UPRATING Of Older US Nuclear Plants

Joe Neubarth

http://www.latimes.com/news/local/la...,7739985.story

U.S. is increasing nuclear power through uprating
Turning up the power is a little-publicized way of getting more electricity from existing nuclear plants. But scrutiny is likely to increase in the wake of Japan's nuclear crisis.

The U.S. nuclear industry is turning up the power on old reactors, spurring quiet debate over the safety of pushing aging equipment beyond its original specifications.

The little-publicized practice, known as uprating, has expanded the country's nuclear capacity without the financial risks, public anxiety and political obstacles that have halted the construction of new plants for the last 15 years.

The power boosts come from more potent fuel rods in the reactor core and, sometimes, more highly enriched uranium. As a result, the nuclear reactions generate more heat, which boils more water into steam to drive the turbines that make electricity.....

Joe Neubarth

Hummmmmm? Higher power brings greater potential problems if you have an emergency, including longer time to shut down. Though I am certain there are enough safety parameters to allow this, right now it almost seem like we are spitting into the wind.

Astronuc

Actually, one can increase the core average linear hear rate, and even reduce the peak linear heat rate by judicious core design. The enrichments are still limited to 5%, but the max is about 4.95% to allow for some uncertainty.

The batch sizes on high duty plants is generally increased. BWRs take advantage of modern 10x10 fuel designs.

Many plants had a lot of margin in the original design, particularly BWRs and moderate/low duty PWRs. Many of the BWRs and moderate/low duty PWRs are on 24-month cycles.

Also, improvement in high and low pressure turbines can grab an extra 2-3% thermal efficiency.

NUCENG

US plants are also getting license renewals from 40 to 60 years.

And a number of US plants have extended operating cycles from 18 months to 2 years.

All plants are working to reduce the length of refueling outages by detailed planning, shifting some maintenance from outage to online, and performance monitoring that allows some maintenance periods to be extended. Lubricating oil analysis, vibration monitoring of rotating machinery, thermography, and heat balance monitoring are examples of monitoring techniques.

Finally the performance trend of US plants has shown a tremendous improvement in reliabilty at the same time. SCRAM reduction programs and all the other programs (including power uprates) have led to continuous growth in nuclear production without building new plants.

Joe Neubarth

"A tremendous improvement in reliability" Now, that sounds reassuring. Sell it as a reliability and durability improvement program, and I am not too concerned. Sell it as Reaching and Stretching to get more and more from old plants, and I feel uneasy; as I said, as if we are spitting into the wind.

All I know from experience is that when you reach too far, sometimes you can topple the ladder.

gmax137

Also consider that the plants don't uprate without NRC approval (it is a change to the operating license, which specifies the maximum core power). The NRC acceptance of the proposed uprates (at least recently, as in the past few years) depends upon showing the uprate to be 'risk-neutral.' This means that actual improvements have been made to the plant (as opposed to simply using the original margin, which may be substantial as Astronuc points out). Improvements might be uprated safety injection pumps, bigger or faster safety relief valves, improved emergency feedwater system, etc.

Dmytry

Sounds like the sure way to bring down safety. Something they're going to be doing until it backfires.

After the Fukushima incident, reading of all the other things that happened - control rods falling out resulting in criticalities, pressure vessels reshaped after getting bent during annealing, the Tokaimura incident - in my opinion nuclear industry had a of respect they never deserved, with a public image of reliability and regulation they never had. On 11th march, they were - as usual - projecting images of the backups for the backups, multiple redundancy, and other stuff - with noise of the reassuring keywords - approvals, regulation, reliability, redundancy, containment. Then we learnt of electrical stuff in the flooded basement, of TEPCO not having enough dosimeters for all the workers, of TEPCO being unable to measure radiation past 1Sv/h , etc. Then it became a level 7, and in few months or few years there is a good possibility it'll be recognized as the worst accident in history (Chernobyl being demoted to second worst).
Now I see nuclear industry as a particularly poorly regulated kind of of toxic chemicals industry.
Operating with very tight profit margin (versus toxic chemicals that don't have nontoxic alternatives) and as such, incapable of affording protection anywhere near that of the toxic chemicals industries. I feel I had been duped. Even ignoring the Fukushima itself - just reading the accidents paint entirely different picture in my mind. A picture of routine violation of protocols and regulations, sporadically resulting in accidents. A picture of plants owners who do not understand the devices they own any more than a regular joe understands his laptop - or his laptop battery. A picture of regulations that are adjusted due to pressure from industry.
It will take a while for the 'pro nuclear' experts to convince me again they have any clue what they are talking about, after what they said on 11th march. Infinite time, really.
Optimists cannot do safety. I am working in the software industry. Optimists are always behind the schedule, always over budget, and always have highly bugged code. I see same in nuclear industry. Optimism, behind schedule, over budget, and screwing up big time, and immense arrogance of people who are so sure they know how stuff works they'll tell stuff on 11th that then turns out to be grossly false. People who can't do elementary calculations (Iodine aerially deposited into #4 spf lol).
I believed in all the safety they claimed before this accident. Not all, but most of it. Now I'm rather pissed I was lied to, and embarrassed I even believed the crooks.

