a seismic event. Over the years though, 

many of the above controls were eliminated or downgraded for various reasons. It is useful to 

review previously implemented controls for ideas on how the Board’s current concerns might be 

addressed. 

During a June 16, 2011, public hearing in Augusta, Georgia, the Board raised concerns 

regarding high consequences to co-located workers due to a potential fire in the Tritium 

Facilities. The Board further communicated this concern to NNSA in a Board correspondence 

dated August 19, 2011, in which the Board identified a shift in the safety philosophy applied to 

the Tritium Facilities at SRS. The Board noted that the downgrading of safety related controls at 

the Tritium Facilities has “weakened the safety posture, reduced the safety margin, and increased 

the potential for both the workers and the public to be exposed to higher consequences.” 

NNSA’s Deputy Administrator for Defense Program sent a letter to the Board on 

November 14, 2011, that relayed the Tritium Facilities commitments to the Board for improving 

safety posture of those facilities. In the attachment to that letter, the field office manager stated 

that, “A review of the control selection for the design basis events considering the new analysis 

will be performed. Emphasis will be placed on utilizing existing passive and active engineered 

controls vice administrative controls. Any changes to controls will be reflected in a future 

update to the Documented Safety Analysis (DSA).” SRNS submitted that DSA update to SRFO

in July 2017. As previously noted, correspondence between SRFO and the SRNS led to a 

revised DSA submitted in November 2018, which is currently in DOE’s review and approval 

process.

Tritium Facilities’ Current Safety Basis—The current safety basis of the Tritium 

Facilities is comprised of a DSA [10] and technical safety requirements (TSR) [11] that are 

derived from the DSA.5

 The DSA and TSR documents contain a set of controls that SRNS 

commits to maintain to assure adequate protection. The DSA is supported by a comprehensive 

hazard analysis documented in the Consolidated Hazards Analysis Process (CHAP) [12], which 

is not subject to NNSA’s review and approval. The CHAP concluded that “[f]or some events, 

the mitigated consequences remained in the B1 or B region [consequence categories that require 

safety class controls for the public or safety significant controls for workers] because available 

controls either did not exist and/or were insufficient” to reduce the unmitigated dose 

consequences to the co-located workers for several high consequence accidents.

 

4

 The RTF startup activities preceded DOE’s creation and issuance of Standard 3009-94. The terminology of 

“safety related” was meant for protection of the public and/or the workers.

5 At the time of this writing the Tritium Extraction Facility (TEF) was operating under a separate safety basis, but 

SRNS combined the two safety bases in the DSA submitted in November 2018. However, TEF has a much smaller 

inventory than the main processing building so it is not discussed extensively in this section.
4 

The calculated dose consequences supporting the current DSA were based on 

calculations performed in 2008. Those calculated dose consequences for the energetic accidents 

of concern in this Recommendation ranged up to 6,300 rem total effective dose (TED) to the colocated workers and about 2 to 13 rem TED to the offsite public [13-17]. While those 

calculations were based on methods and assumptions accepted at the time, they do not meet 

current DOE expectations for safety basis calculations. More recent analysis, completed by 

SRNS in 2013, concluded that, using current methodology and assumptions, the calculated dose 

consequences would increase by a bounding factor of 7.42 for the co-located worker and a 

bounding factor of 3.45 for the offsite public [18]. It should be noted that NNSA reduced the 

limit on the total amount of tritium that can be present within the Tritium Facilities by about half 

in 2011, as discussed in the November 14, 2011, letter to the Board, but that reduction has not 

been included in the bounding factors given above. These factors are bounding values because 

there will be some variation in the parameters specific to each accident scenario.

Feasible solutions to address concerns could consist of several controls, each providing 

layers of protection. Furthermore, solutions may require pursuing controls that dramatically 

reduce the probability of an initiator, but may not fully prevent an accident. For example, a 

seismic power cut off system may eliminate many, but not all, ignition sources present in a 

facility following a seismic event because some systems may be required to continue to function 

or may have stored energy. Similarly, the reliability of systems like fire suppression systems 

may be improved through upgrades and modifications or performance of additional surveillances 

and maintenance, but they may not be able to be fully qualified to protect individuals after all 

seismic events.

