ML20198S987
| ML20198S987 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/06/1986 |
| From: | Lempges T NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| IEB-86-001, IEB-86-1, NMP-18647, NUDOCS 8606110205 | |
| Download: ML20198S987 (1) | |
Text
NMP-18647 i
NIAGARA MOH AWK POWER CORDORATION NIAGARA MOHAWK 30o ERIE BOULEVARD WEST SYRACUS E, N. Y 132O2 4
vce scese an aatos 4
June 6, 1986 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 RE:
IE Compliance Bulletin 86-01/ Docket 50-220 Gentlemen:
Bulletin 86-01 requested a determination as to whether a single failure of the RHR/ECCS minimum recirculation valve could prevent proper ECCS response. We have reviewed the design and concluded that the design of the minimum recirculation flow valves at Nine Mile Point Unit 1 precludes this type of event.
The Unit 1 ECCS and Shutdown Cooling systems are substantially different in design from the RHR/ECCS systems of a BWR 3, 4, 5, or 6.
The minimum flow valves on the core spray system are spring actuated relief valves, which open when core spray pump discharge pressure exceeds the spring force. Each of the two core spray loops has its own minimum flow valve. Therefore, the single failure of one valve would not cause the failure of the redundant system. The Containment Spray system does not utilize minimum flow valves and is l
separated from the core spray system. The shutdown cooling system is separate from the ECCS systems and is classified non-safety related.
l Therefore, we conclude that Nine Mile Point Unit 1 is not vulnerable to the type of event described in Bulletin 86-01.
Sincerely, hK05005 860606
"[
G 20 Wra R
Thomas E. Lempges Vice President Nuclear Generation 1
TEL/asg 0
i cc:
Dr. Thomas E. Murley Regional Administrator g f,3 pp. iso H Wt.IM g g c.
- ---_-