ML19308B697

Submits Comments Re Potential for Operator Action to Terminate HPI Following Initial Stage of Loca.Mandatory That Full Injection Flow Be Maintained.Recommends Written Guidelines for Termination of HPI

ML19308B697
Person / Time
Site:	Crane, Davis Besse
Issue date:	02/09/1978
From:	Dunn B BABCOCK & WILCOX CO.
To:	Taylor J BABCOCK & WILCOX CO.
References
TASK-TF, TASK-TMR NUDOCS 8001160759
Download: ML19308B697 (2)

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' COCK L WILCOX COMPMlY

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.f S ERATION GROUP

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j Jim Taylor, Manager, Licensing

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f en Tert M. Dunn, Manas;er. ECCS Analysis (2138) i.

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j y,.............................gh Pressure Infectics February 9, 1978 hThis ceno addresses a(serious concern Nthin ICCS Analysis abou:

Etential for operator action to terminate high pressure in'je' ction' follow '

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• ing the initial stage of a LOCA.

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. Successful ICCS operation during s=all breaks depends on :he acct =:ulated reactor coolant syste= inveitory as vell II an the ICCS injection rate.

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As such, ;it is tandatory that full, injection-l flov be r.aintained frc= the point of emergency safety features actuation

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.systen (ESFAS) actuatica u=ril the high pressure injectica rate can fully l

cc=pensate for the reactor heat 1 cad.. As the injection rate depends en

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the reactor coolan:

syst'an pressure, the ti=e at which a co=pensating r..t.atch-up occurs is variable and cannot.be specified as a fixed ne=ber It is quite possible, for c a=ple, -that~he high pressure injection ay

-successfully =atch up vi:b all heat sources at ti=e :

3...:en pressurization be Ndequate at.se=e later time t and that due to sys-.

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. The. direct concern here rose out of the..

rece.n 1seident a;; Toledo._ During the acciden: the operator terminated high pressure injection due to an ap-l

. parent sys:e recevery indicated by high.. level v".-hin the pressuri:er.

..This actien vould haw been acceptable only af ter the pri=ary syste= had * -

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._been in a subcoeled state., Analysis of the data fron the transient cur-

{ rently indica es that the system vas in _a two-phase. state and as such did

..not contain ' sufficient capacity to. allow high pressure injection ter=ina-l

_ tion. This beca=e evident at

• -.i sene 20 to ~30 minutes 'follering termination

.R-of injection when the pressurizer level again collapsed and injection had

,to be reinitiated.

During the 20 to 30 ninutes of noninjection ficv.they

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