I still believe though that EU's nuclear energy is different. That the designs are less clouded by arrogance. That the safety is not designed by optimists.

NUCENG

What do you think is reaching too far? We are focused on the events at Fukushima which clearly exceeded the conditions in their design basis. The plant wasn't expected to see these conditions of a 9.0 earthquake and a 14+ m tsunami. There is a massive economic loss and significant impact on the lives of the workers and people who live in Japan. So far, the only deaths have been industrial accident to a crane operators and two drownings during the tsunami. Some workers may be getting doses that could affect their long term health. If you want to indict the nuclear industry for the performance at Fukushima daiichi I would direct that effort to researching earthquakes and external flooding events. If the Fukushima design had included those natural phenomena, Fukushima might be back on line now. But there would still have been thousands of Japanese dead and hundreds of thousands displaced.

Joe, I will provide information as truthful and as accurate as I can, based on my knowledge, experience, and training. If I am wrong about something, I will admit it as soon as I know. I will try to provide evidence to support my arguments as well. I can't and won't argue with sarcasm. I won't belittle you and will try to keep my own sarcasm to a simmer. If you want to challenge me, give me the courtesy of a specific argument or question. I have worked on three power uprates. at different plants. What do you want to know?

Dmytry

What I can't get over with is what was told on 11th and how much it differed from reality. However you turn that, it is inexcusable. It is obvious that if I had been anti nuclear "because a basement flood could take a reactor out" before Fukushima I would of been totally ridiculed anywhere as ignorant of the safety systems and redundancy etc, naive, n stuff. (Hell, I could of myself ridiculed someone proposing that!) I had been indeed myself duped into believing all the propaganda, believing in safety, believing that backup generators can be brought on site and be trivially connected right to the pumps bypassing any switchboard, believing that there would be big helicopters to deliver this stuff on site quickly, believing standard voltages and frequencies are used to permit regular backup gens to be used. (That is very much the case in EU from what I know but how I can trust myself not to be duped about that either?)
The fact that it was caused by tsunami is no excuse for the lies (direct, indirect, and lies by omission) that made me believe flooded basement cant possibly result in this.

The European perspective is that: we have specialized accident mitigation equipment despite lacking significant earthquake or tsunami risk (see KHG, Areva has equivalent).
Japanese a: did not have anything equivalent even after Tokaimura criticality incident, b: had extreme reluctance/delay accepting help (obviously, to accept help is to acknowledge that they themselves could of been more prepared than they were), c: got robots on site 37 days after the accident, versus few hours for KHG.
Americans a: uprate their reactors a lot (20%), b: are apologetic for the Japanese unreadiness as if it was normal not to be prepared for disaster flooding a nukeplant basement (here it is not normal at all), c: Japanese are using those puny US military bomb disposal etc bots, not special nuclear accident robotics, which is sort of indicative of US also lacking specialized equipment ala KHG (correct me if I am wrong). (I still believe EU reactors are a lot safer even though I am far less sure in validity of my judgement after being shown I can be duped about reactors elsewhere)

NUCENG

You have every right to question nuclear safety. But if you worked in the industry you would have learned to question it every day, not just when there has been an accident. Have we been perfect, No. At Fukushima they didn't get the earthquake or tsunami design basis correct. You list examples of other accidents and near misses. I could point out many more. But the reason we know about them is that we in the industry try to learn from mistakes and prevent recurrence. Airplane and auto manufacturers have the same profit motive and learn from their accidents as well. You know that more people die in accidents while flying or driving than from nuclear accidents. So how mad are you about that? Are they also crooks? We'd better start building more prisons.

Optimism may not work with safety, but if pessimism is carried to excess we'd still be living in caves with a life expectancy of 30 years. Progress requires a balance of both. If you think the EU approach is safer, you haven't looked up accidents they have had.

Dmytry

Lies about safety, that is what is unforgivable. Nuclear industry flat out lied to create image of a plant that can't be taken out by a basement flood (whatever is the cause). You want it to be specific - a tsunami, that was not predicted, geophysicist's fault. No, it is a general design fault, a really big one. Electrical stuff in basement, inability to power the pumps if that equipment is taken out, etc. Single point of failure - an open door during a flood.

edit: also this attitude, 'have we been perfect'. Right, have you been perfect the plant would of kept running. Have you had common sense, there would have been generators and connection equipment ready for chopper delivery to any plant within hours, connecting to pumps directly. You do not need to predict tsunami to be able to handle it without meltdown. All you need is awareness of extent of own imperfection.

gmax137

I agree completely.

What does that mean? People can lie, an 'industry' cannot. Who lied to you? I have worked in nuclear for over 30 years and I never lied to you.

