ML19220B617
| ML19220B617 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/11/1977 |
| From: | Ross D Office of Nuclear Reactor Regulation |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| TASK-TF, TASK-TMR NUDOCS 7904270110 | |
| Download: ML19220B617 (4) | |
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'Jatt chron Dockat No'. 50-323 MDIDFAIDUM FOR:
D. 3. Vassallo, Assistatat Director for LURs, DF:I FROM:
D. F. Ross, Jr., Assistant Director for Reactor Safety, DSS
SUBJECT:
TEREE MILE ISLA'!D LiiIT NO. 2 - OVERPRESSURIZATIO::
Plant Name:
Three Mile Island Cait No. 2 Docket Ut.nber:
50-320 Licensing Sts;;e:
OL Responsible Branch LWR-4 and Project Manager:
Harley Silrer Systems Safety Dranch Involved:
Reactor Systems Branch Review Status:
Additional Information Requested contains the current requirements for overpressure protection features and lists the additional information required from the applicant.
If the applicant cannot satisfy the requirements and supporting documentation for a long-term solution, an interim position will be required.
0:'f h.1)gr?i W ci Denwood F. Rcss, Jr., Assfs' tant Director for Reactor Safety Division of Syst ema Safety
Enclosure:
Infor=ation Eaquest cc: S. Entinuer T. Novak R. Heineman G. Mazetis D. Ross S. Israel S. Varga R. Frahm H. Silver J. Watt
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Centact: Jim 2att, NF2 49-27591
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- u. s, messanasseer reti=Tiaea cericas se,4.sse.ies Form AIC 419 (Rev. 9 53) AXCM 02 0 80-308
ENCLCSURE 1 s
Overpressure Protection Position The f ollowing requirements for overpressure protection during startup or shutdown presstre transients are provided fot your guidance.
1.
Credit for coerator action. No credit can be taken for operator action until 10 minutes after the operator is =ade aware that a
transient is in progress.
2.
Sic le failure criteria. The pressure protection system should be designed to protect the vessel, given any event initiating a pressure Redundard or diverse pressure protection systems will be transient.
considered as =eetin; the single failure criteria.
3.
Testability. Provisions for periodic testing of the overpressure protection systec(s) and co=ponents shall be provided.
The progra of tests and f requency or schedule thereof will be selected to assure functional capability when required.
4.
Seismic desirn and IEEE 279 criteria.
Ideally, the pressure protection system (s) should meet both seismic Category I and IEEE 279 criteria.
The basic objective, however, is that the systes(s) should not be vulnerable to an event which both causer a pressure trausie and causes a failure of equipment needed to terminate the trans 5.
Reliability. The system (s) provided =ust not reduce the reliability of the emergency core cooling system or residual 'aeat removal syste -
Requirements for Additional Infor=ati n
Discussion:
The staf f acknowledges receipt in Amendment 51 of ySAR Section 7.6.1.8 (Overpressuritation of Primary Coolant System);
avever, it is too brief to permit adequate evaluation.
The following internation is required for comparison with the requirements identified above.
1.
Provide a summary description of all design, operational features, and procedures for Three Mile Island Unit No. 2 provided to mitigate the consequences of potential pressure transients which could violate Appendix G.
2.
Identify events that could potentially result in violation of Appendix G li=its.80-309
_2_
they establish the Provide analyses of these events and show howsi:ing of rel Provide a 3.
table of components utilized in this phase o l
such Identify the seismic and safety classification of aach and a so se time, information as design flow, pressure or pressure drop, respon to system functions.
etc., as may be important he following
- 4. Provide a table identifytng t:te operator actions for t nor=al caneuvers:
shutdown to cold shutdown 1
Hot Cold shutdown operations 2.
Cold shutdown to startup 3
ssure and For each of the =aneuvers, provide curves of primary system preIde of expected actions is te=perature versus time.
A partial list actions on the pressure curve.
as follows:
)
- Cut-in point of DER system (operator action ion)
-- Isolation point of DER system (operator act Cut-in point of RC pumps Shut-of f point of RC pu=ps
-- Setpoint of RER relief valve
-- Automatic isolation setpoint of DHR
-- Isolation of core flooding tanks.
-- Isolation of ECCS i r
-- Initiatica of nitrogen bubble in the pressur ze
-- Initiatioa of steam bubble in the pressuri:er ions scheduled for
- 5. Discuss instructions for any test or maintenance operat Discusa sure event.
cold shutdown which could possibly lead to an overpres d
how these potential overpressure events will be avoide.
- to Appendix G is the principal While overpressure protection relativt.
d in staff discussions.
concern herein, two other concerns have recurreisolation o a.
ps removal'eapability.
while operating could cause loss of decay heat
- One, reduce features added to provide overpressure protection sig
- Two, t of whether ECCS reliability.
provisions to preclude loss of pu=ps and an asse1s d
s degrade ECCS reliability.
80~310
a Staff cc:=ents relative to FSAR Section 7.o.l.3 1.
The proposed temperature sense point is in the hot leg.
How do you incrnd to correlate this with the vessel metal temperature?
2.
Discuss how the proposed overpressure protection system satisfies the above r.quirements.
e 80~311