ML20059E241
| ML20059E241 | |
| Person / Time | |
|---|---|
| Issue date: | 04/07/1992 |
| From: | Zuber N Advisory Committee on Reactor Safeguards |
| To: | Boehnert P Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-CT-2018, NUDOCS 9311030141 | |
| Download: ML20059E241 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION ADVISORY COMMITTEE ON REACTOR SAFEGUARDS g
W ASHINGT ON, D. C. 20555 3
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April 7, 1992 o,
Senior Staff Engineer Paul Boehnert, MEMORANDUM FOR:
Nuclear Reactors Branch, ACRS
@NovakZuber,InvitedExpert FROM:
PHENOMENA HYDRAULIC
SUBJECT:
SUBCOMMITTEE MEETING ON GE/BWR POWE ACRS THERMAL BETHESDA, MARYLAND
- 1992, PROGRAM, MARCH 26, to your request, the following are my comments subject subcommittee In response issues discussed during the concerning the meeting:
GE/ Utility Presentations GE) and Detroit The presentations by General Electric Company (
set forth by the Edison (DE) met the requirements
" walk-through" of 1.
that is, they presented a
i their program together with a status to-date.
subcommittee, as the presentation comprehensive uprate.
The " walk through" was addressed the important topics related to a power f their I realize that GE and DE presented the status to-date o code calculations performed many 2.
program. and reliance on, years ago, for the present power levels.
This was done use of, without finding out whether or not the bases of these still valid or adequate f or the uprated calculations were power level.
For Example:
STR Spray penetration and cooling were based on SAFER /CE adequacy of should recall that the ihd a) this code to perform such calculations was establ s eb One calculations.
TRAC for the present power level.
Similar TRAC (several years ago) calculations were r.ot performed for the uprated power, i5 3
which has a different (flatter) radial profile.
(region A) in the The boundary of the unstable regionpower-flow m for the b)
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l "old" power profile, although ORNL Iras shown that a (which will be used for the increases this unstable region.
s flatter radial profile j
uprated power operation)
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MEMORANDUM April 7, 1992 Page 2
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I could cite additional examples,..however,.
these-two illustrate the cause of my concern.
It may well be that the "old" calculations will be still valid for the uprated power
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levels; nevertheless, GE should demonstrate their validity when, and if, they use them.
3.
GE's discussion of the calculations performed with power levels of 102% and 104.5%, was rather opaque.
GE should be asked to be more precise and clarify' t'he discussion.
4.
GE presented results of calculations,. which show a 30%
decrease of water level due to a power increase of 5%.
Such a big effect is rather surprising; it is not clear whether it is real or. caused by a deficiency of the code.
GE should be asked to. address'this question.
i NRR Presentations 1.
The presentation by the staff were comprehensive. The program is well organized, directed and managed,.it should lead to an improved and more efficient licensing procedure.
2.
The position taken by the staff and the constraints listed in I
SECY-91-401, are technically sound, responsible, quantifiable and reasonable.
i 3.
Questions raised by the staff to clarify unexpected results and resolve potential issues attest to intellectual curiosity and professional respectability.
Such an attitude is most reassuring and it should be commended.
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