ML15008A119
| ML15008A119 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 01/06/2015 |
| From: | Blanch P - No Known Affiliation |
| To: | Bill Dean Region 1 Administrator |
| Pickett D V | |
| References | |
| Download: ML15008A119 (2) | |
Text
1 Paul M. Blanch Energy Consultant 6 January 2015 Mr. William Dean Regional Administrator Region 1 U.S. Nuclear Regulatory Commission King of Prussia PA
SUBJECT:
Indian Points Safety Related Systems, Structures and Components defined in 10 CFR 50.2 REFERENCEs:
Entergys 10 C.F.R. 50.59 Safety Evaluation (ML14253A339), dated August 21, 2014 Indian Point Nuclear Generating Unit Nos. 2 & 3
Dear Bill:
While reviewing Entergys referenced 50.59 evaluation I noted Entergys statement:
The existing pipeline automation and control system, which will be used for the proposed new 42 inch pipeline near IPEC, does not provide for an automatic isolation of the closest upstream and downstream mainline valves upon the detection of a pipeline rupture. The two closest actuated valves are located at mile post 2.61 on the west side of the Hudson River and at mile post 5.47 just east of IPEC. They would require an operator to take action to close these valves. The system, however, is monitored 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day and an alarm would immediately alert the control point operator, located in Houston, Texas, of an event and isolation would be initiated. This would result in all the gas between these valves at the time of closure being able to vent or burn.
The estimated time to respond to the alarm (less than one minute) and the closure time of the valves (about one minute) was used as the basis for an assumed closure time of three minutes for the analysis performed in the attached report.1 [emphasis added]
This is a very clear statement that the closure time of three minutes is the basis for the mitigation of accidents impacting potential offsite exposures and maintaining the reactor in a safe shutdown condition.
10 CFR 50.2 defines safety-related structures, systems and components (SSCs) as follows:
Safety-related structures, systems and components means those structures, systems and components that are relied upon to remain functional during and following design basis events to assure:
1 Withheld under 10 CFR 2.390
2 (1) The integrity of the reactor coolant pressure boundary (2) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (3) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the applicable guideline exposures set forth in § 50.34(a)(1) or § 100.11 of this chapter, as applicable.
Failure of the 42-inch valves to close or close within the three-minute assumed time may impact the consequences of an accident due to the consequential damage and ability to fight any resulting fires.
This is the case with both the proposed new gas transmission line and the three existing gas lines that pass within a few hundred feet of vital SSCs.
It appears that the valves, or at least their closing function, meet the 10 CFR 50.2 criteria for being classified as safety-related components. It is not apparent that associated administrative controls (e.g., periodic testing of the valves and response training for workers) are in place to provide reasonable assurance this important role will get performed when needed.
Please explain why these valves and supporting systems are not classified as safety related as defined in 10 CFR 50.2.
I am willing to discuss with your staff the numerous potential failures that may affect the ability to maintain the reactors in a safe shutdown condition and/or mitigate the consequences of an accident due to failure of the remote valves and/or piping systems.
I am looking forward to your prompt response.
Sincerely,