Recommendation 2019-02, 28517-28526 [2019-12918]

Agencies

• Defense Nuclear Facilities Safety Board

[Federal Register Volume 84, Number 118 (Wednesday, June 19, 2019)]
[Notices]
[Pages 28517-28526]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12918]


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DEFENSE NUCLEAR FACILITIES SAFETY BOARD


Recommendation 2019-02

AGENCY: Defense Nuclear Facilities Safety Board.

ACTION: Notice; Recommendation.

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SUMMARY: The Defense Nuclear Facilities Safety Board has made a 
Recommendation to the Secretary of Energy concerning adequate 
protection of public health and safety in the event of an energetic 
accident at the Tritium Facilities at the Savannah River Site. Pursuant 
to the requirements of the Atomic Energy Act of 1954, as amended, the 
Defense Nuclear Facilities Safety Board is publishing the 
Recommendation and associated correspondence with the Department of 
Energy and requesting comments from interested members of the public.

DATES: Comments, data, views, or arguments concerning the 
recommendation are due on or by July 19, 2019.

ADDRESSES: Send comments concerning this notice to: Defense Nuclear 
Facilities Safety Board, 625 Indiana Avenue NW, Suite 700, Washington, 
DC 20004-2001. Comments may also be submitted by e-mail to 
[email protected].

FOR FURTHER INFORMATION CONTACT: Glenn Sklar at the address above or 
telephone number (202) 694-7000.

SUPPLEMENTARY INFORMATION:

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 fatality \1\ 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.
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    \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.
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    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\
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    \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.)
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    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

[[Page 28518]]

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 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-life \4\ 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\
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    \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.
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    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.''
    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.

Bruce Hamilton, Chairman

Recommendation References

    1. Canadian Nuclear Safety Commission, Health Effects, Dosimetry 
and Radiological Protection of Tritium, Minster of Public Works and 
Government Services Canada, INFO-0799, 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

[[Page 28519]]

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 3009-94. 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) \6\ [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 Company \7\ (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

[[Page 28520]]

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 (TEDE,\8\ 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.]
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    \6\ Final Safety Analysis Reports were a predecessor to the 
current Documented Safety Analysis documents.
    \7\ 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.
    \8\ 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.
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    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 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 related \9\ 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.
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    \9\ 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.
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    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.\10\ 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.
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    \10\ 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.
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    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 
co-located 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.

[[Page 28521]]

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 
multi-facility 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 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.

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.
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, S-ESR-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 Multiple-Facility/Multiple-Contractor Seismic 
Event, Rev. 03, F9640052.DRSC000103, April 2012.

[[Page 28522]]

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 TRIT-111, 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.

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

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) \11\ 
to the co-located 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].\12\ 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]
---------------------------------------------------------------------------

    \11\ 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.
    \12\ 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.
---------------------------------------------------------------------------

    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 rad,\13\ 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.
---------------------------------------------------------------------------

    \13\ 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.
---------------------------------------------------------------------------

    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 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

[[Page 28523]]

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.

                   Table 1--Threshold Dose and Dose Rate Criteria With No Medical Intervention
----------------------------------------------------------------------------------------------------------------
                         Threshold criteria [8]                             Corresponding tritium total dose *
----------------------------------------------------------------------------------------------------------------
                                    Threshold dose                                             Time to threshold
            Criteria                     rate           Threshold dose        Total dose             dose
----------------------------------------------------------------------------------------------------------------
Acute Threshold for 1%            ~50 rad/hr and up.  100 rad...........  18,000 rem TED....  2 hours.
 Mortality**.
Upper Protracted Threshold for    ~10-30 rad/hr.....  150 rad...........  3,500 rem TED.....  15 hours.
 1% Mortality.
Lower Protracted Threshold for    ~0.3 rad/hr.......  200 rad...........  250 rem TED.......  28 days.
 1% Mortality.
Acute Threshold for 50%           ~50 rad/hr and up.  300-500 rad.......  18,000 rem TED....  6 hours.
 Mortality.
Upper Protracted Threshold for    ~10--30 rad/hr....  450-750 rad.......  3,500 rem TED.....  45 hours.
 50% Mortality.
Lower Protracted Threshold for    ~0.8 rad/hr.......  600-1000 rad......  750 rem TED.......  31 days.
 50% Mortality.
----------------------------------------------------------------------------------------------------------------
* 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 tritium 
contamination in the field and assessment of potential intakes require 
specialized equipment, expertise, and most importantly, timely 
response.\14\
---------------------------------------------------------------------------

    \14\ 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.
---------------------------------------------------------------------------

    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 safety-class 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.

