My colleagues have been discussing the need for Re-Review of those assumptions that form the Bases upon which they are licensed. These include seismic activity (San Onofre), and other factors which current and future nuclear power plants are licensed. The following discussion shows that we desperately need to Review Multiple Windowed Events who's Aggregate Effects could lead to a Fukushima.
http://www3.nhk.or.jp/daily/english/10_26.html
The operator of the damaged Fukushima Daiichi nuclear plant says radiation levels in one of the reactor buildings remain too high for workers to do their jobs.
Tokyo Electric Power Company, or TEPCO, sent 9 workers into the No.3 reactor building for about 20 minutes on Thursday, in a bid to start stabilizing the reactor.
The utility plans to inject nitrogen gas into the containment vessel to prevent accumulated hydrogen from causing an explosion. It also intends to install a system to cool the reactor with circulating water.
The workers withdrew after measuring radiation of 100 millisieverts per hour near the reactor's containment vessel.
TEPCO says it intended to limit the workers' exposure to below 5 millisieverts per hour. But as all 9 received higher doses, it has suspended work while considering a course of action.
Friday, June 10, 2011 20:23
+0900 (JST)
This is a true conundrum. This simple task is extremely important to accomplish, however as we have discussed, the Radiation Fields make all work more complicated.
Specifically, the workers need to attach a Nitrogen Hose to a valve very close to the Reactor Containment Vessel.
ο - This task will allow Nitrogen to inert Containment in order to prevent another Hydrogen Explosion.
ο - In order to route the hose through the maze of pipes and wreckage, workers need to spend time in the Radiation Fields.
ο - The Fields they are encountering are Deadly. 100 milliSieverts = 10,000 milliRem which is 10 Rem/Hour (Wholebody Dose)
ο - The Japanese Emergency Radiation Worker Dose Wholebody Limit Raised to 25 Rem. This is not per Year, it is a Total Dose for an Emergency Activity. (we have a similar measure in the United States and a 50 Rem Total for a Life Saving Measure) - This is a mere 2 and a half hour Stay Time before over exposure occurs! This also assumes that there is such a thing as a "Safe Limit" of exposure.
ο There are by no means enough qualified, trained, nuclear professionals in Japan or just about anywhere else I can think of to control, contain, repair, mitigate, or otherwise restore the Fukushima site.
ο Fukushima workers' exposure tops 650mSV http://www3.nhk.or.jp/daily/english/10_33.html
o Detailed tests have found that 2 workers who were exposed to radiation at the crippled Fukushima nuclear plant received doses of more than twice the government-mandated emergency limit.
o The men in their 30s and 40s were each found in early June to have been exposed to over 250 millisieverts -- the new higher limit for exposure that the government introduced after problems began at the Fukushima Daiichi plant.
o The National Institute of Radiological Sciences conducted 2 more rounds of detailed tests to measure the amount of radioactive iodine and cesium the 2 men could have inhaled.
o After analyzing the men's work shifts since the March 11th disaster, the Institute concluded that the man in his 30s was exposed to 678 millisieverts, and the man in his 40s, 643 millisieverts. Internal exposure accounted for more than 80 percent of the figures.
o The 2 men were on duty in the central control rooms of reactors No.3 and No.4. They have told the health and labor ministry that they don't remember whether they wore protective masks or not when a hydrogen explosion occurred at the No.1 reactor on March 12th.
o The Institute said separately that it is conducting detailed tests on another Fukushima worker in his 50s, who could have received a radiation dose above the emergency limit.
Reading this carefully, we don't know how much Radioactive Dose, the two men actually received. This is because they are using a Crude Measurement of the workers' Whole body Exposure. This measurement does NOT account for the CEDE (Committed Effective Dose Equivalent), which is a more accurate determination of which organ has received a Dose. When added to the CEDE, we will learn that these workers have been exposed to much more radiation than currently believed (Total Effective Dose Equivalent - TEDE)
ο - 650 milliSieverts is 65,000 milli Rem which is 65 Rem. This is more than twice the "allowable safe Emergency Dose" permitted by government.
ο - It is unknown how much Internal Dose these men received since March 11.
Pray for their health. There are NO replacements for their knowledge, experience, and capabilities.
ο - One Event of sufficient Duration to prevent Emergency On-Site Power to keep running after Loss of Offsite Power or,
ο - Two or More Events, within a fairly tight Time Frame that also prevent Maintaining On-Site Power with Loss of Offsite Power
ο - Flooding can take away Offsite Power, based on its Duration and Location BUT it may remove
o -
On-Site Power Supplies such as Emergency Diesel Generators, Electrical
Power Distribution (even if the Diesels are OK, you can't get the power to the
equipment with damaged electrical
buses), flooding may submerge Critical Cooling Water Pumps.
v Right Now, the Fort Calhoun Nuclear Power Plant is working to Prevent Loss of those Cooling Water Pumps.
v !!!!Low-level emergency declared at nuclear power plant Fort Calhoun Nebraska http://journalstar.com/news/state-and-regional/nebraska/article_d2b85355-0bc8-5733-b3ad-6997395d23a6.html
v The Omaha Public Power District on Monday declared a low-level emergency at its Fort Calhoun Nuclear Station due to rising Missouri River waters.
v This plant is in Nebraska and is in an Unusual Event - See Notification Event Number: 46929 ( http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2011/20110606en.html )
v Aerial View - http://maps.google.com/?ie=UTF8&t=k&ll=41.519704,-96.078819&spn=0.005575,0.008669&z=17
IF the flooding worsens, then there is cause for alarm. The Plant's emergency procedures REQUIRE such Notification in order to prepare. However, if flooding does remove Cooling Pumps (at the River) OR Diesel's ability to provide Power AND there is another event:
ο - Wild Fire under Power Lines?
