Neil Baldwin

M. Neil Baldwin

During his career with B&W (BWXT), Neil Baldwin made many significant contributions to the company and to the nuclear industry. Some of these contributions, according to the recollections of his colleagues, are summarized below. No such compilation could capture everything Neil has added to the body of knowledge relating to nuclear science and technology, or what his association has meant, professionally and personally, to those of us who were privileged to have worked with him. We nevertheless trust that the reminiscences below will encompass at least some of the highlights. We apologize in advance for any errors or omissions, which are solely ours, not Neil’s. While the fog of time may have diminished the precision of our recollections, it has left our respect and affection for this highly esteemed colleague fully intact.

Early projects to which Neil contributed were the critical experiments for the Nuclear Ship Savannah and later, the full scale testing of the actual nuclear core used on the ship. The fuel was clad in stainless steel and retained perfect integrity throughout its life. Neil was part of the technical group that performed over 10,000 experiments without a mishap. He would be part of the pre-operational meetings where any question or problem about an experiment would be fully discussed and resolved before any operation began. The motto was that we were all responsible for each other, our safety and our lives.

As Operations Supervisor for both the LPR and CX-10 reactor facilities, Neil directed the safe operation of these facilities for the better part of two decades. These reactors were important tools of the Lynchburg Research Center’s nuclear R&D complex, and their safe and efficient operation was essential to the LRC’s overall nuclear enterprise. Under Neil’s leadership, these facilities performed without incident, providing important additions to the country’s nuclear technology base, while contributing to the professional growth and development of a cadre of nuclear scientists and engineers, many of whom remain in the profession today.

One of the challenges confronting the nuclear industry in the 1970’s, and which still persists today, is interim storage of spent nuclear fuel. Neil planned and directed the experimental program that provided the integral reactor physics data needed for utilities to store their burgeoning quantity of spent nuclear fuel more compactly but safely, thereby significantly extending the capacity of on-site storage basins. This work, which was performed for the Energy Research and Development Administration (ERDA - later DOE) was used to identify and correct non-conservative biases in the state-of-the-art neutronic models, and remains an industry benchmark today. These experiments were conducted in the B&W critical experiment facility known as CX-10.

In directing the spent fuel critical experiment program, Neil provided one of the earliest demonstrations of formal quality assurance program implementation for nuclear research at B&W’s Lynchburg Research Center. This demonstration proved highly successful, winning praise from customer auditors and providing the pedigree on the research results that have allowed the project data to continue to be used for validation of neutronic models more than 25 years after the experimental work was conducted. This example typified Neil’s thoroughness in analyzing and recording experimental results, for which he helped to set the company standard. B&W critical experiment reports, which reflected Neil’s approach to documentation, were cited by industry representatives as the exemplar for accuracy and rigor.

During his tenure at CX-10, Neil was responsible for a series of experimental reactor physics campaigns, referred to collectively as The Physics Verification Experiments, that supported the continuous improvement of B&W’s nuclear reactor fuel element designs. His work was important to the refinement and validation of the improving B&W fuel designs, and to licensing them for use in our customers’ pressurized water reactors.

In the aftermath of the TMI 2 reactor accident, the instrument used to monitor boron concentration in the moderator/coolant failed because of the high levels of radioactivity released into the coolant by the damaged core. Because of the significant chemical contamination of the coolant, the alternate chemical method was yielding inconsistent, questionable results. This presented a serious problem, because boron is an effective neutron absorber - consequently, reaching and maintaining a safe boron concentration in the coolant was essential to assuring that a secondary criticality, owing to movement/reconfiguration of core debris, could be averted. Neil devised and implemented a non-chemical, non-instrumental approach to verifying boron concentration by measuring the effect of TMI coolant sample aliquots on the reactor period of the Lynchburg Pool Reactor (LPR). This effect was measured and compared to the effect of known boron samples, and used as an analog of boron concentration in the TMI samples. This important work helped to validate the safety basis of the crippled TMI reactor.

The LPR was also used as a training tool for power reactor operator candidates. As Operations Supervisor for the LPR, Neil planned and directed the training of numerous power reactor operators on an actual reactor facility, many of whom had the opportunity to manipulate the controls of a nuclear reactor for the first time under the aegis of the training program Neil helped to develop and maintain.

In one of the final experimental programs at the CX-10 facility, Neil planned and directed the performance of the so-called gadolinium criticals. This experimental program, part of a joint B&W/EPRI/DOE/Duke Power project, was conducted to investigate the physics of using gadolinium oxide to replace boron carbide lumped burnable poison in pressurized water reactors. This approach could help to improve neutron economy, extend fuel burn-up, and avoid the generation of a tritium waste stream. Neil directed the experimental reactor physics measurements of these water-moderated lattices, which consisted of gadolinia-urania fuel rods co-mingled with rods of urania fuel. These measurements included a number of lattice parameters, including power distribution, reactivity effects, and conversion ratios. One of Neil’s unique contributions was the development and application of an approach for measuring the conversion ratio of fertile material (i.e., U-238) without requiring chemical separation. This streamlined the process, and eliminated a potential source of significant error in the measurement. This program was very successful, and culminated in full-batch implementation of gadolinia-urania fuel in a pressurized water power reactor. The final design and licensing of this fuel load was based on the reactor physics experiments that Neil performed.

As the LTC closed its experimental facilities, Neil joined the LTC’s Nuclear Criticality Safety Group. His Manager, Bob Lewis, once remarked, “Neil is one of those rare examples of a person making a complete career shift late in his professional life”. Work in nuclear criticality safety is highly analytical and computer-oriented, as opposed to Neil’s earlier experimental work. Neil remained with the nuclear criticality unit as it was absorbed into the NPD, and thereafter until his retirement from B&W. After retirement Neil worked part-time for the nuclear criticality safety unit for several years. One of NPD’s product lines was (and is) the production of research and test reactor fuel for various universities and national laboratories. Most of Neil’s time while in the Unit was in the support of the criticality safety for the operation of that product line. Because the various research and test reactor fuel elements are usually different in their physical design and fuel loadings, Neil devised what he termed the “design umbrellas” for the various types of research and test reactor elements. His methodology permitted grouping the various designs rather than evaluating each individual element and allowed for a more efficient evaluation of safety. Neil presented a paper at an American Nuclear Society meeting on this methodology with a great deal of interest by the criticality safety community as well as by the NRC. The method is still in use at NPD.

We remember Neil’s integrity, kindness, and diligent search for scientific truth. His even temperament and gentle, unassuming manner disguised a determined resolve to “get it right”, and he remained always faithful to that principle. His legacy endures in the enormous body of his technical work, and in the hearts and minds of his collaborators.