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, S-ESR-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

[[Page 28524]]

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.

Correspondence With the Secretary of Energy

Department of Energy Request for Extension of Time

March 12, 2019
The Honorable Bruce Hamilton
Chairman
Defense Nuclear Facilities Safety Board
625 Indiana Avenue NW, Suite 700
Washington, DC 20004

    Dear Chairman Hamilton:
    The Department of Energy (DOE) received the Defense Nuclear 
Facilities Safety Board (DNFSB) Draft Recommendation 2019-1, Safety of 
the Savannah River Site Tritium Facilities, on February 11, 2019, and 
is currently coordinating its review among relevant offices. In 
accordance with 42 U.S.C. 2286d(a)(2), the Department requests a 30-day 
extension to provide comments. DOE's Under Secretary for Nuclear 
Security, Lisa E. Gordon-Hagerty, will provide the response to the 
DNFSB by April 12, 2019.
    DOE is committed to the safe operations at the Savannah River Site 
Tritium Facilities. As you may be aware, DOE has already taken actions 
to address concerns identified in the Draft Recommendation. A 30-day 
extension will afford DOE sufficient time to assess the Draft 
Recommendation's findings, supporting data, and analyses.
    If you have any questions, please contact Ms. Nicole Nelson-Jean, 
Manager of the Savannah River Field Office, at (803) 208-3689.
Sincerely,
Rick Perry

Defense Nuclear Facilities Safety Board Response to Extension Request

March 15, 2019
The Honorable James Richard Perry
Secretary of Energy
U.S. Department of Energy
1000 Independence Avenue SW
Washington, DC 20585-1000

    Dear Secretary Perry:
    The Defense Nuclear Facilities Safety Board is in receipt of your 
March 12, 2019, letter requesting a 30-day extension to provide 
comments on the Board's Draft Recommendation 2019-01, Safety of the 
Savannah River Site Tritium Facilities.
    In accordance with 42 U.S.C. 2286d(a)(2), the Board is granting the 
extension for an additional 30 days.
Yours truly,
Bruce Hamilton
Chairman

Department of Energy Comments on Draft Recommendation

The Honorable Bruce Hamilton, Chairman
Defense Nuclear Facilities Safety Board
625 Indiana NW, Suite 700
Washington, DC 20004

