NIST Center for Neutron Research Safety 

Briefing

Photo credit: Brian Renegar January 4, 2023
NCNR – A National User Facility

30 beam instruments/experiments | ~40% of U.S. scientific productivity in neutrons

demand >> supply (2-3X)

>3000 research participants/year

1200 patents ~50 companies/year
February 3, 2021 – Unplanned Shutdown

Fission products detected in confinement 

building upon normal reactor startup causing 

reactor to automatically shut down 

10 staff members contaminated (sent home after 

decontamination)

No health/safety impacts to staff, public, or 

environment

The event posed no risk to personnel nor the 

community

The NIST reactor remains shut down until reactor 

readiness complete and NRC authorizes restart

Feb 4: confinement re-entry aborted due to 

elevated CO2 level in lower levels of building
Incident Reviews/Investigations

Technical Working Group Investigation – May 2021

Determined root causes of event | Proposed corrective actions to prevent recurrence

Safety Evaluation Committee Investigation – August 2021

Reviewed TWG report, root causes and event response | Proposed corrective actions and program 

improvements

External Consultants’ Reviews – February 2022

Reviewed incident, NIST’s analysis, corrective actions, and the NIST-wide response to the incident

NRC Special Inspection – March 2022

Evaluated NIST response and analysis | Identified 7 apparent license violations

CO2 Exposure Investigation – May 2021

Determined root causes of event | Proposed corrective actions to prevent recurrence
Incident Analysis

Direct Cause: A fuel element was not latched at 

reactor startup on February 3, 2021

Note: Unlatched fuel elements in 1981 and 1993 led to reactor shutdowns 

before damage could occur. The follow-on investigations in 1981 and 1993 

were insufficient. Though changes were made in latch verification 

procedures, the 2021 event shows that effective corrective actions were 

not developed.
7 Apparent Violations

TS 2.1: Exceeding the safety limit (fuel cladding temperature)

TS 3.1.3: Core configuration (FE 1175 not latched in place)

TS 6.4: Procedures (inadequate fuel handling procedure)

TS 6.4: Procedures (insufficient guidance monitoring abnormal nuclear channel 

readings during startup)

TS 6.4: Inadequate emergency response procedures (though NCNR acted within 

required timeframe)

TS 3.9.2.1: Fuel handling within the reactor vessel (failure to implement proper latch 

verification method to assure that FE 1175 was adequately latched)

10 CFR 50.59: Changes, tests, and experiments (refueling tool changes requiring a 

change to TS)

Leadership: failure to address loss of 

experience in Reactor Operations

March 16, 2022
Root Cause Analysis

Instruments, Equipment, & Tools

Deficiencies in the fidelity of latch determination equipment and tools

Procedures

Inadequacies in latch checking procedures

Procedural compliance not enforced

Qualifications & Training

Inadequacy of training and qualification program

Management Systems

Insufficient change management system

Inadequate oversight of refueling operations

Culture of complacency in reactor operations group

ROOT CAUSES
Root Cause Analysis

Instruments, Equipment, & Tools

Deficiencies in the fidelity of latch determination equipment and tools

Procedures

Inadequacies in latch checking procedures

Procedural compliance not enforced

Qualifications & Training

Inadequacy of training and qualification program

Management Systems

Insufficient change management system

Inadequate oversight of refueling operations

Culture of complacency in reactor operations group

ROOT CAUSES

Leadership Values and Actions

Problem Identification and Resolution 

Work Processes

Continuous Learning

Safety Communications

Questioning Attitude

Environment for Raising Concerns

Root causes directly related to 

broader safety culture issues
Corrective Actions

Management Systems

• Expand change management program

• Qualify supervisors on refueling and oversight

• Add operations crew shift for training and maintenance

• Elevate Aging Reactor Management program

• Include tool changes in change management program 

• All operations staff participate in corrective actions

• Add incentives for proactive improvements in safety

• Leadership field presence, staff engagement and mentoring

Qualifications & Training

• Require proficiency training prior to all refuelings

• Implement Continuous Learning Program: hands on + 

classroom

• Redesign operator and supervisor training programs with 

emphasis on critical activities

• Structure training with consistent performance 

requirements for critical operations tasks

Procedures

• Rewrite procedures to capture all necessary detail and to 

be consistent with standard on procedure use & adherence

• Require visual check that fuel elements are latched 

• Require training for all operations staff on procedure use 

and adherence

• Perform rotation latch check of all fuel elements prior to 

starting primary pumps. A redundant rotation latch check 

will be performed by a second qualified individual.

Instruments, Equipment, & Tools

• Develop visual check that fuel elements are latched 

• Analyze and document that improved processes provide 

adequate defense against unlatching

• Assess efficacy of tools and implement changes as needed

• Modify index plate to facilitate rotation latch verification

• Discontinue use of height check form of latch verification

• Implement administrative controls to ensure that no tool 

contact with fuel head is permitted following visual check

• Improve refueling test stand for training
Confirmatory Order

ADR sessions: May 10, 19, June 2

CO issued: August 1, 2022

CO deadline(s): through March 2027 (32% complete as of 12.22.2022)

Contents

Completed corrective actions (visual latch verification)

Planned corrective actions (5th reactor operations shift)

Communications (NIST Director’s message)

Nuclear safety program assessments

• Nuclear safety culture

• Nuclear operations, training, etc.

• Problem Identification and Resolution Program

• Employee Concerns Program

• Safety Culture Monitoring Panel

Training (refueling and requalification changes)

Procedures (procedure use & adherence)

Benchmarking (research & power reactors)

Employee Engagement (Rewards & Recognition Program)

Leadership Accountability (SEC, SC training, conference presentations, staffing)

Technical matters (assess options replacing reliance on admin controls for fuel latching, 

automatically secure CO2 following SCRAM, configuration management)

August 1, 2022
Improving Nuclear Safety Culture

NSCIP: benchmarking, 

continuous improvement, 

education, communications, 

monitoring & assessment

Baseline nuclear safety 

culture assessment 

performed with planned 

annual assessments. 

