Criticality Safety Support Group (CSSG)

About the CSSG

The Criticality Safety Support Group (CSSG) was formed in response to Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 97-2, Criticality Safety. The CSSG functions as the technical support group to the Nuclear Criticality Safety Program (NCSP) Manager, providing operational and technical expertise pertinent to the criticality safety needs of DOE missions. This expertise is relevant to integral experiments, nuclear data, methods, training, and organizational structures supporting the development and execution of the NCSP. Additionally, the scope of CSSG activities also includes reviewing:

  • Activities or conditions that have the potential for serious degradation of nuclear criticality safety at DOE facilities
  • New nuclear facility designs where criticality is a credible hazard
  • New or revised DOE directives, standards and guides related to criticality safety
  • Contractor nuclear criticality safety programs at DOE facilities in support of DOE line management

The CSSG conducts its work in accordance with a Charter, Work Instructions, and Membership Policy as approved by the NCSP Manager.

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CSSG Members

The CSSG consists of 10 current members including the Chair and Deputy Chair. The members are selected from DOE and its Contractors to provide a collective knowledge spanning the broad spectrum of nuclear criticality safety technology and safety areas. The 10 current members are the only voting members of the CSSG. Emeritus status is comprised of formerly Current members. Ex-officio members are appointed to provide expertise in a specific area of criticality safety. All members are appointed by, and serve with the approval of the NCSP Manager.


 David Hayes David Hayes | Bio
dkhayes [at] (dkhayes[at]lanl[dot]gov)
 Kevin Reynolds Kevin Reynolds | Bio
Deputy Chair
Y-12 National Security Complex
kevin.reynolds [at] (kevin[dot]reynolds[at]pxy12[dot]doe[dot]gov)
Photo Jennifer Alwin Jennifer Alwin | Bio
jalwin [at] (jalwin[at]lanl[dot]gov)
Photo David Erickson David Erickson | Bio
SRS, ret.
DG_Erickson [at] (DG_Erickson[at]blueheron[dot]us)
 David Heinrichs David Heinrichs | Bio
heinrichs1 [at] (heinrichs1[at]llnl[dot]gov)
 Jerry Hicks Jerry E. Hicks | Bio
DOE, ret.
jerryhicks [at] (jerryhicks[at]aol[dot]com)
 Thomas McLaughlin Thomas McLaughlin | Bio
LANL, ret.
tpm [at] (tpm[at]pobox[dot]com)
 James Morman James Morman | Bio
jamorman [at] (jamorman[at]anl[dot]gov)
 Catherine Percher Catherine Percher
%20percher1 [at] (percher1[at]llnl[dot]gov)
 Robert Wilson Robert Wilson | Bio
DOE, Ret.
robertwilson1976 [at] (robertwilson1976[at]gmail[dot]com)


Ex-officio Members

Photo Angela Chambers Angela Chambers | Bio
Angela.Chambers [at] (Angela[dot]Chambers[at]nnsa[dot]doe[dot]gov)
Photo Doug Bowen Doug Bowen | Bio
bowendg [at] (bowendg[at]ornl[dot]gov)
Photo Cris Eberle Cris Eberle | Bio
cris_s_eberle [at] (cris_s_eberle[at]orp[dot]doe[dot]gov)
Photo Brenda Hawks Brenda Hawks | Bio
brenda.hawks [at] (brenda[dot]hawks[at]orem[dot]doe[dot]gov)
Photo Michael Zerkle Michael Zerkle | Bio
Michael.Zerkle [at] (Michael[dot]Zerkle[at]unnpp[dot]gov)


Emeritus Members

 Michaele Brady Raap Michaele C. Brady | Bio
Deputy Chair
PNNL, ret.
MikeyBrady [at] (MikeyBrady[at]aol[dot]com)
 Calvin Hopper Calvin Hopper | Bio
ORNL, retired | Career Award
hoppercm [at] (hoppercm[at]comcast[dot]net)
 Kevin Kimball Kevin Kimball | Bio
Y12, retired
kimballkd [at] (kimballkd[at]ornl[dot]gov)
 Jerry McKamy Jerry McKamy | Bio
NNSA, retired
jnmckamy [at] (jnmckamy[at]lanl[dot]gov)


Past Members

 Richard Anderson Richard Anderson | Bio
Photo Adolf Garcia Adolf Garcia
Career Award | Rest in Peace
Photo Davis Reed Davis Reed | Bio
Retired, inactive
silhouette Thomas Reilly | Career Award
WSMS, Ret.
Photo Hans Toffer Hans Toffer | Bio
Fluor Gov't Group, retired
Rest in Peace | Career Award
 E. Fitz Trumble E. Fitz Trumble | Bio
fitz.trumble [at] (fitz[dot]trumble[at]amentum[dot]com)
 R. Michael Westfall R. Michael Westfall | Bio
ORNL, retired | Career Award