RCSLK9, PWR Coolant System Leak Rate

1 - Description of program or function: RCSLK9 was developed to analyze the leak tightness of the primary coolant system for any pressurized water reactor (PWR). From given system conditions, water levels in tanks, and certain system design parameters, RCSLK9 calculates the loss of water from the reactor coolant system (RCS) and the increase of water in the leakage collection system during an arbitrary time interval. The program determines the system leak rates and displays or prints a report of the results. During the initial application to a specific reactor, RCSLK9 creates a file of system parameters and saves it for future use. 2 - Method of solution: RCSLK9 provides the inspector with the capability to independently analyze the leak tightness of PWR reactor coolant systems. By taking two sets of water inventory data in the RCS and in leak collection tanks, separated by a time interval, and applying RCSLK9, the inspector can obtain the gross leak rate for the RCS and the rate at which the leakage is being collected. The gross leak rate for the cooling system is found by dividing the inventory loss in pounds by the product of the elapsed time between inventories and the density of water. The quotient is converted to gallons per minute. To determine the identified leak rate for the RCS and the chemical and volume control system (CVCS) during the test, the amount of water collected in the pressurizer relief tank and the reactor drain tank must be calculated. Water inventories for the pressurizer relief tank and the reactor drain tank are determined from measured levels and the tank calibration curves or tank dimensions. To find the identified leak rate for the cooling system, RCSLK9 divides the combined inventory gain in pounds for the reactor drain tank and the pressurizer relief tank by the product of the elapsed time between inventories and the density of water. The test data required for calculating the identified leak rate are the water levels in the tanks and the test duration. The unidentified leak rate is calculated by subtracting the identified leak rate from the gross leak rate. 3 - Restrictions on the complexity of the problem: RCSLK9 assumes that the hot and cold legs of the RCS have equal volumes