Ole Christen Reistad

• Reistad, Ole; Glaser, Alex; Frank, Rebecca D. & Kaald, Sindre (2022). Document-Based Nuclear Archaeology. Science and Global Security. ISSN 0892-9882. 30(2), p. 95–107. doi: 10.1080/08929882.2022.2111880. Full text in Research Archive
• Maharramova, Sabina; Beere, William H. Åstorp; Eitrheim, Knut Kjærand Frellumstad; Reistad, Ole & Walderhaug, Tord (2018). Comparison of HELIOS-2.1 and SCALE-6.1 codes on pin-cell model. Annals of Nuclear Energy. ISSN 0306-4549. 117, p. 155–164. doi: 10.1016/j.anucene.2018.03.026. Full text in Research Archive Show summary

  Deterministic HELIOS-2.1 and SCALE-6.1 codes are compared using pin-cell models for light water reactor (LWR) and heavy water reactor (HWR) cases. The main objective of this study is to identify the origins of any discrepancies between compared codes. The infinite multiplication factor kinf, flux distribution, absorption, fission, production reaction rates, and burn-up dependent concentrations of major fuel isotopes, are investigated herein and compared. Comparison of kinf has shown that the codes are in good agreement for both the LWR and HWR cases. The codes showed differences in the isotope number density of up to 6% in the case of prominent isotopes, and for 235U and 239Pu at 60 GWd/tU in the LWR case. These differences were, approximately 20% for 235U and 30% for 239Pu in the HWR case. It is concluded that these discrepancies are attributed to differences in the modelling of the thermalisation process in the HWR case. This needs to be investigated further to determine the root cause. Possible causes could be the neutron group structure, cross section condensation, treatment of up-scatter, angle dependence of scatter, and spatial homogenisation during source iterations.

• Hinderstein, Corey; Newman, Andrew & Reistad, Ole (2012). From HEU minimization to elimination: Time to change the vocabulary. Bulletin of the Atomic Scientists. ISSN 0096-3402. 68(4), p. 83–95. doi: 10.1177/0096340212451591. Full text in Research Archive
• Reistad, Ole Christen; Hustveit, S & Roudak, S (2008). Operational and accident survey of Russian nuclear submarines for risk assessments using statistical models for reliability growth. Annals of Nuclear Energy. ISSN 0306-4549. 35(11), p. 2126–2135. doi: 10.1016/j.anucene.2008.02.017. Full text in Research Archive

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• Persson, Mats; Michelsen, Maja & Reistad, Ole (2012). Forsker Maja fridde best. [Journal]. Halden Arbeiderblad. Full text in Research Archive
• Backe, Steinar; Enger, Elin; Hustveit, Styrkaar; Høibråten, Steinar; Kippe, Halvor & Mykkeltveit, Svein [Show all 15 contributors for this article] (2012). The United Kingdom - Norway Initiative: Further Research into Managed Access of Inspectors During Warhead Dismantlement. Full text in Research Archive
• Emblemsvåg, Jan; Ordonez, Cesar; Tamm, Cristian Garrido; Ortigosa, Javier Santos; Colilles, Yolanda Mugica & Pérez, Alejandria [Show all 21 contributors for this article] (2024). Final Report of the Nuclear Propulsion for Merchant Ships I (NuProShip I) project. Norges Teknisk og Naturvitenskapelig Universitet. Full text in Research Archive Show summary

  This report contains the results of two years of research (2023 and 2024) performed under the context of Nuclear Propulsion for Merchant Ships (NuProShip) I, funded by the Research Council of Norway. The successor project, NuProShip II, is well underway as of January 2025. Starting from the nuclear reactor core and working ourselves outwards to the reactor systems, waste handling, ship systems, ship design, crew and more, we have performed a number or research tasks as presented in this report. Since we started at the nuclear reactor core, based on the idea that we need the right nuclear technology before anything else, the report is dominated by the large amount of work done to select the best possible reactor technologies. We have selected reactors among all the known reactor concepts by yearend 2022, some 80+ of them, as detailed in Chapter 2. First, we applied a set of 11 exclusion criteria that were very clearcut, after which we had about 8 possible reactor concepts left. These 8 reactor concepts were subsequently subjected to another 26 criteria for further selection. The end result is three reactor concepts; 1) molten-salt reactor using TRISO fuel designed by Kairos Power (USA), 2) a helium gas-cooled reactor using TRISO fuels designed by Ultra Safe Nuclear Corporation (USA), and 3) a lead-cooled reactor designed by Blykalla (Sweden). By selecting these reactor concepts and studying their intrinsic properties, we realized that one single reactor technology cannot address the entire shipping industry. In NuProShip II, we will continue working on this. Preliminary results, however, indicate that the MSR will work best with large ships that need steam turbines. The helium gas-cooled reactor will work best with ships that need electric propulsion system. The lead-cooled reactor will work best in situations where the load is more stable situations such as baseload operation. Once these overall findings were clear, the two other work packages – discussed in Chapters 3 and 4 – could start working in earnest. In Chapter 3 we find a lot of insights from a ship design and class society perspective. This is a complex area, and to gain a complete overview of it is difficult, which will go on well into NuProShip II as well. This is evident for the HAZID overview for which many issues are still not solved. However, we have started to get a very good overview of the class requirements and international regulations. Most of the results presented here must nonetheless be viewed as preliminary. The challenge is to go from the high, conceptual level down to a concrete ship, such as the Cadiz Knutsen owned by Knutsen OAS. This ship has served as a mental reminder of what we are working on, and the ship is also used as a practical working case. The same can be said about the work presented in Chapter 4. Researching what skills the crew needs, what qualifications they must have and therefore develop an education and training system is also complex work. The fact is that none of the reactor technologies we have identified have ever been used at sea. The closest is the lead-bismuth cooled reactor used unsuccessfully in the Russian navy. One finding that seems to be very clear is that some remote monitoring/operations of ships must be implemented. Naval ships are today largely self-contained, and for that reason they have a reactor crew that is too large for commercial chips of any sort due to both the availability of crew but ultimately also costs. Therefore, remote monitoring/operations is seen as key enabler. Obviously, all the topics discussed in Chapter 3 are also extended well into NuProShip II. The report does not contain much information about costs. The reason is that it is basically too early for making any trustworthy estimates. However, this will be adressed in NuProShip II.

• Anthony, Ian; Chambers, David; Dahlberg, Joakim; DeLand, Sharon; Hinderstein, Corey & Kelley, Robert [Show all 12 contributors for this article] (2014). Innovating Verification: New Tools & New Actors to Reduce Nuclear Risks - Building Global Capacity. Nuclear Threat Initiative. Full text in Research Archive

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