ML20011E594

Proposed Tech Specs Re Bases for Boration Sys,Including Boric Acid Pumps & Boric Acid Storage Tanks

ML20011E594
Person / Time
Site:	Davis Besse
Issue date:	02/01/1990
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20011E404	List: ML20011E403 ML20011E594
References
NUDOCS 9002160190
Download: ML20011E594 (3)

Text

- , _ _ -- . - .-- - - - - _ - - _ - - - - - - - - . - - .

• Docket Nu barl50-346 I i Licenes Number NPF-3

.'. Serial Nu ber 1747'

-Attachment

'Page 1 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1.4 MINIMUM TEMPERATURE FOR CRITICALITY This specification ensures that the reactor vill not be made critical 1 with the reactor coolant system average temperature less than 525'F. '

This limitation is required to ensure (1) the moderator temperature coefficient is within its analysed temperature range, (2) the protective instrumentation is within its normal operating range, (3) the pressuriser is capable of being in an OPERABLE status with a steam bubble, and (4) the reactor pressure vessel is above its minimum RT g temperature.

3/4.1.2. BORATION SYSTEMS The boron injection systes ensures that negative reactivity contro I available_ during each mode of facility operation. The components G:F4M fQperform this function include (1) borated water sources, 2) makeup or DHR pumps, (3) separate flow paths, (4) boric acid pumps, (5) associated heat tracing syst-- - mad (6) an emergency power supply from operable; emergency busses. i - - - - - -

l -

Vith the RCS average temperature above 200'F, a minimum of tvo separate and redundant boron injection systems are provided to ensure single functional capability in the event an assumed failure renders one of the systems inoperable'. Allowable out-of-service periods ensure that ainor component repair or corrective action any be completed without undue risk to-overall facility safety from. injection system failures during the repair period.

The boration capability of either system is sufficient to provide a SHUTD0VN MARGIN from all operating conditions of 1.0% Ak/k after xenon decay and cooldown to 200'F. The maximum boration capability requirement occurs from full power equilibrium xenon conditions and requires the equivalent of either 7373 gallons of 8742 ppa borated water from the boric acid storage tanks or 52,726 gallons cf 1800 ppa borated L

vater from the borated water storage tank.

The requirement for a minimum available volume of 482,778 gallons of

, borated water in the borated water storage tank ensures the capability l; for borating the RCS to the desired level. The specified quantity of L borated water is consistent with the ECCS requirements of Specification 3.5.4; therefore, the larger volume of borated water is specified.

Vith the RCS temperature below 200'F, one injection system is acceptable vithout single failure censideration on the basis of the t

II ,

DAVIS-BESSE, UNIT 1 B 3/4 1-2 Amendment No.11, g2160190900203 33, 36, 45, 61, 123 p ADOCK 05000346 p

L PDR

' i Dockat Nu:ber 50-346- 5'

+ Lictnsa Number NPF-3' a ,

Page 2

-REACTIVITY CONTROL SYSTEMS-

'" h l

l BASES _

]

l 3/4.1.2 BORATION SYSTEMS (Continued) stable reactivity condition of the reactor and the additional restrictions prohibi. ting CORE ALTERATIONS and positive reactivity change ,

in the event the single injection system becomes inoperable.

The boron capability required below 200'F is sufficient to provide a SHUTD0VN MARGIN of 1% Ak/k af ter xenon decay and cooldown from 200'F to 70'F. This-condition requires either 600 gallons of 7875 ppa borated water from the boric acid storage system or 3,000 gallons of 1800 ppa borated water from the borated water storage tank.

• The botton 4 inches of the borated water storage tank are not available, '

and the instrumentation is calibrated to reflect the available volume.

All boric acid tank volume is available. The limits on water volume, and-boron concentration ensure a pH value of between 7.0 and 11.0 of the solution recirculated within containment af ter a design basis accident.

The pH band minimises the evolution of iodine and minimises the effect of chloride and' caustic stress corrosion cracking on mechanical systems

, and components. ,

The OPERABILITY of one boron injection system during REFUELING ensures that this system is available for reactivity control while in MODE 6.

3/4.1.3 MOVABLE CONTROL ASSEMBLIES The specifications of this section (1) ensure that acceptable power distribution limits are maintained, (2) ensure that the minimum SETTfDOUN MARGIN is maintained, and (3) limit the potential effects of a rod i ejection accident. OPERABILITY of the control rod position indicators is required to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits.

The ACTION statements which permit limited variations from the' basic requirements are accompanied by additional restrictions which ensure that the original criteria are met. For example, misalignment of a safety or regulating rod requires a restriction in THERMAL POVER. The reactivity worth of a misaligned rod is limited for the remainder of the fuel cycle to prevent exceeding the assumptions used in the safety analysis.

The position of a rod declared inoperable due to misalignment should not be. included in computing the average group position for determining the OPERABILITY of rods vith lesser misalignments.

DAVIS-BESSE, UNIT 1 B 3/4 1-3 Amendment No.123

~1 y> 7 . ,

r-:"

l'

.Dockat Nurber-50-346- .

F ._.,

'.* 1Lic:nsa Nuzber NPF-3 i g'

Serial. Number 1747 Attachment"  ;

r' Page 3- j Insert 1. ]

(The boric acid pumps'and the boric acid storage tanks are only required in ,

the. event.of tornado damage to.the borated water storage tank. Since they are only needed'following damage to safety-related equipment due to.a tornado, the boric acid pumps and the boric acid storage tanks are not classified as

-safety-related equipment.) '

t 4

1 P

1 l

,.