[Federal Register Volume 69, Number 240 (Wednesday, December 15, 2004)]
[Notices]
[Pages 75047-75049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-27426]


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DEFENSE NUCLEAR FACILITIES SAFETY BOARD

[Recommendation 2004-2]


Active Confinement Systems

AGENCY: Defense Nuclear Facilities Safety Board.

ACTION: Notice, recommendation.

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SUMMARY: The Defense Nuclear Facilities Safety Board has unanimously 
approved Recommendation 2004-2, for DOE to consider. Recommendation 
2004-2 deals with the confinement of hazardous materials at defense 
nuclear facilities in the Department of Energy complex.

DATES: Comments, data, views, or arguments concerning the 
recommendation are due on or before January 14, 2005.

ADDRESSES: Send comments, data, views, or arguments concerning this 
recommendation to: Defense Nuclear

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Facilities Safety Board, 625 Indiana Avenue, NW., Suite 700, 
Washington, DC 20004-2001.

FOR FURTHER INFORMATION CONTACT: Kenneth M. Pusateri or Andrew L. 
Thibadeau at the address above or telephone (202) 694-7000.

    Dated: December 10, 2004.
A.J. Eggenberger,
Vice Chairman.

Recommendation 2004-2 to the Secretary of Energy, Pursuant to 42 U.S.C. 
2286a(a)(5), Atomic Energy Act of 1954, As Amended

    Dated: December 7, 2004.
    There is a long-standing safety practice in the design, 
construction, and operation of nuclear facilities to build-in and 
maintain structures, systems, and components that contain or confine 
radioactive materials. The Department of Energy (DOE) establishes 
requirements to ensure such containment or confinement. In the 
hierarchy of safety controls, passive design features are preferred 
over active systems; however, controls must be capable of performing 
their intended function. Passive confinement systems are not 
necessarily capable of containing hazardous materials with 
confidence because they allow a quantity of unfiltered air 
contaminated with radioactive material to be released from an 
operating nuclear facility following certain accident scenarios. 
Safety related active confinement ventilation systems will continue 
to function during an accident, thereby ensuring that radioactive 
material is captured by filters before it can be released into the 
environment.
    The enclosed technical report, DNFSB/TECH-34, Confinement of 
Radioactive Materials at Defense Nuclear Facilities, compares the 
benefits of including a safety-related active confinement 
ventilation system to those of relying only on a passive confinement 
system. This technical report illustrates that using only a passive 
confinement system for an existing or new defense nuclear processing 
facility would not account for many safety considerations such as 
post-accident monitoring and response, and may result in the release 
of an undeterminable amount of radioactive materials, the 
consequences of which could approach that of the unmitigated 
scenarios.
    The Defense Nuclear Facilities Safety Board (Board) has advised 
DOE in various ways during the past decade regarding the need to pay 
increased attention to the design and operational reliability of the 
confinement ventilation systems at defense nuclear facilities. These 
Board efforts include transmittal of a technical report on May 31, 
1995, Overview of Ventilation Systems at Selected DOE Plutonium 
Processing and Handling Facilities, a letter to the Deputy Secretary 
of Energy dated July 8, 1999, and Recommendation 2000-2, 
Configuration Management, Vital Safety Systems, on March 8, 2000. 
This advice has helped DOE improve the reliability of its 
confinement ventilation systems. However, DOE requirements have 
become less prescriptive during the last decade as DOE Order 
6430.1A, General Design Criteria Manual, was replaced with DOE Order 
420.1, Facility Safety, and its subsequent revisions. Furthermore, 
it has become apparent that the Board's advice on confinement 
systems is not being rigorously pursued as evidenced by the 
following:
    <bullet> On December 27, 2002, the Board sent a letter to the 
National Nuclear Security Administration (NNSA) regarding the 
confinement concept used for the Highly Enriched Uranium Materials 
Facility at the Y-12 National Security Complex. The proposed 
confinement concept was based on isolating the radioactive material 
in the building using a passive confinement system under certain 
abnormal events. The Board communicated safety concerns associated 
with this concept in the letter; subsequently, the confinement 
concept for HEUMF was modified to adopt a safety-related active 
ventilation system.
    <bullet> On April 12, 2004, the Board sent a letter to the 
Administrator of NNSA regarding similar safety issues related to the 
confinement systems for the plutonium facility at the Lawrence 
Livermore National Laboratory. The proposed approach utilized 
passive confinement of radioactive material from the facility during 
certain accident scenarios. Further, because the offsite dose 
consequences of such an unfiltered release were calculated to be 
below DOE's evaluation guideline (25 rem), the proposal included 
downgrading the existing safety-class active confinement ventilation 
system to a safety-significant system. The Board believed that the 
new approach was inconsistent with a defense-in-depth philosophy. 
Subsequently, the Livermore Site Office commissioned an independent 
calculation of the amount of the unfiltered release. These 
calculations yielded results that were an order of magnitude greater 
than the original building leakage estimates--clearly indicating 
that significant uncertainties existed in the analytical techniques. 
As a result, NNSA decided to maintain the existing safety-class 
active confinement ventilation system.
    <bullet> On August 27, 2004, the Board sent a letter to the 
Under Secretary of Energy regarding the confinement approach 
proposed for the Salt Waste Processing Facility at the Savannah 
River Site. The confinement concept for this new facility is based 
on isolation of the process building using passive confinement 
during accident scenarios. The Board suggested that the salt waste 
facility should be designed with a safety-related active ventilation 
system.
    A number of existing facilities (including the TA-55 Plutonium 
Facility, the Device Assembly Facility, and the Hanford Evaporator) 
rely on passive or non-safety related confinement systems. More 
importantly, designs for proposed facilities (including Chemistry 
and Metallurgy Research Replacement Facility and the Salt Waste 
Processing Facility) are based on the same passive confinement 
concept and use an assumed quantitative value for the building leak 
path factor as a design criterion.
    These examples illustrate two primary concerns. First, a 
reliance on calculations that do not appropriately account for large 
uncertainties is not defensible. These analytically determined 
building leak path factors are based on a combination of several 
computer programs that were not specifically designed for this 
purpose. Furthermore, it is generally impossible for these programs 
to model the true conditions of a real accident because of the 
uncertain behavior of the workers and emergency crews responding to 
the event.
    Second, these examples represent a fundamental change in DOE's 
approach to protection of the public near defense nuclear 
facilities. DOE appears to be using the evaluation guideline of 25 
rem exposure at the site boundary as a design criterion and an 
allowable dose to the public. This is contrary to the Board's July 
8, 1999 letter to the Deputy Secretary of Energy that states ``the 
25 rem evaluation guideline is not to be treated as a design 
acceptance criterion nor as a justification for nullifying the 
general design criteria relative to defense-in-depth safety 
measures.'' It is also contrary to DOE-STD-3009 that states that the 
25 rem evaluation guideline ``is not to be treated as a design 
acceptance criterion.'' However, the Board continues to see 25 rem 
at the site boundary used as an acceptance criterion for the 
performance of confinement systems. The Board is concerned that in 
these examples DOE and its contractors are underestimating the 
significance of the performance requirements for a confinement 
ventilation system and are relying on questionable calculations of 
offsite doses to evaluate performance. The Board reiterates that the 
25 rem evaluation guideline is solely to be used for guidance for 
the classification of safety controls, and not as an acceptable dose 
to the public for the purpose of designing or operating defense 
nuclear facilities.
    Notwithstanding the concerns discussed above, DOE continues to 
pursue a passive confinement approach in the design of some new 
nuclear facilities that have the potential for a radiological 
release. The Board recognizes that DOE's defense nuclear complex is 
comprised of a wide variety of nuclear facilities with an equally 
diverse range of materials, forms, activities, and proximities to 
the public. For this reason, it is difficult to prescribe a single, 
broadly-applicable design requirement. However, in light of the 
examples discussed above, the Board believes a more prescriptive 
design requirement is needed.
    The Board further recognizes that certain Hazard Category 2 and 
3 defense nuclear facilities may not benefit significantly from an 
active confinement ventilation system. An example would be a 
facility that stores radioactive material in protected, safety-class 
containers. Other examples may be certain tritium facilities, 
outside storage locations, burial grounds, or facilities with 
planned declining nuclear material inventories and scheduled for 
decommissioning in the near future. This recommendation is not meant 
to require an active confinement ventilation system in all such 
cases.
    Therefore, the Board recommends that DOE:
    1. Disallow reliance on passive confinement systems and require 
an active confinement ventilation system for all new and existing 
Hazard Category 2 defense nuclear facilities with the potential for 
a

