Certifying Nuclear Reactors: How The NRC Approved Its First Small Modular Reactor Design

The US Nuclear Regulatory Commission (NRC) recently announced that it had approved certification of NuScale’s SMR (small modular reactor) design, completing its Phase 6 review of NuScale’s Design Certification Application (DCA). What this means is that SMRs using NuScale’s reactor design can legally be constructed within the US as soon as the rulemaking process completes. An NRC certification would also mean that certification of the design in other countries should pose no significant hurdles.

A question that remains unanswered at this point for most is how this certification process at the NRC actually works. Are there departments full of engineers at the NRC who have been twiddling their thumbs for the past decades while the US nuclear industry has been languishing? What was in the literally millions of documents that NuScale had to send to the NRC as part of the certification process, and what exactly are these six phases?

Stay tuned for a crash course in nuclear reactor certification, after a bit of SMR history.

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Bunnie’s Betrusted Makes First Appearance As Mobile, FPGA-Based SoC Development Kit

Recently, [Bunnie Huang] announced his Precursor project: a spiffy-looking case housing a PCB with two FPGAs, a display, battery and integrated keyboard. For those who have seen [bunnie]’s talk at 36C3 last year, the photos may look very familiar, as it is essentially the same hardware as the ‘Betrusted’ project is intended to use. This also explains the name, with this development kit being a ‘precursor’ to the Betrusted product.

In short, it’s a maximally open, verifiable, and trustworthy device. Even the processor is instantiated on an FPGA so you know what’s going on inside the silicon.

He has set up a Crowd Supply page for the Precursor project, which provides more details. The board features a Xilinx Spartan 7 (XC7S50) and Lattice iCE40UP5K FPGA, 16 MB SRAM, 128 MB Flash, integrated WiFi (Silicon Labs WF200-based), a physical keyboard and 1100 mAh Lio-Ion battery. The display is a 200 ppi monochrome 336 x 536 px unit, with both the display and keyboard backlit.

At this point [bunnie] is still looking at how much interest there will be for Precursor if a campaign goes live. Regardless of whether one has any interest in the anti-tamper and security features, depending on the price it might be a nice, integrated platform to tinker with.

Adding WiFi To The Acorn Electron

In the continuing quest by countless hobbyists to allow every 1980s 8-bit home computer to experience the joys of an online experience that doesn’t involve a 9600 baud modem, [Roland Leurs] has created a cartridge-based module for the Acorn Electron that adds WiFi, which he showed off at the virtual ABug conference in September 2020.

The Acorn Electron is a Synertek 6502-based computer that was released in the UK in August of 1983. It’s a budget version of the well-known BBC Micro educational/home computer, with 32 kB of RAM and featuring BBC BASIC v2 in its ROM. [Roland]’s ElkWiFi card slots into an available cartridge slot, after which the onboard ESP8266 (ESP-1 module) can be enabled and used as a WiFi modem.

Acorn Electron with Plus 1 expansion, ElkWiFi and additional expansion card inserted.

The board features the Exar ST16C2552CJ dual UART chip, one channel of which connects to the ESP-1 module, with the other channel used as an uncommitted UART header. The control logic is implemented in VHDL and flashed to the onboard Xilinx CPLD, and a 128 kB RAM module is used as WiFi data buffer.

Although a definite niche product, reading through the forum thread makes one really appreciate the technical complexity and joy once things are beginning to work reliably. It also shows one of the few cases where an ESP-1 module is used for its original purpose: as an easy way to add WiFi functionality with full WiFi and TCP stack, without burdening the main CPU.

(Thanks, BaldPower)

Hard Disk Drives Have Made Precision Engineering Commonplace

Modern-day hard disk drives (HDDs) hold the interesting juxtaposition of being simultaneously the pinnacle of mass-produced, high-precision mechanical engineering, as well as the most scorned storage technology. Despite being called derogatory names such as ‘spinning rust’, most of these drives manage a lifetime of spinning ultra-smooth magnetic storage platters only nanometers removed from the recording and reading heads whose read arms are twitching around using actuators that manage to position the head precisely above the correct microscopic magnetic trace within milliseconds.

Despite decade after decade of more and more of these magnetic traces being crammed on a single square millimeter of these platters, and the simple read and write heads being replaced every few years by more and more complicated ones, hard drive reliability has gone up. The second quarter report from storage company Backblaze on their HDDs shows that the annual failure rate has gone significantly down compared to last year.

