siemens - Public Service Commission

4.3 Thermohydraulic And Mechanical Design Of The Reheaters
4.3.1 The Existing And The Proposed Reheater Bundles
In the last 30 years, TEI has been involved in the design and fabrication of reheater
bundles for service in its own line of MSRs, as well as in Westinghouse, G.E. and
Alstom MSRs.
TEI’s design approach is to provide a reheater tube field whose width is greater
than its height as compared to your OEM “standard” reheater, whose height is
larger than its width. The benefits of TEI’s design approach are quite evident in
view of the excessively high pressure differentials across the MSR internals. TEI
proposes to Progress Energy such a wider design, (High Capacity), as the best
suitable for CR-3.
The reasons for such proposed replacement are as follows:
1. The existing bundles reportedly are deficient in performance (TTD and AP)
as compared to the original design heat balance.
2. The existing bundles are, by now, in all likelihood, distorted and may contain
tubes which are damaged and failing. This trend for decay has shown to be
accelerating for older bundles. (The ones in CR-3 are about 20 years old).
3. Continuing maintenance of the existing bundles is costly and time
consuming.
4. The existing bundles, due to their excessively “slim” tube layout, caused an
unacceptable pressure drop, and are susceptible to “lift” during flow spikes
(valve testing).
5. The new High Capacity bundles proposed for replacement at CR-3 are very
effective, and proven to last in hundreds of applications over many years.
6. The High Capacity bundles are of refined ferritic S.S. tubing. They utilize
much higher quality material (restricted chemistry) and contain fins of
premium quality as compared to your existing ones.
7. The High Capacity bundles are designed to maintain their structural form (no
deformations) for the remaining plant life so as to eliminate any future tube
distortion and tube failures.
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