ML20034A274

Proposed Tech Specs Re Hpi,Chemical Addition & Low Temp Overpressure Protection Sys

ML20034A274
Person / Time
Site:	Rancho Seco
Issue date:	04/12/1990
From:	SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:
Shared Package
ML20034A273	List: ML20034A272 ML20034A274
References
NUDOCS 9004200669
Download: ML20034A274 (6)

Text

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RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS-Limiting Conditions for Operation HIfM PREC1URE INXC""0N. CHEMICAL ADDLTION SYSTEMS 3.2 OVERPRE11URE PR0"!C"LON (LTOP) i Anali ethility Specification 3.2.1 applies to the operational status of the high I

injection and chemical addition systems.

operational status of the Low Temperature Overpressure Prot System when the RCS temperature falls below 350*F and the Specification 3.2.2 is not applicable when the Reactor Vess head is removed, when any one of the 4 OTSG atmosphere.

removed.

QMeetive Specification 3.2.1 provides for adequate boration under all ope conditions to assure ability to bring the reactor to a cold shutdown Specification 3.2.2 defines the necessary conditions for preventing an excessive overpressure transient to occur at low.

condition.

tasei fication I

The reactor shall not remain critical unless the following 3.2.1 conditions are met:

Two pumps. capable of supplying high pressure injection j

3.2.1.1 are operable (also see Specification 3.3).

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The borated water storage tank and'its flow path to the 3.2.1.2 reactor for high pressure injection are operable.

i A source of concentrated boric acid solution in add to the borated water storage tank is available and 3.2.1.3 This requirement is fulfilled by the operable.

This tank shall concentrated boric acid storage tank.

contain at least the equivalent of 10,000 gallons of System piping and valves necessary to 7,100 ppe boron. establish a flow path for high pressure in also be operable and shall have at'least the same One temperature as the boric-' acid storage tank.The concentrated associated boric acid pump is operable.

boric acid storage tank water shall not be less than 70F,

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and at least one channel of heat tracing shall be The operable for this tank's associated piping. con i

shall not exceed 8,500 ppe boron.

9004200667 900412 PDR ADOCK 05000312 P

PNV Amendment No. 29, 69,.42, 97 3-17 1

RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting conditions for Operation l

The' Low Temperature Overpressure Protection System will requite the 3.2.2 following conditions:

LTOP will be manually enabled prior to the Reactor coolant 3.2.2.1 system temperature dropping below 350'F during plant cooldown.

3.2.2.1.1 Manual enabling of L10P shall be accomplished by placing the Key Select Switch for the EMOV to the " Low" position i

90-and by placing HV-21505 in the "Open" ~ position.

All HPI Systems will be locked out-whenever the RCS 3.2.2.2 temperature is below 350*F.

This shal.1 be done by opening and tagging-the circuit breakers for the four HP!

SFV-23809, SFV-23811; and Motor-0perated Valves (Loop A:

Loop 8: HV-23801, SFV-23812) with the valves in the closed position. except as specified.below:

90--

i During Makeup, Letdown and Purification System i

90-3.2.2.2.1 startup, any of the four HP! MOVs spectfied in 3.2.2.2 above, which are performing the required isolation function, may be individually opened as required to fill and vent the respective injection line subject to

.l the conditions stated in 3.2.2.2.2 and 3.2.2.2.3 below:

i All HPI-Makeup pump breakers shall be racked out and f

3.2.2.2.2 tagged during the filling and venting specified in l

3.2.2.2.1.

Only one of the four HPI MOVs specified in 3.2.2.2 3.2.2.2.3 above may be open at any one time, and it shall be closed and its breaker racked out and tagged upon completion of its line's filling and venting.

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3.2.2.3 The-makeup tank water level is to be less than 86 inches.

The pressurizer water level will be maintained at or below 3.2.2.4 j

220 inches at system pressures above 100 psig and less than 275 inches for pressures less than or equal to 100 psig except during RCS filling and draining.

When the RCS temperature is below 350'F, the core flood 3.2.2.5 tank discharge valves are closed and the circuit breakers for the motor operators are racked out before the RCS pressure is decreased to 600 psig, except as specified 90-below:

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Amendment No. 82. 90.

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RANCHO SECO UNIT 1 l

TECHNICAL SPECIFICATIONS 1

Limiting Conditions for Operation l

When the Core riood Tank pressure is below 500 psig, the discharge valves shall be allowed to remain open

3. 2. 2. 5.1 90-or be opened.

When LTOP is required, only one HPI pump will be operated

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except during the' transition of pumps that will supply.

