ML20072A406
| ML20072A406 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/07/1983 |
| From: | Bradley E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8306100110 | |
| Download: ML20072A406 (4) | |
Text
., p* #
i PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 CDW ARD G. S AU ER, J R.
12151841-4000 vece passeommt mmo esmEmat covasst GUGENE J. BR ADLEY assoceava esmanas crumse6 OON ALD SLANKEN RUDOLPH A. CHILLEMI
- f. C. MI R K H A LL T, H. M AH ER CORN ELL June 7, 1983 PAUL AUERBACH assistant esNERab coUmsEb EDW ARD J. CULLEN. J R.
THOM AS H. MILLER, J R.
IZENE A. McMEN N A assistant counes6 Mr.
A.
Schwencer, Chief Licensing Branch No. 2 Division of Licensing U.
S.
Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Limerick Generating Station, Units l&2 Response to Reactor Systems Branch Draft Safety Evaluation Report (DSER)
Reference:
A.
Schwencer to E.
G.
- Bauer, Jr.,
Letter dated March 11, 1983 File:
GOVT l-1 (NRC)
Dear Mr. Schwencer:
The attached document is a final response to Reactor System Branch (RSB) Draft Safety Evaluation Report Item No.
3, Higt/ Low Pressure Interlocks on Limerick ECCS INJECTION VALVES, as discussed at the ICSB and RSB joint meeting held in Bethesda, Maryland on May 17, 1983.
Sincerely, Euge e J Br dley 8306100110 830607 PDR ADOCK 05000352 E
PDR RJS/gra/19
\\
Copy to:
See Attached Service List ifI
v'
,:s cc:
Judge Lawrence Brenner (w/
enclosure)
Judge Richard F. Cole Judge Peter A. Morris Troy B. Conner, Jr., Esq.
An'n P. Ilodgdon, Esq.
Mr. Frank R. Romano Mr. Robert L. Anthony Mr. Marvin I. Lewis Judith A. Dorsey, Esq.
l Jacqueline I. Ruttenberg Thomas Y. Au, Esq.
Mr. Thomas Gerusky Director, Pennsylvania Emergency Management Agency Steven P. Hershey Charles W. Elliott, Esq.
Donald S. Bronstein, Esq.
Mr. Joseph H. White, III David Wersan, Esq.
Robert J. Sugarman, Esq.
Martha W. Bush, Esq.
Atomic Safety and Licensing Appeal Board Atomic Safety and Licensing Board Panel Docket and Service Section
~
HICH/ LOW PRESSURE INTERLOCKS ON LIMERICK ECCS INJECTION VALVES e.
NRC - RSB POSITION (per DSER transmitted to PECo on 3/11/83)
Interlocks of ECCS Injection Valves (6.3)
The HPCI system incorporates relief valves to protect the components and piping from inadvertent overpressure conditions resulting from either thermal expansion or backpressure leakage into the low pressure portions of the system.
The Core Spray and LPCI (RRR) systems are not designed to withstand normal reactor operating pressure. Each of the low pressure lines that interface with the reactor coolant system has a testable check valve inside primary containment backed up by a normally closed motor-operated gate valve outside of containment. Relief valves are provided in the low pressure lines to protect against leakage from the reactor coolant system. An interlock ir provided on the motor-operated valves which prevents their opening until the differential pressure across the valve is below a specified value.
We require that (A) this interlock be present at all times for both automatic and manual valve actuation, and (B) that the setponts be such that the valve cannot be opened until reactor coolant pressure is below that of the low pressure ECC system involved.
l
RESPONSE
i Part (A)
The interlock is present at all times for both automatic and manual valve actuation for both low pressure ECC systems.
The following valves are ' series combinations of motor operated valves and testable check valves, which isolate low pressure ECC systems from the higher pressure primary system.
l Core Spray (A Loop)
E21-F006A Core Spray Testable Check Valve E21-F005 Core Spray MOV E21-FOO4A Core Spray MOV Core Spray (B Loop)
E21-F006B Core Spray Testable Check Valve E21-F038 (HV 108)
Core Spray Testable Check Valve E21-F037 Core Spray MOV E21-F004B Core Spray MOV LPCI (All 4 Loops) l Ell-F017A, B, C, D LPCI MOV Ell-F041A, B,C,D LPCI Testable Check Valves l
r v
\\
/ A '
v.
The normally closed Core Spray injection valves (E21-F005 and E21-F037) and the normally open, Core Spray injection valves (E21-F004A and E21-F004B) are interlocked by high reactor pressure (one out of two twice logic) to prevent their receiving an opening signal upon automatic system initiation.
In addition, the valves are interlocked by limit switches to prevent both valves in each loop from being opened manually at the same time during testing.
Ell-F017A, B, C, D LPCI Injection MOV's are interlocked to prevent opening when differential pressure across the valves exceeds the setpoint.,
This interlock applies to manual or automatic opening.
i Part (B)
The permissive for Core Spray System injection is based on direct reactor pressure, nominally 450 psig.
The permissive for opening the LPCI injection valves is based on the differential pressure across the valve, a nominal range of 50-100 psid.
These Limerick features meet all applicable codes and regulations. Also the recommendations of Branch Technical Position ICSB 3 were followed in evaluating ECCS low pressure interlocks on an individual case basis (Section B.5).
Limerick's LPCI injection valve permissive is based on the differential pressure across the valve.
The differential pressure setpoint range for the LPCI injection valves was selected such that the low pressure portion of the RHR piping will be protected from over-pressurization above the j
maximum service pressure, 500 psig.
The 50-100 psid setpoint range is based on the rated maximum pump discharge head prior to opening the LPCI injection valve, 360 psig.
This gives a pressure range of 410-460 psig downstream of the injection valve necessary to satisfy the permissive.
The final selection of the differential pressure permissive setpont will i
be within the 50-100 psid range and will consider the final system configuration and performance characteristics.
When the permissive has been satisfied and the LPCI injection valve opens, injection into the reactor will begin when the system pressure upstream of the check valve exceeds the reactor pressure.
If reactor pressure begins to rise above pump discharge head, the check valve will close, thus preventing high reactor pressure from over-pressurizing the low pressure RHR system pipe.
15/6 4