The question is whether this means that HDDs stand to become only more reliable over time, and how upcoming technologies like MAMR and HAMR may affect these metrics over the coming decades.

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Historical Satellite Tracker Saved From Scrap Heap

In a bit of rare Australian space news, the  Arnhemland Historical Society has managed to save one of the satellite trackers used during the 1960s and 1970s from the scrap heap. As the Space Race intensified during the 1950s and 1960s, every nation wanted a piece of this new technology. A number of European nations banded together in the form of ELDO, the European Launcher Development Organisation.

Australia was a partner in this program, with launches of the Europa-1 and Europa-2 rockets taking place from Woomera, South Australia. Initially the UK’s cancelled Blue Streak IRBM program provided the first stage for Europa-1, but this was later replaced with the French Diamant. France also provided the Coralie second stage in addition to the German-developed Astris third stage.

The satellite tracker being dismantled at the South Australian defence base before it was trucked north. (Photo: Arnhemland Historical Society)

The first launch of the Europa-1 took place in 1966, with the rocket performing well, but inaccurate readings from a radar station leading to the rocket to be wrongly instructed to self-destruct. Of nine launches, four were successful, with the satellite trackers at Arnhemland providing tracking support. Ultimately, the many technical setbacks led to the demise of ELDO, and it was merged by the 1970s into what is now the European Space Agency, with its main launch site in Kourou, French Guiana.

Despite the lack of success, these early days at Woomera were instrumental in getting Europe’s feet wet in the development of the Ariane rockets. Woomera’s rocketing days may also not be over yet, with NASA having announced  in 2019 plans to use Woomera for launches.

Maybe one day Arnhemland will have its own space port, with the old satellite track on display to remind of those early days.

[Top photo: The ELDO satellite trackers were state-of-the-art when they stood in Gove in the 1960s. (Supplied: Arnhemland Historical Society)]

(Thanks, David)

GitHub’s Move Away From Passwords: A Sign Of Things To Come?

Later this month, people who use GitHub may find themselves suddenly getting an error message while trying to authenticate against the GitHub API or perform actions on a GitHub repository with a username and password. The reason for this is the removal of this authentication option by GitHub, with a few ‘brown-out’ periods involving the rejection of passwords to give people warning of this fact.

This change was originally announced by GitHub in November of 2019, had a deprecation timeline assigned in February of 2020 and another blog update in July repeating the information. As noted there, only GitHub Enterprise Server remains unaffected for now. For everyone else, as of November 13th, 2020, in order to use GitHub services, the use of an OAuth token, personal token or SSH key is required.

While this is likely to affect a fair number of people who are using GitHub’s REST API and repositories, perhaps the more interesting question here is whether this is merely the beginning of a larger transformation away from username and password logins in services.

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Evaluating Raspberry Pi As A Programmable Logic Controller

It should be no surprise to many that one can use a Raspbery Pi SBC as an industrial controller, but is it any good at that? That was the question which [Dough Reneker] and [William Shaffer] built a test rig to see how a Raspberry Pi performs in head to head tests. They compared a Python-based control loop on a Raspberry Pi 3B against an C0-12DD1E-2-D AutomationDirect CLICK Programmable Logic Controller (PLC) using a simple water heating example.

A major snag with using the Raspberry Pi as a PLC is the lack of industrial I/O capacity. This requires additional hardware, in this case adding a four-channel ADC board as well as a custom board to condition the signals. The Raspberry Pi looks for 0-3 V inputs where industrial control applications are usually in the -10 to 10 V range and often use a 4-20 mA current loop.

Using a PLC leverages so-called ladder logic, where each action depends on conditions. With each update scan, the PLC ensures that all input conditions are translated into the appropriate output conditions in real-time. It’s only job is to monitor the process at hand and it does this very well.

Here the flexibility and generic nature of the Raspberry Pi running Linux was a disadvantage. Unlike the PLC, the lack of a hard real-time OS means you can’t guarantee the Pi will be as responsive to changing inputs.

The behavior of the two systems showed that while both did the task they were programmed for, the Raspberry Pi was decidedly more erratic. Although one could program around a lot of these issues (presumably using Linux in stripped-down, soft real-time configuration with interrupt-driven native code), the effort needed to make a Raspberry Pi system suitable for an industrial environment shows why single-board computers haven’t seen adoption as replacements for PLCs.

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