The year 2007 ACRS manipulation to relocate Appendix K to a regulatory guide

The year 2007 ACRS manipulation to relocate Appendix K to a regulatory guide

There are current manipulations to relocate Appendix K to a regulatory guide. The following three bullets are copied from ML14204A009, July 23, 2014.

• Bert Dunn from AREVA provided a presentation recommending relocating the requirements in Appendix K to a regulatory guide (ADAMS Accession No.ML14175A094).

• There was a significant amount of follow-on discussion on this topic, and the NRC staff noted that this was the first time this recommendation had been presented. Industry noted that this recommendation will likely come to the NRC in the form of a formal written comment, associated with the request for comment on renumbering the regulations.

• In a later discussion on the Appendix K topic, NRC’s Office of General Counsel (OGC) noted that there is no legal reason why this information cannot be moved to a regulatory guide, but that both NRC and industry need to be aware of the implications.

AREVA (and likely others) seek to relocate the requirements in Appendix K to a regulatory guide because regulatory guidance is not enforceable.

Following is relevant history.   During 2007, the ACRS encouraged the Chairman of the NRC to move the requirements in Appendix K to a regulatory guide.  NRC staff responded that since regulatory guidance is not enforceable it cannot substitute for regulatory requirements.

Following are excerpts from those letters:

On May 23, 2007, Chairman of ACRS sent a letter to NRC Chairman Klein, PROPOSED TECHNICAL BASIS FOR THE REVISION TO 10 CFR 50.46 LOCA EMBRITTLEMENT CRITERIA FOR FUEL CLADDING MATERIALS, ML071490090.

The ACRS recommended that, “The staff should complete planned research needed to provide a sound basis for a regulatory guide applicable to current and future zirconium-based cladding alloys.”

On July 11, 2007, NRC staff replied to ACRS, PROPOSED TECHNICAL BASIS FOR THE REVISION TO 10 CFR 50.46, ML071640115.

The NRC staff pointed out that, “However, an important regulatory challenge in developing a performance-based regulatory requirement for any type of fuel cladding is the need to develop objective and legally-enforceable acceptance criteria. Since regulatory guidance is not enforceable it cannot substitute for regulatory requirements.”

Clearly, AREVA (and likely others) seek to relocate the requirements in Appendix K to a regulatory guide because regulatory guidance is not enforceable.

In its letter of May 23, 2007, the ACRS erroneously declares that, “The correlation specified for the rates of steam reaction with the cladding is viewed by the technical community as an anachronism.”  The fact is that while the correlation specified for the rates of steam reaction with the cladding is indeed an anachronism, it is not viewed as such by the NRC staff as well as by the Nuclear Energy Institute (NEI). In fact, the correlation specified for the rates of steam reaction with the cladding is fiercely defended by the NRC staff as well as by the Nuclear Energy Institute.

 

This defense is well documented by the NEI in its comment 16 opposing PRM-50-93, “The Baker-Just correlation, using the current range of parameter inputs, has been shown to be conservative and adequate to assess Appendix K ECCS performance. Data published since the Baker-Just correlation was developed has clearly demonstrated the conservatism of the correlation above 1800°F,” refer to ML101040678, Industry Comments on Petition for Rulemaking (PRM-50-93); Multi-Rod (Assembly) Severe Fuel Damage Experiments. Docket ID NRC-2009-0554, April 12, 2010.

The NRC also fiercely defends Baker-Just. In its analysis of PRM-50-76, “The Baker-Just correlation (Reference 4) using the current range of parameter inputs is conservative and adequate to assess Appendix K ECCS performance. Virtually every data set published since the Baker-Just correlation was developed has clearly demonstrated the conservatism of the correlation above 1800°F.” refer to Memo to Matthews/Black-Technical Safety Analysis of PRM-50-76, A Petition for Rulemaking to Amend Appendix K to 10 CFR Part 50 and Regulatory Guide 1.157 - ML041210109, April 29, 2004.

It appears that the above erroneous declaration by the ACRS was designed to augment its recommendation to relocate the requirements in Appendix K to a regulatory guide that would not be enforceable.

TEPCO to abandon AREVA system amid contaminated water crisis

Following is from ENFORMABLE.  It is revealing.  What if Pacific Northwest, formerly called WPPSS, had to cope with a situation like this on the Columbia River?

Tokyo Electric has determined that it will cease use of AREVA’s decontamination system, which uses chemicals to remove radioactive materials from water, as it has not lived up to expectations since it was installed.  The utility will file an application with the Nuclear Regulation Authority in order to scrap the system.