Dmytry

I based my opinion on the safety on what various people working in the industry say, combined. The end result was - I was deceived into believing that a nuclear power plant cannot be taken out like this by a basement flood, not here, nor anywhere else (except maybe places like iran, north korea, etc) . Not just me, but pretty much everyone I know wouldn't ever have thought it is a possibility. It is equivalent to how nearly everyone in soviet union was deceived regarding safety of RBMK.

edit: what's about you. When you heard basement was flooded - did you think it would result in massive core damage at 3 reactors and fuel fire at SPF #4 ? Did you even suspect they wouldn't be able to power pumps by delivering some generators by chopper or something? Or were you also duped into believing that nuclear reactors are more robust against unexpected? Are you surprised that accident robots have trouble taking radiation readings because camera on one robot can't see dial of radiation monitor carried by another robot? Or does that not surprise you?

Astronuc

What does this rant have to do with "Uprating of older US nuclear plants"?

What do "control rods falling out resulting in criticalities, pressure vessels reshaped after getting bent during annealing, the Tokairmura incident" have to do with Fukushima or Uprating US NPPs? As far as I know, there is no indication of control rods falling out of Fukushima units, their vessels haven't been annealed, and Tokaimura is at another site, and has nothing to do with commercial NPP for power production. The Tokaimura accident was a research project, and obviously they were not following safety procedures of the kind that are mandatory at a commercial NPP.

As for Fukushima, no one here at PF made any guarantees, since we did not know the situation. I don't remember any professional from the nuclear industry here making promises or guarantees about Fukushima.

And none of this has anything to do with uprating US power plants.


As far as I know, there have been no changes to safety limits on US plants. We have done the uprates because of better analysis and better monitoring of the plants.

I heard from one contact that by March 12, his particular utility had already instituted reviews of emergencies procedures and the design bases of all their plants to ensure they wouldn't be caught off-guard like FK. They didn't wait to be told by the NRC or INPO, but rather they were being proactive. As far as I know, they didn't discover any deficiencies.

In addition to supervision by NRC and INPO, US utilities have internal surveillance programs, and they are always identifying areas for improvements.

Dmytry

You don't understand. It is an organizational issue, whenever plants can be uprated or not. Whenever you can trust that the safety evaluations would be carried out accurately. Not a technical issue. It is obvious enough that a plant can technically be uprated. It is less obvious that you aren't doing it like this - the design core probability of accident is say 1 accident in 20 000 core-years, the actual is somewhere better than that, and you're bringing it down to 20 000. Even then, the probability of getting the safety calculations wrong seems much larger than estimated probability of accident, rendering the estimates moot.

Dmytry

for the control rods falling out:
http://search.japantimes.co.jp/cgi-b...0070323a3.html

It's up to OP to decide if my points are relevant when he's forming an opinion whenever he can or can't trust up-rating. My opinion - 20% up-rating cannot be trusted due to the commercial pressure for go-ahead. Sorry, it is not technical. I don't think anyone here has the time (years) to evaluate uprating project in detail by himself to form an opinion on technical grounds.
edit: for the other fail.
http://www.bloomberg.com/news/2011-0...t-reactor.html
The Fukushima is useful as example because it is in a spotlight at the moment - it provides insight in the daily life of a nuclear plant, which was 'chosen' by natural disaster. It may seem totally irrelevant to uprating to you - technically it is - but it provides insight into the 'human factor' involved.

NUCENG

I have spent years working on power uprates at three different plants. And I was not alone. Every project had a core team of about 10 full time engineers covering every engineering discipline, environmental, regulatory, health physics, operations and many other expertise areas. We were supported by contractors, vendors, and the original plant design companies. Every product was independently verified. In addition the project analysis was reviewed by NRC staff so numerous it seemed we were their only project. The final reports were issued for public comment and hearings. NRC staff work was reviewed by the ACRS a gaggle of PhD's who were very knowledgeable about risks and design bases.

This may not help your opinion of us, but about ten years ago I was involved in technical assist reviews at a number of plants PWRs and BWRs. In 3 plants I found exactly the issue that killed Fukushima (i.e., safety related electrical switchgear, batteries, and diesels in turbine building basements that were vulnerable to flooding. These conditions were corrected at those plants by protecting the equipment from internal and external flooding. At one plant I even submitted a contention report to NRC based on evidence that the resident NRC inspectors at that plant had knowledge of that vulnerability without taking action. Those findings and their solutions were published in operating experience reports, industry alerts, and regulatory generic communications. The Japanese had access to those reports. I don't know whether they took action or not. Even if they did and used the design basis tsunami, their actions didn't handle a 14+m surge.

If you find an industry more focused on safety, please let us know and we will learn from them. If you know how to predict the unpredictable, you can become a very rich man. If you just want to be mad and rant about arrogance and stupidity, you will probably be ignored.