Questions Regarding the Implementation of the Gas Accumulation Progra
The inspectors identified an
URI regarding the implementation of the Gas Accumulation Program at Braidwood. Specifically, the inspectors were concerned with whether a number of surveillance frequencies that were contained in the Surveillance Frequency Program meet the requirements as specified in procedure ERAA2009, Managing Gas Accumulation. Additionally, the inspectors were concerned with the basis for not increasing the frequency of the
UT examinations following the discovery of a void on October 20, 2015. At the end of the inspection period, the licensees investigation on the cause of an unexpected void growth, and the potential surveillance frequency discrepancies was ongoing. Resolution of this issue will be based on the inspectors review of the licensees completed investigation. On March 15, 2016, while performing a semi-annual gas monitoring surveillance on Unit 2 under 2BwOSR 3.2.22,
ECCS and
Containment Spray Venting and Valve Alignment/UT Verification Surveillance, a gas void was found along line 2SI03BA, which is a
SI line that feeds the A and D
SI hot leg injection lines. The ultrasonic examination revealed that a 0.960 cubic foot void was present. A void had been previously identified in the same location on October 20, 2015, which had a volume of 0.25 cubic feet. Calculation BRW150100M was performed in October 2015 to justify operability of the
SI system. The calculation produced a void size acceptance criteria of 0.389 cubic feet. Upon identification of the void in March 2016, the licensee declared the 2A
SI train
inoperable due to the previously established acceptance criteria of 0.389 cubic feet not being met, and entered
LCO 3.5.2,
ECCS Operating, Condition A, which required that the affected train be restored to an
operable status within 7 days. The licensee exited the LCO on March 16, 2016 upon completion of a revision to calculation BRW150100M, which documented a revised acceptance criteria of 1.5 cubic feet. During this inspection period, the inspectors reviewed the licensees revision to the aforementioned calculation, and the requirements contained in procedure ERAA2009. Based on their review, the inspectors questioned the basis for not increasing the frequency of the
UT examinations following the discovery of the void on October 20, 2015. Additionally, the inspectors were concerned with the frequency of inspection of a number of locations outside the missile barrier (17 for Unit 1 and 19 for Unit 2), which appeared to conflict with what was specified in the procedure. Specifically, the locations in question were examined at an 18 month frequency, although the procedure stated that frequency of once per refueling outage shall be used only for locations that are inaccessible due to actual (not just posted) high radiation conditions. Finally, the inspectors had a concern regarding the means by which gas accumulation was managed for locations inside the missile barrier, since the prescribed locations were only monitored once upon Mode ascension from an outage. The licensee entered the inspectors concerns into their
CAP as
IR 2644532 and
IR 2640751. At the conclusion of the inspection, two work group evaluations were in progress to: 1) address the void growth observed since October 2015, and 2) evaluate the compliance with the program document procedure, ERAA2009. This
URI will remain open until the evaluations are completed and the inspectors review the evaluations to determine whether a performance deficiency exists. (
URI 05000456/20160104; 05000457/201600104; Questions Regarding the Implementation of the Gas Accumulation Program)