3.2.2.6 Reactor Coolant Pump seals ar.$ makeup flow for the RCS.

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The makeup and purification system and chemical addition systems prov This is control of the reactor coolant system boron concentration.'

normally accomplished by using either the mak The alternate method of boration will concentrated boric acid storage tank.

etion pumps taking suction be the use of the makeup or high pressure in directly from the borated water storage tank t

The quantity of boric acid in storage from either of the two above-me sources is sufficient to borate the reactor coolant system to a 1 percen suticritical margin in the cold condition (70F) at the worst time in core with a stuck control rod assembly. The maximum required is the equiva

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9586 gallons of 7100 ppm boron. This' requirement is satisfied by req minimum volume of 10,000 gallons, of. 7100 ppm in the concentrated.

The minimum volume for the borated storage tank during critical operations. gallons of 1800 ppe boron), as spe p

water storage tank (390,000section 3.3, is based on refueling volume the cold shutdown requirement.. The specification L

l failure will not prevent boration to a cold condition.

i boric acid solution given include the boron necessary.to account for. xenon-decay.

The primary method of adding boron to the pr L

tank using the 50 gpa boric acid pumps.

pumps, the required volume of boric acid can be inj borated water storage tank using the high pressure injection pumps.

hours.

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Amendment No. 6f, 82, 90 3-18 l

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' RANCHO SECO UNIT 1-TECHNICAL-SPECIFICATIONS Limiting Conditions for Operation 14131 (Continued) i Concentration of boron in.the concentrated boric acid storage tank may be higher than the concentration which'would crystallize at ambient conditions.

For this reason and to ensure that a flow of boric acid is available when I

needed, this tarik and its, associated. piping will be kept above 70F (30F above the crystallization temperature for the concentration present). -Once'in the high* prAssure injection system, the concentrate is sufficiently well mixed and diluted so that normal system temperatures ensure boric acid solubility.

The'valuk of 70F is-significantly above the crystallization temperature for a 90--

. solution containing 12,200 rpm boron;3 The Low Temperature Overpressure Protection System (LTOP) consists of both an active and a passive subsystem.

The active subsystem utilizes the Electro M

Matic Operated Valve (EMOV) which provides overpressure protection during normal plant operation. - The EMOV actuation; circuitry has been modified to I

provide a second setpoint (500 psig) that is used during* low-temperature operations.

The low setpoint is manually enabled at 350 F by' positioning a key-operated switch in the Reactor control 1 Room; An. alarm will soundtin the Reactor Control Room'if the: reactor coolant pressure falls below 450~ps,ig and

'After the key-operated switch is not selected for low-temperature operation.:

selection of low temperature operation;' additional-alarms will occur If "i

either HPI pump-breaker.is not racked out; if either SealiInjection flow is greater than 42 jpm or makeup flow is greater than 135. gpe;. if HPI' valves are y

not closed; and if the'EMOV block valve HV-21505 is not open.. The passive g

subsystem.is based on the plant design and operating philosophy that precludes the plant from being in'a water solid condition (except for system

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hydrotests).

90-Injection line filling and venting:is accomplished without an energized Makeup or High Pressure Injection pump.. Nitrogen overpressure.-in the Makeup i

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l tank provides.the motive force for fluid flow:during> this evolution. This

-nitrogen overpressure is. limited procedurally'to'30 psig, and mechanically to-100 psig by the relief valve on the Makeup tankt !This. pressure' clearly does not approach the'EMOV low setpoint.

The exception to' core flood discharge valves being closed and their motor.

operator deenergized is based on the Core Flood Tank pressure being reduced to-less than the-EMOV low'setpoint of 500 psig. Nithout the potential for-RCS overpressurization,-the valve need not be administratively: required to-be

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closed. This provides for other surveillance testing and' maintenance on the-Core Flood System.

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Amendment No. 82, 87.-90 3-18a E

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1 RANCHO SECO ljNIT 1 4

TECHNICAL SPECIFICATIONS Limiting Conditions for Operation The Rancho Seco Reactor Coolant system always operates ~with a steam or gas

- space in the pressurizeri the steam bubble is replaced with nitrogen during.

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plant.cooldown when system pressure is reduced. The requirements for a maximum pressurizer level provides for a sufficient vapor space.in the pressurizer to retard the rate of, increase of RCS pressure, as compared to a' In this manner, water solid system for all' mass and heat input-transients.

the. operator will have time to recognize that a pressure transient is 'In progress-and'_ take action to mitigate the incident.

For these reasons the pressurizar water level will be maintained at or below 220; inches at systsm' n

1 pressures < above :100 psig;and less' than 275 inches for system pressures less -

than or eaval'to 100 psig.- The only exception:to these. requirements will te

i when the RL'S is being filled or drained. Ouring the filling process the pressurizer is_ filled with water 'up to the:320 inch level. 'The High' Point Vents are opened and nitrogen is' injected into the. pressurizer hence forcing.

the coolant into the loops. Subsequently, the High Point Vents are closed, a

'steari bubble is drawn:and the' nitrogen is releasedithrough.the. pressurizer vents. 'Ouring the draining process.: the' pressurizer is depressurized, the H1 h Point Vents'and RCS Hot. Leg Vents'are opened thus' reducing the RCS'to 0

- atmospheric pressure, _The loop coolant level and' pressurizer' level' equalize

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at 320 inches and draining _ can then take place.