ο - Coronal Mass Ejection?
ο - How about a FIRE in the On-Site Electrical Power System !!!!!
JUNE 8 Event Number 46932 - They ACTUALLY LOST SPENT FUEL POOL COOLING for a short Duration.
o FIRE
IN THE WEST SWITCHGEAR ROOM
o "At
0940 CDT an alert (HA 2, EAL 1) for operating Mode less than 210 degrees F
[was] declared for a fire affecting the operability of plant safety systems
required to establish or maintain safe shutdown. Time of fire was 0930 CDT.
Control room received multiple alarms [and] 480 V bus 1B4A amps were observed
to be oscillating. Bus 1B4A was secured [and] buses 1B3A and 1B3A-4A were lost.
Halon activated properly. [At] 0956 CDT all notifications to applicable
personnel were completed. At 1000 CDT 4160v buses 1A2 / 1A4 were secured to
facilitate fire fighting. Spent fuel pool cooling was lost [as a result of the
de-energized busses and the licensee] entered AOP-36 for loss of SFP cooling.
Heat up rate [was] determined by STA. Current time to boil for SFP is 88.3 hrs.
Spent fuel pool cooling is currently back in service. This condition is being
reported pursuant to 10 CFR 50.72(a)(1)(i) for declaration of an emergency
class specified in the licensee's approved emergency plan."
o Plant
was in AOP-1 for flood mitigation. The fire is not believed to be flood
related. Plant remains in AOP-1.
o At
about 0930 CDT the licensee noted fire in the west switchgear room. The fire
brigade responded and found a room filled with smoke but no active fire. Halon
did discharge in the room. At 0956 CDT, offsite assistance was called and Blair
Fire Department responded to the site. Blair Fire Department confirmed no
active fire in the switchgear room. All offsite power remained available as
well as the emergency diesel generators if needed. The licensee is currently
attempting to ventilate the room. A thorough inspection of the affected area
and determine the caused of the electrical fault will be facilitated once the
room has been fully ventilated.
o The
licensee has notified appropriate State and local government. The licensee
notified the NRC Resident Inspector. A media or press release is also
anticipated.
o *
* * UPDATE FROM ROBERT KROS TO HOWIE CROUCH AT 1313 EDT ON 6/7/2011 * * *
o "Entered
Alert for HA 3, EAL 1 access to a vital area (Switchgear and Turbine Building
basement) due to toxic gases present from the fire in the West Switchgear
room."
o The
licensee entered HA 3 at 1144 CDT. Their exit criteria is that the switchgear
room is cleared for unimpeded access.
o The
licensee has notified the NRC Resident Inspector. Notified the R4IRC (Kennedy)
o *
* * UPDATE FROM ROBERT KROS TO WILLIAM HUFFMAN 1421 EDT ON 6/7/11 * * *
o At
1315 CDT, Fort Calhoun Nuclear Station has exited Alert HA 2, EAL. It has been
confirmed that no fire remained in the vital area. Plant shutdown cooling
remained in-service and spent fuel pool cooling was restored and temperature
verified to be lowering. The licensee has also exited Alert HA 3, EAL 1 after
it was confirmed that the environmental conditions from the event and
associated Halon discharge does not affect the ability to safely operate or
safely shutdown the reactor due to being in Mode 5 and shutdown cooling
remaining in-service. Fort Calhoun remains in Unusual Event HU 1, EAL 5 for
River Level greater than 1004' elevation as reported under EN #46929.
o The
licensee has notified appropriate State and local government. The licensee has
also notified the NRC Resident Inspector. The NRC made notifications of the
event termination to DHS, FEMA, DOE HHS and USDA
Cooper Nuclear Plant and other energy Plants Preparing for High-Water http://www.newspressnow.com/localnews/28178031/detail.html
Similar situation for this Omaha Nebraska Plant - See Event Event Number: 46941 (http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2011/20110610en.html ) Dated Today!
ο "Additionally, the current and projected flooding conditions of the Missouri River high river levels have resulted in some media inquiries regarding potential changes in plant operation. Public information personnel and Management have responded to these inquiries with information on the impact of river level and preparations for additional actions should conditions warrant additional protective actions.
ο "Current river level is approximately 896 ft. MSL, three feet below the elevation which requires declaration of a NOUE, and approximately 4.8 feet below the crest of the 1993 flood, which was the highest flood recorded at the site. Current river elevation is 7 feet below grade elevation. A press release is not planned at this time. River level is currently projected to be 897.5 ft by Tuesday 6/14.
ο "Current river level is characterized as Moderate Flooding by the National Weather Service. There are currently no operational problems due to river conditions.
Two Nebraska Plants, near Omaha getting Offsite-Power from the Same Grid, on the Same River. We not only have to consider responding to the needs of a plant in need, but we have to prepare for Multiple Challenges for co-located plants. This is an interesting dimension.
Lastly - The Prairie Island Nuclear Plant in Minnesota had to declare its Emergency Diesels Out of Service because of HIGH OUTSIDE AIR TEMP
This should be enough for now. . . . Chris in Delaware