Reed Reactor Visitor Information

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Visits and Tours

School visits can be very flexible. We usually include a one hour tour where we cover some basic nuclear science, why Reed has a reactor, and what we use the reactor for. We also run the reactor at full power so the students can see the Cherenkov radiation (blue glow).

In addition to the tour we can run some labs with the students. These labs require no prior knowledge and students often get a lot out of them. A tour is normally limited to 12 people, but 24 can be accomodated with enough planning.

Visits and tours must be arranged at least a week before the planned date. Either email us at reactor@reed.edu or call (503) 777-7222. We meet visiting groups in the Chemistry Building Lobby.

Directions to Reed College can be found here and a campus map can be found here. The Chemistry Building is on the east side of campus, so the east parking lot is closest, but it normally fills up by 10 am.

Labs and Demonstrations

These are the labs we do most often. Each takes about 45 minutes.

Detecting Radiation

We place some radioactive material (most of it naturally occurring, like salt substitutes, fiestaware, lantern mantels, rocks, etc.) under a piece of paper and have the students use radiation monitors to discover where it is. Then we uncover it and discuss what each one is, what is causing the radioaction, etc. We also discuss the different types of radiation—alpha, beta, gamma—and demonstrate some of the properties of each.

Half Life

We take a material with a short half life and have the students take measurements of the activity. When they plot the data they get a lovely exponential and can determine the half life of the material.

Time, Distance, Shielding

We use this lab to demonstrate the basic principles of radiation protection.

Neutron Activation Analysis

Here we take samples that have been irradiated in the reactor and look for trace elements in them. This involves looking at spectra on the computer with some software we have. This is our main area of research.

Each lab works best with 6-12 students, and we can run as many as two in parallel with the reactor tour. If there are fewer than 10 students, we can do just a tour (1 hour), or we can do a tour and then a lab (~2 hours). If there are more than 12 but fewer than 24, half can do the lab with the other half in the tour. The two halves swap when they are done for a total of about two hours. With more students we can rotate through the labs (~3 hours), but multiple visits are preferred in such cases.

We have over two dozen student operators at Reed who run most of the labs. It's nice to have the interaction with the Reed students.

[ Visits and Tours | Labs and Demonstrations | Sample Preparation Instructions ]

Sample Preparation Instructions

This provides guidelines for preparing samples for routine irradiation at the Reed Reactor Facility. To request and schedule NAA for these samples, please fill out and submit this form.

Equipment which may be needed

5/8 dram polyethylene vials (called small inner vials in this procedure)
2 dram polyethylene vials (called large outer vials in this procedure)
ethanol, methanol, or other cleaning agent approved by the director
disposable gloves
plastic tweezers to hold the vials
a diamond scribe
a permanent ink marker
soldering gun (which has never been used on metal) to heat seal polyethylene vials
micro-pipette and appropriate sized tips (for liquid samples)
large Kim-Wipes or equivalent
High precision balance
Western Family brand sandwich bags
other containers approved by the director

The following materials need special approval before irradiation

samples containing elemental mercury, or substances where mercury is a major component
material containing more the 1 mg of uranium or thorium per sample container
samples containing materials which are classified as flammable, water reactive, or corrosive. If approved, such experiments must at minimum be doubly encapsulated.
organic solvents and other potentially unstable chemicals (even if not flammable). Evaluation of the potential to off-gas, sublime, volatilize or produce aerosols may be required. If approved, such experiments must at minimum be doubly encapsulated.
samples containing or irradiated in association with more than trace amounts of elements with large neutron-absorption cross sections, including Cd, In, and B. An assessment of the reactivity effect, or the reactivity effect of previously run similar samples, may be required.
materials which, for any reason, cannot be encapsulated.
Explosive materials may not be irradiated under any circumstances.
No experiment shall be performed which may lead to the failure of a fuel element.

Cleaning Sample Vials

Note: If measurement of the mass is necessary for your experiment, clean the vials at least one hour before preparing your samples. The samples and inner polyvials should be handled with clean plastic tweezers, gloves, and other similar clean surfaces to ensure that samples are not contaminated by material on hands, metal tweezers, or other elements from the environment.