In conjunction with the enablement of LTOP at 350'F and the subsequent-restriction'on= pressurizer level, analysis has.shown that the.HPI system is:

not.nesded when RCS temperature falls.below 350'F. lThe requirement.for a maximum makeup ~ tant level limits-the_ mass: input available;from the tank should the makeup valve fail open.

When LTOP conditions are. required, only one:of the two HPI. pumps or.the' i

makeup ~ pump will'be allowed to operate.: Rancho Seco normally operates with

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_ the makeup pump supplying makeup and seal-injection.: Should, in the unlikely :

L Levent, degradation of this pupp occur while in the LTOP mode.it would be i

necessary.to, start one of the HPI pumps before stopping :the_ makeup pump.

This scenario-would result in a brief overlap-time period where an increase-l-

in. flow through the makeup line would occur. However, because the. operator is aware of'the LTOP conditions, it is expected that this brief trans'ttch stage would not significantly increase the level of the pressurizer and the probability of an over-pressurization incident.

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-Amendment No. 90 90--

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[ :.p RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting Conditions for Operation Separate power supplies are provided for the EMOV circuitry and 1 TOP alarm!

which alert.the operator of an overpressurization' event-so that a single:

This assures power source failure will not disable the.EMOV and LTO These alarms are high pressurizer level, high - high l

the EMOV is disabled.-

pressurizer level, and high makeup ta'nk water level.

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REFERENCES 1:USAR Subsections 9.2 and 9.3 2 USAR Figure.6.2-1 J,

3 Technical Specification 3.3-I l

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. sacRAMestTo MU864CML UT1MTV DISTRICT 62015 Street. *O Sos 15830. Sewe* to CA

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ACHINUC 89-261 Decemcer 4, 1989

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U. S. Nuclear Regulatory Commission Document Control Desk F1LE C0FY i

Attn:

Washingtor.. 0C 20555 i

c Dockst No. 50-312 Rancho Seco Nuclear Generating' Station License No. OPR-54 TECHNICAL SPECIFICATIONS 7

Attention: George Knighton d

The District is defueling the. Rancho Seco Nuclear Generating S The T

is in an extended autage for an as-yet undetermined duration.,

SFP) is an movement of spent fuel assemblies-into the spent fuel pool:(

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l activity previously analyzcd'and described in the' Updated. Safe The removal of all fuel.from the Reactor Vessel and lthough.

Reactor Building results in the plant being in a co Report (USAR).-

tions.

not specifically defined as a Mode in the Technicali Specifica Therefore, the District has evaluated the.Techn to this letter presents the-results of this evaluation.

The criteria used to' determine'the applicabili on meetingLthose Specifications related to the following:-

1 Maintain spent' fuel pool cooling.

1.

2 r Maintain offsite releases as. low as reasonably achievabl g]f Provide monitoring of offsite releases to' ensure compliance y

3.

release limits, g,l The District will maintain the Spent' Fuel Pool C p

Mr-k1 the p

more than adequate capacity to maintain the pool temperature,be V

• Technical Specification required '140*F.

of B'.76'million BTU /HR greatly exceeds the decay heat load BTU /HR. 5The system capacity is actually greater than this du L

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y AGM/NUC 8g.261

George Knighton, J

t re is below the design winter months when'the outside ambient. tempera u ture increases in v

r the coming sumer months, the spent fuel-pool decrease to 2.78 million BTU /HR by June 7, 1990.

FP the conservative With the reactor defueled and the fuel stored in the S ling for lineup for the Decay Heat Removal (OHR) system is to provid urposes other the SFP. :The OHR system must be-declared inoperable for p i

l Specification than SFP cooling.. pursuant to the requirements of Techn ca In 3.9.2. when tr4e. system is being used for cooling.of the SFP.

f DHR for SFP addition, Tect.nical Specification 3.9.3 restricts the use o l t is cooling to no more than 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> per 12-month period w is not applicable when the reactor.is defueled since the DHR system l

not in Cold Shutdown.

i tions. The required to be OPERA 8LE to satisfy other Tech L

serve as a backup SFC system..

ces The Technical Spe*ifications do not require the, emergency pow be OPERABLE wher N reactor is defueled.

iated with measure, the Br e 41 diesel generator. and-related -buses as ciated diesel generator provides emergency power to~the major loads a the available DH4 d Nuclear Service with OHR (OHR, Nuclear Service Cooling Hater (NSW), anIn add' tion,' through the use'of' the21 and 38203-Raw Hater (NRH) pump motors).