    Dear Chairman Hamilton:
    The Department of Energy's National Nuclear Security Administration 
(DOE/NNSA) appreciates the opportunity to review the Defense Nuclear 
Facilities Safety Board (DNFSB) Draft Recommendation 2019-1, Safety of 
the Savannah River Site Tritium Facilities. DOE/NNSA is fully committed 
to ensuring continued safe operations of all our facilities and 
providing assurance of adequate protection of our workers, the 
environment, and the public. DOE/NNSA believes that ongoing actions at 
the Tritium Facilities at the Savannah River Site (SRS) adequately 
address DNFSB concerns outlined in your Draft Recommendation, and make 
the need for additional actions in response to a DNFSB Recommendation 
unnecessary. The commitment to safety in the Tritium Facilities has not 
wavered, and there has been no change in the safety philosophy in the 
Tritium Facilities.
    As noted in the Draft Recommendation, DOE/NNSA committed in 2011 to 
develop a new analytical model for dose consequences for SRS. In 2011, 
DOE/NNSA outlined a plan to update the atmospheric dispersion model, 
which was completed in 2014. Implementation of that new analysis began 
shortly thereafter and included a review of the safety controls 
selection and hierarchy. DOE/NNSA decided to combine all of the Tritium 
Facilities' safety bases and to conduct a holistic revision to the 
Documented Safety Analysis (DSA). The new analysis placed additional 
emphasis on passive and engineered controls over administrative and 
programmatic controls. The new combined DSA was submitted to DOE/NNSA 
in July 2017. After an exhaustive review, significant changes were 
identified, including development of a formal strategy that will 
continue to strengthen the controls available to protect collocated 
workers from large energetic events postulated by the safety analysis. 
The DOE/NNSA DSA review also generated hundreds of additional comments 
to be addressed in the DSA resubmittal, which was delivered to DOE/NNSA 
in November 2018. Subject matter experts from across DOE and NNSA are 
completing a review of the resubmitted DSA and have generated a number 
of additional items requiring further action. The new analysis 
continues to conservatively demonstrate that, even for a full facility 
release, the dose consequences to the public remain below the 
evaluation guideline. Action items addressed in the collocated worker 
risk reduction strategy have been placed in a commitment schedule 
submitted to DOE/NNSA and are being actively managed.
    The Department believes that actions contained in the Draft 
Recommendation 2019-1 are already in place or in development to 
continue the improvements to provide adequate protection of Tritium 
Facilities workers, the environment, and the public. The current 
Tritium Facilities DSA contains appropriate safety significant controls 
and the new analysis, when implemented, will only strengthen that 
safety posture. Considering the on-going work, the Draft Recommendation 
would not drive the need for any additional actions. Additionally, 
resources needed to respond to a DNFSB recommendation would divert 
those critical resources that are needed to continue the improvements 
underway to ensure safety of the collocated workers and/or the public.
    We appreciate the Board's perspectives and look forward to 
continued positive interactions with you and your staff. If you have 
any questions, please contact Ms. Nicole Nelson-Jean, Manager of the 
Savannah River Field Office, at (803) 208-3689.
Sincerely,
Lisa E. Gordon-Hagerty
Enclosure

Enclosure--Comments on DNFSB Draft Recommendation 2019-1

Safety of the Savannah River Site Tritium Facilities

    Over the past several years, the Department of Energy's National 
Nuclear Security Administration (DOE/NNSA) and the Savannah River Site 
(SRS) Management and Operating contractor, Savannah River Nuclear 
Solutions (SRNS), have taken actions to improve the Tritium Facilities 
safety posture. A new hazards analysis has been conducted along with a 
revision to the Documented Safety Analysis (DSA). This new analysis has 
further emphasized identifying passive and engineered controls over 
administrative and programmatic controls. The Board's technical staff 
was recently provided a draft of the new DSA. DOE/NNSA has reviewed the 
documents and provided the contractor with comments along with comments 
from a separate review

[[Page 28525]]