Mitigative controls, such as minimizing the number of non-essential personnel in close 

proximity to the Tritium Facilities; using readily available technologies to minimize humidity in 

the air of buildings used for sheltering in place; and having pre-approved plans for decreasing the 

biological half-life of tritium, could potentially reduce both the number of individuals with 

intakes and the severity of those intakes. The development of near- and long-term solutions may 

involve an integrated approach using multiple forms of controls. 

Analysis of Emergency Preparedness at the Savannah River Site. 

The attachment to the NNSA letter dated November 14, 2011, described improvements 

that would be made to the site Emergency Preparedness program to respond to a significant 

event at the Tritium Facilities. The Tritium Facilities conducted several seismic and/or multifacility drills and exercises in subsequent years. The Board’s staff observed these drills and 

exercises and the planned improvements. The drills and exercises improved communications 

and coordination among the Tritium Facilities and helped improve coordination of protective 

actions with other nuclear facilities within H-Area. The Tritium Facilities also have made 

emergency preparedness drill and exercise scenarios more challenging by including deflagrations 

and stack collapses, and have tested their ability to respond to accidents during night shifts, when 

staffing is lower.

However, the Tritium Facilities Emergency Preparedness program has not prepared 

responses to the full range of credible accidents in the DSA and the Emergency Planning 
5 

Hazards Assessments (EPHA). The DSA includes credible scenarios with co-located worker 

doses reaching calculated dose consequences in the thousands of rem. The radiological 

consequences in the EPHAs [19, 20] are usually lower because of differences in the analytical 

methodologies and assumptions, but still range up to 700 rem TED for co-located workers and 

62 rem TED for workers at the nearby central training facility (which also includes a cafeteria). 

However, the dose consequences to workers in the most challenging drills and exercises [21, 22] 

were less than 5 rem TED. 

The default protective actions for the Tritium Facilities’ Emergency Action Levels are to 

evacuate the immediate area, and for all others to remain indoors (as well as close all doors and 

windows, and turn off ventilation to the building) [23, 24]. During tritium drills and exercises, 

this usually involves having workers evacuate the affected process area and/or evacuate from the

affected building to another nearby building within the Tritium Facilities. However, the EPHA 

has scenarios where the maximum distance for the Threshold for Early Lethality may extend up 

to 320 meters, beyond the Tritium Facilities fence line. 

Part of the reason for the lower radiological consequences in the drills and exercises is 

that the assumed releases are much smaller because the Seismic Tritium Confinement System is 

assumed to function and confine the inventory during a seismic event. However, the DSA does 

not qualify this system to be credited during a seismic event. Additionally, the drills and 

exercises often limit explosions and fires to one room, rather than involving the entire building, 

as the DSA and EPHA assume. Because the radiological consequences in the drill and exercise 

scenarios are much lower than those in the DSA and EPHA, the drill and exercise scenarios 

assume that Tritium Facilities personnel can remain safely indoors indefinitely, that operators 

can perform their assumed response actions with little impact from the release, that those 

workers evacuating to another building within the Tritium Facilities do so without any adverse 

effects, and that the medical response is usually limited to injured workers with relatively minor 

contamination or intakes. 

Using radiological consequences from the severe accidents in the DSA or EPHA, 

however, might drive the need to evacuate personnel at the Tritium Facilities, and possibly other 

nearby areas, to a safer location to avoid a significant intake. SRS does not have any procedural 

guidance or criteria for when workers should evacuate the Tritium Facilities area, and possibly 

other nearby areas, rather than remain indoors, due to the potential for acute radiological 

consequences [23-26]. Furthermore, SRS has not conducted exercises involving evacuation of a 

large number of workers from an area due to a radiological release, nor has the site planned for 

the related logistical issues such as evacuating or monitoring a large number of workers to 

determine which ones may be at risk of a significant tritium uptake and may require medical 

intervention. 
6 

Findings, Supporting Data, and Analysis References

[NOTE: The current SRS contractor, Savannah River Nuclear Solutions assumed responsibility 

for the site in August 2008. The prior contractor at the site, Westinghouse Savannah River 

Company, assumed responsibility for the site in 1989. In 2005, Westinghouse Savannah River 

Company changed its name to Washington Savannah River Company.] 

