Peter S. Winokur, Chairman

Jessie H. Roberson, Vice Chairman

John E. Mansfield

Joseph F. Bader

DEFENSE NUCLEAR FACILITIES

SAFETY BOARD

Washington, DC 20004-2901

May 9,2012

The Honorable Steven Chu

Secretary ofEnergy

U.S. Department ofEnergy

1000 Independence Avenue, SW

Washington, DC 20585-1000

Dear Secretary Chu:

On May 9, 2012 the Defense Nuclear Facilities Safety Board (Board), in accordance with

42 U.S.C. § 2286a(a)(5), unanimously approved Recommendation 2012-1, Savannah River Site

Building 235-F Safety, which is enclosed for your consideration. This Recommendation

identifies the need to execute actions that can reduce the hazards associated with the material at

risk that remains as residual contamination within Building 235-F.

After you have received this Recommendation and as required by 42 U.S.C. § 2286d(a),

the Board will promptly make it available to the public. 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 the Department ofEnergy

(DOE) under the Atomic Energy Act of 1954, 42 U.S.C. §§ 2161-2168, as amended, please

arrange to have it 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 ofDOE Responses and

Implementation Plansfor Board Recommendations..

Sincerely,

~~l.S,../}- Peter S. Winokur, Ph.D.

Chairman

Enclosure

c: Mr. David Huizenga

Dr. David C. Moody, III

Mrs. Mari-Jo Campagnone
RECOMMENDATION 2012-1 TO THE SECRETARY OF ENERGY

Savannah River Site Building 235-FSafety

Pursuant to 42 U.S.C. § 2286a(a)(5),

Atomic Energy Act of 1954, As Amended

Dated: May 9, 2012

Background

The Defense Nuclear Facilities Safety Board (Board) believes that the Department of

Energy (DOE) needs to take action to remove and/or immobilize the residual contamination

within Building 235-F because ofthe potential dose consequences to collocated workers and the

public. Furthermore, the Board believes that DOE must also take near-term action to more

effectively prevent a major fire in Building 235-F.

Building 235-F at the Savannah River Site (SRS) houses several partially deactivated

processing lines including the Plutonium Fuel Form (PuFF) facility, Actinide Billet Line,

Plutonium Experimental Facility, and the old metallography lab glovebox. Building 235-F no

longer has a DOE mission. It is currently operated in a surveillance and maintenance mode and

is normally unoccupied.

With the exception ofresidual contamination, Building 235-F has been de-inventoried of

special nuclear material. The remaining residual contamination is the principal hazard posed by

Building 235-F and includes a significant quantity ofplutonium-238 (Pu-238). More than

95 percent ofthe Pu-238 is located in the PuFF facility; approximately 82 percent is concentrated

in 2 ofthe 9 PuFF facility cells. It should be noted that the residual Pu-238 contamination is a

fine ball-milled powder that is in a highly dispersible form, which increases the potential dose

consequences associated with a radiological release.

The responsible SRS contractor, Savannah River Nuclear Solutions (SRNS), has

determined that the unmitigated consequences of a seismically-induced full-facility fire are

greater than 10 rem offsite and 27,000 rem to the collocated worker at 100 meters. F-Area

routinely has more than a thousand site workers who are normally in the facilities, construction

sites, and trailers located adjacent to Building 235-F. Some ofthe trailers that house workers are

located within the Building 235-F fence line.

While DOE does not conduct any operations within Building 235-F, fires could start

inside the building if energized electrical equipment or wiring failed or was damaged during a

seismic or other natural hazard event. Electrical sparks or heat from electrical equipment could

ignite adjacent combustible material. Two ofthe key preventive controls for fire scenarios are

eliminating potential ignition sources and controlling the amount of combustibles. In September

2011, during a walkdown ofBuilding 235-F, the Board's staffidentified a significant quantity of

transient and fixed combustibles and unnecessary electrical equipment that had not been air

gapped. DOE has taken action to remove the transient combustible material and to limit access
to Building 235-F. However, no actions are currently planned to remove the fixed combustibles

or unneeded electrical equipment.

In the event of a fire, Building 235-F has several vulnerabilities. First, the Building

235-F fire detection system is not credited, does not provide complete coverage, nor is the

building normally occupied; consequently, a fire could smolder and burn undetected. Second,

Building 235-F does not have a fire suppression system to prevent an incipient stage fire from

growing into a room fire. Third, Building 235-F does not have fire barriers with a qualified fire

rating to prevent the spread of a fire to adjacent rooms. The Building 235-F Fire Hazards

Analysis notes that the subdividing walls and floors are in many places incomplete or penetrated

and are not adequately sealed to achieve a qualified fire rating. In addition, some of the existing

walls contain cellulose, which is combustible and could allow a room fire to spread to other

portions of the building. Fourth, the absence of standpipes or hose connections inhibits the

ability of the fire department to fight a fire inside Building 235-F. To combat a fire, firefighters

would need to prop open the exterior doors to allow the passage of fire hoses; this would allow

smoke and firewater, potentially contaminated with radioactive material, into the environment.

The July 2011 draft of the Basis for Interim Operations (BIO), prepared by SRNS notes

that the Building 235-F structure can only provide limited confinement during or following a

seismic event because seismically-induced building cracks may develop. Consequently, the

building structure cannot be credited as a control to prevent a post-seismic unfiltered release. In

2010, DOE took action to improve the safety posture of Building 235-F by reducing the height of

the abandoned stack located adjacent to the building. The contractor's structural analysis

indicated that the concrete stack, prior to the height reduction, could have collapsed onto

Building 235-F during a seismic event causing significant structural damage.

