New NUF Study Material

[Rennhack]

I'm working on making some new NUF study material for the site.  To include new abreviated stufy guides, and new practice tests.  Below is a sample of an abreviated study guide for RP-2 Radiation And Contamination

Noble Gas & Fission Products
•   Fission product activity in reactor coolant can result from fuel rod/element cladding failure/ defects/impurities and is a major category of plant radiation source production during shutdown maintenance.
•   Monitoring reactor coolant fission product activity provides the most accurate determine if there has been a fuel element cladding failure on a fuel rod during normal operations.
•   Fission products are the most abundant during reactor plant power operations.
•   One contributor to reactor coolant gaseous activity during power operations is Tritium, shortly after the reactor is shutdown in a PWR is Xenon (Xe) 133.
•   Krypton (Kr) 85, Kr-87, Sr-90. I-131, Xe-133, and Cs-137 are all fission products.
•   Noble gases such as Krypton and Xenon are a major source of activity in a PWR & BWR main steam line and are normally removed from the reactor coolant by using/venting to the Gaseous Radwaste System, the environment, and using a Degasifier.
•   Halogens such as iodine are normally removed from the reactor coolant by using purification ion exchange.

Activation / Corrosion Products
•   Neutron activation of reactor coolant corrosion products is a method (major category) of plant radiation source production & radiation exposure during shutdown maintenance.
•   The Reason why Stellite is a Health Physics problem/ radiological hazard in a nuclear environment is because Stellite contains a high percentage of Cobalt (Co) 59 which becomes highly radioactive Co-60 when activated via neutron bombardment. Stellite material is used in reactor parts and components in the reactor coolant system.
•   Co-60, an activated corrosion product, decays producing two high energy-gammas 100% of the time and is a major contributor of reactor coolant activity/dose rates in a nuclear power plant.
•   Stellite valve seating surfaces is NOT a source of fission products in the plant systems (It's an activation product).
•   Ni-58 is a major component of stainless steel and Inconel and when activated produces Co-58 which is an activated corrosion product and a major contributor to the reactor coolant activity level/dose Rates.
•   Manganese (Mn) 54 and Iron 59 are activated corrosion products.

Other
•   Good reason for performing decontamination: Reduces chances of ingestion, Reduces the need for protective clothing, Exposure reduction, and Minimize airborne activity levels.
•   Potential sources of radioactive airborne contamination: Failure of HEPA filter, Welding on radioactive components/ systems, Leak or venting of reactor primary coolant system, Breach of a containment system (i.e., glove box, tent, etc.), and Suspension of loose surface contamination and radioactive spills.
•   Nitrogen (N) 16 is the primary source of radiation in a Boiling Water Reactor (BWR)  main steam line during normal operations, however, it is not a problem immediately after shutdown.
•   Sufficient delay time must be taken in the design of sampling lines to assure decay to negligible levels before the coolant reaches the sample point for N-16.
•   Soluble metal ions such as cesium and barium are normally removed from the reactor coolant by using purification ion exchange.
•   Ar-41 contributes to post shutdown dose rates 5 minutes after shutdown.
•   Activated corrosion products and fission product activity are major sources of plant radiation exposure during shutdown.

Comments and corrections are always welcome.

[techtoolong]

Thanks for all of your help.

[Laundry Man]

Mike,
Granted I haven't taken that test in many years, but the ion exchange sounds right on.  I still remember teaching my techs that same concept.  Very nice of you to update the information.
LM

[AaronBuchanan]

Thanks for the help, was referred here by an instructor, registered to take the quiz, and this place is now on my fav's. Throw everything you got at us on the quiz, we need it right now...

[littletommy]

Anyone have a short, understandable explanation of how a GM detector would respond to N-16 gammas compared to the same fluence of gammas at the energy at which the meter was calibrated (say 662 kev)?

[GLW]

Anyone have a short, understandable explanation of how a GM detector would respond to N-16 gammas compared to the same fluence of gammas at the energy at which the meter was calibrated (say 662 kev)?

yeah, this guy,...

https://ehs.berkeley.edu/sites/default/files/lines-of-services/radiation-safety/G-M_pancake_detectors.pdf

you really should read it,...

[Rennhack]

yeah, this guy,...

https://ehs.berkeley.edu/sites/default/files/lines-of-services/radiation-safety/G-M_pancake_detectors.pdf

you really should read it,...

Great paper.  What it says is "It would respond about the same."

[Marlin]

yeah, this guy,...

https://ehs.berkeley.edu/sites/default/files/lines-of-services/radiation-safety/G-M_pancake_detectors.pdf

you really should read it,...

I like the paper but I do not know of many friskers calibrated to 662 kev gammas (cesium). I think he is asking about dose rate meters I can't imagine a situation that I would use a frisker in an N-16 flux (6000 kev) I have used friskers to ballpark dose, heck the Navy even taught us a thumb rule for it 1200 to 1500 cpm for 1 mr/hr (Co-60 1000 kev). Dose rate GM detectors have compensating shields which change the response. The flatest GM meter over the span of 600 to 6000 kev was the teletector (6112 analog) if I remember right and it had a compensating shield.

My    through the cobwebs of a couple of decades ago.

[Rennhack]

How about "Depending on the tube, between 1:1 and 1:2 ratio."?

https://hps.org/hpspublications/articles/allard.html

Ratio of N-16 Gamma Response Relative to Cs-137
GM Tube    Ratio    Comments
N1002/8767    1.88    Through mica window.
N1002/BNC    1.90    Through mica window.
N1003    1.96    Through mica window.
N201    1.71    Through 0.047" SS wall.
N205    1.90    Through 0.010" SS wall.
N210/BNC    1.58    Through 0.109" SS wall.
H220/7840    1.90    Through mica window.
N107    1.61    Through 30 mg/sq.cm SS wall.
N112    1.65    Through 30 mg/sq.cm SS wall.
N114    1.73    Through 30 mg/sq.cm SS wall.
N115-1    1.09    Through 80 mg/sq.cm SS wall.
N115-1S1    1.42    Through 80 mg/sq.cm SS wall with high Z filter.
N116-1    1.24    Through 80 mg/sq.cm SS wall.
N116-1SE    1.63    Through 80 mg/sq.cm SS wall with high Z filter.
N117-1    1.74    Through 30 mg/sq.cm SS wall.
N1l7-1S    1.73    Through 30 mg/sq.cm SS wall with high Z filter.
N118-1    1.03    Through 120 mg/sq.cm SS wall.
N118-1S    1.49    Through 120 mg/sq.cm SS wall with high Z filter.
N302    1.76    Through 0.020" SS wall.
N305    1.82    Through 0.010" SS wall.
N305S    1.99    Through 0.010" SS wall with high Z filter.
NP315-6    1.52    Through 0.020" SS wall, platinum plated inside.
NP334-6    1.48    Through 0.012" SS wall, platinum plated inside.
NP358-6    1.69    Through 0.009" SS wall, platinum plated inside.

[hamsamich]

GLW excellent read.  Cleared up some EC misconceptions I had.....

[hamsamich]

I don't think the friskers are calibrated with gammas.  But they will react to gamma.  I think his 450% curve is based on just taking a frisker and making a KEV gamma response curve based on 662 keV gammas to have a reference.  662 gamma equals one.  just because.