1. Defense Nuclear Facilities Safety Board, Annual Report to Congress, April 1993. 

2. Westinghouse Savannah River Company, RTF Safety Analysis Report, DOE Approval 

Copy, Rev.1, WSRC-SA-1-1, August 28, 1992. 

3. K.R. O'Kula, RTF Compliance with Department of Energy Safety Goal, WSRC-TR-93-

183, April, 1993. 

4. Westinghouse Savannah River Company, RTF Safety Analysis Report, Attachment 5.B 

Integrated DBE Analysis, Vol 20, Revision 0, WSRC-SA-1-1, August 23, 1993. 

5. N.K. Savani, Request for Information on the DBE Analysis, SRT-TML-93-0052, May 5, 

1993. 

6. J. Robertson, Determining Inventory LCOs for RTF, S NMP-SDG-93-0076, Revision 4, 

September 20, 1993. 

7. Westinghouse Savannah River Company, RTF Final Safety Analysis Report, Inventory 

Control, Revision 0, WSRC-SA-1-1-VOL-19, August 26, 1993. 

8. Westinghouse Savannah River Company, RTF Final Safety Analysis Report, Integrated 

DBE Analysis, Revision 0, WSRC-SA-1-1-VOL-20, August 26, 1993. 

9. S.J. Robertson, White Paper; Basis for MID Calculations for RTF DBA and BDBA 

Scenarios, September 20, 1993. 

10. Savannah River Nuclear Solutions, LLC, Tritium Facilities Documented Safety Analysis, 

Rev. 23, WSRC-SA-1-2, Vol. 1 and 2, May 2017. 

11. Savannah River Nuclear Solutions, LLC, Tritium Facilities Technical Safety 

Requirements, Rev. 28, WSRC-TS-96-17, May 2017. 

12. Savannah River Nuclear Solutions, LLC, Tritium Facilities Consolidated Hazards 

Analysis, Rev. 11, WSRC-TR-2004-00163, May 2017. 

13. Washington Savannah River Company, Tritium Facilities Loss of Confinement Accident 

Analysis (U), Rev. 0, S-CLC-H-01127, February 2008. 

14. Washington Savannah River Company, Tritium Facilities Fire Accident Analysis (U), 

Rev. 0, S-CLC-H-01131, February 2008. 
7 

15. Washington Savannah River Company, Tritium Facilities Explosion Accident Analysis 

(U), Rev. 0, S-CLC-H-01137, February 2008. 

16. Washington Savannah River Company, Tritium Facilities Natural Phenomena Plus Fire 

Accident Analysis (U), Rev. 0, S-CLC-H-01139, February 2008. 

17. Washington Savannah River Company, Tritium Facilities Natural Phenomena Plus Loss 

of Confinement Accident Analysis (U), Rev. 0, S-CLC-H-01144, February 2008. 

18. Savannah River Nuclear Solutions, Dispersion Modeling Project Implementation, SESR-G-0033, Rev. 0, October 2013. 

19. Savannah River Nuclear Solutions, LLC, Emergency Planning Hazards Assessment for 

the Tritium Facilities (TF), Rev. 10, S-EHA-H-00006, March 2016. 

20. Savannah River Nuclear Solutions, LLC, Emergency Planning Hazards Assessment for 

the Tritium Extraction Facility (TEF), Rev. 2, S-EHA-H-00009, January 2016. 

21. Savannah River Nuclear Solutions, LLC, Savannah River Site 2012 Site Emergency 

Response Organization Emergency Preparedness Evaluated Exercise MultipleFacility/Multiple-Contractor Seismic Event, Rev. 03, F9640052.DRSC000103, April 

2012. 

22. Savannah River Nuclear Solutions, LLC, Savannah River Tritium Enterprise 2017 

Facility Emergency Preparedness Evaluated Exercise, Rev. 00, F3040087.DRSC000100, 

July 2017. 

23. Savannah River Nuclear Solutions, LLC, Emergency Classification (EALs), Rev. 29 EPIP 

TRIT-001, IPC 1, May 1, 2017. 

24. Savannah River Nuclear Solutions, LLC, FEC Response Actions, Rev. 35, EPIP TRIT111, April 24, 2018. 

25. Savannah River Nuclear Solutions, LLC, Fire and Fire Alarm Response, Process 

Buildings, Rev. 31, EOP TRIT-1468, May, 31, 2018. 