The decontamination system was set up in June 2011, three months after the onset of the Fukushima Daiichi nuclear disaster.  The design was so complicated that it took 50 welders more than a month to put the system together.  In the first three months, the system processed 76,000 tons of contaminated water, but was repeatedly forced to be shut down by a variety of problems.

For the last three years the system has been unused and kept out of operations and in the meantime, TEPCO has introduced a new system to process the ever-accumulating amounts of contaminated water at the crippled plant.

One of the problems will be dismantling and disposing of the decontamination system, as it has become contaminated itself after processing the radioactive materials.  The radiation levels measured in the system posed a risk to workers during operation and maintenance of the system.

TEPCO is still facing an uphill battle when it comes to dealing with water storage at the Fukushima Daiichi plant.  Underneath the plant, an enormous amount of ground water continues to flow directly into the ocean.

The utility has a limited amount of water it can store in storage tanks on site, and need to both stem the accumulation of contaminated water on site and the amount of contaminated water reaching the Pacific Ocean.

Three months ago, TEPCO attempted to divert some of the flow of ground water with an underground bypass, but failed to achieve any meaningful results.

The utility filed another application with the NRA this week, which if approved, would allow them to construct a new system for the collection and discharge of contaminated groundwater after it has been processed in order to remove some radioactive materials back into the Pacific Ocean.

This new groundwater dumping plan will likely face fierce opposition from local fisherman, who feel like they have been making continual concessions for TEPCO – which will undoubtedly affect the future of their own ability to operate, with little or no results.

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Sensors within fuel rod assemblies: W developing with academics

20 June 2014

Nuclear power plant operators may soon be able to monitor a reactor core by using sensors within fuel rod assemblies that literally scream the type and location of a problem, Michael Heibel, technical programme manager at Westinghouse, told World Nuclear News.

Westinghouse has applied for a patent on the device it is developing with academics from the Pennsylvania State University and Idaho National Laboratory. The team is building a prototype they plan to test at the Breazeale research reactor early in January 2015 and Westinghouse expects to bring the device to market by 2019, Heibel said.

Based on the thermo-acoustic engine principle – turning heat into sound – these devices do not require electric power supply. That fact has safety and cost benefits, Heibel said.

Using a thermo-acoustic neutron sensor, or an array of them, in the reactor to monitor the core power distribution and the temperature distribution, removes the need for tubing, wiring and vessel penetrations that are required to support existing surveillance instruments. That reduces the costs associated with maintaining such equipment, Heibel said. Plant operators will be able to monitor the core much more accurately, allowing them to produce more electricity from the same amount of uranium, he said.

Asked whether the device could be seen as a potential passive safety measure developed in the wake of Fukushima, Heibel said it would indicate "when melting is imminent".

"The more heat input you have, which you get when you have lost cooling, the louder it's going to scream," he said.

The "scream" is the frequency of sound wave produced according to the length of each device's resonance chamber.

Ideally, each fuel rod would have its own particular frequency, so plant operators would be able to determine by listening outside the reactor which fuel rods have an issue, if any, Heibel said.

Although these devices could be built into the fuel rods themselves, the Westinghouse team is looking at loading a number of them into a single tube that goes into the instrument thimble located inside the centre of a fuel assembly.

"We would be able to monitor different axial positions in every fuel assembly in the core and from that we could get fission rate and temperature information. Fission rate is probably the most important for the commercial nuclear power industry outside of extreme accident conditions," Heibel said.

Each device is somewhere between five and eight inches (13-20 centimetres) long, depending on the length of its resonance chamber. "We want each one to have a slightly different frequency, so that when we're listening, we can tell which assembly contains that particular device and we can then infer what the power distribution in that assembly is doing," Heibel said. Up to seven of these devices will go into each fuel assembly, he said.

Asked whether the device is being designed specifically for Westinghouse fuel rods, Heibel said, "We do have proprietary information associated with this specific application. It is not something off the shelf," he said. In its patent search, Westinghouse did not find any comparable devices being patented at this time, he said.

The sensors require a "signal processing system" to generate the core condition information in a form an operator can work with, he said.

"This investment generates the best return if the sensors are integral to the fuel. Ideally this system will be capable of being back-fit into existing fuel assemblies and be made integral to new fuel assembly designs," he said.

Researched and written
by World Nuclear News

No amount of belief makes something a fact.

No amount of belief makes something a fact. -James Randi, magician and skeptic (b. 1928)