team from the DOE's Office of Enterprise Assessments. After the review 
teams' comments are resolved, the new DSA will be approved, which is 
anticipated to occur in 2019.
    As noted in the Draft Recommendation, the new DSA includes updated 
dose consequence calculations. The calculations use a bounding Material 
at Risk (MAR) and default to extremely conservative factors, such as 
100 percent tritium oxide conversion, a ground plume release, and 
structural failures during a seismic event. Although MAR reductions 
have been implemented, further reductions listed in the DSA would raise 
the security classification of the documents. However, even with the 
extreme conservatism in the parameters selected, including a 
simultaneous release of all the tritium, from all the multiple 
facilities within 20 minutes as a ground plume; the postulated 
consequences to the public remain below the Evaluation Guideline of 
DOE-STD-3009-94, Preparation Guide for US. Department of Energy 
Nonreactor Nuclear Facility Documented Safety Analyses. In addition, 
the modeling does not account for any Emergency Response actions, 
personnel self-protection actions, nor any subsequent response actions 
to mitigate the consequences. Based on the current DSA, and the new DSA 
in review, the risk to the public remains low.
    The new DSA postulates a small set of energetic events that rely on 
credited Specific Administrative Controls (SAC) that perform preventive 
functions. Seismic events in the Tritium Facilities present another 
challenge as some legacy buildings remain in service while the Tritium 
Finishing Facility capital line item project establishes a modem, safe, 
and secure replacement to the H-Area Old Manufacturing Facility. The 
new DSA includes a number of new credited features, for example:
     The 217-H Vault walls and fire damper have been upgraded 
and are now designated as Safety Class (SC) features that prevent a 
release of MAR from the building. Other passive fire barriers are also 
credited.
     New SACs for fire water tank volume verification and other 
new Fire Suppression Surveillances have been added.
     All current Programmatic Controls have been replaced by at 
least one SAC.
     Additional analyses are planned for other buildings and 
Systems, Structures, and Components (SSCs) to determine suitability for 
upgrading the functional classification.
     In 2018, DOE/NNSA requested and received from SRNS, a 
strategy for risk reduction to the collocated worker (U-ESR-H-00163, 
Rev.0). This strategy describes the SRNS plans for additional 
structural analyses and control development for the remaining 
facilities during a potential seismic event. It also includes 
analytical analysis for dose reduction (e.g. tritium oxidation 
conversion rates and plume rise phenomena). In the aggregate, the plan 
includes 19 commitments that are being pursued and managed (SRNS-T0000-
2018-00227, Transmittal of the Schedule for Implementing the Strategy 
for Risk Reduction to the Co-Located Worker in Tritium Facilities).
     Longer term plans include the Tritium Finishing Facility 
capital line item project, to replace the H-Area Old Manufacturing 
(HAOM) facility with a seismically qualified facility with a dedicated 
SC fire suppression system.
    As noted in the Draft Recommendation, SRS has worked hard to 
improve its Emergency Preparedness (EP) program. The current EP program 
provides the appropriate training required for individuals to respond 
to alarms, abnormal operations, and emergencies across SRS. The Tritium 
Facilities EP program maintains a fully qualified team that performs 
approximately 50 drills per year to train and validate the 
organization's ability to respond to various scenarios, from weather 
induced incidents to large energetic events. DOE/NNSA is confident that 
appropriate drills are conducted for events as required by DOE.
Safety Posture
    The Draft Recommendation discusses the control set from the 1990s 
as being eliminated or downgraded and this result is a perceived shift 
in safety philosophy in managing the Tritium Facilities safety posture. 
DOE/NNSA assures the DNFSB that there has not been a shift in the 
safety philosophy, but rather changes in operations and new hazards 
analysis techniques have driven a change in the control strategy. 
Larger and more complex full facility events are now postulated in the 
safety analysis that rendered previous administrative individual tank 
Limiting Condition for Operations of the past less effective. 
Operational events have an adequate set of controls identified, whether 
SSCs or administrative. Several other controls mentioned in the draft 
recommendation include the Highly Invulnerable Encased Safes (HIVES), 
ventilation systems, and the seismic detection and isolation system. 
The HIVES continue to be credited as safety significant to protect 
reservoirs in a seismic event and the ventilation systems and seismic 
confinement system are designated as formal Defense-in-Depth/Important 
to Safety (DID/ITS). DID/ITS systems are listed in the current DSA with 
a safety function, are controlled by the Unreviewed Safety Question 
(USQ) process and cannot be eliminated without DOE/NNSA approval. It 
was determined that these systems currently cannot be qualified as 
safety significant without further analysis and upgrade. Part of the 
risk reduction strategy is to analyze various buildings and SSCs for 
seismic qualification, with the goal of determining the effort needed 
to upgrade the seismic detection and isolation system and ventilation 
system to safety significant controls if necessary. The plan will also 
evaluate the need for installing seismic detection and isolation 
systems on additional equipment in H-Area New Manufacturing (HANM) 
facility and the Tritium Extraction Facility (TEF).
    The Savannah River Field Office (SRFO) is routinely involved in the 
development and review of documents supporting the basis of the DSA. 
SRFO safety engineers attend and provide comment on a number of 
development safety programs, such as the Consolidated Hazards Analysis 
Process, Facility Operations Safety Committee, and DSA/Technical Safety 
Requirements (TSR) development meetings.
    The hazards analysis for the new DSA has a small number of 
scenarios that rely on credited SACs that perform preventive functions. 
These scenarios can be categorized into four groups:
     Process explosion--There are two events in HANM and two in 
TEF that conservatively involve one or two process tanks. This would be 
caused by an inadvertent introduction of oxygen into the system or 
inadvertent movement of tritium. Although many SSCs provide a defense 
in depth function (e.g., inerted gas glovebox confinement, ventilation, 
tritium air monitors, etc.), the hazard analysis team did not feel 
these SSCs would fully mitigate or prevent the events. Therefore, 
specific administrative controls are specified to prevent the event.
     Firearms discharge--There is an inadvertent firearms 
discharge scenario. Tritium air monitors are credited to alert 
personnel of a release if an inadvertent firearm discharge were to 
cause a confinement breech. DOE/NNSA requires security personnel to 
routinely access the facilities and they are trained on proper 
response.
     External impacts--These events include vehicle crashes, 
crane drops,