480-volt cross-tie brenkers (breakers 3A21 and 3A203,=or:38 l

as presented in' Attachment 3), the Bruce GM Diesel genera i

l the remaining loads required to maintain this. conservative:d ese These remaining loads are primarily environmental control' loads such as the Nuclear generator backup' ability.

/ Technical _ Support Center (CR/TSC) t td Heating Ventilation and Air Conditioning (HVAC) systems.: As Building (NSEB) and Control Room in Attachment 3. the cross-tie breakers connect:the i

Use of the within a train, and do act effect the independence of. tra ns.._-

d by.the 480-volt. cross-tie breakers was previously analyzed and. approve NRC as' detailed in Technical Specification Amendment Number the Appropriate. routine maintenance and testing Will be performe 1

OHR -

Bruce GM diesel generator being maintained to system.

Specification tests:'

a 4.6.3.A.1,

.2,.3 -and.4-1.

4.6.3.A.5, (no_ fast starts will be performed) 2.

r 4.6.3.B.1,

.2, and.3 3.

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AGM/NUC 89-261

, George Knighton l

Start testing of the Bruce GM Olesel generator will This frequency reduces unnecessary starts J

d The-likelihood of while ensuring the engine is available when needed.1 f

needing diesel backup power is very low since the probability of a t loss of offsite power.at Rancho Seco, as'ststed in the O i

U April 17. 1989 Power, is less than once in^20 years.

The auto start and auto load capabilities of the Bruce GM diesel-

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generator are not> required'to be kept in service unlikely event of a loss of offsite power.

i APCSB 9-2, the'very conservative assumptions of Branch Technical Posit on show that'it takes a minimum of 21.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> for the SFP to from an initial temperature of.110*F-on a loss of SPC (see AttachmentThe.

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1).

This time is valid for December 5 1989.

minimize thermal stresses on-the SFP (see USAR sectioni5 L

pool is-capable of withstanding stresses up toland including those-resulting from a pool. temperature of 212*F.

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Out-of-service time for systems being maintained available will be 1

controlled through " Administrative Action Statements" that.will be l

developed through an evaluation of the effects of equ 4

hour limit will be set for each of the systems bei.ng maintained available

~It is expected that the " Administrative Action Statements" will be periodically updated to reflect changes'in the p determining actions to.be taken if one of-these " Administrative Action-Statements"-will not be met.

Those systems not being maintained OPERABLE or "available" as describ in this letter, and not required for routine plant activities, will be~

1ayed up in accordance with detailed plans developed by.the District.

These plans incorporate' vendor recommendations, industry experience, sound engineering practices.to provide for long-term protection and preservation of the' systems for potential future use and are available o s

These' plans call'for layup activities site for review and inspection.

such as hand rotation of rotating equipment ~to' ensure bearings remain a

lubricated and free, draining and dehumidification of piping to reduce maintain a protective environment, continued purch fuel oil for all four emergency diesel generators. etc.

l The Specifications listed on Attachment 2 to this letter will continue'to be met which will ensure compliance with the requirements of-the Rancho

. It is Seco Technical Specification in the defueled condition.

will occur as' conditions at the plant change.

The District will also

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provided in writing to the NRC as they occur.

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D-AGM/NUC 8g.261

.4 George Knighton submit a set of Defueled Technical Specification for NRC review and a in the near future to further document the list of. systems required in tt'e defueled condition.

Members of your staff with questions requiring additional information or extension 4913.

clarification may contact Steve Crunk at.(209) 333 2935, s

Sincerely, 7

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%% rw u-Dan R. Keuter Assistant General Manager Nuc1 ear.

Attachments cc w/atch:

J. B. Martin, NRC, Walnut Creek A. D'Angelo NRC, Rancho Seco i

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'A ATTACHMENT 2 Technical Specification Number Section 1.

Definitions Applicable When Noving Fuel in the spent 3.0 Monitor R15028 only.

3.8.1

' fuel storage area.

3.8.12 3.9.1 Only for systems required to be OPERA 8LE 3.9.5 3.12 i

j 3.14 3.15 3.16 i

3.17 3.18 3.21 3.22 3.23 3.24 3.25 3.26 3.29 Page 4'.7b #444, 44b 44d. 45, 46. 47, 51, 63 l

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Table 4.1-1 Table 4.1-2

1. 8, 9, 10, 11 L

Table 4.1-3

1. 2, 4, 6, 8-Only for systems required.to be OPERA 8LE'-

4.14 i-4.15 4.18 4.19 4.20 4.21 4.22 r

4.25 4.26 4.27 4.28 1

4.29 4.30 4.34 l

Section 5.

Design Features Administrative _ Controls -(except 6.18)

Section'6.0 L

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