For trace analysis all work should be performed in a laminar flow hood if it is available. Turn on the hood about 20 minutes before starting work. Clean a beaker of at least 400 mL capacity. Rinse the beaker at least twice with the purest water available and with pure ethanol, then fill it about half full with pure ethanol. Methanol and acetone are both acceptable substitutes for ethanol. Place a Kim-Wipe down on your work surface; be careful not to touch the side that is face up. Clean all of your plastic vials and pipette tips by immersing them in batches into the ethanol in the beaker. Also clean the gripping end of a pair of plastic tongs. Using the clean plastic tongs, agitate the vials. They should soak for a minimum of thirty seconds. Do not leave the vials immersed for long periods of time since they will discolor.

Remove the vials and pipette tips one at a time with the tongs. Allow the excess ethanol to drip back into the beaker. Place the vials and pipette tips on the clean Kim-Wipe. Wash your other tools at this time. If at any time the ethanol becomes visibly dirty dispose of it and use fresh ethanol. Allow the vials to air dry for at least an hour before weighing. Pipette tips may take longer.

Notes about sample containers
Only materials which have been tested in the reactor can be used to hold your samples. Usually you will be provided with high purity polyethylene vials. Do not use polyvinyl chloride (PVC) vials; chlorine activates very well and so vials made of PVC become highly radioactive. If you wish to use any other material (including plastic bags) you may arrange to have it tested first. At the time of this writing only Western Family brand sandwich bags are tested as safe for use in the reactor. Many plastics are made by metal catalysis and some have enough metal in them to become quite radioactive.

Preparing Your Work Area

It is very important to avoid contamination of samples and standards with anything that you don't want to measure. Dirt, dust, and fingerprints all will contaminate a sample. A clean work area helps prevent contamination. It should be cleaned at the time you use it. Do not assume that anything is clean. Clean all non paper surfaces and tools with alcohol (ethanol or methanol). Wear disposable gloves while cleaning to avoid spreading salt from your fingerprints around your work space and onto your tools. Avoid working on metal surfaces or surfaces painted with paints that are dissolved by alcohol or water. Clean absorbent paper, clean plastic, clean Formica or resin top tables are the best work surfaces. Absorbent paper can be changed quickly if you spill something. Change your gloves frequently. If you rub your nose or scratch your head it's time to change your gloves.

Weighing And Sealing the Sample

Weighing is not required if the irradiation is designed only to determine content, not concentration. Do not use the balance unless you have been shown how previously. Wear gloves while you handle the vials; do not use metal tools unless they are coated with plastic. Weigh the cleaned empty small inner vial and record its weight. Fill the small vial about 3/4 full with sample material and close it. Do not spill sample on the outside of the vial. If you spill any, wash the outside of the vial with alcohol and let it dry before proceeding. Do not clip the tabs yet! Now weigh the vial with the sample in it; record that weight. Clip the tabs from the vial. If you have a diamond scribe, etch a sample number on the vial. Do not use ink! If the sample is liquid, seal the small vial with a clean soldering iron. A clean soldering iron is one which has not been used on anything other than plastic vials. Soldering should occur under a functioning hood, since inhaling burning plastic is both unpleasant and unhealthy.

After sealing, rinse the outside of the small inner vial with ethanol and allow it to air dry. Rinse the large outer polyvial with ethanol and allow it to dry. Place the inner vial inside the outer vial, close the lid, and label the outer vial with a permanent marker. Labels should include the experimenter's initials and institution. For example, sample #1 from John Peter Doe at Portland State University should be labeled PSUJPD1. Set it aside in a clean place. The outer vial need not be washed on the outside if the sample will be transferred after irradiation, and may likewise be handled with bare hands. Nevertheless, keeping the outer vial clean is desirable in minimizing contamination after irradiation. If double encapsulation is necessary, heat seal the outer vial. When in doubt, seal the outer vial, but unless sealing is required by procedure, it unnecessarily forces the person transferring the samples to handle them for a longer period of time.

If the sample will not fit in the small inner vial, seal it in the outer vial, following the weighing procedure described above. The outer vial should be sealed. If desired, Western Family brand sandwhich bags may be sealed around the outer vial to prevent leaking. Samples which will not fit into an large vial shall be discussed with the director before irradiation.

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