ML20094C254
| ML20094C254 | |
| Person / Time | |
|---|---|
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-10.4.2, NUREG-75-87, NUREG-75-87-10.4.2, SRP-10.04.02-01, SRP-10.04.02-1, NUDOCS 9511020119 | |
| Download: ML20094C254 (4) | |
Text
_ _ _
NUREG 75/087 p naq o.
U.S. NUCLEAR REGULATCRY COMMISSICN 0
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7, STANDARD REVIEW PLAN i.'% * * *. * #j OFFICE OF NUCLEAR REACTOR REGULATION
.v SECTION 10.4.2 MAIN CONDENSER [VACUATION SYSTEM REVIEW RESPONSIBILITIES Primary - Effluent Treatment Systems Bra nch (ETSB)
Secondary - None I.
AREX OF REVIEW At the construction permit (CP) stage of review. ETSB reviews tiie infonnation in the 'appli-cant's safety analysis report (SAR) in the specific areas that follow. At the operating license (OL) stage of review, the ETSB review consists of confirming the design accepted at the CP stage.
1.
The main condenser evacuation system (MCES) generally.onsists of two subsystems:
the " hogging" or startup system which initially establishes main condenser vacuum, and the normal system which maintains condenser vacuum once it has been established. The review of each MCES subsystem includes the design, design objectives capacity method of operation, and factors that influence gaseous radioact'.e <..aterial handling, e.g.,
system interfaces and potential bypass routes. The E1!3 review includes the system pipingandinstrumentationdiagrams(P& ids).
2.
The quality group classifications of piping and equipment. and the bases governing the design criteria chosen are reviewed.
3.
Design features to preclude the possibility of an explosion if the potential for explo-sive mixtures exist! are reviewed.
Provisions incorporated to sample and monitor radioactive materials in gaseous effluents from the MCES are reviewed in Standard Review Plan (SRP) 11.5.
II.
ACCEPTANCE CRITERIA The applicant's design should meet the following criteria:
1.
The MCES capacity should be consistent with the industry guidelines given in Reference 2.
Either mecnanical vacuum pumps or steam jet air ejectors may be used for hogging (startup) or normal evacuati,,n of the main condenser.
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2.
The components of the system may be designed to Quality Group D as defined in Regula-tory Guide 1.26 (Ref. 3) and to a non-seismic design classification.
3.
If there is a potential that explosive mixtures may exist, the MCES should be dasigned to withstand the effects of an explosion or provide redundant instrumentation to l
detect and annunciate the buildup of potentially explosive mixtures. Instrumentation with sutomatic alarm and control functions should be provided to continuously monitor concentrations of the appropriate gases in portions of the system having the potential for containing explosive mixtures. The design should include precautions to stop continuous leakage paths, i.e., provisions for liquid seals downstream of rupture j
discs and for prevention of pennanent loss of the liquid seals in the event of an explosion.
l 4
Provisions to control and monitor releases of radioactivity to the environment from tre MCES must conform to General Design Criteria 60 and 64 (Ref. 1).
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REVIEW PROCEDURES The reviewer will select and emphasize material from this review plan as may be appropriate for a particular case.
1.
In the ETSB review of the MCES, the P&lDs are reviewed to determine the flow paths of gases through the system, including all bypasses, and the points of release of gaseous wastes to the environment er other systems. This infonnation is used in SRP 11.3 to calculate the quantity of radioactive material released annually in gaseous effluents during normal operations, including anticipated operational occurrences. ETSB vert-fies that water from the mechanical vacuum pumps and condensate from the steam jet air l
ejectors are classified as radioactive liquids and treated accordingly.
i 2.
ETSB reviews the equipment quality group classifications.
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3.
If there is a potential that explosive mixtures may exist, ETSB determines whether the
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applicant has designed the MCES to withstand the effects of such an explosion, or has provided redundant instrumentation to detect, annunciate, and prevent the buildup of potentially explosive mixtures. ETSB will also detennine if the applicant's design includes adequate provisions to stop continuous leakage paths after an explosion.
I IV.
EVALUATION FINDINGS ETSB verifies that sufficient information has been provided and that the review is adequate I
to support conclusions of the following type, to be included in the staff's safety evalua-tion report:
"The main condenser evacuation system includes equipment and instruments to establish and maintain condenser vacuum and to prevent an uncontrolled release of radioactive material to the environment. The scope of our review included the system capability to l
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transfor radioactive gases to the gaseous waste or ventilation systems, the design provisions incorporated to monitor and control releases of radioactive materials in gaseous effluents in accordance with General Design Criteria 60 and 64 and the quality j
group classification of equipment and components used to collect gaseous radioactive wastes relative to the guidelines of Regulatory Guide 1.26. We have reviewed the appli-cant's system descriptions, piping and instrumentation diagrams, and design criteria for the components of the main condenser evacuation system. The basis for eteptance l
in our review has been conformance of the applicant's designs, design criteria, and design bases for the innin condensor evacuation system to the applicable regulations and regulatory guides referenced above, as well as to branch technical positions and in-dustry standards. Based on our evaluation, we find the proposed main condenser evacuation system acceptable."
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l V.
REFERENCES 10 CFR Part 50, Appendix A General Design Criterion 60, " Control of Releases of l
1.
Radioactive Materials to the Environnent," and Criterion 64, " Monitoring Radioactivity
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Releases."
2.
"StandardsforSteamSurfaceCondensers,"6thEd.,HeatExchangerInstitute(1970).
3.
Regulatory Guide 1.26 " Quality Group Classifications and Standards for Water,
Steam, and Radioactive-Waste-Containing Components of Nuclear Power Plants "
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