ML20209G365

Affidavit of Wl Brooks Supporting Applicant 860818 Motion for Authorization of Fuel Loading & Precritical Testing

ML20209G365
Person / Time
Site:	Braidwood
Issue date:	09/08/1986
From:	Brooks W Office of Nuclear Reactor Regulation
To:
Shared Package
ML20209G335	List: ML20209G329 ML20209G353 ML20209G365 ML20209G377
References
OL, NUDOCS 8609120439
Download: ML20209G365 (3)

Text

. _ _ - - - _ .-_- . . . . . -_-_-. - -

1 i

UNITED STATES OF AMERICA j

NUCLEAR REGULATORY COMMISSION BEFORE TIIE ATOMIC SAFETY AND LICENSING BOARD In the Matter of ) *

! )

l COMMONWEALTH EDISON COMPANY ) Docket Nos. 50-456

) 50-457 l

j (Braidwood Station, Units 1 and 2) )

AFFIDAVIT OF WALTER L. BROOKS I, Walter L. Brooks, being duly sworn, depose and state

1. I hold the position of Nuclear Engineer, Reactor Systems Branch , Division of Pressurized Water Reactors - A, Office of Nuclear Reactor Regulation in the Nuclear Regulatory Commission (NRC). I

! have held that and similar positions with NRC since 1974. Before t

that I was employed for 21 years by Gulf United Nuclear Corporation and its predecessor companies as a reactor physicist. Most of my work has been in the field of core physics.

2. I hold a Bachelor of Arts degree in mathematics from Lincoln i Memorial University (1943) and Masters (1950) and Doctorate (1953) in l

j physics from New York University.

i

3. The purpose of my testimony is to address the ability to perform fuel loading and precritical testing in Braidwood without reliance i upon electrical equipment for protection of the health and safety of the i

public.

4. The only threat to public health and safety in the performance

of the proposed fuel loading and testing arises from an inadvertent i

8609120439gy90g ADOCK O %DR

! PDR G

1

. - - - , . . _ , . , . , , - - - . - - - - - - - - - , .-,------.,-.-,-,~--.-------.----.-.--,----.,n- . - - -

criticality in the core. The unirradiated fuel does not contain any fission products and is not sufficiently radioactive to pose a threat if it were dropped and broken.

5. In the event that coolant is lost from the core (from a postulated pipe break) no reduction in the margin to criticality occurs.

The dry core is less reactive than the moderated core even with 2000 ppm boron in the coolant and, therefore the margin is increased. Since the fuel contains no heat source (i . e . fission products) cooling is not required and no equipment is needed to protect the health and safety of the public.

6. Criticality in the core can be avoided by maintaining a suffi-ciently high boron concentration in the coolant water. Calculations reported in the Braidwood FSAR (Table 4.3.2) show that the critical boron concentration for the core without control rods is 1135 parts per million (ppm) at cold zero power conditions (680F,15 psla) and 1046 ppm at hot zero power conditions (557aF, 2250 psia). These values have been calculated by standard codes and methods which have been approved by the NRC staff. The design value of the uncertainty in this quantity is 50 ppm. Examination of a large number of startup reports comparing predicted and measured values of hot zero power concentration yielded a value of 22 ppm for the average deviation. I thus concur with the Applicant's assertion that the critical boron concentration over the range of test condition to be encountered is less than 1200 ppm. The Applicant proposes to maintain a boron concentration of 2000 ppm in the core and

_1_

makeup water. If this concentration is maintained, I conclude that inadvertent criticality will not occur during the tests. This conclusion is based on the fact that the only reactivity increasing action to be taken during the tests is withdrawal of rods (heating the water increases the ,

margin to criticality) , but the quoted values of critical boron were calculated with all rods out.

7. The Applicant proposes to isolate the core and makeup water systems from any sources of non-borated water and to perform surveillance to assure that the boron concentration is maintained.

The Staff requested and received information from the Applicant concerning the manner by which the Applicant's proposal would be implemented. The Affidavit by Bernard Mann addresses the Staff's evaluation of the Applicant's proposed methods of assuring isolation and surveillance of the reactor coolant system to assure that the boron concentration of 2000 ppm is maintained. Region III will monitor the Applicant's isolation and surveillance procedures to assure that they are properly performed (Ronald N. Gardner affidavit).

k '5 Walter L. Brooks Subscribed and sworn to before me this 8th day of September,1986

~

m s

~

Notar ublic

! My Commission expires: 7/1/90 l

l l

b