Actions developed and 

implemented in response to 

assessment

Benchmarked nuclear safety 

culture at INL-ATR and ORNLRRD and adopted several 

practices.

Nuclear Safety Culture 

Monitoring Panel

Employee Concerns Program

Rewards & Recognition 

Program (SGC&IP)

Procedure Use & Adherence 

methods

HPI tools (e.g. pre-job briefs)

Weekly discussion of lessonslearned from safety incidents 

at NIST and elsewhere

POD meeting

Lessons from NIST incident 

shared in the community
External Consultants

Alexander Adams, Jr.

Chief, U.S. Nuclear Regulatory Commission 

Research and Test Reactors Licensing Branch 

(retired)

Dr. Julia Phillips

Vice President & CTO, Sandia National 

Laboratory (retired), Executive Emeritus 

National Science Board

Dr. Thom Mason

Director, Los Alamos National 

Laboratory, President and CEO of Triad 

National Security, LLC (Triad)

Dr. Eric Kaler

President, Case Western Reserve University
External Consultants

Findings and Observations

“The importance of neutrons for research in important forefront areas of scientific inquiry, coupled with the 

dearth of other capacity for these experiments elsewhere in the U.S. makes it imperative to restart NCNR as 

soon as it is safe to do so.” – Julia Phillips (NSB)

“...the aborted re-entry on Feb 4 is noteworthy because over the course of the whole incident it represents the 

gravest threat to life that occurred...” – Thom Mason (LANL)

“The NCNR analyses of the root causes are also, I believe, comprehensive and accurate.” – Eric Kaler (CWRU)

“Observations during the site visit (Feb 1, 2022) showed a commitment to improving safety culture at all levels 

of NCNR management and staff.” – Al Adams

“NIST services (e.g. HR) do not seem to fully understand some of the differences in the environment in which 

NCNR operates relative to the rest of NIST. The fact that other federal entities (e.g. NRC) can compensate 

potential reactor operators at a much higher rate than NCNR can suggests that creativity and possibly advocacy 

on the part of HR may be required to address some of the most serious issues surrounding the restart and 

continued safe operation of NCNR.” – Julia Phillips (NSB)
External Consultants

...beyond NCNR’s initial corrective actions

Recommendation Action

Improve alignment and integration between NCNR and NIST-level programs 

(corporate support/oversight). Improve alignment and integration between 

NCNR and NIST/OSHE safety management.

NCNR Director and CSO coordinating in the development of new NIST-wide 

and NCNR programs. 

CSO is ex-officio member of reactor safety oversight committee.

New NCNR Safety Program Coordinator highly engaged with OSHE staff. 

OSHE to embed a new safety staff member at NCNR.

Improve leadership engagement at NIST level.

NCNR Director provides annual reactor safety briefing for the NIST Director; 

ADMR and ADLP members of team providing oversight for meeting the 

requirements of the Confirmatory Order.

Elevate risk management of NCNR at the NIST-level, including reviews. 

Provide the resources needed for corrective actions in full.

NCNR unplanned outage tracked in the NIST Enterprise Risk Management 

system as among top two enterprise risks. Budget requirements 

communicated to NIST leadership and resources needed for corrective actions 

provided.

OHRM should explore creative options to recruit, retain, and hire reactor 

operators, including exploring position classification for reactor operators to 

compete with industry.

In progress.
External Consultants

“Skepticism about management’s ability to secure the necessary financial resources 

for a fifth shift can also be traced to staff observation of the difficulty in resolving 

long-standing safety concerns of a non-nuclear nature (examples cited include 

ladders and stairwells). This reflects a NIST challenge of deferred maintenance and 

insufficient funding to address infrastructure deficiencies that is not limited to NCNR 

however the inadvertent message sent to staff that impacts the nuclear safety 

culture is that safety is not as important as the marquee scientific investments that 

do attract funding.” – Thom Mason (LANL)

“In short, the NCNR Director has the responsibility for the safe operation of NCNR but 

lacks the authority and resources to implement some actions required to ensure safe 

operations.” – Julia Phillips (NSB)
Issues Management

Unresolved water leaks: Leak diverters 

used as long-term water leak control 

measures (note that Guide Hall leak 

diverter is near electrical equipment).

Emergency doors need 

to be replaced. 

Aging site steam system 

leaks resulted in 

unplanned outages for 

repairs and unanticipated 

emergent hazards.

Falling roof flashing – hazard 

to personnel.
Issues Management

NOV 7, 2022
Three things that impact NIST safety and culture

Issues management 1 – NIST lacks the capacity to address infrastructure issues in a timely manner.

Issues management 2 – NIST lacks a centralized, integrated, corporate-wide IT system that supports all aspects of 

issues management and allows managers to monitor safety performance quickly and easily. (e.g. reporting issues 

and tracking corrective actions from inspections, incident investigations and other input; data queries/reports; 

asset management; management observations, maintenance work requests, lessons-learned, employee 

suggestions, etc.). The current “system” is composed of a set of unconnected applications that are a pain point 

for users as well as managers who seek to pull data to assess performance.

Telework – The safety culture in an operationally-driven organization like a laboratory or user facility is best 

nurtured and maintained through in-person engagement. It is especially critical for supervisors to be on-site and 

present during laboratory operations planning and performance. As scientific operations continue to build tempo 

towards pre-pandemic levels, full on-site staffing should be the starting point. Only after the organization has 

gained relevant experience with full operations should telework and remote work be considered and phased in 

with a watchful eye on safety culture and safe operations.