[[Page 28526]]

and airplane crashes. Events for the vehicle crashes and crane drops 
have specific administrative controls credited to minimize the 
potential for these events.
     Seismic event--These events may also include fires. The 
217-H vault walls, fire damper and other fire barriers are new SC 
controls that will be added in the DSA update. DOE/NNSA recognizes that 
additional controls are desired for these events and are currently 
working through similar DSA review team comments with SRNS. 
Additionally, the risk reduction strategy places emphasis on qualifying 
and developing controls for seismic events. The strategy takes a multi 
prong approach to include evaluating the feasibility of upgrading 
current DID/ITS controls and evaluating an alternate fire suppression 
system.
Emergency Preparedness
    SRS EP support organizations, like the SRS Fire Department, are 
trained and routinely evaluated to ensure that they can properly 
respond to an event in any facility across the site. For example, 
during the 2018 Site Exercise, the SRS emergency response team 
responded to a complex multi-facility and multi-contractor event that 
included H-Area, Tritium, and H-Tank Farm. Site level evaluated 
exercises routinely involve multiple local, county, state, and federal 
agencies in the response efforts. In a trend to further challenge all 
organizations, the 2018 exercise tested the site's Emergency Response 
Organization (ERO) ability to manage a complex event with potential 
off-site consequences, the Area Emergency Coordinators ability to 
manage multiple issues within an impacted area, and the ERO's ability 
to manage these issues along with the balance of the site to protect 
onsite employees and the public. SRS has addressed several 
opportunities for improvement identified in the exercise that included 
logistical challenges in the movement of personnel from impacted areas 
and conducting appropriately scoped drills to validate the emergency 
response effectiveness. DOE/NNSA believes that drills conducted by SRNS 
are properly scoped and use valid assumptions pertaining to the 
facility processes and safety systems.
    As noted, the SRS and Tritium Facilities EP programs have made 
significant improvements over the past several years. The EP programs 
are adequate to continue protecting the SRS workers and the surrounding 
public.
Postulated Dose Consequences
    Attachment B of the DNFSB Draft Recommendation 2019-1 discusses the 
postulated high worker doses documented in the DSA and the 
corresponding potential health consequences. DOE standards require that 
nuclear facilities perform conservative accident analyses. The tritium 
analysis is very conservative and uses many bounding assumptions (e.g.; 
MAR, 100 percent oxide conversion, ground level release, and others). 
Per DOE-STD-3009-94, this conservative analysis is used to quantify the 
``theoretical'' dose consequences to (1) determine if any SC SSC is 
required and (2) provide insight for selecting the appropriate SC 
SSC(s) for each design basis accident scenario. This analysis was never 
intended to calculate predicted or expected accident consequences for 
collocated workers or members of the public. Doses of this magnitude 
are not expected for any event. In fact, a best estimate determination 
by SRNS for a full tritium fire event conservatively indicates a 
postulated exposure reduction factor of over 25 from what is listed in 
the DSA (S-ESR-H-00031, Rev. 0). This best estimate used the bounding 
MAR and did not factor in the effects of plume rise that would exist 
from a large fire. Additionally, the MAR in the Tritium Facilities is 
spread out over multiple facilities and mostly contained in various 
storage vessels (some robust) in gas form and on hydride beds. It would 
not be expected that 100 percent of the MAR would be released in any 
event and all within a 20-minute timeframe. The Savannah River 
Emergency Protection Program is well prepared to protect the workers in 
the very unlikely occurrence of a large-scale event at the Tritium 
Facilities.

(Authority: 42 U.S.C. 2286d(b)(2))

    Dated: June 13, 2019.
Joyce L. Connery,
Acting Chairman.
[FR Doc. 2019-12918 Filed 6-18-19; 8:45 am]
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