ML19254G119
Text
b MAR 12 1980 Cocket No. 50-289 MEMORANDUM FOR:
R. H. Vollmer Director. THI Support FROM:
G. R. Mazetis, Section Leader, Reactor Systems Branch, DSS
SUBJECT:
TMI-1 RESTART REVIEW From a request from Harley Silver on 3/11/80, I am provided the below suggested options which need further internal discussion and management input with regard to latest Med Ed positions:
A.
Automatic Reactor Coolant pump Trip
Background:
(NUREG-0623, " Generic Assessment of Delayed RC Pump Trip During Small Break LOCA in PWRs"). The staff SER on 1NI-1 Restart states that "...it is the staff position that adequate time has existed since the Order to impicment the automatic reactor pump trip prior to power operation" (TMI-1 Order dated August 9,1979). Met Ed has recently infomed us (enclosure) that reconsideration of trip parameters is causing further delay.
-- Options:
1.
Continue our current SER position e.lch requests installation prior to rest:.rt with the potential for delay iminent.
2.
Allow postponement of the installation beyond restart to some other designated date. The technical basis for this postponement would of course be the same as the other operating B&W plants..1.e.,
designated second ope ator to trip pumps.
B.
Emergency Feedwater Systes
Background:
(NUREG-0578, *TMI-2 Lessons Learned Task Force Status Report and Short Tem Recomendations"). We have noted in the TMI-1 restart SER that item 2.1.7a of NUREG-0578 requires the automatic EFW function to be single failure proof. The THI-1 EFW flow control valves are connected to ICS and, as such, do not meet this requirement. Met Ed fr,itially comitted to a safety-grade modification by June 1,1980; however, recent information from Met Ed indicates that this schedule was incorrect.
Current projections go beyond restart (complete installation during first refueling outage). See also our enclosed memo 16Xy66 dated 2/28/80.
Contact:
Jerj Maze tis,-NRR 49-29406 omcc.
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g NRC Form 318A (4 79) NRCM 02040
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R. H. Vollmer MAR 12 1980 i
-- Options:
1.
Continue to request safety-grade installation prior to restart with the potential for delay iminent.
7.
Allow postponement of the installation beyond restart to some other designated date. The technical basis for this postponement would
(
be the availability in the control room of Het Ed's new manual EFW station which is separated fran ICS. A weakness in this option is the otso, votion that OTSG 1evel instrumentation also interfaces with ICS.
C.
Miscellaneous (For H. Silver)
Several additions for the TMI-1 Supplement are enclosed. Also enclosed is a paragraph to be added to our transmittal MXym dated March 5,1980.
I recomend we move.quickly to decide and infom Met Ed of our position on "A" and "B" above.
Original signed by:
Gerald R. Mazetis, Section Leader Reactor Systems Branch Division of Systems Safety cc:
H. Denton Dist e
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T. Novak RSB Rdg.
S. Israel G. Mazetis J. Wenniel Mazetis chron P. Norian J. Voglewede P. Matthews R. Fitzpatrick B. Boger S. Newberry H. Silver I
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NRC Form 3180 (4 79) NRCV 0240 e u..... w e = = = = =,...
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i SU??LDENT 1. ?.GT 3 OUESTION 11.
3 e long-tarn require =en: of II Sulletin 79-05C requires the 3&W licensees to subsi: a desig.. which vill assure autoca:ic tripping of the operating reac:or coolan pu=ps (RC?s) under all circu=scances in which :his action say be needed. I: has been shown :hrough analy-sis :ha: this ::1p is needed for a cer:ain spec::..s of s=all break LOCAs.
?:1er to final design accep ability, :he follevi=g condi:1ons =ust be satisfied:
Charac: eristic curves for RCP current /pover versus void fraction a.
- ust be fully de=custrated and docu=enced based upon e::isting da:a and supplemented as necessary vi:h confir=accry' da:a
- es:
cbtained f:cm fu:ure tests such as LOFT, full scale tes:ing, e:c.;
b.
Justifica:1on for the RC? current / power se:poin: nust be shown;
- and, Satisfactory respenses to :he following =ust be received.
c.
RIS?CNSE The ec= plex 1:7 and schedule of responding to 1:ess (a) and (b) above and :he desire :o ec= place :his =odifica:1on in a c1=ely canner have lead us to re-consider :he selection of RCP pcwer as a trip parameter. We are currently considering the following options:
1.
RC? ::1p on EPI wi.h coinciden lov saturation =argin.
2.
RCP trip on lov saturation =argin coly.
3.
RCP trip on EP! with coincident RC? power just below nor_al RC?
power fluctuation.
When one of the above options has been selec:ed, appropriate information will be p:cvided in response to items (a) through (c) of this questien.
An. 13
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,, g MEMOPANDUM FOR: Harley Silver, Project Manager, TMI-l Restart LJ G. R. Mazetis, Section Leader, Reactor Systems Branch, DSS /l, THRU:
FRCM:
Jared Wermiel, Auxiliary Systems Branch, DSS
SUBJECT:
TMI-l RESTART REVIEW, APPLICATION OF SRP SECTION 10.4.9,
" AUXILIARY FEEDWATER SYSTEM" REQUIREMENT FOR PIPE RUPTURE As part of our review for restart of TMI-1, we are evaluating the present TMI-l emergency feedwater (ERI) system design against the current require-ments of SRP Section 10.4.9, Auxiliary Feedwater System. This review resulted in an SER open item concerning postulated pipe ruptures in the EFW pump dis-charge lines (Question 12, Supplement 1, Part 2 of the Restart Report}.
The enclosure is our evaluation of the licensee's response to this item. We find the existing EFW system acceptable.
Jared Wermiel Auxiliary Systems Branch Division of Systems Safety
Enclosure:
As stated cc:
R. Mattson R. Vollmer V. itenaraya P. itatthews R. Fitzpatrick T. Nock S. Israel B. Joger y.Mazetis S. Newberry t
T00Vo2 0 3/
INSERT FOR 3/5/80 MEM0 Additionally, the licensee has referred to the TMI-1 " feed-and-bleed" capability, given that all feedwater (both main and auxiliary) were lost.
As noted in NUREG-0565, " Generic Evaluation of Small Break Loss-of-Coolant Accident Behavior in Babcock & Wilcox Designed 177-FA Operating Plants,"
in the event of a loss of natural circulation, plants with the lowered loop design could still provide adequate core cooling in a feed-and-bleed mode which utilizes both HPI trains to inject water into the reactor coolaat system wh'ile bleeding water out the system through the break, PORV, or safety valves.
Although confirmatory 'nformation is being sought generically by the NRC to support this made of operation, such as experimental data to test the performance of the PORV and safety valves under normal, transient, and accident conditions, we recognize the availability of this feed-and-bleed backup capability.
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