ML19289G022
| ML19289G022 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/13/1979 |
| From: | Miraglia F Office of Nuclear Reactor Regulation |
| To: | Stello V Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7906250100 | |
| Download: ML19289G022 (6) | |
Text
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I April 13,1979 NOTE TO:
V. Stello, Jr., Director, TMI Operations f
FRCH:
F. 'J. Miraglia, Jr., Coordinator, Team B l
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The attached report on penetration availability was prepared by IEC3 staff and is provided for your infomation.
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F. J. Miraglia, Jr.
Coordinator Team B
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PENETRATION AVAILABILITY ABSTRACT: This report presents, in abreviated form, a summary of the Staff's efforts in evaluating the ability to monitor the Three Mile Island Unit 2 reactor pressure and level using instruments outside of the containment.
INTRODUCTION: The following penetrations were identified by Bill Millstead as being suitable for making pressure measurements during natural circulation.
(1) PR 538 (2) R 541 (3) R 546 (4) R 591 (5) R 592 DISCUSSION:
It was recognized that some of these penetrations are separated from the primary system by check valves which swing in the " wrong" direction, but Chuck Graves of the RSB has stated that pressure measurements can be made (once the valve is lifted off of its seat) as long as no flow occurs in the out of containment direction.
FINDINGS:
1.
The following penetrations / valve strings are available for measuring pressure:
PENETRATION VALVES (inboard out)
(a) R 538 RC-Vil7 Pressurizer CA-V1 steam space RC-V122 Pressurizer CA-V3 water space RC-V123 RC-P-1A CA-V6 Section n { C) 1, ) ')
2 (b) R 541 MU-VlA or MU-VlB RC-P-1A and MU-V2A or MU-V2B Suction (both A or both B)
(c) R 591 or R592 RC Pump discharge Isolated by inboard check valve little or no flow will be tolerated (d) R 546 CF-V3A or B Core Flood tank Vents WDG-V2 2.
The following combinations of penetrations and valve strings are presented in lighest to lowest point of connection to the primary system.
(a) R 546 CP V3A & WDG-V2 CF V3B & WDG-V2 (b) R 538 RC-Vil7 & CA-V1 (c) R 538 RC-V123 & CA-V6 R 541 MU-Vil. & MU-V2A MU-VlB & MU-V2B R 591 MU-V402C R 592 MU-V402D (d) R 538 RC-V122 & CA-V3 3.
The following valves are not powered by onsite sources, RC-Vil7, RC-V122, RC-V123, CF-V3A, CF-V38, CF-V2A, and CF-V28.
4.
Of the valves which are powered by onsite sources, the folicwing penetrations are associated:
(a) R 538 Division 2(CA-V1, V3, V6)
(b) R 541 Both Divisions (MU-VlB & 28)*
Division 1 (MU-VlA & 2A)*
- including interlocks (c) R 546 Division 2 (WDG-V2)
(d) R 591 & 592 No electrical valves inboard
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3 5.
The location of the sample points are in TMI Unit 1 Nuclear Sampling Rcom in the TM: Unit 1 Control Tower and the Unit 2 Sample Hood.
6.
The elevations of the pipe runs and penetrations are not known.
7.
The following valves have been verified as meeting the qualifi-cations stated in FSAR Section 3.11.2 (60 psig, 286'F 100% RH, and 2.8 x 10 Rad). These are Limitorque valve actuators CA-V1 RC-Vil7 RC-V122 CA-V6 RC-V123 8.
The following documents were used to obtain the information above:
PENETRATION REFERENCE (a) R 538 DWG 2034, 2031 FSAR Tables 6.2-15 9.3-2 FSAR Figures of 8.3 and 9.3-2
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(b) R 541 DWG 2024, 2029 FSAR Table 6.2-15 FSAR Section 8.3 (c) R 546 DWG 2028, 2024, 2034 (d) R 591 & 592 DWG 2024 249 i21 m=w-e o
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Conclusions:==
Based on the information which is presently available:
1.
Most of the motor operated valves of interest are Limitorque valves 7
and are qualified beyond 2.8 x 10 Rad.
Therefore, radiation induced damage need not be considered.
2.
It is not prudent to use any of the available penetration points to attempt to infer any sort of level information by differential pressure.
RECOMMENDATIONS:
Based on "e available data and the conclusions which are drawn therefrom the staff recommends:
1.
That the available penetrations not be used for differential pressure measurements unti!.. ore is known about the actual routing (and therefore elevat;ons) of the affected piping.
2.
That, should recommendations 1 be disregarded, the following penetration /
valve pairs be used as (a) First Choice:
Reference leg R 546 (CFV3A or CFV3B and WDG-V2)
Measured leg R538 (RCV122&CA-VB)
(b) Second Choice R 546 (CFV3A or CFV3B and WDG-V2)
Measured leg R 538 (RC-V123&CA-V6)
(c) Third Choice Reference leg R 538 (RC-Vll7 & CA-V1)
Measured leg R 541 (MU-VlA & MU-V2A) or (MU-BlB & MU-V28)
(In the event ".at valves CF/WDA are used it will be necessary to charge the lines by filling the core flooding tanks through the N2 supply or the tank cross connect lines)
5 (It will also be necessary to determine the relative heights of the penetration used to determine the level which is actually being measured.
(It could end up being negative)
(The pressurizer must be flooded with ficw established via RCV177 & CA-V1 if alternative 3 is used) This will result in an atmospheric release.
3.
The best penetration of system pressure measurement is R 533 via RCV122 &
CA-V3.
4.
All valves which are listed in Result 3 above should be opened at this time.
5.
Isometric drawings (with dimensions) should be provided for the following piping runs:
(a) Pressurizer steam space sample line from the steam space to valve CA-V208.
(b) Pressurizer water space fr m the pressurizer water space to penetration R 538.
(c) Reactor coolant pump RC-P-1A suction letdown tap to valve CA-V6.
(d) Reactor Coolant Pump RC-P-1A suction to valve MU-V376.
(e) Discharge of RC-P-2A to valve MU-V16C.
(f) Discharge of RC-P-1A to valve MU-V160.
(g) Core Flood Tanks lA and 1B.o PENETRATION R 546.
6.
No external pressure measurement (except at the pressurizer) should ce attempted while a reactor coolant pump is operating, t
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