ML19221A470
| ML19221A470 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/08/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | Harold Denton, Mattson R, Stello V Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19221A466 | List: |
| References | |
| NUDOCS 7905230053 | |
| Download: ML19221A470 (5) | |
Text
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NOTE T0:
H. Denton V.
Stello R. Mattson FROM:
NRR TECHNI CAL REVIEW TEAM Westinghouse is proposing to build a DHR system to serve as a backup to the existing DHR system that would be operative in approximately 15 days.
This system would at best be of the same quality of the existing system and would not preclude scakage since flanged connections and pumps with mechanical seals would be used.
We have reviewed the proposed system design and suggest that it be modified to provide as leak tight a system as possible, This would require:
welding of flanged connections pressurizing between double gland valve seals sealed pump (if available)
This alternate approach could take 5 to 10 days longer. provides the pros and cons of the designs.
Enclosure 2 provides acceptable dose limits for Appendix ! and Part 20.
It is the review group opinion that as leak tight a system as possible be designed within a reasonable time restraint which we consider to be 30 days maximum.
NRR TECHNI CAL REVI EW TEAM 7 9 0 3 2 3 ce33 -
163 049
a PRO - W RHR DESIGN Timely Back-Up Capability (15 Days)
One more system which boys additional time down the road for flow and cooling capability.
Skid concept buys HP advantage in installation and removal.
CON - W DESIGN Not better and could be worse than existing system R.W.T.
Leakage (Mech. seals on pumps, valves with single packings (?),
and flanged connections) - potentially unacceptable of fsite doses.
Physically large heat exchanger not needed for heat but for fl ow (ha rd to handle) (won' t fit on skid).
16J nCD 7
UJU e
PRO - NRC ALTERNATIVE Leaktight system with inward leakage (wel ded connec t i ons ).
Longer term operability Smaller heat Rx with bypass loop could mount on one -kid Simpler Installation Greater assurance of QA due to longer lead time Be t te r rioni toring capabil i t ies (!&C)
CON - NRC ALTERNATIVE Longer time needed to obtain (pumps, valves)gassemble, and fabricate (@ 20-30 days).
Additional piping (@ 3/4") needed for positive sealing Booster pump needed to assure Icakage in proper direction.
163 oc; oa
B GENERI C CONS IDEPATIONS Additional loading on auxiliary building Timely cican-Jp Of auxiliary building Functionability of RHR valves inside containment Ticing into existing lines Seismic Consideration 163 052
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D4 CLOSURE 2 TIME / DAYS ALLOWABLE LEAK RATE IN GPM TO MEET APPENDIX l
_PA RT 2 0 Now (4/9/79) 0.0023 0.21 15 0.0092
- 0. d4 30 0.037 3.36 60 0.30 26.88 163 053 i