26. Savannah River Nuclear Solutions, LLC, Response to Severe Weather and Natural 

Disasters, Rev. 21, AOP TRIT-6122, IPC-1, August 16, 2018. 
A-1 

Attachment

Summary of Board Correspondence concerning Safety at the Tritium Facilities

• December 18, 1995 

• To: Assistant Secretary for Environmental Management 

• Subject: Central Training Facility capability to respond to releases

• March 18, 1999 

• To: Under Secretary of Energy

• Subject: Review of Draft Consolidated Tritium Safety Analysis Report 

• December 7, 1999 

• To: Assistant Secretary for Defense Programs

• Subject: Design review for Tritium Extraction Facility

• July 19, 2002 

• To: National Nuclear Security Administration Deputy Administrator for Defense Programs

• Subject: Seismic safety at the Tritium Extraction Facility

• July 16, 2010 

• To: NNSA Administrator and Assistant Secretary for Environmental Management 

• Subject: Inclusion of controls concern at the Savannah River Site 

• August 19, 2011 

• To: NNSA Administrator

• Subject: Review of Safety Basis, Savannah River Site Tritium Facilities

• August 7, 2014 

• To: NNSA Administrator

• Subject: Summary of Board views on current challenges faced by NNSA

• January 7, 2016 

• To: NNSA Administrator

• Subject: Review of the Tritium Extraction Facility Documented Safety Analysis

• June 4, 2018 

• To: Secretary of Energy

• Subject: Review of the Revised Documented Safety Analysis at Tritium Facilities
B-1 

Supplemental Staff Analysis of Dose Consequences 

The calculated dose consequences supporting the current DSA were based on 

calculations performed in 2008. Those calculated dose consequences for the energetic accidents 

of concern in this Recommendation ranged up to 6,300 rem total effective dose (TED)1 to the colocated workers and about 2 to 13 rem TED to the offsite public [1-5]. Those calculations were 

based on methods and assumptions accepted at the time. More recent analysis, completed by the 

SRS contractor in 2013, concluded that using current methodology and assumptions would 

increase the calculated dose consequences by a bounding factor of 7.42 for the co-located worker 

and a bounding factor of 3.45 for the offsite public [6].2 It should be noted that SRS lowered the 

limit on the total amount of tritium that can be present within the Tritium Facilities by about a 

factor of two in 2011, but that reduction has not been included in the bounding factors given 

above. These factors are bounding values because there will be some variation in the parameters 

specific to each accident scenario. The calculations supporting the revised DSA indicate that 

calculated dose consequences for the co-located worker could exceed 18,000 rem TED for some 

scenarios. [7] 

According to the International Commission on Radiation Protection (ICRP), the threshold 

dose for a 1 percent incidence rate of fatality in an exposed population is 100 rad3, and the 

threshold for a 50 percent incidence of fatality in an exposed population is 300 to 500 rad, 

assuming no medical intervention [8]. The onset of radiation-induced sickness generally 

coincides with the 1 percent fatality threshold. These thresholds are for acute exposures that are 

the result of external radiation sources at very high dose rates, such as those that occur during a 

criticality accident.

However, high protracted exposures that occur over periods of days to weeks can also 

result in injury or fatality, but with somewhat higher thresholds. ICRP reports that for exposures 

where the dose rate is about 20 rad/hour the thresholds may increase by about 50 percent, and if 

the dose is delivered over the period of a month the thresholds may double [8]. This increase in 

thresholds is due to the fact that for lower dose rates, the body has more opportunity to repair the 

damage, thus reducing the likelihood of injury or fatality. Therefore, protracted doses are 

evaluated by looking at both the accumulated dose and the rate at which the dose accumulates. 

For internal exposures such as the situations addressed in this Recommendation, the dose 

to an exposed individual is cited as the committed effective dose, which is the total dose that has 

accumulated in the body until the radioactive material has either decayed away or been 

eliminated through biological processes. The accumulation time is dependent on the specific 

 

1 There are two basic components to an individual’s radiation dose, the dose from internal emitters and the dose 

from external emitters. Prior to 2007, the dose from internal emitters such as tritiated water was measured in rem 

Committed Effective Dose Equivalent (rem CEDE); the dose from external radiation sources such as an X-ray 

machine was measured in rem Effective Dose (rem ED); and the sum of the two components was the Total Effective 

Dose Equivalent (rem TEDE). In 2007 the units were changed to committed effective dose (rem CED) and total 

effective dose (rem TED), but they are numerically equivalent to doses in rem CEDE and rem TEDE. 2 These multiplication factors only apply to the calculated radiological dose consequences for certain accident 

scenarios (depending on the input parameters). Other accident scenarios may have a smaller multiplication factor.

