TS 3.5.3 ECCS - Operating

Question 1

LCO 3.5.3
2 ECCS trains shall be OPERABLE

APPLICABILITY: ___

Answer 1

MODES 1 and 2

MODE 3 with PZR pressure > 1837 psia or with RCS Tc > 485F

Question 2

The function of the ECCS is to provide core cooling and negative reactivity to ensure that the reactor core is protected after any of the following accidents:

a. ___
b. ___
c. ___
d. ___

Answer 2

a. LOCA
b. CEA ejection accident
c. Loss of secondary coolant accident, including uncontrolled steam release or loss of FW
d. SGTR

Question 3

The addition of negative reactivity is designed primarily for ___ because ___

Answer 3

…Loss of secondary coolant accident

…because primary cooldown could add enough positive reactivity to achieve criticality and return to significant power

Question 4

There are 2 phases of ECCS operation:
1 ___
2 ___

Answer 4

1. Injection

2. Recirculation

Question 5

Each ECCS train consists of ___ and ___

Answer 5

HPSI and LPSI subsystems

Question 6

LCO 3.5.3 helps to ensure that the following acceptance criteria, established by 10 CFR 50.46 for ECCSs, will be met following a LOCA:

a. ___
b. ___
c. ___
d. ___
e. ___

Answer 6

a. Max fuel element cladding temperature is < 2200F
b. Max cladding oxidation < .17 times total thickness
c. Max H2 generation from a Zirconium water reaction is < .01 times hypothetical if all metal were to react
d. Core maintained in coolable geometry
e. Adequate long term cooling capability maintained

Question 7

LCO 3.5.3 also limits the potential for a post-trip return to power following a ___ and ensures that CTMT temp limits are met.

Answer 7

Steam Line Break (SLB)

Question 8

LCO 3.5.3 CONDITION

A. One LPSI subsystem inoperable.

Answer 8

A.1 Restore subsystem to OPERABLE status (7 days)

Question 9

The availability of at least ___% of the ECCS flow equivalent to a single OPERABLE ECCS train is implicit in the definition of Condition A.

Answer 9

100%

Question 10

LCO 3.5.3 CONDITION
B. 1 or more trains inoperable for reasons other than Condition A.
AND
At least 100% of the ECCS flow equivalent to a single OPERABLE ECCS train available.

Answer 10

B.1 Restore train(s) to OPERABLE status (72 hours)

Question 11

An ECCS train is inoperable if ___

Answer 11

…it is NOT capable of delivering the design flow to the RCS.

Question 12

The intent of this Condition is to maintain a combination of OPERABLE equipment such that ___

Answer 12

…100% of the ECCS flow equivalent to 100% of a single OPERABLE train remains available.

Question 13

LCO 3.5.3 CONDITION

C. Required Action and associated Completion Time not met.

Answer 13

C.1 Be in MODE 3 (6 hours)
AND
C.2 Reduce PZR pressure to < 1837# (12 hours)
AND
C.3 Reduce Tcold to < 485F (12 hours)

Question 14

Per SR 3.5.3.1, A valve that receives an actuation signal is allowed to be in a nonaccident position provided the valve auto repositions within ___

Answer 14

…the proper Stroke Time

Question 15

Per SR’s 3.5.3.4-6, the following valve actuations MUST be verified:
___

Answer 15

“on an actual or simulated RAS, the CTMT sump isolation valves open, and the HPSI, LPSI and CS minimum bypass recirculation flow line isolation valves and combined SI mini flow valve close.”