I am a current licensed senior reactor operator.
It’s all about procedure use and adherence, operator fundamentals, and conservative decision making.
As operators we need to be aware of the plant and be capable of recognizing if we are in a situation which needs the reactor shut down...
It’s an interesting way to ask the question. The void coefficient is negative because light water reactors are undermoderated during normal operating conditions, meaning a reduction in moderator density will result in a loss of necessary moderation and a negative impact on reactivity.
In normal operation, the contamination levels in the fuel are less. If you have leaking fuel cladding, you may approach those limits.
The limits are high enough to support some limited fuel leakers. In BWR plants, we’ve even seen some fish mouth type ruptures where local power was suppressed...
A plant is given a guaranteed MW electric output rating when its commissioned or when major maintenance or upgrades alter this rating. The reactor is only rated during licensing activities and is a MW thermal rating.
If your plant is running more efficient than expected, you can exceed 100%...
We talked about this I’m the last emergency procedure committee meeting. At unit 3 they were trying to open safety relief valves to keep the reactor depressurized when HPCI finally stalled out and failed so they could inject seawater. They were trying! The srvs were not opening because battery...
The nrc is not supposed to be promoting the industry. That’s why it was formed and separated from the atomic energy commission.
The industry heavily tried to advertise the SAFER/FLEX program throug the nuclear energy institute. Sadly they weren’t very effective as their YouTube videos barely...
The initial NAIIC report didn’t not see evidence of an SBLOCA between the earthquake and tsunami and this was later confirmed in follow up studies. We do know we saw 36-38 gpm of Reactor recirculation pump seal leakage that developed over several hours (expected design leakage is less than 50...
It’s not really deliberate. It’s just something we maintain. One of the dozens of programs that protect nuclear safety that aren’t even thought about day to day. It’s not really a low profile policy. I mean, what’s the announcement? Business as usual in nuclear plant : )
SBO was outside of the original design basis and nrc regulations were put in place to require adequate coping. Considering that a LOOP is a once in a decade to once in the lifetime of the plant event, then to have all diesels fail and have no onsite power, that’s very low risk so the nrc allowed...
Pct is for LOCA response. The IC/RCIC systems are not for LOCA response although they help with smaller LOCAs.
I do know that quad cities does have a separate safe shutdown pump (400 gpm) in addition to their RCIC and HPCI systems. I believe it’s motor driven but not positive. So it provides...
The owners group emergency procedure committee started on post Fukushima findings right away, and about 3 years later all plants had to issue changes.
Well, all units have some level of core melt, so all we know is seawater injection at that point prevented a liner melt through.
One of the...
The objective is to protect the health and safety of the public first, and prevent core damage second. The priorities have flip flopped on how exactly you do that though. For example, there was a point in time where you took actions to preserve the containment even if it meant losing core...
A station blackout is only a 4-6 hour event. And it’s a specific event based mitigation guideline, not an emergency operating procedure. Your EOPs are always used, even in a station blackout. However if you were in an SBO you would use those procedures in tandem with the EOPs. The EOPs don’t...
First up, your comment that the EPGs were short sighted is not informed. I know the men (Ken Ross from KLR, Bill Williamson from TVA, and others) who created the BWR symptomatic EPGs. The EPGs were separated into the EOPs for all events up until core damage, and SAGs (Severe accident...
We need to clear up this misconception about what happened at unit 1.First off, the operators performed all required actions in accordance with the BWR Owners Group Emergency Procedure Guidlines (EPGs).
You have to simultaneously stabilize level and pressure, then commence a controlled...