In addition to fires, loss of confinement accidents could also release radioactive material.

For instance, a release could be caused by a breach of the confinement or the ventilation system

during a seismic event. However, the Building 235-F confinement ventilation system cannot be

relied upon to continue to perform its safety function during or following a seismic event. The

draft BIO states that non-load-bearing building elements may fail during a Performance

Category-3 seismic event, resulting in impact damage to safety-related structures, systems, and

components such as ventilation ducts. The draft BID states that the metal ventilation ducts may

leak after an earthquake because they are not completely welded and that the concrete roof

exhaust tunnel may develop cracks.

Loss of confinement can be caused by degraded equipment. The deteriorated condition

of the PuFF facility was noted in an October 1991 report by DOE's Office ofNuclear Safety,l

which identified as an issue the integrity of elastomer seals that form part of the confinement

boundaries inside Building 235-Fa In addition to degradation with age, these elastomer seals also

degrade with exposure to Pu-238. Although identified two decades ago, this issue remains. The

cells have numerous penetrations (e.g., glove ports, viewing windows, ventilation supply and

1 U.8. Department of Energy, 1991, Report ofan Investigation into the Deterioration ofthe Plutonium Fuel Form

Fabrication Facility (PuFF) at the DOE Savannah River Site, DOE/=NS-0002P,

http:U\vww.osti.gov(bridge/servlets/pur1/6246281-tBgi3H/6246281.pdf.

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exhaust, utility services). In the draft BIO, SRNS stated that "the [elastomer] seals around the

cell and glovebox penetrations are expected to be in a degraded condition due to the years of

operation in a radiation environment." The continued deterioration of the elastomer seals

increases the potential for the spread of the contamination outside of the cells. Even under

normal operations, a loss of confinement from these cells would greatly increase the complexity

and hazard associated with decontamination and decommissioning of Building 235-F.

DOE conducted a small fire drill at Building 235-F in December 2011, which simulated a

minor radiological release. While DOE conducts periodic drills, DOE has not conducted a

Building 235-F radiological drill involving the adjacent Mixed Oxide Fuel Fabrication Facility or

Waste Solidification Building construction sites to examine how these facilities would respond to

a significant radiological release from Building 235-F. In the event of a significant radiological

release, the amount of mitigation provided by sheltering in place may not be sufficient to protect

nearby workers. This is especially true for seismically-induced fires, since the same seismic

event may also damage nearby trailers and administrative buildings.

The Board has previously identified the need to address the residual contamination in

Building 235-F. In a June 12, 2003, letter to the Secretary of Energy, the Board noted that the

risk associated with several hazard.s in Building 235-F, including the Pu-238 residual

contamination, had been accepted rather than eliminated. The report enclosed with the June

letter further noted that DOE should consider decontaminating areas with residual contamination

to reduce the risk associated with a potential release. Since that time, DOE has on a number of

occasions evaluated options and developed plans to address the residual contamination.

However, these efforts have not successfully transitioned from planning to execution, and the

residual contamination and the hazard it poses still remain in Building 235-F.

Conclusion

The Board believes that due to the potential dose consequences to collocated workers and

the public, it is unacceptable for the residual contamination within Building 235-F to continue to

remain unaddressed.

Recommendation

Given the continuing hazard posed by Building 235-F as detailed above, the Board

recommends that DOE:

1. Take action to immobilize and/or remove the Pu-238 that remains as residual

contamination within Building 235-F.

2. Concurrent with sub-Recommendation 1, take near-term. actions and implement

compensatory measures to improve the safety posture of Building 235-F and reduce

the potential for and severity of a radiological release, including but not limited to the

following.

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a. To the extent feasible, remove from Building 235-F all transient and fixed

combustibles that are not directly necessary for surveillance and maintenance

activities and ensure that the transient combustible loading in the facility remains

as low as reasonably achievable.

b. Ensure that all electrical equipment not necessary to support facility safety

systems, life safety, or surveillance and maintenance activities is de-energized and

air gapped. Remove all electrical ,and support equipment remaining within former

process areas that is not necessary for surveillance and maintenance.

c. Evaluate the condition and operability of early detection and alarm systems in the

PuFF facility, such as the heat and smoke detectors (with the exception of those

located within the PuFF facility cells, if evaluating them would require intrusion

into the cells). Take action, as necessary, to ensure that these systems are credited

in the safety basis, are remotely monitored, provide reliable detection of hazards,

and are maintained in accordance with National Fire Protection Association 72,

National Fire Protection Alarm and Signaling Code.

3. Concurrent with sub-Recommendation 1, take action to ensure that the SRS

emergency response to a radiological release from Building 235-F is adequate and

effective, including but not limited to the following.

a. Ensure that an integrated emergency response plan is in place that considers the

collocated workers in facilities, construction sites, and trailers located adjacent to

Building 235-F. Development of this plan should include an evaluation of the

specific locations where collocated workers are directed to shelter in place to

ensure their adequate protection during and following a potential radiological

release from Building 235-F.

b. Ensure that periodic coordinated drills in response to a simulated event at

Building 235-F are conducted. Such drills should include appropriate response

actions by personnel in the adjacent facilities and construction sites, such as

sheltering in place or evacuating depending on proximity to the simulated plume

of radioactive material.

The Board urges the Secretary to a\Tail himself of the authority under the Atomic Energy

Act (42 U.S.C. § 2286d(e)) to "implement any such recommendation (or part of any such

recommendation) before, on, or after the date on which the Secretary transmits the

implementation plan to the Board under this subsection..'.:..".;s. .........__.....

Peter S. Winokur, Ph.D.,

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