The dry out criterion (MCPR) has been calculated for the most limiting H2-events for Forsmarks unit 2 and 3, at operating points that are normally not analyzed before each cycle. The operating points that normally are regarded as the ones with the lowest margin to dry out are the ones where the thermal power is the highest at agiven recirculation flow. This report shows that this is not the case for Forsmark 3. MCPR-values at partial power operating points are higher for the limiting case inside rather than on the boundary of the region of operation. It is therefore recommended that the method for determining the dry out criterion for Forsmark 3 is revised to account for this effect. It is recommended that the number of operating points studied is increased or that a conservative value is established of how large the effect of operating point can have on MCPR. This conclusion does not, however, apply to Forsmark 2 where the most limiting case has its largest MCPR-values at the boundary. The effect on MCPR of changing the A/B- and scram-runback ramps of the recirculation pumps for Forsmark 3 has also been calculated. The alternative rampused was found to give a decrease in the MCPR value between about 20-30 units, depending on fuel type, at partial power operation. The full power limit would not change because the most limiting case at full power is not dependent on the runback ramp of the recirculation pumps.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-146263 |
| Date | January 2011 |
| Creators | Isaksson, Jonas |
| Publisher | Uppsala universitet, Tillämpad kärnfysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | Swedish |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | UPTEC F, 1401-5757 ; 11001 |
Page generated in 0.0022 seconds