ML20136E484

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Forwards Document Re Plant Large Break LOCA Issues
ML20136E484
Person / Time
Site: Saint Lucie  NextEra Energy icon.png
Issue date: 10/24/1996
From: Mark Miller
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To: Landis K, Mellen L
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17229A261 List: ... further results
References
FOIA-96-485 NUDOCS 9703130218
Download: ML20136E484 (4)
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From: ' Mark Miller / 4f7

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0/2k/ 2:52p

Subject:

Large Break LOCA conference Call

  • Roy Zimmerman is going to have a conference call with the licensee (Bohlke) at 1600 .

4 today (thursday). Attached is.a document to try to get you up to speed if you want to brief Stew or be involved.

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i 9703130218 970306 l PDR- FOIA BINDER 96-485 PDR

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St. Lucie Large Break LOCA Issue Timeline 10/10 Licensee receives call from NRR Reactor Systems Branch (SRXB). Bob Jones. Tim Collins, et al inform licensee verbally that the Seimens Large Break' .

Code ('86 Model) has an error. Issue involves code displaying non-physical behavior during the reflood stage. As reflood rates increase from 1 to 1.7 in/sec, heat transfer coefficient decrease. NRR requests affected utilities to propose actions to bring themselves into compliance with 10 CFR 50.46 and to explain those actions at a meeting in OWFN on 10/16. NRR stated that this constituted the licensees

  • official notification. No reference was made to orders 50.54(f) etc.

10/16 At meeting. Seimens explained that they dealt with the problem by repeMorming analyses with the heat transfer coefficient truncated (clamped) at the 1.77 in/sec value and that the analyses employed a " collapsed liquid" model vice the less conservative " quench time" model. NRR appeared satisfied. FPL's analysis resulted in a loss of about 27 degrees of margin.

10/23 At 1630. NRR contacts FPL and informs them that they have found that the

" quench time" model was used and that the clamped' heat transfer coefficient methodology was unsat in light of this.

Later that evening, FPL engineer is contacted at home by NRR reiterating that the approach use'd by FPL wasn't acceptable.

Seimens applies new approach, involving the use of an interpolated value of heat transfer coefficient, obtained between the values corresponding to 1 and 1.77 in/sec and using the " quench tank" model. Approach takes PCT from 1912 to 2027 F for St. Lucie.

10/24 NRR calls licensee. Tim Collins says he doesn't have a problem with the approach taken by Seimens and asks Weinkam'what the basis for continued operation is. Weinkam responds that the issue is being evaluated under their Appendix B program, and operability will be considered under GL 91;18 guidelines. Weinkam emphasizes that he believes that he is in compliance with 50.46 and that the' CR process will formalize that position. Collins says NRR needs letter by 10/25 showing the results of the licensee's analysis. Weinkam responds that he cannot respond that quickly, that the Seimens results will require review for proprietary information, will have to be OC'd and reviewed for accuracy under 50.9, and that will take time. Collins responds that unless FPL can produce the analyses by 10/25 a Director's Decision will have to be made based on FPL's inability to show results. Weinkam asks if NRC will be producing any paperwork on the issue. Collins states that he '

cannot get it out that fast. The discussion then makes several laps around this logic loop. ,

At the end of the call. FPL states that they will produce a letter indicating their confidence in their compliance with 50.46. that the formal evaluation .

results will be forwprded when completed, and providing a schedule by 10/25.

Collins indicates that this is acceptable.

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v' At 1330, PM informs SRI of a desire by AD/ Projects /NRR to speak with Art Stall at 1600 on the issue and describing his intent to contact licensing on the issue. At 1415. Weinkam informs SRI that the call has been arranged between Bohlke and Zimmerman. Weinkam stated that PM said the call would be "one way" and that NRR would inform the licensee as to what to include in the letter.

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Mi.ller's Concerns  : / j

1. . NRR clearly is ratcheting the'11censee with not-to thinly veiled threats of a ,

' shutdown order:unlessf the information. required 'is not provided to NRR.in one day, j

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2. While 50.46'contains 30 day' reporting criteria for code errors resulting in an error '

of greater than 50 F. The requirement to' report in less than that time is a backfit; .!

37 .NRR is demanding that the licensee perform all of these actions outside the bounds of .

~ established processes (e.g. orders) and without regard to 10 CFR 50 Appendix B '{

allowances for time to evaluate the conditions.

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4. NRR is willing to accept significantly-less than what they originally requested. If -  !

the issue is so s1gnificant as to require a shutdown order in the absence of l analytical results, accepting a statement of compliance with a promise to followup  !

does.not serve public health and' safety, if it's really that important, we should j either have NRR on site inspecting the issue to independently verify satisfactory  ;

analyses have been performed or we should shut them down. .

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