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radiological release. These systems are expected to be classified as 
safety-class or safety-significant as required by a conservative 
application of DOE-approved methodology, and should be designed and 
maintained to function during abnormal and accident conditions. 
Exceptions to such classifications should be approved at a level in 
DOE that ensures a consistent, conservative approach throughout the 
complex.
    2. Disallow reliance on passive confinement systems and require 
an active confinement ventilation system for all new and existing 
Hazard Category 3 defense nuclear facilities with the potential for 
a radiological release. These systems would not ordinarily be 
classified as safety-class or safety-significant unless such 
designation is required by the DOE-approved methodology.
    3. Revise all applicable DOE directives pertaining to operation 
of existing facilities, design and construction of new facilities, 
and major modifications to existing facilities, in accordance with 
Items 1 and 2 above. These revisions should include guidance for 
determining when a facility would not benefit from an active 
confinement ventilation system.
    4. Assess existing facilities, ongoing major modifications, and 
new design/construction projects, to ensure that:
    (a) The confinement strategy described above is implemented, and
    (b) The 25 rem evaluation guideline is used solely for 
classification of safety controls.
    Section 42 U.S.C. 2286d(e) provides authority to the Secretary 
of Energy to ``implement any such Recommendation (or part of any 
such Recommendation) before, on, or after the date on which the 
Secretary of Energy transmits the implementation plan to the Board 
under this subsection.'' The Board suggests that the Secretary of 
Energy consider taking action on Item 4 above in parallel with the 
development of an Implementation Plan for this Recommendation.
    In addition, the Board's Recommendation 2004-1, Oversight of 
Complex, High-Hazard Nuclear Operations, addresses the need for 
complex-wide consistency in the application of DOE requirements and 
expectations. The Board expects the mechanisms established in 
response to Recommendation 2004-1 would likewise ensure consistent, 
conservative implementation of the confinement requirement provided 
here.

John T. Conway,
Chairman.
[FR Doc. 04-27426 Filed 12-14-04; 8:45 am]
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