3 The rad is a unit of absorbed dose, which is the quantity used for evaluating the potential for deterministic ionizing 

radiation effects such as acute injury or fatality. In the case of tritiated water vapor, the absorbed dose in rad is 

numerically equal to the committed effective dose.
B-2 

radioactive material and its chemical form. Some materials such as tritium gas are not retained 

in the body for any significant amount of time; other materials, such as plutonium oxide, will be 

retained in the body for many years.

Dose Consequences to Workers and Co-Located Workers: The behavior of tritiated 

water in the body can be modelled in a straightforward manner. For the doses evaluated here, it 

is assumed that the exposures occur within a 3-minute or 20-minute time period in accordance 

with the specific DSA scenarios, and that the biological half-life of tritiated water in the body is 

10 days [9]. Although the intake is of a short duration, the rate at which the radiation from the 

decay of the tritium deposited in the body is determined by the biological half-life. Therefore, 

the doses from tritiated water in the body tend to be protracted doses, and must be compared 

against the ICRP’s protracted dose thresholds. Given these conditions, the total dose and dose 

rates associated with an intake of tritiated water are inherently related to each other such that one 

can predict either parameter if the other parameter is known. This relationship allows one to 

directly determine the specific total dose and dose rate associated with each of the ICRP 

mortality thresholds discussed above. 

Table 1 shows that a postulated total dose of about 18,000 rem TED will exceed the dose 

threshold for radiation-induced sickness within the first two hours, and a postulated dose of 

about 3,500 rem TED will exceed the onset of radiation-induced sickness within the first fifteen

hours (the onset of radiation-induced sickness generally coincides with the 1 percent fatality 

threshold). Once the absorbed doses exceed the injury threshold, the onset of symptoms of 

radiation-induced sickness likely will occur within hours to a day. When these symptoms are 

observed, medical personnel would begin more aggressive life-saving interventions on those 

individuals. 
B-3 

Table 1. Threshold Dose and Dose Rate Criteria with no medical intervention 

Threshold Criteria [8] Corresponding Tritium

Total Dose*

Criteria Threshold 

Dose Rate

Threshold 

Dose Total Dose 

Time to 

Threshold 

Dose

Acute Threshold

for 1% 

Mortality** 

~50 rad/hr 

and up 100 rad 18,000 rem TED 2 hours 

Upper 

Protracted 

Threshold for 

1% Mortality

~10 - 30 rad/hr 150 rad 3,500 rem TED 15 hours 

Lower 

Protracted 

Threshold for 

1% Mortality

~0.3 rad/hr 200 rad 250 rem TED 28 days

Acute Threshold 

for 50% 

Mortality

~50 rad/hr 

and up 300-500 rad 18,000 rem TED 6 hours 

Upper 

Protracted 

Threshold for 

50% Mortality

~10 - 30 rad/hr 450-750 rad 3,500 rem TED 45 hours 

Lower 

Protracted 

Threshold for 

50% Mortality

~0.8 rad/hr 600-1000 rad 750 rem TED 31 days

* When a range of doses or dose rates is used in the threshold criteria, the corresponding 

tritium dose and time to threshold dose were determined using the lower values in order to 

identify the lowest total dose that would exceed the specified threshold dose. 

** A 1 percent or 50 percent mortality threshold means that at the specified dose and dose 

rate values, fatalities could be expected in 1 percent or 50 percent of the exposed 

population, with no medical intervention. 

Prior to the onset of radiation-induced sickness, early medical intervention for tritiated 

water intakes could be taken by aggressively increasing fluid exchange in the patient. This could 

reduce the biological half-life to as little as three days [10]. Such intervention would reduce the 

total dose by up to about 60 percent, but would have no impact on the dose already accumulated 

in the individual prior to the onset of treatment. However, tritium’s chemical and radiological 

characteristics create difficult challenges that complicate the approaches to responding to such 

accidents and providing medical assistance to exposed individuals. For example, detection of 
B-4 

tritium contamination in the field and assessment of potential intakes require specialized 

equipment, expertise, and most importantly, timely response.

