Natural Resources committee  We still have more work to do to be able to complete that assessment. We have two challenges that have to be met. One challenge is to get the proper inspection equipment to the location inside the vessel where the leak and corrosion exist. We're producing special tooling to be able to deliver inspection equipment to that location, and we need to complete that inspection.

Natural Resources committee  It's hard to put a fixed date on that, but I would say that it's probably more than a week away. It's probably at least two weeks away at this point.

Natural Resources committee  The sequence is that we need to take the fuel out first and then that allows us to drain the heavy water from the vessel. Excuse me, but in my last answer, when I suggested two weeks, we may have to add that two weeks to the end of the time that we defuel the reactor, and that's a three-to-four-week exercise, which started a week ago.

Natural Resources committee  Mr. Chairman, NRU shut down automatically on May 14 due to a loss of off-site power. A decision was made not to restart due to evidence of a heavy-water leak. The small heavy-water leak, which was the cause of the extended shutdown, continues at about four to five kilograms an hour.

Natural Resources committee  That's correct. A facility like Chalk River has a low chronic level of tritium release, both through the ventilation system and through the liquid effluents that are treated in our waste treatment centre and released. That is correct.

Natural Resources committee  The isotope supply reliability program is a fairly broad program. It involves improvements to equipment and systems and to procedures. It involves long-term planning for succession planning for staffing for the NRU reactor. Currently the majority of the work to implement improvement will be done with the reactor in operation or during normally scheduled maintenance outages.

Natural Resources committee  If I can speak to that, many of the changes that will be made at the NRU reactor and the other isotope production facilities will be done with the NRU in operation. This is actually going to be quite different from the refurbishment of a commercial CANDU reactor in that the work that's being done does not affect the reactor vessel itself or the core materials.

Natural Resources committee  I would give something of a layman's perspective and note the fact that generally tritium has a relatively short stay time in the human body.

Natural Resources committee  First of all, I believe you're mixing several items here. Let me start at the back and say that all of our releases are controlled and monitored and they all fall orders of magnitude below regulatory limits. That's the start. The second piece is that tritium is a radioisotope, it is hazardous, so in the workplace we treat it as a hazardous material.

Natural Resources committee  Yes, that is correct. You're speaking of the latest leak, which occurred this past weekend.

Natural Resources committee  Yes, the total amount of tritium that would have been released as a result of the event on the weekend was initially estimated to be about 18 kilograms, and with more refined calculations we determined that it was in the order of 11 kilograms. That's 11 kilograms of heavy water that would have been released through the ventilation system.

Natural Resources committee  Mr. Chair, the simple answer is that a temporary repair has been done. The section of piping that had a leak, which amounted to two small pinholes, was physically isolated by closing valves to take it out of service and stop the leak. Late yesterday a temporary patch was put over it to assure no leakage until a proper repair can be done.

Natural Resources committee  In the case of this piece of piping, we haven't made a decision on whether we would do the repair within a scheduled maintenance outage or whether we would do the repair online. It isn't urgent to put that equipment back in service. We have duplicate equipment.

Natural Resources committee  I don't actually have a number for that water. I might clarify, from the previous line of questioning, that 47 kilograms of heavy water leaked in December. Of that, a total of 4.5 kilograms evaporated, was released through the NRU stack, and was monitored and recorded. About 14 kilograms of the higher-concentration water was recovered.