ML19309D279
| ML19309D279 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/29/1980 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-27, NUDOCS 8004100211 | |
| Download: ML19309D279 (5) | |
Text
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Th PHILAD ELPHI A ELECTRIC COM PANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 QIS) 841-5o01 SHI ELDS L. D A LTROFF stactacpao Tion February 29, 1980 IE Bulletin 79-27 Mr. Boyce H.
Grier, Director Office of Inspection & Enforcement Region I US Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 D e a r '.. r. Grier:
This is in response to y ou r letter a2 November 30, 1979, which forwarded IE Bulletin 79-27.
The actions requested and our resp ons es are lis ted s equentially below.
Actions to Be Taken by, Lic en s e e s 1.
Review the class-1-E and non-class 1-E buses supplying p ower to safety and non-safety related instrumentation and cont rol systems which could af f ect the ability to achieve a cold shutdown condition usin g exis ting p rocedu res or p rocedu res developed under item 2 below.
For each bus:
a) identify and review the alarm and/or in di c a ti on provided in the control room to alert the op erator t o the loss of power to the bus.
b) identify the instrument and control system loads connected to the bus and evaluate the effects of loss of p ow e r t o these loads including the ability to achieve a cold shutdown condition.
c) describe any p rop osed design modifications resulting from these reviews and evaluations, and y our p rop osed schedule for imp le me n tin g thos e modifications.
8004100
- 2 II
Mr. Boyce H.
G rie r, Director Page 2 Re,sp o n s e :
The Class 1-0 and non-Glars 1-E buses (dis t ribu tion panels) supplying p ower to saf ety and non-safety related instrumentation and control systems which could affect the ability to achieve a c old shutdown using exis ting p rocedu res have been reviewed.
a)
The distribution panels listed in Table I supply power for all of the instruments identified in response 1.b.
below.
These panels have been reviewed to determine an alarm that would alert the op erat or t o the loss of p ow e r t o t h a t panel.
At least one alarm has been identified which specifically indicates loss cf power to each panel with the exception of the 00Y02a, 00Y03, 20Y30, 30Y30, 20Y32, and 30Y32 panels.
For these panels a review is still in p rogress to identify a process alarm that is associated with both the loss cf feed and the instruments f ed f rom that feed.
b)
The p ower s ou rces feeding the controls used to achieve a safe shutdown were designed to meet the single failure criteria.
As a result, the plant can be placed in a hot shutdown condition f ollowing the loss of any power supply (to include either a set of fuses, distribution panel, diesel generator, or safeguard b a t t e ry ).
The plant can be placed in a eold shutdown condition for the loss of any power s ou rce, with the exception of the c ont rols for the valves in the shutdown cooling suction line.
However, an alternate p ower s ou rce could be provided to these valves within the required time frame to permit them to be opened if their p rimary s ou rc e of power and control were lost.
The instruments in the control room which provide information to the op erator t o achieve a cold shutdown have been identified and are listed in Table II.
An analysis is being perf ormed to determine if each of these instruments has an alternate instrument fed from a different dis t ribution panel t o monitor the s ame process parameter.
For th os e ins truments which do not have an alternate indication, additional review is in p rogress to determine if there is a procedural method for determining the missing variable.
This review should be completed by March 31, 1980.
c)
Possible design modifications and a s ch e du le for implementing these modifications have not been determined pending the c omp le t i on of the reviews mentioned above.
It is anticipated that these reviews and a schedule f or implementation of any p r op os e d changes will be c omp le t e by March 31, 1980.
!! r. Bcyco H. Grior. Diroctor Pego 3 A_c t_i o n to be.Taken b y Li_c e n s e_e s_ :
2.
Prepare emergency procedures or review existing ones that will be used by control room operators, including p rocedures required t o achieve a cold shutdown condition, upon loss of p ow e r t o each class 1-E and non-class 1-E bus supplying power to saf ety and non-s af ety related instrument and control systems.
The emergency procedures should include:
a) the diagnos tics /a larms /indicat ors /s ymp ton resulting from the review and evaluation conducted per item 1 above.
b) the use of alternate indication and/or control circuits which may be p ow e re d from other non-class 1-E or class 1-E ins t ru me nt a t i on a6d control buses.
c) methods for restoring p ow e r to the bus.
Describe any p rop os ed design modification or administrative controls to be imp le me n t e d resulted from these procedures, and your p rop osed s chedule for implementing the changes.
Re_sppnsy The review of emergency p roce du res and the development of one new procedure based on Action Items 2.a), b), and c) is continuing a t the p res ent time.
A new procedure is being written for the loss of the non-class 1-E uninterruptuble AC distribution panel (YS0) to indicate what actions the op e ra t o r s h ou ld take in case of the loss of this panel.
In addition, a list of all instruments associated with certain critical 120 volt feeds is being developed f or use by the op e ra t ors.
It is anticipated that a schedule for possible design modifications and administrative controls to be implenented as a result of the review of emergency p roce du res will be complete by March 31, 1980.
Actions to be Taken by Licensees 3.
Re-review IE Circular No. 79-02, Failure of 120 Volt Vital AC P ower Supplies, dated January 11, 1979, to include both class 1-E and non-class 1-E safety related p ower supply interters.
Based on a review of operating experience and y ou r re-review of IE Circular 79-02, describe any p rop os ed design modifications or administrative cont rols to be implemented as a result of the re-review.
fi r. Bcyco H. Grior, Diroctor Pago 4 Ee8P.p_ns,e Based on a re-review of IE Circular No. 79-02, there are no design modifications or administrative controls necessary for class 1-E or non-class 1-E safety related p ower supply inverters.
Very truly yours, s
Wf#'/'y/
cc:
US Nuclear Regulatory Commission Office of Inspection & E n f o r c e me.n t Division of Reactor Operations Inspection Washington, DC 20555 1
PBAPS TABLE I DISTRIBUTION PANELS Unit 2 Common Unit 3 20Y15 00YO2 30Y15 20Y21 00YO3 30Y21 20Y22 30Y22 20Y30 30Y30 20Y32 30Y32 20Y33 30Y33 20Y34 30Y34 20Y35 30Y35 20Y37 30Y37 20Y50 30YSO 20D23 30D23 20D24 30D24
-2AD25 3AD25 2BD25 3BD25 2AD45 3AD45 2BD45 3BD45 RPS Bus A RPS Bus A RPS Bus B RPS Bus B 1
+
1 f
e
PBAPS r
TABLE II INSTRUMENTATION IDENTIFIED FOR REVIEW Reactor - level, pressure vessel - temperature Torus - level, temperature Drywell - pressure, t e mp e ra tu re Rod Position Information System Neutron Monitoring Standby Liquid Control level, pressure High Pressure Coolant Injection - all instrumentation Reactor Core Isolation Cooling - all instrumentation Core Spray - all instrumentation Residual Heat Removal /High Pressure Service Water -
all instrumentation Standby Cas Treatment S ys tem - f low, filter pressure differential Emergency Cooling Towers Relief Valves Radiation Monitoring - reactor building vents, stack, control room Condenser Vacuum Condensate Storage Tank Level Recire. Pumps, M-G sets flow, speed, temperature, controls Instrument Air Pressure Turbine Building Cooling Water - temp eratu re React or Building Cooling Water - temp erature Service Water - p ressure
.