4

It must also be recognized that the dose to co-located workers is calculated at 100 meters 

from the release point or at the point of plume touchdown, whichever results in a higher dose. 

Doses within that first 100 meters could be much higher, depending on the release mechanism 

and plume travel path. However, current models cannot accurately estimate doses to individuals 

nearer than 100 meters, as the doses are very sensitive to the specifics of each release 

mechanism, the effects of building wakes, the location of the individual, and a variety of other 

parameters. Consequently, radiation-induced sickness or fatalities within the facility workers 

should be anticipated for all accidents where the 100-meter dose is above 100 rem TED. 

Dose Consequences to the Offsite Public: While the facilities’ DSAs estimate that the 

calculated dose consequences to individuals beyond the site boundary from these accidents are 

low enough to avoid immediate acute health effects, they do represent the potential for an 

increased likelihood of latent cancer fatalities in the exposed population [8]. In addition, the 

calculated dose consequences challenge DOE’s evaluation guideline of 25 rem TED for safetyclass controls. (The evaluation guideline is not to be viewed as an acceptable dose; it is a tool for 

determining the need for safety class controls.) However, the currently approved DSAs do not 

provide an adequate set of controls to prevent or mitigate some of these accidents. 

It is no coincidence that the calculated dose consequences to the offsite public approach 

the evaluation guideline for the same accident scenarios that result in very high calculated dose 

consequences to facility workers and co-located workers. As discussed in the Board’s Technical 

Report, Protection of Collocated Workers at the Department of Energy’s Defense Nuclear 

Facilities and Sites [DNFSB/Tech-20, 1999], protection of the offsite public rests heavily on 

measures taken to protect co-located workers, and protection of co-located workers rests heavily 

on measures taken to protect the immediate facility workers. In other words, protection of the 

public begins with the protection of the workers. 

 

4 The Board’s staff does not have confidence that current field equipment can provide the ability to rapidly screen a 

large group of individuals for potential intakes. Given these circumstances, the onset of symptoms from acute 

radiation sickness may be the first signs of a significant tritium intake, which would preclude early medical 

intervention. Dealing with the large number of people who could be adversely affected by a significant release at 

the Tritium Facilities could severely strain or overwhelm local emergency response and medical resources. 
B-5 

REFERENCES

1. Washington Savannah River Company, Tritium Facilities Loss of Confinement Accident 

Analysis (U), Rev. 0, S-CLC-H-01127, February 2008. 

2. Washington Savannah River Company, Tritium Facilities Fire Accident Analysis (U), 

Rev. 0, S-CLC-H-01131, February 2008. 

3. Washington Savannah River Company, Tritium Facilities Explosion Accident Analysis 

(U), Rev. 0, S-CLC-H-01137, February 2008. 

4. Washington Savannah River Company, Tritium Facilities Natural Phenomena Plus Fire 

Accident Analysis (U), Rev. 0, S-CLC-H-01139, February 2008. 

5. Washington Savannah River Company, Tritium Facilities Natural Phenomena Plus Loss 

of Confinement Accident Analysis (U), Rev. 0, S-CLC-H-01144, February 2008. 

6. Savannah River Nuclear Solutions, Dispersion Modeling Project Implementation, SESR-G-0033, Rev. 0, October 2013. 

7. Savannah River Nuclear Solutions, Consolidated Hazard Analysis for the Savannah 

River Site Tritium Facilities, S-CHA-H-00030, Rev. 0, June 2017. 

8. International Commission on Radiation Protection, 2007 Recommendations of the 

International Commission on Radiological Protection, ICRP 103, Volume 37, No. 2-4., 

New York: Elsevier Ltd., 2007. 

9. Canadian Nuclear Safety Commission, Health Effects, Dosimetry and Radiological Protection of 

Tritium, Minster of Public Works and Government Services Canada, INFO-0799, April 2010.

10. Carbaugh, E H, et al. Methods and Models of the Hanford Internal Dosimetry Program, 

PNNL-MA-860, Pacific Northwest National Laboratory, Richland, WA, PNNL-15614, 

Rev. 1, September 2009.