ML20050B602
| ML20050B602 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 04/02/1982 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Miraglia F Office of Nuclear Reactor Regulation |
| References | |
| SBN-244, NUDOCS 8204060117 | |
| Download: ML20050B602 (2) | |
Text
PUBUC SERVICE SEMON SWIM E
.::1g Office:
Companyof New HW 1671 Worcester Road Framinoham, Massachusetts 01701 (617) - 872 - 8100 April 2, 1982 O
f S
- J SBN-244 T.F. B 7.1.2 RECE(MC g
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7 APR 0519826 United States Nuclear Regulatory Commission y D ictat tmag g;.g
//
DOguna Washington, D. C. 20555 Attention:
Mr. Frank J. Miraglia, Chief Licensing Branch #3 N
Division of Licensing
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) USNRC Letter, dated February 12, 1982, " Request for Additional Information," F. J. Miraglia to W. C. Tallman (c)
PS Nil Le t t e r, d,t ed Ma rc h 12, 1982, " Responses to 450 Series RAls; ( Accide n t Evaluation Branch)," J. DeVincentis to F. J. Miraglia Su bj ec t :
Response to RAI 450.3; ( Accident Evaluation Branch)
Dear Sir:
We have enclosed a response to the subject RAI, which you forwarded in Ref e re nce (b).
This response was not included in the Reference (c) responses.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY b,W J. DeVincentis Project K1 nager Attachment t
i f 8204060117 820402 PDR ADOCK 05000
T 4
RAI 450.3 As'a result of our review of the main.steamline break-analysis, we have determined that the FSAR does not contain sufficient information for us to complete an independent review as prescribed by SRP Section 15.1.5, Appendix A.
Therefore, provide the following information:
1.
The time sequence of events until plant cooldown is achieved.
2.
Estimates of steam releases from the affected steam generator until isolation of the generator is achieved.
3.
Estimates of steam releases-from the unaf fected steam generator j
for the 0-2 hour and - the 0-8 hour time periods.
.j i
If the affected s'eam generator is isolated, identify the operator 4.
t actions necessary and the time to achieve isolation.
RESPONSE
1.
Reactor trip occurs at the time of the steamline break and the MSIV's are closed at approximately 8 seconds. Followin.; the automatic termination of emergency feedwater to the affected steam generator, the operator will follow standard operating procedures to maintain stable plant conditions and to go to cold shutdown. However, the analysis in FSAR Section 15.1.5 does not assume credit for the automatic isolation feature of the emergency feedwater system.
2.
Estimates of steam releases from.the affected steam generator are given in Table 6.2-66.
It should be noted that -the. steam releases given in Table 6.2-66 were calculated without credit for the automatic isolation feature of the emergency feedwater system.
Manual isolation of emergency feedwater was assumed to-occur at 30 minutes after the break. The' steam generator will blow down its inventory until the bl6wdown rate equals the emer-gency feedwater flow rate to it.
3.
Once the unaffected steam generators are isolated by MSIV closure (% B seconds), there will be no steam release from them other than ~ nominal leakage or ' normal blowdown. Section 15.1.5,.3 presents the assumptions for steam releases from both affected and unaffected steam generators following the postulated rupture.
The Section 15.1.5.3 evaluation does assume a leakage rate from both affected and unaffected steam generators for conservatisu.
4.
No operator actions are required to isolate the affected steam generator.
The MSIV, MJIV, 'and EFW isolation valves are closed automatically.
However, the FSAR Section 15.1.5 analysis conser-vatively assumes that EFW to the affected steam generator is manually isolated at 30 minutes.