Das pharmakologische Profil von Sildenafil zeigt neben der PDE5-Inhibition auch eine geringe Aktivität an der PDE6 in der Retina. Dies erklärt visuelle Nebenwirkungen wie Farbsehstörungen, die gelegentlich auftreten. Die orale Bioverfügbarkeit beträgt etwa 40 %, mit einer hohen Bindung an Plasmaproteine. Das Verteilungsvolumen ist groß, sodass die Substanz rasch in verschiedene Gewebe gelangt. Die Metabolisierung erfolgt hepatisch und produziert einen aktiven Metaboliten, der die pharmakologische Wirkung ergänzt. Nebenwirkungen sind dosisabhängig und umfassen Kopfschmerzen, Hautrötung und Dyspepsie. Bei Vergleichen innerhalb der Wirkstoffklasse wird viagra original regelmäßig als Beispiel für eine Substanz mit schneller, aber kurzzeitiger Wirkung aufgeführt.

What is killing the nuclear renaissance?

What is killing the Nuclear
Renaissance?
10th IAEE European Conference
Steve Thomas ([email protected])
PSIRU (), Business School
University of Greenwich
2. Shortages of skills and manufacturing capability; 3. Unnecessary delays in licensing and planning; The US programme
• Announced 2001, first plants to be in service by 2010 but orders not now likely before 2012 • Assumed Gen III+ plants economic but subsidies • Range of subsidies offered but loan guarantees key • Initially expected to cover 80% of debt, 50% of total cost. Now expected to cover 80% of total cost • Originally subsidies for 6 units, now 15 (5 designs) • Expected cost up from $1000/kW to >$5000/kW so • 31 units proposed but many not likely to proceed The UK programme
• Gen III+ plants not assumed to be economic but government committed not to offer subsidies • 4 designs examined by NII but 2 withdrawn and • EDF and RWE/E.ON both expecting to build 4 units • EDF will choose EPR but RWE/E.ON have not • Now lobbying by utilities for subsidies, eg a levy or Why no orders?
• Financial crisis? Will make finance harder but
• Shortages of skills and manufacturing capability?
If Renaissance does start, will inhibit it but not preventing orders now • Unnecessary delays in licensing and planning?
Original schedules optimistic but no reason for regulators to delay for no good reason Design deficiencies: EPR?
• Offered by Areva NP (Areva/Siemens) and derived • Certified France, Finland, under review USA, UK • Chosen by EDF for UK & 6 units proposed for USA • Under construction Finland, France, on order China • Olkiluoto > 3 years late and 50-60% over budget • Flamanville > 20% over budget after 2 years work • Instrumentation & control problems: Finnish regulator threatening not to allow start-up and UK regulator not allowing certification Design deficiencies: AP-1000?
• Offered by Toshiba/Westinghouse and scaled up • AP-600 certified by NRC 1997 after 5 years but no • Certified by US (2006) after 5 more years • Revisions to design submitted after approval and not • Under review in UK and reports of tension between Design deficiencies: ESBWR?
• Offered by GE-Hitachi & probably most radical • Good progress with NRC but no review outside • 6 units proposed for USA but all in doubt • Exelon said it wanted ‘more mature designs’ that offered ‘more certain cost structures and better availability of information.’ Design deficiencies: ABWR?
• Offered by GE-Hitachi & Toshiba in competition • First ordered 1989, certified by NRC 1997 • 4 units in service and 2 under construction in Japan • Interest from India but no interest in Europe or • NRC approval expires 2012: what will be required for renewal (aircraft protection, instrumentation)? • Will this make it gen III+ (cf AP-1000 experience)? Design deficiencies: APWR?
• Late start with NRC, earlier version reviewed by • 30 years of development but still no orders • Is Mitsubishi experienced enough? No experience Escalating costs
• Up to 2002, nuclear industry predicted construction • 2009: Ontario tenders $6700/kW and $10000/kW • Cost estimates before construction always an under- • If cost pass-through to consumers not guaranteed, • Loan guarantees protect vendors & banks and allow • They don’t protect utilities from bankruptcy or from • If costs over-run, borrowing will be very expensive • Estimated default rate for USA 50% so expensive to Conclusions
• Scale of political support unprecedented • Pro: decisions on planning, regulatory approval and • Con: vulnerable to changes of government • If fundamentals of technology and economics are • Outcome may be a handful of heavily subsidised units in USA, one or two loss-making plants in UK • What would be the opportunity cost for renewables Déjà Vu?
• In 60s, vendors kick-started ordering with 12 grossly underpriced orders that nearly bankrupted them • Designs were scaled up too fast and economies made on materials to bail out the economics • These had consequences on reliability for decades • Is the $1000/kW claim forcing vendors to make • Now mistakes will be paid for by utilities, vendors, banks and taxpayers if loan guarantees are offered

Source: http://www.aaee.at/2009-IAEE/uploads/presentations_iaee09/P_thomas_stephen.pdf