ML20151H087
| ML20151H087 | |
| Person / Time | |
|---|---|
| Issue date: | 09/21/1981 |
| From: | Fioravante N Office of Nuclear Reactor Regulation |
| To: | Parr O Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20151H089 | List:
|
| References | |
| FOIA-88-92 NUDOCS 8110200062 | |
| Download: ML20151H087 (4) | |
Text
-.
l /
' ' '- .m,#c, '
UNITED STATES -
. .,. g j * ,
NUCLEAR REGULATORY COMMISSION
- r ]
C -/ WA$wtNGTON. D. C. 20555 i c l gg ? '.1 F1 1 MD'.ORAND'JM FOR: Olan D. Farr, Chief Auxiliary Systems Branch Division of Systems Integration 1
FROM: N. E. Fioravante Auxiliary Systems Branch 1 Division of Systems Integration :
SUBJECT:
SUW.ARY OF MEETING CONCERNING APPENDIX R SAFE SHUTDOWN REVIEW I On Thursday, August 20, 1981 members of the NRC staff and the Brookhaven l staff met for the purpose of resolving differences of interpretation of Appendix R Section III.G and III.L, and to discuss proposed acceptance criteria for dedicated and alternative systems. A list of attendees is enclosed. The interpretations and proposed criteria agreed upon by a majority of the attendees will be used by Brookhaven in the review of
.cperating plants until further direction is provided by ASb.
The topics discussed and the positions agreed upon are presented below:
- 1. The definition of hot standby (or hot shutdown) and cold shutdown equipment was addressed. Hot standby (or hot shutdown) and cold shutdown conditions will be determined by the technical specifications for the plant under review and equipment will be categorized by the '
equionent's purpose. Thus, equipment used to achieve cold shutdown will be classified as cold shutdown equipment; even if, the equipment is initiated and used in the hot standby condition.
- 2. A discussion of the time required to achieve cold shutdown was conducted to clarify what appears to be conflicting statements in Appendix R.Section III.G of Appendix R states that systems required to achieve cold shutdown should be capable of being re-paired within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Thus, a plant could remain in a hot shutcown condition for this period of time and then initiate co'd shutdown at 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. hever,Section III.L of Appendix R states that the plant shall be capable of achieving cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The problem is not so much the time to achieve cold shutdown, but that Section III.G appears to allow a plant to maintain hot shutdown (or hot standby) for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> using only onsite power and then proceed to ccid shutdown using either onsite l
or offsite power. Secticn III.L indica'es that a plant must be l
l
-l U
l flloROOM ilo v A & l
1 s.
2 Appendix capable of achieving cold shutdown using only ensite power.
R, Section Ill.L clearly states that offsite tc.er is assumed lost i l
for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. It was agreed that Section III.L culd be used for guidance. Thus, a plant should have the capability of repairing equipment and achieving cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> using only onsite power. The 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is only an upper limit, a licensee may limit the repairs and achieve cold shutdown in a shorter time frame'.
- 3. Definition of alternative and dedicated systems were briefly discussed.
l Except for plants that are building a standby shutdownAppendix facility, R the does ;
division between alternative and dedicated is unclear. I not provide clear guidance of the division between alternative and dedicated from the system aspect; however, Appendix R makes a clear l l
distinction between the classification of dedicated and alternative with regard to when the modification must be implemented. Since the classification of the system does not effect the review or technical merit of the shutdown system, an agreement was reached that neither Brookhaven nor ASB reviewers would make a judgment that the licensee's shutdown equipment were alternative or dedicated. The teminology chosen by the licensee will be used.
- 4. The sizing of dedicated and alternative shutdown systems was discussed in reference to spurious signals resulting from a fire. The size of systems used for primary inventory makeup would be controlled by the number of spurious signals which open the primary system. The type and number of spurious signals resulting from a fire in the cable spreading room or control room which resulted in opening of the primary system could not easily be addressed. We generally agreed that the ECCS equipment would provide a good starting point for protection against spurious signals, in that the ECCS is designed to handle a limited number of LOCAs. Thus, three options for handling spurious signals are proposed: 1) require all plants to provide fire protection for the ECCS equipment, 2) require the dedicated or altemative system be of equal capacity to the ECCS equipment, or 3) require the dedicated or alternative system be of capacity demonstrated adequate by analysis which considers spurious signals. In that, Appendix R does not require protection of the ECCS equipnent and does not consicer a LOCA c:ncurrent with a fire, we agreed to limit the reviews to spurious signals resulting from fire damage to safe shutdown cabling and associated circuits.
Thus, the capacity of the dedicated or i .ernative systems will be based on normal 1oss of offsite power ? quired by Appendix R and limited spurious signals as stated at We concluded that the issue of spurious signals be investigaa seoarately and not under the current Appendix R reviews.
I
O i
\ .
. l
- 5. The instrumentation needed for safe shutdown was addressed for PWR's and BWR's. The instrumentation recommended for PWR's are:
)
a) pressurizer pressure and level b) reactor coolant hot leg temperature and either cold l
leg temperature or TAVG
! c) steam generator pressure and level (wide range) I 1
d) source range flux monitor dkg n o s +ie is, s heu,,mQu h, sMehu,rn eya % s e) actue; ';;w me: w -a - te fnr mil prps-use d (euy < eta-t;73 f) level indication for all tanks used (CST)
The instrumentation recomrended for BWR's are:
a) reactor water level, pressure .an442 ;erature=
b) suppression pool level and temperature c) emergency or isolation condenser level c6 n o s + s'c, a s %, Jh~n % s WJou.m sy s % S d) ac"11 #1mu me ru :mcrt: f:- =11 ~' re u:ed e) level indication for all tanks used Appendix R does not require one remote shutdown panel; but only addresses the capability of having one train of systems available to shutdown. In order to assure adequate control of process variables during the shutdown operation, it was agreed that all instrumentation except flow measurement and tank level indication should be limited to the smallest number of location. Plants using multiple shutdown panels should demonstrate that communication between operators is adequate to shutdown the plant.
- 6. The limiting condition on the use of fire pumps was discussed. A number of licensee's have indicated the need to use fire pumps for providing makeup water or as a source of cooling water after the fire has been extinguished.
We concluded that the use of fire pumps is not prohibited by Appendix R.
However, the condition for when the pumps are needed and the time required to realign the pumps to the fire protection system would be reviewed on a case by case basis to determine the acceptability of the fire pumps.
. 8.
4
- 7. The types of repairs allowed for cold shutdown were discussed.
While the replacement of cabling will be permitted, mechanical repairs such as replacing a valve or pump will,be reviewed to demonstrate practicably within the limited time available.
Procedures for repairing damaged equipment should be prepared in acvance along with replacement equipment (i.e. , cable made-up with terminal lugs attached). Also, replacement equipment will be stored onsite. All repairs should be of sufficient quality control to assure safe operation. Repairs not permitted are the removal of fuses for isolation, the use of jumper cables and the use of clip leads behind control panels.
Also discussed was the ability to make repairs in the fire damaged area. It was concluded that if repairs were to be made in the area where the fire occurred, the licensee would have to demonstrate that sufficient time was allowed to cool the area and protect the repairs from remaining heat sources.
hYs -
N. E. Fioravante Auxiliary Systems Branch Division of Systems Integration
Enclosure:
As stated cc: R. Hall /BNL E. MacDougall/BNL V. Lettieri/BNL 1
_ . . _ _ _