ScribbleLive

@lillymunster yes, i said that i cannot see from your docs that (additional) drillings have been made lately.

@Edano I couldn't tell either by that statement if they refer to the previous drilling or new drilling.

@Edano the document with that comment, Now that I have it unlocked I translated various parts that were not obvious what they were. The remainder reviews old news.

@lillymunster okay, then it refers to past events, maybe a summary.

@Elaine, this doc has some minor INES level events at a reactor in Sweden. www.ecology.at

greetings to all

@dean hi dean ! is it normal (possible) that core water levels falls under fuel top on cold shutdown ?

@Edano, I would say that if the fuel is removed in a normal planned shutdown the water level can be taken that low.. or lower,,,, if there is fuel in the core absolutely not "unless" there is an issue

@dean forget my questions ! it is a conversion error, i just saw it.

@ Pedro... this statement , if I read it correctly is breaking the law.... I can't believe they would say this...
""The operator has decided to shut down the NPP and cut the connection to the grid as a preventive measure, before automatic shutdown would be enforced by the safety systems, adds the CSN in a press release. The organism assures that "the safety systems have operated correctly".".

@Edano.. it is possible and has either come close or actually happened where the water level in the vessel has been accidently taken that low... PEOPLE ERROR

@dean this all seemed related to all those system testing and shutdowns.

Dean - is the residual heat removal system part of the emergency systems or part of the normal maintenance systems to operate the reactor? They seem to be messing with them quite a bit at 5-6

From 10:03 am to 10:43 am on August 8, we stopped the residual heat removal system
pump (D) in order to switch the power source of the pump (C) as well as conducting its
commissioning (C)
- In order to repair the outlet valve of Unit 5 residual heat removal system seawater
pump (D), from 9:45 am to 10:42 am, September 26, we switched the seawater
pump from B system (permanently installed) to A system (temporarily installed).

@dean are those RHR units intended to operate for months on end?

Low Pressure Emergency Core Cooling Systems
The low pressure emergency core cooling systems consist of two separate and independent systems, the
core spray system and the low pressure coolant injection (LPCI) mode of the residual heat removal
system. The core spray system consists of two separate and independent pumping loops, each capable
of pumping water from the suppression pool into the reactor vessel. Core cooling is accomplished by
spraying water on top of the fuel assemblies.
The low pressure coolant injection mode of the residual heat removal system provides makeup water to
the reactor vessel for core cooling under loss of coolant accident conditions. The residual heat removal
system is a multipurpose system with several operational modes, each utilizing the same major pieces
of equipment. The low pressure coolant injection mode is the dominant mode and normal valve lineup
configuration of the residual heat removal system. The low pressure coolant injection mode operates
automatically to restore and, if necessary, maintain the reactor vessel coolant inventory to preclude fuel
cladding temperatures in excess of 2200EF. During low pressure coolant injection operation, the residual
heat removal pumps take water from the suppression pool and discharge to the reactor vessel.

brb

@ lilly.. exactly.. it sounds as if the main RHR system and supporting sea water system was damaged so the new switching of power and temporary sea water system was put in place

@ lilly.. I doubt that the RHR has the capacity to remove much more than the "residual" heat after the decay heat has all been removed and the temps are lower... I'm sure the RHR system would have been overwhelmed and the heat exchanger could have boiled from the heat..

@ Pedro, breaking the law may be too rough,,, the intent it seemed was for the utility plant to remove the nuclear plant from the electrical grid system with the idea of bypassing the safety shutdown systems